Merge tag 'arc-v3.11-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull first batch of ARC changes from Vineet Gupta:
 "There's a second bunch to follow next week - which depends on commits
  on other trees (irq/net).  I'd have preferred the accompanying ARC
  change via respective trees, but it didn't workout somehow.

  Highlights of changes:

   - Continuation of ARC MM changes from 3.10 including

       zero page optimization
       Setting pagecache pages dirty by default
       Non executable stack by default
       Reducing dcache flushes for aliasing VIPT config

   - Long overdue rework of pt_regs machinery - removing the unused word
     gutters and adding ECR register to baseline (helps cleanup lot of
     low level code)

   - Support for ARC gcc 4.8

   - Few other preventive fixes, cosmetics, usage of Kconfig helper..

  The diffstat is larger than normal primarily because of arcregs.h
  header split as well as beautification of macros in entry.h"

* tag 'arc-v3.11-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (32 commits)
  ARC: warn on improper stack unwind FDE entries
  arc: delete __cpuinit usage from all arc files
  ARC: [tlb-miss] Fix bug with CONFIG_ARC_DBG_TLB_MISS_COUNT
  ARC: [tlb-miss] Extraneous PTE bit testing/setting
  ARC: Adjustments for gcc 4.8
  ARC: Setup Vector Table Base in early boot
  ARC: Remove explicit passing around of ECR
  ARC: pt_regs update #5: Use real ECR for pt_regs->event vs. synth values
  ARC: stop using pt_regs->orig_r8
  ARC: pt_regs update #4: r25 saved/restored unconditionally
  ARC: K/U SP saved from one location in stack switching macro
  ARC: Entry Handler tweaks: Simplify branch for in-kernel preemption
  ARC: Entry Handler tweaks: Avoid hardcoded LIMMS for ECR values
  ARC: Increase readability of entry handlers
  ARC: pt_regs update #3: Remove unused gutter at start of callee_regs
  ARC: pt_regs update #2: Remove unused gutter at start of pt_regs
  ARC: pt_regs update #1: Align pt_regs end with end of kernel stack page
  ARC: pt_regs update #0: remove kernel stack canary
  ARC: [mm] Remove @write argument to do_page_fault()
  ARC: [mm] Make stack/heap Non-executable by default
  ...

arch/arc/Kconfig

@@ -184,6 +184,7 @@ config ARC_CACHE_PAGES
 
 config ARC_CACHE_VIPT_ALIASING
 	bool "Support VIPT Aliasing D$"
+	depends on ARC_HAS_DCACHE
 	default n
 
 endif	#ARC_CACHE
@@ -361,13 +362,6 @@ config ARC_MISALIGN_ACCESS
 	  Use ONLY-IF-ABS-NECESSARY as it will be very slow and also can hide
 	  potential bugs in code
 
-config ARC_STACK_NONEXEC
-	bool "Make stack non-executable"
-	default n
-	help
-	  To disable the execute permissions of stack/heap of processes
-	  which are enabled by default.
-
 config HZ
 	int "Timer Frequency"
 	default 100

arch/arc/Makefile

@@ -9,25 +9,27 @@
 UTS_MACHINE := arc
 
 ifeq ($(CROSS_COMPILE),)
-CROSS_COMPILE := arc-elf32-
+CROSS_COMPILE := arc-linux-uclibc-
 endif
 
 KBUILD_DEFCONFIG := fpga_defconfig
 
 cflags-y	+= -mA7 -fno-common -pipe -fno-builtin -D__linux__
 
-LINUXINCLUDE	+=  -include ${src}/arch/arc/include/asm/defines.h
-
 ifdef CONFIG_ARC_CURR_IN_REG
 # For a global register defintion, make sure it gets passed to every file
 # We had a customer reported bug where some code built in kernel was NOT using
 # any kernel headers, and missing the r25 global register
-# Can't do unconditionally (like above) because of recursive include issues
+# Can't do unconditionally because of recursive include issues
 # due to <linux/thread_info.h>
 LINUXINCLUDE	+=  -include ${src}/arch/arc/include/asm/current.h
 endif
 
-atleast_gcc44 :=  $(call cc-ifversion, -gt, 0402, y)
+upto_gcc42    :=  $(call cc-ifversion, -le, 0402, y)
+upto_gcc44    :=  $(call cc-ifversion, -le, 0404, y)
+atleast_gcc44 :=  $(call cc-ifversion, -ge, 0404, y)
+atleast_gcc48 :=  $(call cc-ifversion, -ge, 0408, y)
+
 cflags-$(atleast_gcc44)			+= -fsection-anchors
 
 cflags-$(CONFIG_ARC_HAS_LLSC)		+= -mlock
@@ -35,6 +37,11 @@ cflags-$(CONFIG_ARC_HAS_SWAPE)		+= -mswape
 cflags-$(CONFIG_ARC_HAS_RTSC)		+= -mrtsc
 cflags-$(CONFIG_ARC_DW2_UNWIND)		+= -fasynchronous-unwind-tables
 
+# By default gcc 4.8 generates dwarf4 which kernel unwinder can't grok
+ifeq ($(atleast_gcc48),y)
+cflags-$(CONFIG_ARC_DW2_UNWIND)		+= -gdwarf-2
+endif
+
 ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
 # Generic build system uses -O2, we want -O3
 cflags-y  += -O3
@@ -48,11 +55,10 @@ cflags-$(disable_small_data)		+= -mno-sdata -fcall-used-gp
 cflags-$(CONFIG_CPU_BIG_ENDIAN)		+= -mbig-endian
 ldflags-$(CONFIG_CPU_BIG_ENDIAN)	+= -EB
 
-# STAR 9000518362:
+# STAR 9000518362: (fixed with binutils shipping with gcc 4.8)
 # arc-linux-uclibc-ld (buildroot) or arceb-elf32-ld (EZChip) don't accept
-# --build-id w/o "-marclinux".
-# Default arc-elf32-ld is OK
-ldflags-y				+= -marclinux
+# --build-id w/o "-marclinux". Default arc-elf32-ld is OK
+ldflags-$(upto_gcc44)			+= -marclinux
 
 ARC_LIBGCC				:= -mA7
 cflags-$(CONFIG_ARC_HAS_HW_MPY)		+= -multcost=16
@@ -66,8 +72,8 @@ ifndef CONFIG_ARC_HAS_HW_MPY
 # With gcc 4.4.7, -mno-mpy is enough to make any other related adjustments,
 # e.g. increased cost of MPY. With gcc 4.2.1 this had to be explicitly hinted
 
-	ARC_LIBGCC		:= -marc600
-	ifneq ($(atleast_gcc44),y)
+	ifeq ($(upto_gcc42),y)
+		ARC_LIBGCC	:= -marc600
 		cflags-y	+= -multcost=30
 	endif
 endif

arch/arc/configs/fpga_defconfig

@@ -1,4 +1,4 @@
-CONFIG_CROSS_COMPILE="arc-elf32-"
+CONFIG_CROSS_COMPILE="arc-linux-uclibc-"
 # CONFIG_LOCALVERSION_AUTO is not set
 CONFIG_DEFAULT_HOSTNAME="ARCLinux"
 # CONFIG_SWAP is not set

arch/arc/configs/nsimosci_defconfig

@@ -1,4 +1,4 @@
-CONFIG_CROSS_COMPILE="arc-elf32-"
+CONFIG_CROSS_COMPILE="arc-linux-uclibc-"
 # CONFIG_LOCALVERSION_AUTO is not set
 CONFIG_DEFAULT_HOSTNAME="ARCLinux"
 # CONFIG_SWAP is not set

arch/arc/configs/tb10x_defconfig

@@ -1,4 +1,4 @@
-CONFIG_CROSS_COMPILE="arc-elf32-"
+CONFIG_CROSS_COMPILE="arc-linux-uclibc-"
 # CONFIG_LOCALVERSION_AUTO is not set
 CONFIG_DEFAULT_HOSTNAME="tb10x"
 CONFIG_SYSVIPC=y

arch/arc/include/asm/arcregs.h

@@ -20,7 +20,6 @@
 #define ARC_REG_PERIBASE_BCR	0x69
 #define ARC_REG_FP_BCR		0x6B	/* Single-Precision FPU */
 #define ARC_REG_DPFP_BCR	0x6C	/* Dbl Precision FPU */
-#define ARC_REG_MMU_BCR		0x6f
 #define ARC_REG_DCCM_BCR	0x74	/* DCCM Present + SZ */
 #define ARC_REG_TIMERS_BCR	0x75
 #define ARC_REG_ICCM_BCR	0x78
@@ -34,22 +33,12 @@
 #define ARC_REG_D_UNCACH_BCR	0x6A
 
 /* status32 Bits Positions */
-#define STATUS_H_BIT		0	/* CPU Halted */
-#define STATUS_E1_BIT		1	/* Int 1 enable */
-#define STATUS_E2_BIT		2	/* Int 2 enable */
-#define STATUS_A1_BIT		3	/* Int 1 active */
-#define STATUS_A2_BIT		4	/* Int 2 active */
 #define STATUS_AE_BIT		5	/* Exception active */
 #define STATUS_DE_BIT		6	/* PC is in delay slot */
 #define STATUS_U_BIT		7	/* User/Kernel mode */
 #define STATUS_L_BIT		12	/* Loop inhibit */
 
 /* These masks correspond to the status word(STATUS_32) bits */
-#define STATUS_H_MASK		(1<<STATUS_H_BIT)
-#define STATUS_E1_MASK		(1<<STATUS_E1_BIT)
-#define STATUS_E2_MASK		(1<<STATUS_E2_BIT)
-#define STATUS_A1_MASK		(1<<STATUS_A1_BIT)
-#define STATUS_A2_MASK		(1<<STATUS_A2_BIT)
 #define STATUS_AE_MASK		(1<<STATUS_AE_BIT)
 #define STATUS_DE_MASK		(1<<STATUS_DE_BIT)
 #define STATUS_U_MASK		(1<<STATUS_U_BIT)
@@ -71,6 +60,7 @@
 #define ECR_V_ITLB_MISS			0x21
 #define ECR_V_DTLB_MISS			0x22
 #define ECR_V_PROTV			0x23
+#define ECR_V_TRAP			0x25
 
 /* Protection Violation Exception Cause Code Values */
 #define ECR_C_PROTV_INST_FETCH		0x00
@@ -79,94 +69,23 @@
 #define ECR_C_PROTV_XCHG		0x03
 #define ECR_C_PROTV_MISALIG_DATA	0x04
 
+#define ECR_C_BIT_PROTV_MISALIG_DATA	10
+
+/* Machine Check Cause Code Values */
+#define ECR_C_MCHK_DUP_TLB		0x01
+
 /* DTLB Miss Exception Cause Code Values */
 #define ECR_C_BIT_DTLB_LD_MISS		8
 #define ECR_C_BIT_DTLB_ST_MISS		9
 
+/* Dummy ECR values for Interrupts */
+#define event_IRQ1		0x0031abcd
+#define event_IRQ2		0x0032abcd
 
 /* Auxiliary registers */
 #define AUX_IDENTITY		4
 #define AUX_INTR_VEC_BASE	0x25
-#define AUX_IRQ_LEV		0x200	/* IRQ Priority: L1 or L2 */
-#define AUX_IRQ_HINT		0x201	/* For generating Soft Interrupts */
-#define AUX_IRQ_LV12		0x43	/* interrupt level register */
-
-#define AUX_IENABLE		0x40c
-#define AUX_ITRIGGER		0x40d
-#define AUX_IPULSE		0x415
-
-/* Timer related Aux registers */
-#define ARC_REG_TIMER0_LIMIT	0x23	/* timer 0 limit */
-#define ARC_REG_TIMER0_CTRL	0x22	/* timer 0 control */
-#define ARC_REG_TIMER0_CNT	0x21	/* timer 0 count */
-#define ARC_REG_TIMER1_LIMIT	0x102	/* timer 1 limit */
-#define ARC_REG_TIMER1_CTRL	0x101	/* timer 1 control */
-#define ARC_REG_TIMER1_CNT	0x100	/* timer 1 count */
-
-#define TIMER_CTRL_IE		(1 << 0) /* Interupt when Count reachs limit */
-#define TIMER_CTRL_NH		(1 << 1) /* Count only when CPU NOT halted */
-
-/* MMU Management regs */
-#define ARC_REG_TLBPD0		0x405
-#define ARC_REG_TLBPD1		0x406
-#define ARC_REG_TLBINDEX	0x407
-#define ARC_REG_TLBCOMMAND	0x408
-#define ARC_REG_PID		0x409
-#define ARC_REG_SCRATCH_DATA0	0x418
-
-/* Bits in MMU PID register */
-#define MMU_ENABLE		(1 << 31)	/* Enable MMU for process */
-
-/* Error code if probe fails */
-#define TLB_LKUP_ERR		0x80000000
-
-/* TLB Commands */
-#define TLBWrite    0x1
-#define TLBRead     0x2
-#define TLBGetIndex 0x3
-#define TLBProbe    0x4
-
-#if (CONFIG_ARC_MMU_VER >= 2)
-#define TLBWriteNI  0x5		/* write JTLB without inv uTLBs */
-#define TLBIVUTLB   0x6		/* explicitly inv uTLBs */
-#else
-#undef TLBWriteNI		/* These cmds don't exist on older MMU */
-#undef TLBIVUTLB
-#endif
 
-/* Instruction cache related Auxiliary registers */
-#define ARC_REG_IC_BCR		0x77	/* Build Config reg */
-#define ARC_REG_IC_IVIC		0x10
-#define ARC_REG_IC_CTRL		0x11
-#define ARC_REG_IC_IVIL		0x19
-#if (CONFIG_ARC_MMU_VER > 2)
-#define ARC_REG_IC_PTAG		0x1E
-#endif
-
-/* Bit val in IC_CTRL */
-#define IC_CTRL_CACHE_DISABLE   0x1
-
-/* Data cache related Auxiliary registers */
-#define ARC_REG_DC_BCR		0x72
-#define ARC_REG_DC_IVDC		0x47
-#define ARC_REG_DC_CTRL		0x48
-#define ARC_REG_DC_IVDL		0x4A
-#define ARC_REG_DC_FLSH		0x4B
-#define ARC_REG_DC_FLDL		0x4C
-#if (CONFIG_ARC_MMU_VER > 2)
-#define ARC_REG_DC_PTAG		0x5C
-#endif
-
-/* Bit val in DC_CTRL */
-#define DC_CTRL_INV_MODE_FLUSH  0x40
-#define DC_CTRL_FLUSH_STATUS    0x100
-
-/* MMU Management regs */
-#define ARC_REG_PID		0x409
-#define ARC_REG_SCRATCH_DATA0	0x418
-
-/* Bits in MMU PID register */
-#define MMU_ENABLE		(1 << 31)	/* Enable MMU for process */
 
 /*
  * Floating Pt Registers
@@ -293,24 +212,6 @@ struct bcr_identity {
 #endif
 };
 
-struct bcr_mmu_1_2 {
-#ifdef CONFIG_CPU_BIG_ENDIAN
-	unsigned int ver:8, ways:4, sets:4, u_itlb:8, u_dtlb:8;
-#else
-	unsigned int u_dtlb:8, u_itlb:8, sets:4, ways:4, ver:8;
-#endif
-};
-
-struct bcr_mmu_3 {
-#ifdef CONFIG_CPU_BIG_ENDIAN
-	unsigned int ver:8, ways:4, sets:4, osm:1, reserv:3, pg_sz:4,
-		     u_itlb:4, u_dtlb:4;
-#else
-	unsigned int u_dtlb:4, u_itlb:4, pg_sz:4, reserv:3, osm:1, sets:4,
-		     ways:4, ver:8;
-#endif
-};
-
 #define EXTN_SWAP_VALID     0x1
 #define EXTN_NORM_VALID     0x2
 #define EXTN_MINMAX_VALID   0x2
@@ -343,14 +244,6 @@ struct bcr_extn_xymem {
 #endif
 };
 
