[SPARC64]: Remove most limitations to kernel image size.

Currently kernel images are limited to 8MB in size, and this causes
problems especially when enabling features that take up a lot of
kernel image space such as lockdep.

The code now will align the kernel image size up to 4MB and map that
many locked TLB entries.  So, the only practical limitation is the
number of available locked TLB entries which is 16 on Cheetah and 64
on pre-Cheetah sparc64 cpus.  Niagara cpus don't actually have hw
locked TLB entry support.  Rather, the hypervisor transparently
provides support for "locked" TLB entries since it runs with physical
addressing and does the initial TLB miss processing.

Fully utilizing this change requires some help from SILO, a patch for
which will be submitted to the maintainer.  Essentially, SILO will
only currently map up to 8MB for the kernel image and that needs to be
increased.

Note that neither this patch nor the SILO bits will help with network
booting.  The openfirmware code will only map up to a certain amount
of kernel image during a network boot and there isn't much we can to
about that other than to implemented a layered network booting
facility.  Solaris has this, and calls it "wanboot" and we may
implement something similar at some point.

Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc64/kernel/head.S

@@ -288,8 +288,12 @@ sun4v_chip_type:
 	/* Leave arg2 as-is, prom_mmu_ihandle_cache */
 	mov	-1, %l3
 	stx	%l3, [%sp + 2047 + 128 + 0x28]	! arg3: mode (-1 default)
-	sethi	%hi(8 * 1024 * 1024), %l3
-	stx	%l3, [%sp + 2047 + 128 + 0x30]	! arg4: size (8MB)
+	/* 4MB align the kernel image size. */
+	set	(_end - KERNBASE), %l3
+	set	((4 * 1024 * 1024) - 1), %l4
+	add	%l3, %l4, %l3
+	andn	%l3, %l4, %l3
+	stx	%l3, [%sp + 2047 + 128 + 0x30]	! arg4: roundup(ksize, 4MB)
 	sethi	%hi(KERNBASE), %l3
 	stx	%l3, [%sp + 2047 + 128 + 0x38]	! arg5: vaddr (KERNBASE)
 	stx	%g0, [%sp + 2047 + 128 + 0x40]	! arg6: empty

arch/sparc64/kernel/smp.c

@@ -284,14 +284,17 @@ static void ldom_startcpu_cpuid(unsigned int cpu, unsigned long thread_reg)
 {
 	extern unsigned long sparc64_ttable_tl0;
 	extern unsigned long kern_locked_tte_data;
-	extern int bigkernel;
 	struct hvtramp_descr *hdesc;
 	unsigned long trampoline_ra;
 	struct trap_per_cpu *tb;
 	u64 tte_vaddr, tte_data;
 	unsigned long hv_err;
+	int i;
 
-	hdesc = kzalloc(sizeof(*hdesc), GFP_KERNEL);
+	hdesc = kzalloc(sizeof(*hdesc) +
+			(sizeof(struct hvtramp_mapping) *
+			 num_kernel_image_mappings - 1),
+			GFP_KERNEL);
 	if (!hdesc) {
 		printk(KERN_ERR "ldom_startcpu_cpuid: Cannot allocate "
 		       "hvtramp_descr.\n");
@@ -299,7 +302,7 @@ static void ldom_startcpu_cpuid(unsigned int cpu, unsigned long thread_reg)
 	}
 
 	hdesc->cpu = cpu;
-	hdesc->num_mappings = (bigkernel ? 2 : 1);
+	hdesc->num_mappings = num_kernel_image_mappings;
 
 	tb = &trap_block[cpu];
 	tb->hdesc = hdesc;
@@ -312,13 +315,11 @@ static void ldom_startcpu_cpuid(unsigned int cpu, unsigned long thread_reg)
 	tte_vaddr = (unsigned long) KERNBASE;
 	tte_data = kern_locked_tte_data;
 
-	hdesc->maps[0].vaddr = tte_vaddr;
-	hdesc->maps[0].tte   = tte_data;
-	if (bigkernel) {
+	for (i = 0; i < hdesc->num_mappings; i++) {
+		hdesc->maps[i].vaddr = tte_vaddr;
+		hdesc->maps[i].tte   = tte_data;
 		tte_vaddr += 0x400000;
 		tte_data  += 0x400000;
-		hdesc->maps[1].vaddr = tte_vaddr;
-		hdesc->maps[1].tte   = tte_data;
 	}
 
 	trampoline_ra = kimage_addr_to_ra(hv_cpu_startup);

arch/sparc64/kernel/trampoline.S

@@ -105,7 +105,7 @@ startup_continue:
 	wr		%g2, 0, %tick_cmpr
 
 	/* Call OBP by hand to lock KERNBASE into i/d tlbs.
-	 * We lock 2 consequetive entries if we are 'bigkernel'.
+	 * We lock 'num_kernel_image_mappings' consequetive entries.
 	 */
 	sethi		%hi(prom_entry_lock), %g2
 1:	ldstub		[%g2 + %lo(prom_entry_lock)], %g1
@@ -119,6 +119,29 @@ startup_continue:
 	add		%l2, -(192 + 128), %sp
 	flushw
 
