Blackfin: optimize double fault boot checking

This moves the double fault data used at boot time into a single struct
which can then easily be addressed with indexed loads rather than having
to explicitly load multiple addresses.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

arch/blackfin/include/asm/pda.h

@@ -54,6 +54,16 @@ struct blackfin_pda {			/* Per-processor Data Area */
 #endif
 };
 
+struct blackfin_initial_pda {
+	void *retx;
+#ifdef CONFIG_DEBUG_DOUBLEFAULT
+	void *dcplb_doublefault_addr;
+	void *icplb_doublefault_addr;
+	void *retx_doublefault;
+	unsigned seqstat_doublefault;
+#endif
+};
+
 extern struct blackfin_pda cpu_pda[];
 
 #endif	/* __ASSEMBLY__ */

arch/blackfin/kernel/asm-offsets.c

@@ -138,6 +138,16 @@ int main(void)
 	DEFINE(PDA_DF_SEQSTAT, offsetof(struct blackfin_pda, seqstat_doublefault));
 	DEFINE(PDA_DF_RETX, offsetof(struct blackfin_pda, retx_doublefault));
 #endif
+
+	/* PDA initial management */
+	DEFINE(PDA_INIT_RETX, offsetof(struct blackfin_initial_pda, retx));
+#ifdef CONFIG_DEBUG_DOUBLEFAULT
+	DEFINE(PDA_INIT_DF_DCPLB, offsetof(struct blackfin_initial_pda, dcplb_doublefault_addr));
+	DEFINE(PDA_INIT_DF_ICPLB, offsetof(struct blackfin_initial_pda, icplb_doublefault_addr));
+	DEFINE(PDA_INIT_DF_SEQSTAT, offsetof(struct blackfin_initial_pda, seqstat_doublefault));
+	DEFINE(PDA_INIT_DF_RETX, offsetof(struct blackfin_initial_pda, retx_doublefault));
+#endif
+
 #ifdef CONFIG_SMP
 	/* Inter-core lock (in L2 SRAM) */
 	DEFINE(SIZEOF_CORELOCK, sizeof(struct corelock_slot));

arch/blackfin/kernel/setup.c

@@ -54,8 +54,7 @@ EXPORT_SYMBOL(mtd_size);
 #endif
 
 char __initdata command_line[COMMAND_LINE_SIZE];
-void __initdata *init_retx, *init_saved_retx, *init_saved_seqstat,
-	*init_saved_icplb_fault_addr, *init_saved_dcplb_fault_addr;
+struct blackfin_initial_pda __initdata initial_pda;
 
 /* boot memmap, for parsing "memmap=" */
 #define BFIN_MEMMAP_MAX		128 /* number of entries in bfin_memmap */
@@ -957,13 +956,16 @@ void __init setup_arch(char **cmdline_p)
 		printk(KERN_EMERG "Recovering from DOUBLE FAULT event\n");
 #ifdef CONFIG_DEBUG_DOUBLEFAULT
 		/* We assume the crashing kernel, and the current symbol table match */
-		printk(KERN_EMERG " While handling exception (EXCAUSE = 0x%x) at %pF\n",
-			(int)init_saved_seqstat & SEQSTAT_EXCAUSE, init_saved_retx);
-		printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr);
-		printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr);
+		printk(KERN_EMERG " While handling exception (EXCAUSE = %#x) at %pF\n",
+			initial_pda.seqstat_doublefault & SEQSTAT_EXCAUSE,
+			initial_pda.retx_doublefault);
+		printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n",
+			initial_pda.dcplb_doublefault_addr);
+		printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n",
+			initial_pda.icplb_doublefault_addr);
 #endif
 		printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
-			init_retx);
+			initial_pda.retx);
 	} else if (_bfin_swrst & RESET_WDOG)
 		printk(KERN_INFO "Recovering from Watchdog event\n");
 	else if (_bfin_swrst & RESET_SOFTWARE)

arch/blackfin/mach-bf561/secondary.S

@@ -76,37 +76,25 @@ ENTRY(_coreb_trampoline_start)
 	SSYNC;
 