-struct bcr_cache {
-#ifdef CONFIG_CPU_BIG_ENDIAN
-	unsigned int pad:12, line_len:4, sz:4, config:4, ver:8;
-#else
-	unsigned int ver:8, config:4, sz:4, line_len:4, pad:12;
-#endif
-};
-
 struct bcr_perip {
 #ifdef CONFIG_CPU_BIG_ENDIAN
 	unsigned int start:8, pad2:8, sz:8, pad:8;
@@ -403,7 +296,7 @@ struct cpuinfo_arc_mmu {
 };
 
 struct cpuinfo_arc_cache {
-	unsigned int has_aliasing, sz, line_len, assoc, ver;
+	unsigned int sz, line_len, assoc, ver;
 };
 
 struct cpuinfo_arc_ccm {

arch/arc/include/asm/bug.h

@@ -18,9 +18,8 @@ struct task_struct;
 void show_regs(struct pt_regs *regs);
 void show_stacktrace(struct task_struct *tsk, struct pt_regs *regs);
 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
-			    unsigned long address, unsigned long cause_reg);
-void die(const char *str, struct pt_regs *regs, unsigned long address,
-	 unsigned long cause_reg);
+			    unsigned long address);
+void die(const char *str, struct pt_regs *regs, unsigned long address);
 
 #define BUG()	do {				\
 	dump_stack();					\

arch/arc/include/asm/cache.h

@@ -18,21 +18,19 @@
 
 #define L1_CACHE_BYTES		(1 << L1_CACHE_SHIFT)
 
-#define ARC_ICACHE_WAYS	2
-#define ARC_DCACHE_WAYS	4
-
-/* Helpers */
+/* For a rare case where customers have differently config I/D */
 #define ARC_ICACHE_LINE_LEN	L1_CACHE_BYTES
 #define ARC_DCACHE_LINE_LEN	L1_CACHE_BYTES
 
 #define ICACHE_LINE_MASK	(~(ARC_ICACHE_LINE_LEN - 1))
 #define DCACHE_LINE_MASK	(~(ARC_DCACHE_LINE_LEN - 1))
 
-#if ARC_ICACHE_LINE_LEN != ARC_DCACHE_LINE_LEN
-#error "Need to fix some code as I/D cache lines not same"
-#else
-#define is_not_cache_aligned(p)	((unsigned long)p & (~DCACHE_LINE_MASK))
-#endif
+/*
+ * ARC700 doesn't cache any access in top 256M.
+ * Ideal for wiring memory mapped peripherals as we don't need to do
+ * explicit uncached accesses (LD.di/ST.di) hence more portable drivers
+ */
+#define ARC_UNCACHED_ADDR_SPACE	0xc0000000
 
 #ifndef __ASSEMBLY__
 
@@ -57,16 +55,10 @@
 
 #define ARCH_DMA_MINALIGN      L1_CACHE_BYTES
 
-/*
- * ARC700 doesn't cache any access in top 256M.
- * Ideal for wiring memory mapped peripherals as we don't need to do
- * explicit uncached accesses (LD.di/ST.di) hence more portable drivers
- */
-#define ARC_UNCACHED_ADDR_SPACE	0xc0000000
-
 extern void arc_cache_init(void);
 extern char *arc_cache_mumbojumbo(int cpu_id, char *buf, int len);
 extern void __init read_decode_cache_bcr(void);
-#endif
+
+#endif	/* !__ASSEMBLY__ */
 
 #endif /* _ASM_CACHE_H */

arch/arc/include/asm/cacheflush.h

@@ -80,17 +80,20 @@ void flush_anon_page(struct vm_area_struct *vma,
 
 #endif	/* CONFIG_ARC_CACHE_VIPT_ALIASING */
 
+/*
+ * A new pagecache page has PG_arch_1 clear - thus dcache dirty by default
+ * This works around some PIO based drivers which don't call flush_dcache_page
+ * to record that they dirtied the dcache
+ */
+#define PG_dc_clean	PG_arch_1
+
 /*
  * Simple wrapper over config option
  * Bootup code ensures that hardware matches kernel configuration
  */
 static inline int cache_is_vipt_aliasing(void)
 {
-#ifdef CONFIG_ARC_CACHE_VIPT_ALIASING
-	return 1;
-#else
-	return 0;
-#endif
+	return IS_ENABLED(CONFIG_ARC_CACHE_VIPT_ALIASING);
 }
 
 #define CACHE_COLOR(addr)	(((unsigned long)(addr) >> (PAGE_SHIFT)) & 1)

arch/arc/include/asm/defines.h

@@ -1,56 +0,0 @@
-/*
- * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#ifndef __ARC_ASM_DEFINES_H__
-#define __ARC_ASM_DEFINES_H__
-
-#if defined(CONFIG_ARC_MMU_V1)
-#define CONFIG_ARC_MMU_VER 1
-#elif defined(CONFIG_ARC_MMU_V2)
-#define CONFIG_ARC_MMU_VER 2
-#elif defined(CONFIG_ARC_MMU_V3)
-#define CONFIG_ARC_MMU_VER 3
-#endif
-
-#ifdef CONFIG_ARC_HAS_LLSC
-#define __CONFIG_ARC_HAS_LLSC_VAL 1
-#else
-#define __CONFIG_ARC_HAS_LLSC_VAL 0
-#endif
-
-#ifdef CONFIG_ARC_HAS_SWAPE
-#define __CONFIG_ARC_HAS_SWAPE_VAL 1
-#else
-#define __CONFIG_ARC_HAS_SWAPE_VAL 0
-#endif
-
-#ifdef CONFIG_ARC_HAS_RTSC
-#define __CONFIG_ARC_HAS_RTSC_VAL 1
-#else
-#define __CONFIG_ARC_HAS_RTSC_VAL 0
-#endif
-
-#ifdef CONFIG_ARC_MMU_SASID
-#define __CONFIG_ARC_MMU_SASID_VAL 1
-#else
-#define __CONFIG_ARC_MMU_SASID_VAL 0
-#endif
-
-#ifdef CONFIG_ARC_HAS_ICACHE
-#define __CONFIG_ARC_HAS_ICACHE	1
-#else
-#define __CONFIG_ARC_HAS_ICACHE	0
-#endif
-
-#ifdef CONFIG_ARC_HAS_DCACHE
-#define __CONFIG_ARC_HAS_DCACHE	1
-#else
-#define __CONFIG_ARC_HAS_DCACHE	0
-#endif
-
-#endif /* __ARC_ASM_DEFINES_H__ */

arch/arc/include/asm/entry.h

@@ -50,194 +50,177 @@
  *      Eff Addr for load = [reg2]
  */
 
+.macro PUSH reg
+	st.a	\reg, [sp, -4]
+.endm
+
+.macro PUSHAX aux
+	lr	r9, [\aux]
+	PUSH	r9
+.endm
+
+.macro POP reg
+	ld.ab	\reg, [sp, 4]
+.endm
+
+.macro POPAX aux
+	POP	r9
+	sr	r9, [\aux]
+.endm
+
 /*--------------------------------------------------------------
- * Save caller saved registers (scratch registers) ( r0 - r12 )
- * Registers are pushed / popped in the order defined in struct ptregs
- * in asm/ptrace.h
+ * Helpers to save/restore Scratch Regs:
+ * used by Interrupt/Exception Prologue/Epilogue
  *-------------------------------------------------------------*/
-.macro  SAVE_CALLER_SAVED
-	st.a    r0, [sp, -4]
-	st.a    r1, [sp, -4]
-	st.a    r2, [sp, -4]
-	st.a    r3, [sp, -4]
-	st.a    r4, [sp, -4]
-	st.a    r5, [sp, -4]
-	st.a    r6, [sp, -4]
-	st.a    r7, [sp, -4]
-	st.a    r8, [sp, -4]
-	st.a    r9, [sp, -4]
-	st.a    r10, [sp, -4]
-	st.a    r11, [sp, -4]
-	st.a    r12, [sp, -4]
+.macro  SAVE_R0_TO_R12
+	PUSH	r0
+	PUSH	r1
+	PUSH	r2
+	PUSH	r3
+	PUSH	r4
+	PUSH	r5
+	PUSH	r6
+	PUSH	r7
+	PUSH	r8
+	PUSH	r9
+	PUSH	r10
+	PUSH	r11
+	PUSH	r12
+.endm
+
+.macro RESTORE_R12_TO_R0
+	POP	r12
+	POP	r11
+	POP	r10
+	POP	r9
+	POP	r8
+	POP	r7
+	POP	r6
+	POP	r5
+	POP	r4
+	POP	r3
+	POP	r2
+	POP	r1
+	POP	r0
+
+#ifdef CONFIG_ARC_CURR_IN_REG
+	ld	r25, [sp, 12]
+#endif
 .endm
 
 /*--------------------------------------------------------------
- * Restore caller saved registers (scratch registers)
+ * Helpers to save/restore callee-saved regs:
+ * used by several macros below
  *-------------------------------------------------------------*/
-.macro RESTORE_CALLER_SAVED
-	ld.ab   r12, [sp, 4]
-	ld.ab   r11, [sp, 4]
-	ld.ab   r10, [sp, 4]
-	ld.ab   r9, [sp, 4]
-	ld.ab   r8, [sp, 4]
-	ld.ab   r7, [sp, 4]
-	ld.ab   r6, [sp, 4]
-	ld.ab   r5, [sp, 4]
-	ld.ab   r4, [sp, 4]
-	ld.ab   r3, [sp, 4]
-	ld.ab   r2, [sp, 4]
-	ld.ab   r1, [sp, 4]
-	ld.ab   r0, [sp, 4]
+.macro SAVE_R13_TO_R24
+	PUSH	r13
+	PUSH	r14
+	PUSH	r15
+	PUSH	r16
+	PUSH	r17
+	PUSH	r18
+	PUSH	r19
+	PUSH	r20
+	PUSH	r21
+	PUSH	r22
+	PUSH	r23
+	PUSH	r24
+.endm
+
+.macro RESTORE_R24_TO_R13
+	POP	r24
+	POP	r23
+	POP	r22
+	POP	r21
+	POP	r20
+	POP	r19
+	POP	r18
+	POP	r17
+	POP	r16
+	POP	r15
+	POP	r14
+	POP	r13
 .endm
 
+#define OFF_USER_R25_FROM_R24	(SZ_CALLEE_REGS + SZ_PT_REGS - 8)/4
 
 /*--------------------------------------------------------------
- * Save callee saved registers (non scratch registers) ( r13 - r25 )
- *  on kernel stack.
- * User mode callee regs need to be saved in case of
- *    -fork and friends for replicating from parent to child
- *    -before going into do_signal( ) for ptrace/core-dump
- * Special case handling is required for r25 in case it is used by kernel
- *  for caching task ptr. Low level exception/ISR save user mode r25
- *  into task->thread.user_r25. So it needs to be retrieved from there and
- *  saved into kernel stack with rest of callee reg-file
+ * Collect User Mode callee regs as struct callee_regs - needed by
+ * fork/do_signal/unaligned-access-emulation.
+ * (By default only scratch regs are saved on entry to kernel)
+ *
+ * Special handling for r25 if used for caching Task Pointer.
+ * It would have been saved in task->thread.user_r25 already, but to keep
+ * the interface same it is copied into regular r25 placeholder in
+ * struct callee_regs.
  *-------------------------------------------------------------*/
 .macro SAVE_CALLEE_SAVED_USER
-	st.a    r13, [sp, -4]
-	st.a    r14, [sp, -4]
-	st.a    r15, [sp, -4]
-	st.a    r16, [sp, -4]
-	st.a    r17, [sp, -4]
-	st.a    r18, [sp, -4]
-	st.a    r19, [sp, -4]
-	st.a    r20, [sp, -4]
-	st.a    r21, [sp, -4]
-	st.a    r22, [sp, -4]
-	st.a    r23, [sp, -4]
-	st.a    r24, [sp, -4]
+
+	SAVE_R13_TO_R24
 
 #ifdef CONFIG_ARC_CURR_IN_REG
 	; Retrieve orig r25 and save it on stack
-	ld      r12, [r25, TASK_THREAD + THREAD_USER_R25]
+	ld.as   r12, [sp, OFF_USER_R25_FROM_R24]
 	st.a    r12, [sp, -4]
 #else
-	st.a    r25, [sp, -4]
+	PUSH	r25
 #endif
 
-	/* move up by 1 word to "create" callee_regs->"stack_place_holder" */
-	sub sp, sp, 4
 .endm
 
 /*--------------------------------------------------------------
- * Save callee saved registers (non scratch registers) ( r13 - r25 )
- * kernel mode callee regs needed to be saved in case of context switch
- * If r25 is used for caching task pointer then that need not be saved
- * as it can be re-created from current task global
+ * Save kernel Mode callee regs at the time of Contect Switch.
+ *
+ * Special handling for r25 if used for caching Task Pointer.
+ * Kernel simply skips saving it since it will be loaded with
+ * incoming task pointer anyways
  *-------------------------------------------------------------*/
 .macro SAVE_CALLEE_SAVED_KERNEL
-	st.a    r13, [sp, -4]
-	st.a    r14, [sp, -4]
-	st.a    r15, [sp, -4]
-	st.a    r16, [sp, -4]
-	st.a    r17, [sp, -4]
-	st.a    r18, [sp, -4]
-	st.a    r19, [sp, -4]
-	st.a    r20, [sp, -4]
-	st.a    r21, [sp, -4]
-	st.a    r22, [sp, -4]
-	st.a    r23, [sp, -4]
-	st.a    r24, [sp, -4]
+
+	SAVE_R13_TO_R24
+
 #ifdef CONFIG_ARC_CURR_IN_REG
-	sub     sp, sp, 8
-#else
-	st.a    r25, [sp, -4]
 	sub     sp, sp, 4
+#else
+	PUSH	r25
 #endif
 .endm
 
 /*--------------------------------------------------------------
- * RESTORE_CALLEE_SAVED_KERNEL:
- * Loads callee (non scratch) Reg File by popping from Kernel mode stack.
- *  This is reverse of SAVE_CALLEE_SAVED,
- *
- * NOTE:
- * Ideally this shd only be called in switch_to for loading
- *  switched-IN task's CALLEE Reg File.
- *  For all other cases RESTORE_CALLEE_SAVED_FAST must be used
- *  which simply pops the stack w/o touching regs.
+ * Opposite of SAVE_CALLEE_SAVED_KERNEL
  *-------------------------------------------------------------*/
 .macro RESTORE_CALLEE_SAVED_KERNEL
 
-
 #ifdef CONFIG_ARC_CURR_IN_REG
-	add     sp, sp, 8  /* skip callee_reg gutter and user r25 placeholder */
+	add     sp, sp, 4  /* skip usual r25 placeholder */
 #else
-	add     sp, sp, 4   /* skip "callee_regs->stack_place_holder" */
-	ld.ab   r25, [sp, 4]
+	POP	r25
 #endif
-
-	ld.ab   r24, [sp, 4]
-	ld.ab   r23, [sp, 4]
-	ld.ab   r22, [sp, 4]
-	ld.ab   r21, [sp, 4]
-	ld.ab   r20, [sp, 4]
-	ld.ab   r19, [sp, 4]
-	ld.ab   r18, [sp, 4]
-	ld.ab   r17, [sp, 4]
-	ld.ab   r16, [sp, 4]
-	ld.ab   r15, [sp, 4]
-	ld.ab   r14, [sp, 4]
-	ld.ab   r13, [sp, 4]
-
+	RESTORE_R24_TO_R13
 .endm
 