+	/* Setup the loop variables:
+	 * %l3: VADDR base
+	 * %l4: TTE base
+	 * %l5: Loop iterator, iterates from 0 to 'num_kernel_image_mappings'
+	 * %l6: Number of TTE entries to map
+	 * %l7: Highest TTE entry number, we count down
+	 */
+	sethi		%hi(KERNBASE), %l3
+	sethi		%hi(kern_locked_tte_data), %l4
+	ldx		[%l4 + %lo(kern_locked_tte_data)], %l4
+	clr		%l5
+	sethi		%hi(num_kernel_image_mappings), %l6
+	lduw		[%l6 + %lo(num_kernel_image_mappings)], %l6
+	add		%l6, 1, %l6
+
+	mov		15, %l7
+	BRANCH_IF_ANY_CHEETAH(g1,g5,2f)
+
+	mov		63, %l7
+2:
+
+3:
+	/* Lock into I-MMU */
 	sethi		%hi(call_method), %g2
 	or		%g2, %lo(call_method), %g2
 	stx		%g2, [%sp + 2047 + 128 + 0x00]
@@ -132,63 +155,26 @@ startup_continue:
 	sethi		%hi(prom_mmu_ihandle_cache), %g2
 	lduw		[%g2 + %lo(prom_mmu_ihandle_cache)], %g2
 	stx		%g2, [%sp + 2047 + 128 + 0x20]
-	sethi		%hi(KERNBASE), %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x28]
-	sethi		%hi(kern_locked_tte_data), %g2
-	ldx		[%g2 + %lo(kern_locked_tte_data)], %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x30]
-
-	mov		15, %g2
-	BRANCH_IF_ANY_CHEETAH(g1,g5,1f)
 
-	mov		63, %g2
-1:
-	stx		%g2, [%sp + 2047 + 128 + 0x38]
-	sethi		%hi(p1275buf), %g2
-	or		%g2, %lo(p1275buf), %g2
-	ldx		[%g2 + 0x08], %o1
-	call		%o1
-	 add		%sp, (2047 + 128), %o0
+	/* Each TTE maps 4MB, convert index to offset.  */
+	sllx		%l5, 22, %g1
 
-	sethi		%hi(bigkernel), %g2
-	lduw		[%g2 + %lo(bigkernel)], %g2
-	brz,pt		%g2, do_dtlb
-	 nop
+	add		%l3, %g1, %g2
+	stx		%g2, [%sp + 2047 + 128 + 0x28]	! VADDR
+	add		%l4, %g1, %g2
+	stx		%g2, [%sp + 2047 + 128 + 0x30]	! TTE
 
-	sethi		%hi(call_method), %g2
-	or		%g2, %lo(call_method), %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x00]
-	mov		5, %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x08]
-	mov		1, %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x10]
-	sethi		%hi(itlb_load), %g2
-	or		%g2, %lo(itlb_load), %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x18]
-	sethi		%hi(prom_mmu_ihandle_cache), %g2
-	lduw		[%g2 + %lo(prom_mmu_ihandle_cache)], %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x20]
-	sethi		%hi(KERNBASE + 0x400000), %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x28]
-	sethi		%hi(kern_locked_tte_data), %g2
-	ldx		[%g2 + %lo(kern_locked_tte_data)], %g2
-	sethi		%hi(0x400000), %g1
-	add		%g2, %g1, %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x30]
-
-	mov		14, %g2
-	BRANCH_IF_ANY_CHEETAH(g1,g5,1f)
-
-	mov		62, %g2
-1:
+	/* TTE index is highest minus loop index.  */
+	sub		%l7, %l5, %g2
 	stx		%g2, [%sp + 2047 + 128 + 0x38]
+
 	sethi		%hi(p1275buf), %g2
 	or		%g2, %lo(p1275buf), %g2
 	ldx		[%g2 + 0x08], %o1
 	call		%o1
 	 add		%sp, (2047 + 128), %o0
 
-do_dtlb:
+	/* Lock into D-MMU */
 	sethi		%hi(call_method), %g2
 	or		%g2, %lo(call_method), %g2
 	stx		%g2, [%sp + 2047 + 128 + 0x00]
@@ -202,65 +188,30 @@ do_dtlb:
 	sethi		%hi(prom_mmu_ihandle_cache), %g2
 	lduw		[%g2 + %lo(prom_mmu_ihandle_cache)], %g2
 	stx		%g2, [%sp + 2047 + 128 + 0x20]
-	sethi		%hi(KERNBASE), %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x28]
-	sethi		%hi(kern_locked_tte_data), %g2
-	ldx		[%g2 + %lo(kern_locked_tte_data)], %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x30]
 