 	/* in case of double faults, save a few things */
-	p0.l = _init_retx_coreb;
-	p0.h = _init_retx_coreb;
-	R0 = RETX;
-	[P0] = R0;
-
+	p1.l = _initial_pda_coreb;
+	p1.h = _initial_pda_coreb;
+	r4 = RETX;
 #ifdef CONFIG_DEBUG_DOUBLEFAULT
 	/* Only save these if we are storing them,
 	 * This happens here, since L1 gets clobbered
 	 * below
 	 */
 	GET_PDA(p0, r0);
-	r5 = [p0 + PDA_DF_RETX];
-	p1.l = _init_saved_retx_coreb;
-	p1.h = _init_saved_retx_coreb;
-	[p1] = r5;
-
-	r5 = [p0 + PDA_DF_DCPLB];
-	p1.l = _init_saved_dcplb_fault_addr_coreb;
-	p1.h = _init_saved_dcplb_fault_addr_coreb;
-	[p1] = r5;
-
-	r5 = [p0 + PDA_DF_ICPLB];
-	p1.l = _init_saved_icplb_fault_addr_coreb;
-	p1.h = _init_saved_icplb_fault_addr_coreb;
-	[p1] = r5;
-
-	r5 = [p0 + PDA_DF_SEQSTAT];
-	p1.l = _init_saved_seqstat_coreb;
-	p1.h = _init_saved_seqstat_coreb;
-	[p1] = r5;
+	r0 = [p0 + PDA_DF_RETX];
+	r1 = [p0 + PDA_DF_DCPLB];
+	r2 = [p0 + PDA_DF_ICPLB];
+	r3 = [p0 + PDA_DF_SEQSTAT];
+	[p1 + PDA_INIT_DF_RETX] = r0;
+	[p1 + PDA_INIT_DF_DCPLB] = r1;
+	[p1 + PDA_INIT_DF_ICPLB] = r2;
+	[p1 + PDA_INIT_DF_SEQSTAT] = r3;
 #endif
+	[p1 + PDA_INIT_RETX] = r4;
 
 	/* Initialize stack pointer */
 	sp.l = lo(INITIAL_STACK);

arch/blackfin/mach-common/head.S

@@ -85,37 +85,25 @@ ENTRY(__start)
 	SSYNC;
 
 	/* in case of double faults, save a few things */
-	p0.l = _init_retx;
-	p0.h = _init_retx;
-	R0 = RETX;
-	[P0] = R0;
-
+	p1.l = _initial_pda;
+	p1.h = _initial_pda;
+	r4 = RETX;
 #ifdef CONFIG_DEBUG_DOUBLEFAULT
 	/* Only save these if we are storing them,
 	 * This happens here, since L1 gets clobbered
 	 * below
 	 */
 	GET_PDA(p0, r0);
-	r5 = [p0 + PDA_DF_RETX];
-	p1.l = _init_saved_retx;
-	p1.h = _init_saved_retx;
-	[p1] = r5;
-
-	r5 = [p0 + PDA_DF_DCPLB];
-	p1.l = _init_saved_dcplb_fault_addr;
-	p1.h = _init_saved_dcplb_fault_addr;
-	[p1] = r5;
-
-	r5 = [p0 + PDA_DF_ICPLB];
-	p1.l = _init_saved_icplb_fault_addr;
-	p1.h = _init_saved_icplb_fault_addr;
-	[p1] = r5;
-
-	r5 = [p0 + PDA_DF_SEQSTAT];
-	p1.l = _init_saved_seqstat;
-	p1.h = _init_saved_seqstat;
-	[p1] = r5;
+	r0 = [p0 + PDA_DF_RETX];
+	r1 = [p0 + PDA_DF_DCPLB];
+	r2 = [p0 + PDA_DF_ICPLB];
+	r3 = [p0 + PDA_DF_SEQSTAT];
+	[p1 + PDA_INIT_DF_RETX] = r0;
+	[p1 + PDA_INIT_DF_DCPLB] = r1;
+	[p1 + PDA_INIT_DF_ICPLB] = r2;
+	[p1 + PDA_INIT_DF_SEQSTAT] = r3;
 #endif
+	[p1 + PDA_INIT_RETX] = r4;
 
 	/* Initialize stack pointer */
 	sp.l = _init_thread_union + THREAD_SIZE;

arch/blackfin/mach-common/smp.c

@@ -45,9 +45,7 @@ struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));
 unsigned long blackfin_iflush_l1_entry[NR_CPUS];
 #endif
 
-void __cpuinitdata *init_retx_coreb, *init_saved_retx_coreb,
-	*init_saved_seqstat_coreb, *init_saved_icplb_fault_addr_coreb,
-	*init_saved_dcplb_fault_addr_coreb;
+struct blackfin_initial_pda __cpuinitdata initial_pda_coreb;
 
 #define BFIN_IPI_RESCHEDULE   0
 #define BFIN_IPI_CALL_FUNC    1
@@ -369,13 +367,16 @@ void __cpuinit secondary_start_kernel(void)
 	if (_bfin_swrst & SWRST_DBL_FAULT_B) {
 		printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n");
 #ifdef CONFIG_DEBUG_DOUBLEFAULT
-		printk(KERN_EMERG " While handling exception (EXCAUSE = 0x%x) at %pF\n",
-			(int)init_saved_seqstat_coreb & SEQSTAT_EXCAUSE, init_saved_retx_coreb);
-		printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr_coreb);
-		printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr_coreb);
+		printk(KERN_EMERG " While handling exception (EXCAUSE = %#x) at %pF\n",
+			initial_pda_coreb.seqstat_doublefault & SEQSTAT_EXCAUSE,
+			initial_pda_coreb.retx_doublefault);
+		printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n",
+			initial_pda_coreb.dcplb_doublefault_addr);
+		printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n",
+			initial_pda_coreb.icplb_doublefault_addr);
 #endif
 		printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
-			init_retx_coreb);
+			initial_pda_coreb.retx);
 	}
 
 	/*