 /*--------------------------------------------------------------
- * RESTORE_CALLEE_SAVED_USER:
- * This is called after do_signal where tracer might have changed callee regs
- * thus we need to restore the reg file.
- * Special case handling is required for r25 in case it is used by kernel
- *  for caching task ptr. Ptrace would have modified on-kernel-stack value of
- *  r25, which needs to be shoved back into task->thread.user_r25 where from
- *  Low level exception/ISR return code will retrieve to populate with rest of
- *  callee reg-file.
+ * Opposite of SAVE_CALLEE_SAVED_USER
+ *
+ * ptrace tracer or unaligned-access fixup might have changed a user mode
+ * callee reg which is saved back to usual r25 storage location
  *-------------------------------------------------------------*/
 .macro RESTORE_CALLEE_SAVED_USER
 
-	add     sp, sp, 4   /* skip "callee_regs->stack_place_holder" */
-
 #ifdef CONFIG_ARC_CURR_IN_REG
 	ld.ab   r12, [sp, 4]
-	st      r12, [r25, TASK_THREAD + THREAD_USER_R25]
+	st.as   r12, [sp, OFF_USER_R25_FROM_R24]
 #else
-	ld.ab   r25, [sp, 4]
+	POP	r25
 #endif
-
-	ld.ab   r24, [sp, 4]
-	ld.ab   r23, [sp, 4]
-	ld.ab   r22, [sp, 4]
-	ld.ab   r21, [sp, 4]
-	ld.ab   r20, [sp, 4]
-	ld.ab   r19, [sp, 4]
-	ld.ab   r18, [sp, 4]
-	ld.ab   r17, [sp, 4]
-	ld.ab   r16, [sp, 4]
-	ld.ab   r15, [sp, 4]
-	ld.ab   r14, [sp, 4]
-	ld.ab   r13, [sp, 4]
+	RESTORE_R24_TO_R13
 .endm
 
 /*--------------------------------------------------------------
  * Super FAST Restore callee saved regs by simply re-adjusting SP
  *-------------------------------------------------------------*/
 .macro DISCARD_CALLEE_SAVED_USER
-	add     sp, sp, 14 * 4
-.endm
-
-/*--------------------------------------------------------------
- * Restore User mode r25 saved in task_struct->thread.user_r25
- *-------------------------------------------------------------*/
-.macro RESTORE_USER_R25
-	ld  r25, [r25, TASK_THREAD + THREAD_USER_R25]
+	add     sp, sp, SZ_CALLEE_REGS
 .endm
 
 /*-------------------------------------------------------------
@@ -252,7 +235,7 @@
 	ld  \out, [\tsk, TASK_THREAD_INFO]
 
 	/* Go to end of page where stack begins (grows upwards) */
-	add2 \out, \out, (THREAD_SIZE - 4)/4   /* one word GUTTER */
+	add2 \out, \out, (THREAD_SIZE)/4
 
 .endm
 
@@ -305,33 +288,28 @@
 	 * safe-keeping not really needed, but it keeps the epilogue code
 	 * (SP restore) simpler/uniform.
 	 */
-	b.d	77f
-
-	st.a	sp, [sp, -12]	; Make room for orig_r0 and orig_r8
+	b.d	66f
+	mov	r9, sp
 
 88: /*------Intr/Ecxp happened in user mode, "switch" stack ------ */
 
 	GET_CURR_TASK_ON_CPU   r9
 
-#ifdef CONFIG_ARC_CURR_IN_REG
-
-	/* If current task pointer cached in r25, time to
-	 *  -safekeep USER r25 in task->thread_struct->user_r25
-	 *  -load r25 with current task ptr
-	 */
-	st.as	r25, [r9, (TASK_THREAD + THREAD_USER_R25)/4]
-	mov	r25, r9
-#endif
-
 	/* With current tsk in r9, get it's kernel mode stack base */
 	GET_TSK_STACK_BASE  r9, r9
 
-#ifdef PT_REGS_CANARY
-	st	0xabcdabcd, [r9, 0]
+66:
+#ifdef CONFIG_ARC_CURR_IN_REG
+	/*
+	 * Treat r25 as scratch reg, save it on stack first
+	 * Load it with current task pointer
+	 */
+	st	r25, [r9, -4]
+	GET_CURR_TASK_ON_CPU   r25
 #endif
 
 	/* Save Pre Intr/Exception User SP on kernel stack */
-	st.a    sp, [r9, -12]	; Make room for orig_r0 and orig_r8
+	st.a    sp, [r9, -16]	; Make room for orig_r0, ECR, user_r25
 
 	/* CAUTION:
 	 * SP should be set at the very end when we are done with everything
@@ -342,7 +320,7 @@
 	/* set SP to point to kernel mode stack */
 	mov sp, r9
 
-77: /* ----- Stack Switched to kernel Mode, Now save REG FILE ----- */
+	/* ----- Stack Switched to kernel Mode, Now save REG FILE ----- */
 
 .endm
 
@@ -369,7 +347,7 @@
  * @reg [OUT] &thread_info of "current"
  */
 .macro GET_CURR_THR_INFO_FROM_SP  reg
-	and \reg, sp, ~(THREAD_SIZE - 1)
+	bic \reg, sp, (THREAD_SIZE - 1)
 .endm
 
 /*
@@ -413,62 +391,25 @@
  * Note that syscalls are implemented via TRAP which is also a exception
  * from CPU's point of view
  *-------------------------------------------------------------*/
-.macro SAVE_ALL_EXCEPTION   marker
+.macro SAVE_ALL_SYS
 
-	st      \marker, [sp, 8]	/* orig_r8 */
+	lr	r9, [ecr]
+	st      r9, [sp, 8]    /* ECR */
 	st      r0, [sp, 4]    /* orig_r0, needed only for sys calls */
 
 	/* Restore r9 used to code the early prologue */
 	EXCPN_PROLOG_RESTORE_REG  r9
 
-	SAVE_CALLER_SAVED
-	st.a    r26, [sp, -4]   /* gp */
-	st.a    fp, [sp, -4]
-	st.a    blink, [sp, -4]
-	lr	r9, [eret]
-	st.a    r9, [sp, -4]
-	lr	r9, [erstatus]
-	st.a    r9, [sp, -4]
-	st.a    lp_count, [sp, -4]
-	lr	r9, [lp_end]
-	st.a    r9, [sp, -4]
-	lr	r9, [lp_start]
-	st.a    r9, [sp, -4]
-	lr	r9, [erbta]
-	st.a    r9, [sp, -4]
-
-#ifdef PT_REGS_CANARY
-	mov   r9, 0xdeadbeef
-	st    r9, [sp, -4]
-#endif
-
-	/* move up by 1 word to "create" pt_regs->"stack_place_holder" */
-	sub sp, sp, 4
-.endm
-
-/*--------------------------------------------------------------
- * Save scratch regs for exceptions
- *-------------------------------------------------------------*/
-.macro SAVE_ALL_SYS
-	SAVE_ALL_EXCEPTION  orig_r8_IS_EXCPN
-.endm
-
-/*--------------------------------------------------------------
- * Save scratch regs for sys calls
- *-------------------------------------------------------------*/
-.macro SAVE_ALL_TRAP
-	/*
-	 * Setup pt_regs->orig_r8.
-	 * Encode syscall number (r8) in upper short word of event type (r9)
-	 * N.B. #1: This is already endian safe (see ptrace.h)
-	 *      #2: Only r9 can be used as scratch as it is already clobbered
-	 *          and it's contents are no longer needed by the latter part
-	 *          of exception prologue
-	 */
-	lsl  r9, r8, 16
-	or   r9, r9, orig_r8_IS_SCALL
-
-	SAVE_ALL_EXCEPTION  r9
+	SAVE_R0_TO_R12
+	PUSH	gp
+	PUSH	fp
+	PUSH	blink
+	PUSHAX	eret
+	PUSHAX	erstatus
+	PUSH	lp_count
+	PUSHAX	lp_end
+	PUSHAX	lp_start
+	PUSHAX	erbta
 .endm
 
 /*--------------------------------------------------------------
@@ -483,28 +424,22 @@
  * by hardware and that is not good.
  *-------------------------------------------------------------*/
 .macro RESTORE_ALL_SYS
+	POPAX	erbta
+	POPAX	lp_start
+	POPAX	lp_end
+
+	POP	r9
+	mov	lp_count, r9	;LD to lp_count is not allowed
 
-	add sp, sp, 4       /* hop over unused "pt_regs->stack_place_holder" */
-
-	ld.ab   r9, [sp, 4]
-	sr	r9, [erbta]
-	ld.ab   r9, [sp, 4]
-	sr	r9, [lp_start]
-	ld.ab   r9, [sp, 4]
-	sr	r9, [lp_end]
-	ld.ab   r9, [sp, 4]
-	mov	lp_count, r9
-	ld.ab   r9, [sp, 4]
-	sr	r9, [erstatus]
-	ld.ab   r9, [sp, 4]
-	sr	r9, [eret]
-	ld.ab   blink, [sp, 4]
-	ld.ab   fp, [sp, 4]
-	ld.ab   r26, [sp, 4]    /* gp */
-	RESTORE_CALLER_SAVED
+	POPAX	erstatus
+	POPAX	eret
+	POP	blink
+	POP	fp
+	POP	gp
+	RESTORE_R12_TO_R0
 
 	ld  sp, [sp] /* restore original sp */
-	/* orig_r0 and orig_r8 skipped automatically */
+	/* orig_r0, ECR, user_r25 skipped automatically */
 .endm
 
 
@@ -513,9 +448,7 @@
  *-------------------------------------------------------------*/
 .macro SAVE_ALL_INT1
 
-	/* restore original r9 , saved in int1_saved_reg
-	* It will be saved on stack in macro: SAVE_CALLER_SAVED
-	*/
+	/* restore original r9 to be saved as part of reg-file */
 #ifdef CONFIG_SMP
 	lr  r9, [ARC_REG_SCRATCH_DATA0]
 #else
@@ -523,29 +456,19 @@
 #endif
 
 	/* now we are ready to save the remaining context :) */
-	st      orig_r8_IS_IRQ1, [sp, 8]    /* Event Type */
+	st      event_IRQ1, [sp, 8]    /* Dummy ECR */
 	st      0, [sp, 4]    /* orig_r0 , N/A for IRQ */
-	SAVE_CALLER_SAVED
-	st.a    r26, [sp, -4]   /* gp */
-	st.a    fp, [sp, -4]
-	st.a    blink, [sp, -4]
-	st.a    ilink1, [sp, -4]
-	lr	r9, [status32_l1]
-	st.a    r9, [sp, -4]
-	st.a    lp_count, [sp, -4]
-	lr	r9, [lp_end]
-	st.a    r9, [sp, -4]
-	lr	r9, [lp_start]
-	st.a    r9, [sp, -4]
-	lr	r9, [bta_l1]
-	st.a    r9, [sp, -4]
-
-#ifdef PT_REGS_CANARY
-	mov   r9, 0xdeadbee1
-	st    r9, [sp, -4]
-#endif
-	/* move up by 1 word to "create" pt_regs->"stack_place_holder" */
-	sub sp, sp, 4
+
+	SAVE_R0_TO_R12
+	PUSH	gp
+	PUSH	fp
+	PUSH	blink
+	PUSH	ilink1
+	PUSHAX	status32_l1
+	PUSH	lp_count
+	PUSHAX	lp_end
+	PUSHAX	lp_start
+	PUSHAX	bta_l1
 .endm
 
 .macro SAVE_ALL_INT2
@@ -558,30 +481,19 @@
 	ld  r9, [@int2_saved_reg]
 
 	/* now we are ready to save the remaining context :) */
-	st      orig_r8_IS_IRQ2, [sp, 8]    /* Event Type */
+	st      event_IRQ2, [sp, 8]    /* Dummy ECR */
 	st      0, [sp, 4]    /* orig_r0 , N/A for IRQ */
-	SAVE_CALLER_SAVED
-	st.a    r26, [sp, -4]   /* gp */
-	st.a    fp, [sp, -4]
-	st.a    blink, [sp, -4]
-	st.a    ilink2, [sp, -4]
-	lr	r9, [status32_l2]
-	st.a    r9, [sp, -4]
-	st.a    lp_count, [sp, -4]
-	lr	r9, [lp_end]
-	st.a    r9, [sp, -4]
-	lr	r9, [lp_start]
-	st.a    r9, [sp, -4]
-	lr	r9, [bta_l2]
-	st.a    r9, [sp, -4]
-
-#ifdef PT_REGS_CANARY
-	mov   r9, 0xdeadbee2
-	st    r9, [sp, -4]
-#endif
 
-	/* move up by 1 word to "create" pt_regs->"stack_place_holder" */
-	sub sp, sp, 4
+	SAVE_R0_TO_R12
+	PUSH	gp
+	PUSH	fp
+	PUSH	blink
+	PUSH	ilink2
+	PUSHAX	status32_l2
+	PUSH	lp_count
+	PUSHAX	lp_end
+	PUSHAX	lp_start
+	PUSHAX	bta_l2
 .endm
 
 /*--------------------------------------------------------------
@@ -595,52 +507,41 @@
  *-------------------------------------------------------------*/
 
 .macro RESTORE_ALL_INT1
-	add sp, sp, 4       /* hop over unused "pt_regs->stack_place_holder" */
-
-	ld.ab   r9, [sp, 4] /* Actual reg file */
-	sr	r9, [bta_l1]
-	ld.ab   r9, [sp, 4]
-	sr	r9, [lp_start]
-	ld.ab   r9, [sp, 4]
-	sr	r9, [lp_end]
-	ld.ab   r9, [sp, 4]
-	mov	lp_count, r9
-	ld.ab   r9, [sp, 4]
-	sr	r9, [status32_l1]
-	ld.ab   r9, [sp, 4]
-	mov	ilink1, r9
-	ld.ab   blink, [sp, 4]
-	ld.ab   fp, [sp, 4]
-	ld.ab   r26, [sp, 4]    /* gp */
-	RESTORE_CALLER_SAVED
+	POPAX	bta_l1
+	POPAX	lp_start
+	POPAX	lp_end
+
+	POP	r9
+	mov	lp_count, r9	;LD to lp_count is not allowed
+
+	POPAX	status32_l1
+	POP	ilink1
+	POP	blink
+	POP	fp
+	POP	gp
+	RESTORE_R12_TO_R0
 
 	ld  sp, [sp] /* restore original sp */
-	/* orig_r0 and orig_r8 skipped automatically */
+	/* orig_r0, ECR, user_r25 skipped automatically */
 .endm
 
 .macro RESTORE_ALL_INT2
-	add sp, sp, 4       /* hop over unused "pt_regs->stack_place_holder" */
-
-	ld.ab   r9, [sp, 4]
-	sr	r9, [bta_l2]
-	ld.ab   r9, [sp, 4]
-	sr	r9, [lp_start]
-	ld.ab   r9, [sp, 4]
-	sr	r9, [lp_end]
-	ld.ab   r9, [sp, 4]
-	mov	lp_count, r9
-	ld.ab   r9, [sp, 4]
-	sr	r9, [status32_l2]
-	ld.ab   r9, [sp, 4]
-	mov	ilink2, r9
-	ld.ab   blink, [sp, 4]
-	ld.ab   fp, [sp, 4]
-	ld.ab   r26, [sp, 4]    /* gp */
-	RESTORE_CALLER_SAVED
+	POPAX	bta_l2
+	POPAX	lp_start
+	POPAX	lp_end
 
-	ld  sp, [sp] /* restore original sp */
-	/* orig_r0 and orig_r8 skipped automatically */
+	POP	r9
+	mov	lp_count, r9	;LD to lp_count is not allowed
 
+	POPAX	status32_l2
+	POP	ilink2
+	POP	blink
+	POP	fp
+	POP	gp
+	RESTORE_R12_TO_R0
+
+	ld  sp, [sp] /* restore original sp */
+	/* orig_r0, ECR, user_r25 skipped automatically */
 .endm
 
 

arch/arc/include/asm/irq.h

@@ -21,6 +21,6 @@
 extern void __init arc_init_IRQ(void);
 extern int __init get_hw_config_num_irq(void);
 
-void __cpuinit arc_local_timer_setup(unsigned int cpu);
+void arc_local_timer_setup(unsigned int cpu);
 
 #endif

arch/arc/include/asm/irqflags.h

@@ -19,6 +19,26 @@
 
 #include <asm/arcregs.h>
 
+/* status32 Reg bits related to Interrupt Handling */
+#define STATUS_E1_BIT		1	/* Int 1 enable */
+#define STATUS_E2_BIT		2	/* Int 2 enable */
+#define STATUS_A1_BIT		3	/* Int 1 active */
+#define STATUS_A2_BIT		4	/* Int 2 active */
+
+#define STATUS_E1_MASK		(1<<STATUS_E1_BIT)
+#define STATUS_E2_MASK		(1<<STATUS_E2_BIT)
+#define STATUS_A1_MASK		(1<<STATUS_A1_BIT)
+#define STATUS_A2_MASK		(1<<STATUS_A2_BIT)
+
+/* Other Interrupt Handling related Aux regs */
+#define AUX_IRQ_LEV		0x200	/* IRQ Priority: L1 or L2 */
+#define AUX_IRQ_HINT		0x201	/* For generating Soft Interrupts */
+#define AUX_IRQ_LV12		0x43	/* interrupt level register */
+
+#define AUX_IENABLE		0x40c
+#define AUX_ITRIGGER		0x40d
+#define AUX_IPULSE		0x415
+
 #ifndef __ASSEMBLY__
 
 /******************************************************************

arch/arc/include/asm/kgdb.h

@@ -31,7 +31,7 @@ static inline void arch_kgdb_breakpoint(void)
 	__asm__ __volatile__ ("trap_s	0x4\n");
 }
 
-extern void kgdb_trap(struct pt_regs *regs, int param);
+extern void kgdb_trap(struct pt_regs *regs);
 
 enum arc700_linux_regnums {
 	_R0		= 0,
@@ -53,7 +53,7 @@ enum arc700_linux_regnums {
 };
 
 #else
-#define kgdb_trap(regs, param)
+#define kgdb_trap(regs)
 #endif
 
 #endif	/* __ARC_KGDB_H__ */

arch/arc/include/asm/kprobes.h

@@ -50,11 +50,9 @@ struct kprobe_ctlblk {
 
 int kprobe_fault_handler(struct pt_regs *regs, unsigned long cause);
 void kretprobe_trampoline(void);
-void trap_is_kprobe(unsigned long cause, unsigned long address,
-			   struct pt_regs *regs);
+void trap_is_kprobe(unsigned long address, struct pt_regs *regs);
 #else
-static void trap_is_kprobe(unsigned long cause, unsigned long address,
-			   struct pt_regs *regs)
+static void trap_is_kprobe(unsigned long address, struct pt_regs *regs)
 {
 }
 #endif

arch/arc/include/asm/mmu.h

@@ -9,6 +9,40 @@
 #ifndef _ASM_ARC_MMU_H
 #define _ASM_ARC_MMU_H
 
+#if defined(CONFIG_ARC_MMU_V1)
+#define CONFIG_ARC_MMU_VER 1
+#elif defined(CONFIG_ARC_MMU_V2)
+#define CONFIG_ARC_MMU_VER 2
+#elif defined(CONFIG_ARC_MMU_V3)
+#define CONFIG_ARC_MMU_VER 3
+#endif
+
+/* MMU Management regs */
+#define ARC_REG_MMU_BCR		0x06f
+#define ARC_REG_TLBPD0		0x405
+#define ARC_REG_TLBPD1		0x406
+#define ARC_REG_TLBINDEX	0x407
+#define ARC_REG_TLBCOMMAND	0x408
+#define ARC_REG_PID		0x409
+#define ARC_REG_SCRATCH_DATA0	0x418
+
+/* Bits in MMU PID register */
+#define MMU_ENABLE		(1 << 31)	/* Enable MMU for process */
+
+/* Error code if probe fails */
+#define TLB_LKUP_ERR		0x80000000
+
+/* TLB Commands */
+#define TLBWrite    0x1
+#define TLBRead     0x2
+#define TLBGetIndex 0x3
+#define TLBProbe    0x4
+
+#if (CONFIG_ARC_MMU_VER >= 2)
+#define TLBWriteNI  0x5		/* write JTLB without inv uTLBs */
+#define TLBIVUTLB   0x6		/* explicitly inv uTLBs */
+#endif
+
 #ifndef __ASSEMBLY__
 
 typedef struct {
@@ -18,6 +52,16 @@ typedef struct {
 #endif
 } mm_context_t;
 
+#ifdef CONFIG_ARC_DBG_TLB_PARANOIA
+void tlb_paranoid_check(unsigned int pid_sw, unsigned long address);
+#else
+#define tlb_paranoid_check(a, b)
 #endif
 
+void arc_mmu_init(void);
+extern char *arc_mmu_mumbojumbo(int cpu_id, char *buf, int len);
+void __init read_decode_mmu_bcr(void);
+
+#endif	/* !__ASSEMBLY__ */
+
 #endif

arch/arc/include/asm/page.h

@@ -96,13 +96,8 @@ typedef unsigned long pgtable_t;
 
 #define virt_addr_valid(kaddr)  pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
 
-/* Default Permissions for page, used in mmap.c */
-#ifdef CONFIG_ARC_STACK_NONEXEC
+/* Default Permissions for stack/heaps pages (Non Executable) */
 #define VM_DATA_DEFAULT_FLAGS   (VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE)
-#else
-#define VM_DATA_DEFAULT_FLAGS   (VM_READ | VM_WRITE | VM_EXEC | \
-				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
-#endif
 
 #define WANT_PAGE_VIRTUAL   1
 

arch/arc/include/asm/pgtable.h

@@ -135,6 +135,12 @@
 /* ioremap */
 #define PAGE_KERNEL_NO_CACHE __pgprot(_K_PAGE_PERMS)
 
+/* Masks for actual TLB "PD"s */
+#define PTE_BITS_IN_PD0	(_PAGE_GLOBAL | _PAGE_PRESENT)
+#define PTE_BITS_IN_PD1	(PAGE_MASK | _PAGE_CACHEABLE | \
+			 _PAGE_U_EXECUTE | _PAGE_U_WRITE | _PAGE_U_READ | \
+			 _PAGE_K_EXECUTE | _PAGE_K_WRITE | _PAGE_K_READ)
+
 /**************************************************************************
  * Mapping of vm_flags (Generic VM) to PTE flags (arch specific)
  *

arch/arc/include/asm/processor.h

@@ -19,6 +19,7 @@
 #ifndef __ASSEMBLY__
 
 #include <asm/arcregs.h>	/* for STATUS_E1_MASK et all */
+#include <asm/ptrace.h>
 
 /* Arch specific stuff which needs to be saved per task.
  * However these items are not so important so as to earn a place in
@@ -28,10 +29,6 @@ struct thread_struct {
 	unsigned long ksp;	/* kernel mode stack pointer */
 	unsigned long callee_reg;	/* pointer to callee regs */
 	unsigned long fault_address;	/* dbls as brkpt holder as well */
-	unsigned long cause_code;	/* Exception Cause Code (ECR) */
-#ifdef CONFIG_ARC_CURR_IN_REG
-	unsigned long user_r25;
-#endif
 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE
 	struct arc_fpu fpu;
 #endif
@@ -50,7 +47,7 @@ struct task_struct;
 unsigned long thread_saved_pc(struct task_struct *t);
 
 #define task_pt_regs(p) \
-	((struct pt_regs *)(THREAD_SIZE - 4 + (void *)task_stack_page(p)) - 1)
+	((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
 
 /* Free all resources held by a thread. */
 #define release_thread(thread) do { } while (0)
@@ -75,11 +72,15 @@ unsigned long thread_saved_pc(struct task_struct *t);
 
 /*
  * Where abouts of Task's sp, fp, blink when it was last seen in kernel mode.
- * These can't be derived from pt_regs as that would give correp user-mode val
+ * Look in process.c for details of kernel stack layout
  */
 #define KSTK_ESP(tsk)   (tsk->thread.ksp)
-#define KSTK_BLINK(tsk) (*((unsigned int *)((KSTK_ESP(tsk)) + (13+1+1)*4)))
-#define KSTK_FP(tsk)    (*((unsigned int *)((KSTK_ESP(tsk)) + (13+1)*4)))
+
+#define KSTK_REG(tsk, off)	(*((unsigned int *)(KSTK_ESP(tsk) + \
+					sizeof(struct callee_regs) + off)))
+
+#define KSTK_BLINK(tsk) KSTK_REG(tsk, 4)
+#define KSTK_FP(tsk)    KSTK_REG(tsk, 0)
 
 /*
  * Do necessary setup to start up a newly executed thread.

arch/arc/include/asm/ptrace.h

@@ -17,12 +17,6 @@
 /* THE pt_regs: Defines how regs are saved during entry into kernel */
 
 struct pt_regs {
-	/*
-	 * 1 word gutter after reg-file has been saved
-	 * Technically not needed, Since SP always points to a "full" location
-	 * (vs. "empty"). But pt_regs is shared with tools....
-	 */
-	long res;
 
 	/* Real registers */
 	long bta;	/* bta_l1, bta_l2, erbta */
@@ -50,22 +44,32 @@ struct pt_regs {
 	long sp;	/* user/kernel sp depending on where we came from  */
 	long orig_r0;
 
-	/*to distinguish bet excp, syscall, irq */
+	/*
+	 * To distinguish bet excp, syscall, irq
+	 * For traps and exceptions, Exception Cause Register.
+	 * 	ECR: <00> <VV> <CC> <PP>
+	 * 	Last word used by Linux for extra state mgmt (syscall-restart)
+	 * For interrupts, use artificial ECR values to note current prio-level
+	 */
 	union {
+		struct {
 #ifdef CONFIG_CPU_BIG_ENDIAN
-		/* so that assembly code is same for LE/BE */
-		unsigned long orig_r8:16, event:16;
+			unsigned long state:8, ecr_vec:8,
+				      ecr_cause:8, ecr_param:8;
 #else
-		unsigned long event:16, orig_r8:16;
+			unsigned long ecr_param:8, ecr_cause:8,
+				      ecr_vec:8, state:8;
 #endif
-		long orig_r8_word;
+		};
+		unsigned long event;
 	};
+
+	long user_r25;
 };
 
 /* Callee saved registers - need to be saved only when you are scheduled out */
 
 struct callee_regs {
-	long res;	/* Again this is not needed */
 	long r25;
 	long r24;
 	long r23;
@@ -99,18 +103,20 @@ struct callee_regs {
 /* return 1 if PC in delay slot */
 #define delay_mode(regs) ((regs->status32 & STATUS_DE_MASK) == STATUS_DE_MASK)
 
-#define in_syscall(regs)    (regs->event & orig_r8_IS_SCALL)
-#define in_brkpt_trap(regs) (regs->event & orig_r8_IS_BRKPT)
+#define in_syscall(regs)    ((regs->ecr_vec == ECR_V_TRAP) && !regs->ecr_param)
+#define in_brkpt_trap(regs) ((regs->ecr_vec == ECR_V_TRAP) && regs->ecr_param)
+
+#define STATE_SCALL_RESTARTED	0x01
 
-#define syscall_wont_restart(regs) (regs->event |= orig_r8_IS_SCALL_RESTARTED)
-#define syscall_restartable(regs) !(regs->event &  orig_r8_IS_SCALL_RESTARTED)
+#define syscall_wont_restart(reg) (reg->state |= STATE_SCALL_RESTARTED)
+#define syscall_restartable(reg) !(reg->state &  STATE_SCALL_RESTARTED)
 
 #define current_pt_regs()					\
 ({								\
 	/* open-coded current_thread_info() */			\
 	register unsigned long sp asm ("sp");			\
 	unsigned long pg_start = (sp & ~(THREAD_SIZE - 1));	\
-	(struct pt_regs *)(pg_start + THREAD_SIZE - 4) - 1;	\
+	(struct pt_regs *)(pg_start + THREAD_SIZE) - 1;	\
 })
 
 static inline long regs_return_value(struct pt_regs *regs)
@@ -120,11 +126,4 @@ static inline long regs_return_value(struct pt_regs *regs)
 
 #endif /* !__ASSEMBLY__ */
 
-#define orig_r8_IS_SCALL		0x0001
-#define orig_r8_IS_SCALL_RESTARTED	0x0002
-#define orig_r8_IS_BRKPT		0x0004
-#define orig_r8_IS_EXCPN		0x0008
-#define orig_r8_IS_IRQ1			0x0010
-#define orig_r8_IS_IRQ2			0x0020
-
 #endif /* __ASM_PTRACE_H */

arch/arc/include/asm/syscall.h

@@ -18,7 +18,7 @@ static inline long
 syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
 {
 	if (user_mode(regs) && in_syscall(regs))
-		return regs->orig_r8;
+		return regs->r8;
 	else
 		return -1;
 }
@@ -26,8 +26,7 @@ syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
 static inline void
 syscall_rollback(struct task_struct *task, struct pt_regs *regs)
 {
-	/* XXX: I can't fathom how pt_regs->r8 will be clobbered ? */
-	regs->r8 = regs->orig_r8;
+	regs->r0 = regs->orig_r0;
 }
 
 static inline long

arch/arc/include/asm/tlb-mmu1.h

@@ -9,9 +9,9 @@
 #ifndef __ASM_TLB_MMU_V1_H__
 #define __ASM_TLB_MMU_V1_H__
 
-#if defined(__ASSEMBLY__) && defined(CONFIG_ARC_MMU_VER == 1)
+#include <asm/mmu.h>
 
-#include <asm/tlb.h>
+#if defined(__ASSEMBLY__) && (CONFIG_ARC_MMU_VER == 1)
 
 .macro TLB_WRITE_HEURISTICS
 

arch/arc/include/asm/tlb.h

@@ -9,18 +9,6 @@
 #ifndef _ASM_ARC_TLB_H
 #define _ASM_ARC_TLB_H
 
-#ifdef __KERNEL__
-
-#include <asm/pgtable.h>
-
-/* Masks for actual TLB "PD"s */
-#define PTE_BITS_IN_PD0	(_PAGE_GLOBAL | _PAGE_PRESENT)
-#define PTE_BITS_IN_PD1	(PAGE_MASK | _PAGE_CACHEABLE | \
-			 _PAGE_U_EXECUTE | _PAGE_U_WRITE | _PAGE_U_READ | \
-			 _PAGE_K_EXECUTE | _PAGE_K_WRITE | _PAGE_K_READ)
-
-#ifndef __ASSEMBLY__
-
 #define tlb_flush(tlb)				\
 do {						\
 	if (tlb->fullmm)			\
@@ -56,18 +44,4 @@ do {									\
 #include <linux/pagemap.h>
 #include <asm-generic/tlb.h>
 
-#ifdef CONFIG_ARC_DBG_TLB_PARANOIA
-void tlb_paranoid_check(unsigned int pid_sw, unsigned long address);
-#else
-#define tlb_paranoid_check(a, b)
-#endif
-
-void arc_mmu_init(void);
-extern char *arc_mmu_mumbojumbo(int cpu_id, char *buf, int len);
-void __init read_decode_mmu_bcr(void);
-
-#endif	/* __ASSEMBLY__ */
-
-#endif	/* __KERNEL__ */
-
 #endif /* _ASM_ARC_TLB_H */

arch/arc/include/asm/unaligned.h

@@ -16,11 +16,11 @@
 
 #ifdef CONFIG_ARC_MISALIGN_ACCESS
 int misaligned_fixup(unsigned long address, struct pt_regs *regs,
-		     unsigned long cause, struct callee_regs *cregs);
+		     struct callee_regs *cregs);
 #else
 static inline int
 misaligned_fixup(unsigned long address, struct pt_regs *regs,
-		 unsigned long cause, struct callee_regs *cregs)
+		 struct callee_regs *cregs)
 {
 	return 0;
 }

arch/arc/include/uapi/asm/ptrace.h

@@ -20,28 +20,31 @@
  *
  * This is to decouple pt_regs from user-space ABI, to be able to change it
  * w/o affecting the ABI.
- * Although the layout (initial padding) is similar to pt_regs to have some
- * optimizations when copying pt_regs to/from user_regs_struct.
+ *
+ * The intermediate pad,pad2 are relics of initial layout based on pt_regs
+ * for optimizations when copying pt_regs to/from user_regs_struct.
+ * We no longer need them, but can't be changed as they are part of ABI now.
  *
  * Also, sigcontext only care about the scratch regs as that is what we really
- * save/restore for signal handling.
+ * save/restore for signal handling. However gdb also uses the same struct
+ * hence callee regs need to be in there too.
 */
 struct user_regs_struct {
 
+	long pad;
 	struct {
-		long pad;
 		long bta, lp_start, lp_end, lp_count;
 		long status32, ret, blink, fp, gp;
 		long r12, r11, r10, r9, r8, r7, r6, r5, r4, r3, r2, r1, r0;
 		long sp;
 	} scratch;
+	long pad2;
 	struct {
-		long pad;
 		long r25, r24, r23, r22, r21, r20;
 		long r19, r18, r17, r16, r15, r14, r13;
 	} callee;
 	long efa;	/* break pt addr, for break points in delay slots */
-	long stop_pc;	/* give dbg stop_pc directly after checking orig_r8 */
+	long stop_pc;	/* give dbg stop_pc after ensuring brkpt trap */
 };
 #endif /* !__ASSEMBLY__ */
 

arch/arc/kernel/asm-offsets.c

@@ -24,9 +24,6 @@ int main(void)
 
 	DEFINE(THREAD_KSP, offsetof(struct thread_struct, ksp));
 	DEFINE(THREAD_CALLEE_REG, offsetof(struct thread_struct, callee_reg));
-#ifdef CONFIG_ARC_CURR_IN_REG
-	DEFINE(THREAD_USER_R25, offsetof(struct thread_struct, user_r25));
-#endif
 	DEFINE(THREAD_FAULT_ADDR,
 	       offsetof(struct thread_struct, fault_address));
 
@@ -49,7 +46,7 @@ int main(void)
 	BLANK();
 
 	DEFINE(PT_status32, offsetof(struct pt_regs, status32));
-	DEFINE(PT_orig_r8, offsetof(struct pt_regs, orig_r8_word));
+	DEFINE(PT_event, offsetof(struct pt_regs, event));
 	DEFINE(PT_sp, offsetof(struct pt_regs, sp));
 	DEFINE(PT_r0, offsetof(struct pt_regs, r0));
 	DEFINE(PT_r1, offsetof(struct pt_regs, r1));
@@ -60,5 +57,7 @@ int main(void)
 	DEFINE(PT_r6, offsetof(struct pt_regs, r6));
 	DEFINE(PT_r7, offsetof(struct pt_regs, r7));
 
+	DEFINE(SZ_CALLEE_REGS, sizeof(struct callee_regs));
+	DEFINE(SZ_PT_REGS, sizeof(struct pt_regs));
 	return 0;
 }

arch/arc/kernel/ctx_sw.c

@@ -23,10 +23,6 @@ __switch_to(struct task_struct *prev_task, struct task_struct *next_task)
 	unsigned int tmp;
 	unsigned int prev = (unsigned int)prev_task;
 	unsigned int next = (unsigned int)next_task;
-	int num_words_to_skip = 1;
-#ifdef CONFIG_ARC_CURR_IN_REG
-	num_words_to_skip++;
-#endif
 
 	__asm__ __volatile__(
 		/* FP/BLINK save generated by gcc (standard function prologue */
@@ -44,8 +40,9 @@ __switch_to(struct task_struct *prev_task, struct task_struct *next_task)
 		"st.a    r24, [sp, -4]   \n\t"
 #ifndef CONFIG_ARC_CURR_IN_REG
 		"st.a    r25, [sp, -4]   \n\t"
+#else
+		"sub     sp, sp, 4      \n\t"	/* usual r25 placeholder */
 #endif
-		"sub     sp, sp, %4      \n\t"	/* create gutter at top */
 
 		/* set ksp of outgoing task in tsk->thread.ksp */
 		"st.as   sp, [%3, %1]    \n\t"
@@ -76,10 +73,10 @@ __switch_to(struct task_struct *prev_task, struct task_struct *next_task)
 
 		/* start loading it's CALLEE reg file */
 
-		"add    sp, sp, %4     \n\t"	/* skip gutter at top */
-
 #ifndef CONFIG_ARC_CURR_IN_REG
 		"ld.ab   r25, [sp, 4]   \n\t"
+#else
+		"add    sp, sp, 4       \n\t"
 #endif
 		"ld.ab   r24, [sp, 4]   \n\t"
 		"ld.ab   r23, [sp, 4]   \n\t"
@@ -100,8 +97,7 @@ __switch_to(struct task_struct *prev_task, struct task_struct *next_task)
 		/* FP/BLINK restore generated by gcc (standard func epilogue */
 
 		: "=r"(tmp)
-		: "n"((TASK_THREAD + THREAD_KSP) / 4), "r"(next), "r"(prev),
-		  "n"(num_words_to_skip * 4)
+		: "n"((TASK_THREAD + THREAD_KSP) / 4), "r"(next), "r"(prev)
 		: "blink"
 	);
 

arch/arc/kernel/entry.S

@@ -142,7 +142,7 @@ VECTOR   reserved                ; Reserved Exceptions
 .endr
 
 #include <linux/linkage.h>   /* ARC_{EXTRY,EXIT} */
-#include <asm/entry.h>       /* SAVE_ALL_{INT1,INT2,TRAP...} */
+#include <asm/entry.h>       /* SAVE_ALL_{INT1,INT2,SYS...} */
 #include <asm/errno.h>
 #include <asm/arcregs.h>
 #include <asm/irqflags.h>
@@ -274,10 +274,8 @@ ARC_ENTRY instr_service
 	SWITCH_TO_KERNEL_STK
 	SAVE_ALL_SYS
 
-	lr  r0, [ecr]
-	lr  r1, [efa]
-
-	mov r2, sp
+	lr  r0, [efa]
+	mov r1, sp
 
 	FAKE_RET_FROM_EXCPN r9
 
@@ -298,9 +296,8 @@ ARC_ENTRY mem_service
 	SWITCH_TO_KERNEL_STK
 	SAVE_ALL_SYS
 
-	lr  r0, [ecr]
-	lr  r1, [efa]
-	mov r2, sp
+	lr  r0, [efa]
+	mov r1, sp
 	bl  do_memory_error
 	b   ret_from_exception
 ARC_EXIT mem_service
@@ -317,11 +314,14 @@ ARC_ENTRY EV_MachineCheck
 	SWITCH_TO_KERNEL_STK
 	SAVE_ALL_SYS
 
-	lr  r0, [ecr]
-	lr  r1, [efa]
-	mov r2, sp
+	lr  r2, [ecr]
+	lr  r0, [efa]
+	mov r1, sp
+
+	lsr  	r3, r2, 8
+	bmsk 	r3, r3, 7
+	brne    r3, ECR_C_MCHK_DUP_TLB, 1f
 
-	brne    r0, 0x200100, 1f
 	bl      do_tlb_overlap_fault
 	b       ret_from_exception
 
@@ -355,8 +355,8 @@ ARC_ENTRY EV_TLBProtV
 	;  ecr and efa were not saved in case an Intr sneaks in
 	;  after fake rtie
 	;
-	lr  r3, [ecr]
-	lr  r4, [efa]
+	lr  r2, [ecr]
+	lr  r1, [efa]	; Faulting Data address
 
 	; --------(4) Return from CPU Exception Mode ---------
 	;  Fake a rtie, but rtie to next label
@@ -368,31 +368,25 @@ ARC_ENTRY EV_TLBProtV
 	;------ (5) Type of Protection Violation? ----------
 	;
 	; ProtV Hardware Exception is triggered for Access Faults of 2 types
-	;   -Access Violaton (WRITE to READ ONLY Page) - for linux COW
-	;   -Unaligned Access (READ/WRITE on odd boundary)
+	;   -Access Violaton	: 00_23_(00|01|02|03)_00
+	;			         x  r  w  r+w
+	;   -Unaligned Access	: 00_23_04_00
 	;
-	cmp r3, 0x230400    ; Misaligned data access ?
-	beq 4f
+	bbit1 r2, ECR_C_BIT_PROTV_MISALIG_DATA, 4f
 
 	;========= (6a) Access Violation Processing ========
-	cmp r3, 0x230100
-	mov r1, 0x0              ; if LD exception ? write = 0
-	mov.ne r1, 0x1           ; else write = 1
-
-	mov r2, r4              ; faulting address
 	mov r0, sp              ; pt_regs
 	bl  do_page_fault
 	b   ret_from_exception
 
 	;========== (6b) Non aligned access ============
 4:
-	mov r0, r3              ; cause code
-	mov r1, r4              ; faulting address
-	mov r2, sp              ; pt_regs
+	mov r0, r1
+	mov r1, sp              ; pt_regs
 
 #ifdef  CONFIG_ARC_MISALIGN_ACCESS
 	SAVE_CALLEE_SAVED_USER
-	mov r3, sp              ; callee_regs
+	mov r2, sp              ; callee_regs
 
 	bl  do_misaligned_access
 
@@ -419,9 +413,8 @@ ARC_ENTRY EV_PrivilegeV
 	SWITCH_TO_KERNEL_STK
 	SAVE_ALL_SYS
 
-	lr  r0, [ecr]
-	lr  r1, [efa]
-	mov r2, sp
+	lr  r0, [efa]
+	mov r1, sp
 
 	FAKE_RET_FROM_EXCPN r9
 
@@ -440,9 +433,8 @@ ARC_ENTRY EV_Extension
 	SWITCH_TO_KERNEL_STK
 	SAVE_ALL_SYS
 
-	lr  r0, [ecr]
-	lr  r1, [efa]
-	mov r2, sp
+	lr  r0, [efa]
+	mov r1, sp
 	bl  do_extension_fault
 	b   ret_from_exception
 ARC_EXIT EV_Extension
@@ -498,11 +490,8 @@ tracesys_exit:
 trap_with_param:
 
 	; stop_pc info by gdb needs this info
-	stw orig_r8_IS_BRKPT, [sp, PT_orig_r8]
-
-	mov r0, r12
-	lr  r1, [efa]
-	mov r2, sp
+	lr  r0, [efa]
+	mov r1, sp
 
 	; Now that we have read EFA, its safe to do "fake" rtie
 	;   and get out of CPU exception mode
@@ -544,11 +533,11 @@ ARC_ENTRY EV_Trap
 	lr  r9, [erstatus]
 
 	SWITCH_TO_KERNEL_STK
-	SAVE_ALL_TRAP
+	SAVE_ALL_SYS
 
 	;------- (4) What caused the Trap --------------
 	lr     r12, [ecr]
-	and.f  0, r12, ECR_PARAM_MASK
+	bmsk.f 0, r12, 7
 	bnz    trap_with_param
 
 	; ======= (5a) Trap is due to System Call ========
@@ -589,11 +578,7 @@ ARC_ENTRY ret_from_exception
 	; Pre-{IRQ,Trap,Exception} K/U mode from pt_regs->status32
 	ld  r8, [sp, PT_status32]   ; returning to User/Kernel Mode
 
-#ifdef CONFIG_PREEMPT
 	bbit0  r8, STATUS_U_BIT, resume_kernel_mode
-#else
-	bbit0  r8, STATUS_U_BIT, restore_regs
-#endif
 
 	; Before returning to User mode check-for-and-complete any pending work
 	; such as rescheduling/signal-delivery etc.
@@ -653,10 +638,10 @@ resume_user_mode_begin:
 	b      resume_user_mode_begin	; unconditionally back to U mode ret chks
 					; for single exit point from this block
 
-#ifdef CONFIG_PREEMPT
-
 resume_kernel_mode:
 
+#ifdef CONFIG_PREEMPT
+
 	; Can't preempt if preemption disabled
 	GET_CURR_THR_INFO_FROM_SP   r10
 	ld  r8, [r10, THREAD_INFO_PREEMPT_COUNT]
@@ -687,17 +672,6 @@ restore_regs :
 	; XXX can this be optimised out
 	IRQ_DISABLE_SAVE    r9, r10	;@r10 has prisitine (pre-disable) copy
 
-#ifdef CONFIG_ARC_CURR_IN_REG
-	; Restore User R25
-	; Earlier this used to be only for returning to user mode
-	; However with 2 levels of IRQ this can also happen even if
-	; in kernel mode
-	ld r9, [sp, PT_sp]
-	brhs r9, VMALLOC_START, 8f
-	RESTORE_USER_R25
-8:
-#endif
-
 	; Restore REG File. In case multiple Events outstanding,
 	; use the same priorty as rtie: EXCPN, L2 IRQ, L1 IRQ, None
 	; Note that we use realtime STATUS32 (not pt_regs->status32) to
@@ -714,8 +688,17 @@ not_exception:
 
 #ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
 
+	; Level 2 interrupt return Path - from hardware standpoint
 	bbit0  r10, STATUS_A2_BIT, not_level2_interrupt
 
+	;------------------------------------------------------------------
+	; However the context returning might not have taken L2 intr itself
+	; e.g. Task'A' user-code -> L2 intr -> schedule -> 'B' user-code ret
+	; Special considerations needed for the context which took L2 intr
+
+	ld   r9, [sp, PT_event]        ; Ensure this is L2 intr context
+	brne r9, event_IRQ2, 149f
+
 	;------------------------------------------------------------------
 	; if L2 IRQ interrupted a L1 ISR,  we'd disbaled preemption earlier
 	; so that sched doesnt move to new task, causing L1 to be delayed
@@ -723,19 +706,15 @@ not_exception:
 	; things to what they were, before returning from L2 context
 	;----------------------------------------------------------------
 
-	ldw  r9, [sp, PT_orig_r8]      ; get orig_r8 to make sure it is
-	brne r9, orig_r8_IS_IRQ2, 149f ; infact a L2 ISR ret path
-
 	ld r9, [sp, PT_status32]       ; get statu32_l2 (saved in pt_regs)
 	bbit0 r9, STATUS_A1_BIT, 149f  ; L1 not active when L2 IRQ, so normal
 
-	; A1 is set in status32_l2
 	; decrement thread_info->preempt_count (re-enable preemption)
 	GET_CURR_THR_INFO_FROM_SP   r10
 	ld      r9, [r10, THREAD_INFO_PREEMPT_COUNT]
 
 	; paranoid check, given A1 was active when A2 happened, preempt count
-	; must not be 0 beccause we would have incremented it.
+	; must not be 0 because we would have incremented it.
 	; If this does happen we simply HALT as it means a BUG !!!
 	cmp     r9, 0
 	bnz     2f

arch/arc/kernel/head.S

@@ -27,6 +27,8 @@ stext:
 	; Don't clobber r0-r4 yet. It might have bootloader provided info
 	;-------------------------------------------------------------------
 
+	sr	@_int_vec_base_lds, [AUX_INTR_VEC_BASE]
+
 #ifdef CONFIG_SMP
 	; Only Boot (Master) proceeds. Others wait in platform dependent way
 	;	IDENTITY Reg [ 3  2  1  0 ]

arch/arc/kernel/irq.c

@@ -28,25 +28,17 @@
  * -Disable all IRQs (on CPU side)
  * -Optionally, setup the High priority Interrupts as Level 2 IRQs
  */
-void __cpuinit arc_init_IRQ(void)
+void arc_init_IRQ(void)
 {
 	int level_mask = 0;
 
-	write_aux_reg(AUX_INTR_VEC_BASE, _int_vec_base_lds);
-
 	/* Disable all IRQs: enable them as devices request */
 	write_aux_reg(AUX_IENABLE, 0);
 
        /* setup any high priority Interrupts (Level2 in ARCompact jargon) */
-#ifdef CONFIG_ARC_IRQ3_LV2
-	level_mask |= (1 << 3);
-#endif
-#ifdef CONFIG_ARC_IRQ5_LV2
-	level_mask |= (1 << 5);
-#endif
-#ifdef CONFIG_ARC_IRQ6_LV2
-	level_mask |= (1 << 6);
-#endif
+	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ3_LV2) << 3;
+	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ5_LV2) << 5;
+	level_mask |= IS_ENABLED(CONFIG_ARC_IRQ6_LV2) << 6;
 
 	if (level_mask) {
 		pr_info("Level-2 interrupts bitset %x\n", level_mask);

arch/arc/kernel/kgdb.c

@@ -169,7 +169,7 @@ int kgdb_arch_init(void)
 	return 0;
 }
 
-void kgdb_trap(struct pt_regs *regs, int param)
+void kgdb_trap(struct pt_regs *regs)
 {
 	/* trap_s 3 is used for breakpoints that overwrite existing
 	 * instructions, while trap_s 4 is used for compiled breakpoints.
@@ -181,7 +181,7 @@ void kgdb_trap(struct pt_regs *regs, int param)
 	 * with trap_s 4 (compiled) breakpoints, continuation needs to
 	 * start after the breakpoint.
 	 */
-	if (param == 3)
+	if (regs->ecr_param == 3)
 		instruction_pointer(regs) -= BREAK_INSTR_SIZE;
 
 	kgdb_handle_exception(1, SIGTRAP, 0, regs);

arch/arc/kernel/kprobes.c

@@ -517,8 +517,7 @@ int __kprobes arch_trampoline_kprobe(struct kprobe *p)
 	return 0;
 }
 
-void trap_is_kprobe(unsigned long cause, unsigned long address,
-		    struct pt_regs *regs)
+void trap_is_kprobe(unsigned long address, struct pt_regs *regs)
 {
-	notify_die(DIE_TRAP, "kprobe_trap", regs, address, cause, SIGTRAP);
+	notify_die(DIE_TRAP, "kprobe_trap", regs, address, 0, SIGTRAP);
 }

arch/arc/kernel/process.c

@@ -55,10 +55,8 @@ asmlinkage void ret_from_fork(void);
  * |     ...        |
  * |    unused      |
  * |                |
- * ------------------  <==== top of Stack (thread.ksp)
- * |   UNUSED 1 word|
  * ------------------
- * |     r25        |
+ * |     r25        |   <==== top of Stack (thread.ksp)
  * ~                ~
  * |    --to--      |   (CALLEE Regs of user mode)
  * |     r13        |
@@ -76,7 +74,10 @@ asmlinkage void ret_from_fork(void);
  * |    --to--      |   (scratch Regs of user mode)
  * |     r0         |
  * ------------------
- * |   UNUSED 1 word|
+ * |      SP        |
+ * |    orig_r0     |
+ * |    event/ECR   |
+ * |    user_r25    |
  * ------------------  <===== END of PAGE
  */
 int copy_thread(unsigned long clone_flags,

arch/arc/kernel/ptrace.c

@@ -40,7 +40,15 @@ static int genregs_get(struct task_struct *target,
 			offsetof(struct user_regs_struct, LOC), \
 			offsetof(struct user_regs_struct, LOC) + 4);
 
+#define REG_O_ZERO(LOC)		\
+	if (!ret)		\
+		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, \
+			offsetof(struct user_regs_struct, LOC), \
+			offsetof(struct user_regs_struct, LOC) + 4);
+
+	REG_O_ZERO(pad);
 	REG_O_CHUNK(scratch, callee, ptregs);
+	REG_O_ZERO(pad2);
 	REG_O_CHUNK(callee, efa, cregs);
 	REG_O_CHUNK(efa, stop_pc, &target->thread.fault_address);
 
@@ -88,8 +96,10 @@ static int genregs_set(struct task_struct *target,
 			offsetof(struct user_regs_struct, LOC), \
 			offsetof(struct user_regs_struct, LOC) + 4);
 
-	/* TBD: disallow updates to STATUS32, orig_r8 etc*/
-	REG_IN_CHUNK(scratch, callee, ptregs);	/* pt_regs[bta..orig_r8] */
+	REG_IGNORE_ONE(pad);
+	/* TBD: disallow updates to STATUS32 etc*/
+	REG_IN_CHUNK(scratch, pad2, ptregs);	/* pt_regs[bta..sp] */
+	REG_IGNORE_ONE(pad2);
 	REG_IN_CHUNK(callee, efa, cregs);	/* callee_regs[r25..r13] */
 	REG_IGNORE_ONE(efa);			/* efa update invalid */
 	REG_IN_ONE(stop_pc, &ptregs->ret);	/* stop_pc: PC update */

arch/arc/kernel/setup.c

@@ -31,14 +31,14 @@
 int running_on_hw = 1;	/* vs. on ISS */
 
 char __initdata command_line[COMMAND_LINE_SIZE];
-struct machine_desc *machine_desc __cpuinitdata;
+struct machine_desc *machine_desc;
 
 struct task_struct *_current_task[NR_CPUS];	/* For stack switching */
 
 struct cpuinfo_arc cpuinfo_arc700[NR_CPUS];
 
 
-void __cpuinit read_arc_build_cfg_regs(void)
+void read_arc_build_cfg_regs(void)
 {
 	struct bcr_perip uncached_space;
 	struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
@@ -182,7 +182,7 @@ char *arc_extn_mumbojumbo(int cpu_id, char *buf, int len)
 	FIX_PTR(cpu);
 #define IS_AVAIL1(var, str)	((var) ? str : "")
 #define IS_AVAIL2(var, str)	((var == 0x2) ? str : "")
-#define IS_USED(var)		((var) ? "(in-use)" : "(not used)")
+#define IS_USED(cfg)		(IS_ENABLED(cfg) ? "(in-use)" : "(not used)")
 
 	n += scnprintf(buf + n, len - n,
 		       "Extn [700-Base]\t: %s %s %s %s %s %s\n",
@@ -202,9 +202,9 @@ char *arc_extn_mumbojumbo(int cpu_id, char *buf, int len)
 	if (cpu->core.family == 0x34) {
 		n += scnprintf(buf + n, len - n,
 		"Extn [700-4.10]\t: LLOCK/SCOND %s, SWAPE %s, RTSC %s\n",
-			       IS_USED(__CONFIG_ARC_HAS_LLSC_VAL),
-			       IS_USED(__CONFIG_ARC_HAS_SWAPE_VAL),
-			       IS_USED(__CONFIG_ARC_HAS_RTSC_VAL));
+			       IS_USED(CONFIG_ARC_HAS_LLSC),
+			       IS_USED(CONFIG_ARC_HAS_SWAPE),
+			       IS_USED(CONFIG_ARC_HAS_RTSC));
 	}
 
 	n += scnprintf(buf + n, len - n, "Extn [CCM]\t: %s",
@@ -237,7 +237,7 @@ char *arc_extn_mumbojumbo(int cpu_id, char *buf, int len)
 	return buf;
 }
 
-void __cpuinit arc_chk_ccms(void)
+void arc_chk_ccms(void)
 {
 #if defined(CONFIG_ARC_HAS_DCCM) || defined(CONFIG_ARC_HAS_ICCM)
 	struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
@@ -272,7 +272,7 @@ void __cpuinit arc_chk_ccms(void)
  * hardware has dedicated regs which need to be saved/restored on ctx-sw
  * (Single Precision uses core regs), thus kernel is kind of oblivious to it
  */
-void __cpuinit arc_chk_fpu(void)
+void arc_chk_fpu(void)
 {
 	struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
 
@@ -293,7 +293,7 @@ void __cpuinit arc_chk_fpu(void)
  *    such as only for boot CPU etc
  */
 
-void __cpuinit setup_processor(void)
+void setup_processor(void)
 {
 	char str[512];
 	int cpu_id = smp_processor_id();

arch/arc/kernel/smp.c

@@ -117,7 +117,7 @@ const char *arc_platform_smp_cpuinfo(void)
  * Called from asm stub in head.S
  * "current"/R25 already setup by low level boot code
  */
-void __cpuinit start_kernel_secondary(void)
+void start_kernel_secondary(void)
 {
 	struct mm_struct *mm = &init_mm;
 	unsigned int cpu = smp_processor_id();
@@ -154,7 +154,7 @@ void __cpuinit start_kernel_secondary(void)
  *
  * Essential requirements being where to run from (PC) and stack (SP)
 */
-int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
+int __cpu_up(unsigned int cpu, struct task_struct *idle)
 {
 	unsigned long wait_till;
 

arch/arc/kernel/stacktrace.c

@@ -79,7 +79,7 @@ static void seed_unwind_frame_info(struct task_struct *tsk,
 		 * assembly code
 		 */
 		frame_info->regs.r27 = 0;
-		frame_info->regs.r28 += 64;
+		frame_info->regs.r28 += 60;
 		frame_info->call_frame = 0;
 
 	} else {

arch/arc/kernel/time.c

@@ -44,13 +44,24 @@
 #include <asm/clk.h>
 #include <asm/mach_desc.h>
 
+/* Timer related Aux registers */
+#define ARC_REG_TIMER0_LIMIT	0x23	/* timer 0 limit */
+#define ARC_REG_TIMER0_CTRL	0x22	/* timer 0 control */
+#define ARC_REG_TIMER0_CNT	0x21	/* timer 0 count */
+#define ARC_REG_TIMER1_LIMIT	0x102	/* timer 1 limit */
+#define ARC_REG_TIMER1_CTRL	0x101	/* timer 1 control */
+#define ARC_REG_TIMER1_CNT	0x100	/* timer 1 count */
+
+#define TIMER_CTRL_IE		(1 << 0) /* Interupt when Count reachs limit */
+#define TIMER_CTRL_NH		(1 << 1) /* Count only when CPU NOT halted */
+
 #define ARC_TIMER_MAX	0xFFFFFFFF
 
 /********** Clock Source Device *********/
 
 #ifdef CONFIG_ARC_HAS_RTSC
 
-int __cpuinit arc_counter_setup(void)
+int arc_counter_setup(void)
 {
 	/* RTSC insn taps into cpu clk, needs no setup */
 
@@ -105,7 +116,7 @@ static bool is_usable_as_clocksource(void)
 /*
  * set 32bit TIMER1 to keep counting monotonically and wraparound
  */
-int __cpuinit arc_counter_setup(void)
+int arc_counter_setup(void)
 {
 	write_aux_reg(ARC_REG_TIMER1_LIMIT, ARC_TIMER_MAX);
 	write_aux_reg(ARC_REG_TIMER1_CNT, 0);
@@ -212,7 +223,7 @@ static struct irqaction arc_timer_irq = {
  * Setup the local event timer for @cpu
  * N.B. weak so that some exotic ARC SoCs can completely override it
  */
-void __attribute__((weak)) __cpuinit arc_local_timer_setup(unsigned int cpu)
+void __attribute__((weak)) arc_local_timer_setup(unsigned int cpu)
 {
 	struct clock_event_device *clk = &per_cpu(arc_clockevent_device, cpu);
 

arch/arc/kernel/traps.c

@@ -28,10 +28,9 @@ void __init trap_init(void)
 	return;
 }
 
-void die(const char *str, struct pt_regs *regs, unsigned long address,
-	 unsigned long cause_reg)
+void die(const char *str, struct pt_regs *regs, unsigned long address)
 {
-	show_kernel_fault_diag(str, regs, address, cause_reg);
+	show_kernel_fault_diag(str, regs, address);
 
 	/* DEAD END */
 	__asm__("flag 1");
@@ -42,14 +41,13 @@ void die(const char *str, struct pt_regs *regs, unsigned long address,
  *  -for user faults enqueues requested signal
  *  -for kernel, chk if due to copy_(to|from)_user, otherwise die()
  */
-static noinline int handle_exception(unsigned long cause, char *str,
-				     struct pt_regs *regs, siginfo_t *info)
+static noinline int
+handle_exception(const char *str, struct pt_regs *regs, siginfo_t *info)
 {
 	if (user_mode(regs)) {
 		struct task_struct *tsk = current;
 
 		tsk->thread.fault_address = (__force unsigned int)info->si_addr;
-		tsk->thread.cause_code = cause;
 
 		force_sig_info(info->si_signo, info, tsk);
 
@@ -58,14 +56,14 @@ static noinline int handle_exception(unsigned long cause, char *str,
 		if (fixup_exception(regs))
 			return 0;
 
-		die(str, regs, (unsigned long)info->si_addr, cause);
+		die(str, regs, (unsigned long)info->si_addr);
 	}
 
 	return 1;
 }
 
 #define DO_ERROR_INFO(signr, str, name, sicode) \
-int name(unsigned long cause, unsigned long address, struct pt_regs *regs) \
+int name(unsigned long address, struct pt_regs *regs) \
 {						\
 	siginfo_t info = {			\
 		.si_signo = signr,		\
@@ -73,7 +71,7 @@ int name(unsigned long cause, unsigned long address, struct pt_regs *regs) \
 		.si_code  = sicode,		\
 		.si_addr = (void __user *)address,	\
 	};					\
-	return handle_exception(cause, str, regs, &info);\
+	return handle_exception(str, regs, &info);\
 }
 
 /*
@@ -90,11 +88,11 @@ DO_ERROR_INFO(SIGBUS, "Misaligned Access", do_misaligned_error, BUS_ADRALN)
 /*
  * Entry Point for Misaligned Data access Exception, for emulating in software
  */
-int do_misaligned_access(unsigned long cause, unsigned long address,
-			 struct pt_regs *regs, struct callee_regs *cregs)
+int do_misaligned_access(unsigned long address, struct pt_regs *regs,
+			 struct callee_regs *cregs)
 {
-	if (misaligned_fixup(address, regs, cause, cregs) != 0)
-		return do_misaligned_error(cause, address, regs);
+	if (misaligned_fixup(address, regs, cregs) != 0)
+		return do_misaligned_error(address, regs);
 
 	return 0;
 }
@@ -104,10 +102,9 @@ int do_misaligned_access(unsigned long cause, unsigned long address,
  * Entry point for miscll errors such as Nested Exceptions
  *  -Duplicate TLB entry is handled seperately though
  */
-void do_machine_check_fault(unsigned long cause, unsigned long address,
-			    struct pt_regs *regs)
+void do_machine_check_fault(unsigned long address, struct pt_regs *regs)
 {
-	die("Machine Check Exception", regs, address, cause);
+	die("Machine Check Exception", regs, address);
 }
 
 
@@ -120,23 +117,22 @@ void do_machine_check_fault(unsigned long cause, unsigned long address,
  *  -1 used for software breakpointing (gdb)
  *  -2 used by kprobes
  */
-void do_non_swi_trap(unsigned long cause, unsigned long address,
-			struct pt_regs *regs)
+void do_non_swi_trap(unsigned long address, struct pt_regs *regs)
 {
-	unsigned int param = cause & 0xff;
+	unsigned int param = regs->ecr_param;
 
 	switch (param) {
 	case 1:
-		trap_is_brkpt(cause, address, regs);
+		trap_is_brkpt(address, regs);
 		break;
 
 	case 2:
-		trap_is_kprobe(param, address, regs);
+		trap_is_kprobe(address, regs);
 		break;
 
 	case 3:
 	case 4:
-		kgdb_trap(regs, param);
+		kgdb_trap(regs);
 		break;
 
 	default:
@@ -149,14 +145,14 @@ void do_non_swi_trap(unsigned long cause, unsigned long address,
  *  -For a corner case, ARC kprobes implementation resorts to using
  *   this exception, hence the check
  */
-void do_insterror_or_kprobe(unsigned long cause,
-				       unsigned long address,
-				       struct pt_regs *regs)
+void do_insterror_or_kprobe(unsigned long address, struct pt_regs *regs)
 {
+	int rc;
+
 	/* Check if this exception is caused by kprobes */
-	if (notify_die(DIE_IERR, "kprobe_ierr", regs, address,
-		       cause, SIGILL) == NOTIFY_STOP)
+	rc = notify_die(DIE_IERR, "kprobe_ierr", regs, address, 0, SIGILL);
+	if (rc == NOTIFY_STOP)
 		return;
 
-	insterror_is_error(cause, address, regs);
+	insterror_is_error(address, regs);
 }

arch/arc/kernel/troubleshoot.c

@@ -117,23 +117,22 @@ static void show_faulting_vma(unsigned long address, char *buf)
 
 static void show_ecr_verbose(struct pt_regs *regs)
 {
-	unsigned int vec, cause_code, cause_reg;
+	unsigned int vec, cause_code;
 	unsigned long address;
 
-	cause_reg = current->thread.cause_code;
-	pr_info("\n[ECR   ]: 0x%08x => ", cause_reg);
+	pr_info("\n[ECR   ]: 0x%08lx => ", regs->event);
 
 	/* For Data fault, this is data address not instruction addr */
 	address = current->thread.fault_address;
 
-	vec = cause_reg >> 16;
-	cause_code = (cause_reg >> 8) & 0xFF;
+	vec = regs->ecr_vec;
+	cause_code = regs->ecr_cause;
 
 	/* For DTLB Miss or ProtV, display the memory involved too */
 	if (vec == ECR_V_DTLB_MISS) {
-		pr_cont("Invalid %s 0x%08lx by insn @ 0x%08lx\n",
-		       (cause_code == 0x01) ? "Read From" :
-		       ((cause_code == 0x02) ? "Write to" : "EX"),
+		pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n",
+		       (cause_code == 0x01) ? "Read" :
+		       ((cause_code == 0x02) ? "Write" : "EX"),
 		       address, regs->ret);
 	} else if (vec == ECR_V_ITLB_MISS) {
 		pr_cont("Insn could not be fetched\n");
@@ -144,14 +143,12 @@ static void show_ecr_verbose(struct pt_regs *regs)
 	} else if (vec == ECR_V_PROTV) {
 		if (cause_code == ECR_C_PROTV_INST_FETCH)
 			pr_cont("Execute from Non-exec Page\n");
-		else if (cause_code == ECR_C_PROTV_LOAD)
-			pr_cont("Read from Non-readable Page\n");
-		else if (cause_code == ECR_C_PROTV_STORE)
-			pr_cont("Write to Non-writable Page\n");
-		else if (cause_code == ECR_C_PROTV_XCHG)
-			pr_cont("Data exchange protection violation\n");
 		else if (cause_code == ECR_C_PROTV_MISALIG_DATA)
 			pr_cont("Misaligned r/w from 0x%08lx\n", address);
+		else
+			pr_cont("%s access not allowed on page\n",
+				(cause_code == 0x01) ? "Read" :
+				((cause_code == 0x02) ? "Write" : "EX"));
 	} else if (vec == ECR_V_INSN_ERR) {
 		pr_cont("Illegal Insn\n");
 	} else {
@@ -176,8 +173,7 @@ void show_regs(struct pt_regs *regs)
 	print_task_path_n_nm(tsk, buf);
 	show_regs_print_info(KERN_INFO);
 
-	if (current->thread.cause_code)
-		show_ecr_verbose(regs);
+	show_ecr_verbose(regs);
 
 	pr_info("[EFA   ]: 0x%08lx\n[BLINK ]: %pS\n[ERET  ]: %pS\n",
 		current->thread.fault_address,
@@ -213,10 +209,9 @@ void show_regs(struct pt_regs *regs)
 }
 
 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
-			    unsigned long address, unsigned long cause_reg)
+			    unsigned long address)
 {
 	current->thread.fault_address = address;
-	current->thread.cause_code = cause_reg;
 
 	/* Caller and Callee regs */
 	show_regs(regs);

arch/arc/kernel/unaligned.c

@@ -187,7 +187,7 @@ fault:	state->fault = 1;
  * Returns 0 if successfully handled, 1 if some error happened
  */
 int misaligned_fixup(unsigned long address, struct pt_regs *regs,
-		     unsigned long cause, struct callee_regs *cregs)
+		     struct callee_regs *cregs)
 {
 	struct disasm_state state;
 	char buf[TASK_COMM_LEN];

arch/arc/kernel/unwind.c

@@ -289,6 +289,8 @@ static void __init setup_unwind_table(struct unwind_table *table,
 			 * instead of the initial loc addr
 			 * return;
 			 */
+			WARN(1, "unwinder: FDE->initial_location NULL %p\n",
+				(const u8 *)(fde + 1) + *fde);
 		}
 		++n;
 	}

arch/arc/kernel/vmlinux.lds.S

@@ -125,6 +125,11 @@ SECTIONS
 		*(.debug_frame)
 		__end_unwind = .;
 	}
+	/*
+	 * gcc 4.8 generates this for -fasynchonous-unwind-tables,
+	 * while we still use the .debug_frame based unwinder
+	 */
+	/DISCARD/ : {	*(.eh_frame) }
 #else
 	/DISCARD/ : {	*(.debug_frame) }
 #endif
@@ -142,15 +147,18 @@ SECTIONS
 		*(.arcextmap.*)
 	}
 
+#ifndef CONFIG_DEBUG_INFO
 	/* open-coded because we need .debug_frame seperately for unwinding */
-	.debug_aranges 0 : { *(.debug_aranges) }
-	.debug_pubnames 0 : { *(.debug_pubnames) }
-	.debug_info 0 : { *(.debug_info) }
-	.debug_abbrev 0 : { *(.debug_abbrev) }
-	.debug_line 0 : { *(.debug_line) }
-	.debug_str 0 : { *(.debug_str) }
-	.debug_loc 0 : { *(.debug_loc) }
-	.debug_macinfo 0 : { *(.debug_macinfo) }
+	/DISCARD/ : { *(.debug_aranges) }
+	/DISCARD/ : { *(.debug_pubnames) }
+	/DISCARD/ : { *(.debug_info) }
+	/DISCARD/ : { *(.debug_abbrev) }
+	/DISCARD/ : { *(.debug_line) }
+	/DISCARD/ : { *(.debug_str) }
+	/DISCARD/ : { *(.debug_loc) }
+	/DISCARD/ : { *(.debug_macinfo) }
+	/DISCARD/ : { *(.debug_ranges) }
+#endif
 
 #ifdef CONFIG_ARC_HAS_DCCM
 	. = CONFIG_ARC_DCCM_BASE;

arch/arc/mm/cache_arc700.c

@@ -73,6 +73,33 @@
 #include <asm/cachectl.h>
 #include <asm/setup.h>
 
+/* Instruction cache related Auxiliary registers */
+#define ARC_REG_IC_BCR		0x77	/* Build Config reg */
+#define ARC_REG_IC_IVIC		0x10
+#define ARC_REG_IC_CTRL		0x11
+#define ARC_REG_IC_IVIL		0x19
+#if (CONFIG_ARC_MMU_VER > 2)
+#define ARC_REG_IC_PTAG		0x1E
+#endif
+
+/* Bit val in IC_CTRL */
+#define IC_CTRL_CACHE_DISABLE   0x1
+
+/* Data cache related Auxiliary registers */
+#define ARC_REG_DC_BCR		0x72	/* Build Config reg */
+#define ARC_REG_DC_IVDC		0x47
+#define ARC_REG_DC_CTRL		0x48
+#define ARC_REG_DC_IVDL		0x4A
+#define ARC_REG_DC_FLSH		0x4B
+#define ARC_REG_DC_FLDL		0x4C
+#if (CONFIG_ARC_MMU_VER > 2)
+#define ARC_REG_DC_PTAG		0x5C
+#endif
+
+/* Bit val in DC_CTRL */
+#define DC_CTRL_INV_MODE_FLUSH  0x40
+#define DC_CTRL_FLUSH_STATUS    0x100
+
 char *arc_cache_mumbojumbo(int cpu_id, char *buf, int len)
 {
 	int n = 0;
@@ -89,8 +116,10 @@ char *arc_cache_mumbojumbo(int cpu_id, char *buf, int len)
 			enb ?  "" : "DISABLED (kernel-build)");		\
 }
 
-	PR_CACHE(&cpuinfo_arc700[c].icache, __CONFIG_ARC_HAS_ICACHE, "I-Cache");
-	PR_CACHE(&cpuinfo_arc700[c].dcache, __CONFIG_ARC_HAS_DCACHE, "D-Cache");
+	PR_CACHE(&cpuinfo_arc700[c].icache, IS_ENABLED(CONFIG_ARC_HAS_ICACHE),
+			"I-Cache");
+	PR_CACHE(&cpuinfo_arc700[c].dcache, IS_ENABLED(CONFIG_ARC_HAS_DCACHE),
+			"D-Cache");
 
 	return buf;
 }
@@ -100,17 +129,23 @@ char *arc_cache_mumbojumbo(int cpu_id, char *buf, int len)
  * the cpuinfo structure for later use.
  * No Validation done here, simply read/convert the BCRs
  */
-void __cpuinit read_decode_cache_bcr(void)
+void read_decode_cache_bcr(void)
 {
-	struct bcr_cache ibcr, dbcr;
 	struct cpuinfo_arc_cache *p_ic, *p_dc;
 	unsigned int cpu = smp_processor_id();
+	struct bcr_cache {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+		unsigned int pad:12, line_len:4, sz:4, config:4, ver:8;
+#else
+		unsigned int ver:8, config:4, sz:4, line_len:4, pad:12;
+#endif
+	} ibcr, dbcr;
 
 	p_ic = &cpuinfo_arc700[cpu].icache;
 	READ_BCR(ARC_REG_IC_BCR, ibcr);
 
-	if (ibcr.config == 0x3)
-		p_ic->assoc = 2;
+	BUG_ON(ibcr.config != 3);
+	p_ic->assoc = 2;		/* Fixed to 2w set assoc */
 	p_ic->line_len = 8 << ibcr.line_len;
 	p_ic->sz = 0x200 << ibcr.sz;
 	p_ic->ver = ibcr.ver;
@@ -118,8 +153,8 @@ void __cpuinit read_decode_cache_bcr(void)
 	p_dc = &cpuinfo_arc700[cpu].dcache;
 	READ_BCR(ARC_REG_DC_BCR, dbcr);
 
-	if (dbcr.config == 0x2)
-		p_dc->assoc = 4;
+	BUG_ON(dbcr.config != 2);
+	p_dc->assoc = 4;		/* Fixed to 4w set assoc */
 	p_dc->line_len = 16 << dbcr.line_len;
 	p_dc->sz = 0x200 << dbcr.sz;
 	p_dc->ver = dbcr.ver;
@@ -132,14 +167,12 @@ void __cpuinit read_decode_cache_bcr(void)
  * 3. Enable the Caches, setup default flush mode for D-Cache
  * 3. Calculate the SHMLBA used by user space
  */
-void __cpuinit arc_cache_init(void)
+void arc_cache_init(void)
 {
-	unsigned int temp;
 	unsigned int cpu = smp_processor_id();
 	struct cpuinfo_arc_cache *ic = &cpuinfo_arc700[cpu].icache;
 	struct cpuinfo_arc_cache *dc = &cpuinfo_arc700[cpu].dcache;
-	int way_pg_ratio = way_pg_ratio;
-	int dcache_does_alias;
+	unsigned int dcache_does_alias, temp;
 	char str[256];
 
 	printk(arc_cache_mumbojumbo(0, str, sizeof(str)));
@@ -149,20 +182,11 @@ void __cpuinit arc_cache_init(void)
 
 #ifdef CONFIG_ARC_HAS_ICACHE
 	/* 1. Confirm some of I-cache params which Linux assumes */
-	if ((ic->assoc != ARC_ICACHE_WAYS) ||
-	    (ic->line_len != ARC_ICACHE_LINE_LEN)) {
+	if (ic->line_len != ARC_ICACHE_LINE_LEN)
 		panic("Cache H/W doesn't match kernel Config");
-	}
-#if (CONFIG_ARC_MMU_VER > 2)
-	if (ic->ver != 3) {
-		if (running_on_hw)
-			panic("Cache ver doesn't match MMU ver\n");
-
-		/* For ISS - suggest the toggles to use */
-		pr_err("Use -prop=icache_version=3,-prop=dcache_version=3\n");
 
-	}
-#endif
+	if (ic->ver != CONFIG_ARC_MMU_VER)
+		panic("Cache ver doesn't match MMU ver\n");
 #endif
 
 	/* Enable/disable I-Cache */
@@ -181,14 +205,12 @@ chk_dc:
 		return;
 
 #ifdef CONFIG_ARC_HAS_DCACHE
-	if ((dc->assoc != ARC_DCACHE_WAYS) ||
-	    (dc->line_len != ARC_DCACHE_LINE_LEN)) {
+	if (dc->line_len != ARC_DCACHE_LINE_LEN)
 		panic("Cache H/W doesn't match kernel Config");
-	}
-
-	dcache_does_alias = (dc->sz / ARC_DCACHE_WAYS) > PAGE_SIZE;
 
 	/* check for D-Cache aliasing */
+	dcache_does_alias = (dc->sz / dc->assoc) > PAGE_SIZE;
+
 	if (dcache_does_alias && !cache_is_vipt_aliasing())
 		panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
 	else if (!dcache_does_alias && cache_is_vipt_aliasing())
@@ -239,11 +261,9 @@ static inline void wait_for_flush(void)
  */
 static inline void __dc_entire_op(const int cacheop)
 {
-	unsigned long flags, tmp = tmp;
+	unsigned int tmp = tmp;
 	int aux;
 
-	local_irq_save(flags);
-
 	if (cacheop == OP_FLUSH_N_INV) {
 		/* Dcache provides 2 cmd: FLUSH or INV
 		 * INV inturn has sub-modes: DISCARD or FLUSH-BEFORE
@@ -267,8 +287,6 @@ static inline void __dc_entire_op(const int cacheop)
 	/* Switch back the DISCARD ONLY Invalidate mode */
 	if (cacheop == OP_FLUSH_N_INV)
 		write_aux_reg(ARC_REG_DC_CTRL, tmp & ~DC_CTRL_INV_MODE_FLUSH);
-
-	local_irq_restore(flags);
 }
 
 /*
@@ -459,8 +477,15 @@ static void __ic_line_inv_vaddr(unsigned long paddr, unsigned long vaddr,
 	local_irq_restore(flags);
 }
 
+static inline void __ic_entire_inv(void)
+{
+	write_aux_reg(ARC_REG_IC_IVIC, 1);
+	read_aux_reg(ARC_REG_IC_CTRL);	/* blocks */
+}
+
 #else
 
+#define __ic_entire_inv()
 #define __ic_line_inv_vaddr(pstart, vstart, sz)
 
 #endif /* CONFIG_ARC_HAS_ICACHE */
@@ -487,7 +512,7 @@ void flush_dcache_page(struct page *page)
 	struct address_space *mapping;
 
 	if (!cache_is_vipt_aliasing()) {
-		set_bit(PG_arch_1, &page->flags);
+		clear_bit(PG_dc_clean, &page->flags);
 		return;
 	}
 
@@ -501,7 +526,7 @@ void flush_dcache_page(struct page *page)
 	 * Make a note that K-mapping is dirty
 	 */
 	if (!mapping_mapped(mapping)) {
-		set_bit(PG_arch_1, &page->flags);
+		clear_bit(PG_dc_clean, &page->flags);
 	} else if (page_mapped(page)) {
 
 		/* kernel reading from page with U-mapping */
@@ -629,26 +654,13 @@ void ___flush_dcache_page(unsigned long paddr, unsigned long vaddr)
 	__dc_line_op(paddr, vaddr & PAGE_MASK, PAGE_SIZE, OP_FLUSH_N_INV);
 }
 
-void flush_icache_all(void)
-{
-	unsigned long flags;
-
-	local_irq_save(flags);
-
-	write_aux_reg(ARC_REG_IC_IVIC, 1);
-
-	/* lr will not complete till the icache inv operation is not over */
-	read_aux_reg(ARC_REG_IC_CTRL);
-	local_irq_restore(flags);
-}
-
 noinline void flush_cache_all(void)
 {
 	unsigned long flags;
 
 	local_irq_save(flags);
 
-	flush_icache_all();
+	__ic_entire_inv();
 	__dc_entire_op(OP_FLUSH_N_INV);
 
 	local_irq_restore(flags);
@@ -667,7 +679,12 @@ void flush_cache_page(struct vm_area_struct *vma, unsigned long u_vaddr,
 {
 	unsigned int paddr = pfn << PAGE_SHIFT;
 
-	__sync_icache_dcache(paddr, u_vaddr, PAGE_SIZE);
+	u_vaddr &= PAGE_MASK;
+
+	___flush_dcache_page(paddr, u_vaddr);
+
+	if (vma->vm_flags & VM_EXEC)
+		__inv_icache_page(paddr, u_vaddr);
 }
 
 void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
@@ -717,7 +734,7 @@ void copy_user_highpage(struct page *to, struct page *from,
 	 * non copied user pages (e.g. read faults which wire in pagecache page
 	 * directly).
 	 */
-	set_bit(PG_arch_1, &to->flags);
+	clear_bit(PG_dc_clean, &to->flags);
 
 	/*
 	 * if SRC was already usermapped and non-congruent to kernel mapping
@@ -725,15 +742,16 @@ void copy_user_highpage(struct page *to, struct page *from,
 	 */
 	if (clean_src_k_mappings) {
 		__flush_dcache_page(kfrom, kfrom);
+		set_bit(PG_dc_clean, &from->flags);
 	} else {
-		set_bit(PG_arch_1, &from->flags);
+		clear_bit(PG_dc_clean, &from->flags);
 	}
 }
 
 void clear_user_page(void *to, unsigned long u_vaddr, struct page *page)
 {
 	clear_page(to);
-	set_bit(PG_arch_1, &page->flags);
+	clear_bit(PG_dc_clean, &page->flags);
 }
 
 

arch/arc/mm/fault.c

@@ -15,6 +15,7 @@
 #include <linux/uaccess.h>
 #include <linux/kdebug.h>
 #include <asm/pgalloc.h>
+#include <asm/mmu.h>
 
 static int handle_vmalloc_fault(struct mm_struct *mm, unsigned long address)
 {
@@ -51,14 +52,14 @@ bad_area:
 	return 1;
 }
 
-void do_page_fault(struct pt_regs *regs, int write, unsigned long address,
-		   unsigned long cause_code)
+void do_page_fault(struct pt_regs *regs, unsigned long address)
 {
 	struct vm_area_struct *vma = NULL;
 	struct task_struct *tsk = current;
 	struct mm_struct *mm = tsk->mm;
 	siginfo_t info;
 	int fault, ret;
+	int write = regs->ecr_cause & ECR_C_PROTV_STORE;  /* ST/EX */
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
 				(write ? FAULT_FLAG_WRITE : 0);
 
@@ -109,7 +110,8 @@ good_area:
 
 	/* Handle protection violation, execute on heap or stack */
 
-	if (cause_code == ((ECR_V_PROTV << 16) | ECR_C_PROTV_INST_FETCH))
+	if ((regs->ecr_vec == ECR_V_PROTV) &&
+	    (regs->ecr_cause == ECR_C_PROTV_INST_FETCH))
 		goto bad_area;
 
 	if (write) {
@@ -176,7 +178,6 @@ bad_area_nosemaphore:
 	/* User mode accesses just cause a SIGSEGV */
 	if (user_mode(regs)) {
 		tsk->thread.fault_address = address;
-		tsk->thread.cause_code = cause_code;
 		info.si_signo = SIGSEGV;
 		info.si_errno = 0;
 		/* info.si_code has been set above */
@@ -197,7 +198,7 @@ no_context:
 	if (fixup_exception(regs))
 		return;
 
-	die("Oops", regs, address, cause_code);
+	die("Oops", regs, address);
 
 out_of_memory:
 	if (is_global_init(tsk)) {
@@ -218,7 +219,6 @@ do_sigbus:
 		goto no_context;
 
 	tsk->thread.fault_address = address;
-	tsk->thread.cause_code = cause_code;
 	info.si_signo = SIGBUS;
 	info.si_errno = 0;
 	info.si_code = BUS_ADRERR;

arch/arc/mm/tlb.c

@@ -55,7 +55,7 @@
 #include <asm/arcregs.h>
 #include <asm/setup.h>
 #include <asm/mmu_context.h>
-#include <asm/tlb.h>
+#include <asm/mmu.h>
 
 /*			Need for ARC MMU v2
  *
@@ -97,6 +97,7 @@
  * J-TLB entry got evicted/replaced.
  */
 
+
 /* A copy of the ASID from the PID reg is kept in asid_cache */
 int asid_cache = FIRST_ASID;
 
@@ -432,9 +433,14 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long vaddr_unaligned,
 {
 	unsigned long vaddr = vaddr_unaligned & PAGE_MASK;
 	unsigned long paddr = pte_val(*ptep) & PAGE_MASK;
+	struct page *page = pfn_to_page(pte_pfn(*ptep));
 
 	create_tlb(vma, vaddr, ptep);
 
+	if (page == ZERO_PAGE(0)) {
+		return;
+	}
+
 	/*
 	 * Exec page : Independent of aliasing/page-color considerations,
 	 *	       since icache doesn't snoop dcache on ARC, any dirty
@@ -446,9 +452,8 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long vaddr_unaligned,
 	 */
 	if ((vma->vm_flags & VM_EXEC) ||
 	     addr_not_cache_congruent(paddr, vaddr)) {
-		struct page *page = pfn_to_page(pte_pfn(*ptep));
 
-		int dirty = test_and_clear_bit(PG_arch_1, &page->flags);
+		int dirty = !test_and_set_bit(PG_dc_clean, &page->flags);
 		if (dirty) {
 			/* wback + inv dcache lines */
 			__flush_dcache_page(paddr, paddr);
@@ -464,12 +469,27 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long vaddr_unaligned,
  * the cpuinfo structure for later use.
  * No Validation is done here, simply read/convert the BCRs
  */
-void __cpuinit read_decode_mmu_bcr(void)
+void read_decode_mmu_bcr(void)
 {
-	unsigned int tmp;
-	struct bcr_mmu_1_2 *mmu2;	/* encoded MMU2 attr */
-	struct bcr_mmu_3 *mmu3;		/* encoded MMU3 attr */
 	struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;
+	unsigned int tmp;
+	struct bcr_mmu_1_2 {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+		unsigned int ver:8, ways:4, sets:4, u_itlb:8, u_dtlb:8;
+#else
+		unsigned int u_dtlb:8, u_itlb:8, sets:4, ways:4, ver:8;
+#endif
+	} *mmu2;
+
+	struct bcr_mmu_3 {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+	unsigned int ver:8, ways:4, sets:4, osm:1, reserv:3, pg_sz:4,
+		     u_itlb:4, u_dtlb:4;
+#else
+	unsigned int u_dtlb:4, u_itlb:4, pg_sz:4, reserv:3, osm:1, sets:4,
+		     ways:4, ver:8;
+#endif
+	} *mmu3;
 
 	tmp = read_aux_reg(ARC_REG_MMU_BCR);
 	mmu->ver = (tmp >> 24);
@@ -505,12 +525,12 @@ char *arc_mmu_mumbojumbo(int cpu_id, char *buf, int len)
 		       "J-TLB %d (%dx%d), uDTLB %d, uITLB %d, %s\n",
 		       p_mmu->num_tlb, p_mmu->sets, p_mmu->ways,
 		       p_mmu->u_dtlb, p_mmu->u_itlb,
-		       __CONFIG_ARC_MMU_SASID_VAL ? "SASID" : "");
+		       IS_ENABLED(CONFIG_ARC_MMU_SASID) ? "SASID" : "");
 
 	return buf;
 }
 
-void __cpuinit arc_mmu_init(void)
+void arc_mmu_init(void)
 {
 	char str[256];
 	struct cpuinfo_arc_mmu *mmu = &cpuinfo_arc700[smp_processor_id()].mmu;

arch/arc/mm/tlbex.S

@@ -39,7 +39,7 @@
 
 #include <linux/linkage.h>
 #include <asm/entry.h>
-#include <asm/tlb.h>
+#include <asm/mmu.h>
 #include <asm/pgtable.h>
 #include <asm/arcregs.h>
 #include <asm/cache.h>
@@ -147,9 +147,9 @@ ex_saved_reg1:
 #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT
 	and.f 0, r0, _PAGE_PRESENT
 	bz   1f
-	ld   r2, [num_pte_not_present]
-	add  r2, r2, 1
-	st   r2, [num_pte_not_present]
+	ld   r3, [num_pte_not_present]
+	add  r3, r3, 1
+	st   r3, [num_pte_not_present]
 1:
 #endif
 
@@ -271,22 +271,22 @@ ARC_ENTRY EV_TLBMissI
 #endif
 
 	;----------------------------------------------------------------
-	; Get the PTE corresponding to V-addr accessed
+	; Get the PTE corresponding to V-addr accessed, r2 is setup with EFA
 	LOAD_FAULT_PTE
 
 	;----------------------------------------------------------------
 	; VERIFY_PTE: Check if PTE permissions approp for executing code
 	cmp_s   r2, VMALLOC_START
-	mov.lo  r2, (_PAGE_PRESENT | _PAGE_U_READ | _PAGE_U_EXECUTE)
-	mov.hs  r2, (_PAGE_PRESENT | _PAGE_K_READ | _PAGE_K_EXECUTE)
+	mov.lo  r2, (_PAGE_PRESENT | _PAGE_U_EXECUTE)
+	mov.hs  r2, (_PAGE_PRESENT | _PAGE_K_EXECUTE)
 
 	and     r3, r0, r2  ; Mask out NON Flag bits from PTE
 	xor.f   r3, r3, r2  ; check ( ( pte & flags_test ) == flags_test )
 	bnz     do_slow_path_pf
 
 	; Let Linux VM know that the page was accessed
-	or      r0, r0, (_PAGE_PRESENT | _PAGE_ACCESSED)  ; set Accessed Bit
-	st_s    r0, [r1]                                  ; Write back PTE
+	or      r0, r0, _PAGE_ACCESSED  ; set Accessed Bit
+	st_s    r0, [r1]                ; Write back PTE
 
 	CONV_PTE_TO_TLB
 	COMMIT_ENTRY_TO_MMU
@@ -311,7 +311,7 @@ ARC_ENTRY EV_TLBMissD
 
 	;----------------------------------------------------------------
 	; Get the PTE corresponding to V-addr accessed
-	; If PTE exists, it will setup, r0 = PTE, r1 = Ptr to PTE
+	; If PTE exists, it will setup, r0 = PTE, r1 = Ptr to PTE, r2 = EFA
 	LOAD_FAULT_PTE
 
 	;----------------------------------------------------------------
@@ -345,7 +345,7 @@ ARC_ENTRY EV_TLBMissD
 	;----------------------------------------------------------------
 	; UPDATE_PTE: Let Linux VM know that page was accessed/dirty
 	lr      r3, [ecr]
-	or      r0, r0, (_PAGE_PRESENT | _PAGE_ACCESSED) ; Accessed bit always
+	or      r0, r0, _PAGE_ACCESSED        ; Accessed bit always
 	btst_s  r3,  ECR_C_BIT_DTLB_ST_MISS   ; See if it was a Write Access ?
 	or.nz   r0, r0, _PAGE_MODIFIED        ; if Write, set Dirty bit as well
 	st_s    r0, [r1]                      ; Write back PTE
@@ -381,18 +381,7 @@ do_slow_path_pf:
 
 	; ------- setup args for Linux Page fault Hanlder ---------
 	mov_s r0, sp
-	lr  r2, [efa]
-	lr  r3, [ecr]
-
-	; Both st and ex imply WRITE access of some sort, hence do_page_fault( )
-	; invoked with write=1 for DTLB-st/ex Miss and write=0 for ITLB miss or
-	; DTLB-ld Miss
-	; DTLB Miss Cause code is ld = 0x01 , st = 0x02, ex = 0x03
-	; Following code uses that fact that st/ex have one bit in common
-
-	btst_s r3,  ECR_C_BIT_DTLB_ST_MISS
-	mov.z  r1, 0
-	mov.nz r1, 1
+	lr  r1, [efa]
 
 	; We don't want exceptions to be disabled while the fault is handled.
 	; Now that we have saved the context we return from exception hence

arch/arc/plat-arcfpga/platform.c

@@ -77,6 +77,7 @@ static void __init setup_bvci_lat_unit(void)
 
 /*----------------------- Platform Devices -----------------------------*/
 
+#if IS_ENABLED(CONFIG_SERIAL_ARC)
 static unsigned long arc_uart_info[] = {
 	0,	/* uart->is_emulated (runtime @running_on_hw) */
 	0,	/* uart->port.uartclk */
@@ -115,7 +116,7 @@ static struct platform_device arc_uart0_dev = {
 static struct platform_device *fpga_early_devs[] __initdata = {
 	&arc_uart0_dev,
 };
-#endif
+#endif	/* CONFIG_SERIAL_ARC_CONSOLE */
 
 static void arc_fpga_serial_init(void)
 {
@@ -152,8 +153,13 @@ static void arc_fpga_serial_init(void)
 	 * otherwise the early console never gets a chance to run.
 	 */
 	add_preferred_console("ttyARC", 0, "115200");
-#endif
+#endif	/* CONFIG_SERIAL_ARC_CONSOLE */
+}
+#else	/* !IS_ENABLED(CONFIG_SERIAL_ARC) */
+static void arc_fpga_serial_init(void)
+{
 }
+#endif
 
 static void __init plat_fpga_early_init(void)
 {
@@ -169,7 +175,7 @@ static void __init plat_fpga_early_init(void)
 }
 
 static struct of_dev_auxdata plat_auxdata_lookup[] __initdata = {
-#if defined(CONFIG_SERIAL_ARC) || defined(CONFIG_SERIAL_ARC_MODULE)
+#if IS_ENABLED(CONFIG_SERIAL_ARC)
 	OF_DEV_AUXDATA("snps,arc-uart", UART0_BASE, "arc-uart", arc_uart_info),
 #endif
 	{}