-	mov		15, %g2
-	BRANCH_IF_ANY_CHEETAH(g1,g5,1f)
+	/* Each TTE maps 4MB, convert index to offset.  */
+	sllx		%l5, 22, %g1
 
-	mov		63, %g2
-1:
+	add		%l3, %g1, %g2
+	stx		%g2, [%sp + 2047 + 128 + 0x28]	! VADDR
+	add		%l4, %g1, %g2
+	stx		%g2, [%sp + 2047 + 128 + 0x30]	! TTE
 
+	/* TTE index is highest minus loop index.  */
+	sub		%l7, %l5, %g2
 	stx		%g2, [%sp + 2047 + 128 + 0x38]
+
 	sethi		%hi(p1275buf), %g2
 	or		%g2, %lo(p1275buf), %g2
 	ldx		[%g2 + 0x08], %o1
 	call		%o1
 	 add		%sp, (2047 + 128), %o0
 
-	sethi		%hi(bigkernel), %g2
-	lduw		[%g2 + %lo(bigkernel)], %g2
-	brz,pt		%g2, do_unlock
+	add		%l5, 1, %l5
+	cmp		%l5, %l6
+	bne,pt		%xcc, 3b
 	 nop
 
-	sethi		%hi(call_method), %g2
-	or		%g2, %lo(call_method), %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x00]
-	mov		5, %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x08]
-	mov		1, %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x10]
-	sethi		%hi(dtlb_load), %g2
-	or		%g2, %lo(dtlb_load), %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x18]
-	sethi		%hi(prom_mmu_ihandle_cache), %g2
-	lduw		[%g2 + %lo(prom_mmu_ihandle_cache)], %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x20]
-	sethi		%hi(KERNBASE + 0x400000), %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x28]
-	sethi		%hi(kern_locked_tte_data), %g2
-	ldx		[%g2 + %lo(kern_locked_tte_data)], %g2
-	sethi		%hi(0x400000), %g1
-	add		%g2, %g1, %g2
-	stx		%g2, [%sp + 2047 + 128 + 0x30]
-
-	mov		14, %g2
-	BRANCH_IF_ANY_CHEETAH(g1,g5,1f)
-
-	mov		62, %g2
-1:
-
-	stx		%g2, [%sp + 2047 + 128 + 0x38]
-	sethi		%hi(p1275buf), %g2
-	or		%g2, %lo(p1275buf), %g2
-	ldx		[%g2 + 0x08], %o1
-	call		%o1
-	 add		%sp, (2047 + 128), %o0
-
-do_unlock:
 	sethi		%hi(prom_entry_lock), %g2
 	stb		%g0, [%g2 + %lo(prom_entry_lock)]
 	membar		#StoreStore | #StoreLoad
@@ -269,47 +220,36 @@ do_unlock:
 	 nop
 
 niagara_lock_tlb:
+	sethi		%hi(KERNBASE), %l3
+	sethi		%hi(kern_locked_tte_data), %l4
+	ldx		[%l4 + %lo(kern_locked_tte_data)], %l4
+	clr		%l5
+	sethi		%hi(num_kernel_image_mappings), %l6
+	lduw		[%l6 + %lo(num_kernel_image_mappings)], %l6
+	add		%l6, 1, %l6
+
+1:
 	mov		HV_FAST_MMU_MAP_PERM_ADDR, %o5
-	sethi		%hi(KERNBASE), %o0
+	sllx		%l5, 22, %g2
+	add		%l3, %g2, %o0
 	clr		%o1
-	sethi		%hi(kern_locked_tte_data), %o2
-	ldx		[%o2 + %lo(kern_locked_tte_data)], %o2
+	add		%l4, %g2, %o2
 	mov		HV_MMU_IMMU, %o3
 	ta		HV_FAST_TRAP
 
 	mov		HV_FAST_MMU_MAP_PERM_ADDR, %o5
-	sethi		%hi(KERNBASE), %o0
+	sllx		%l5, 22, %g2
+	add		%l3, %g2, %o0
 	clr		%o1
-	sethi		%hi(kern_locked_tte_data), %o2
-	ldx		[%o2 + %lo(kern_locked_tte_data)], %o2
+	add		%l4, %g2, %o2
 	mov		HV_MMU_DMMU, %o3
 	ta		HV_FAST_TRAP
 
-	sethi		%hi(bigkernel), %g2
-	lduw		[%g2 + %lo(bigkernel)], %g2
-	brz,pt		%g2, after_lock_tlb
+	add		%l5, 1, %l5
+	cmp		%l5, %l6
+	bne,pt		%xcc, 1b
 	 nop
 
-	mov		HV_FAST_MMU_MAP_PERM_ADDR, %o5
-	sethi		%hi(KERNBASE + 0x400000), %o0
-	clr		%o1
-	sethi		%hi(kern_locked_tte_data), %o2
-	ldx		[%o2 + %lo(kern_locked_tte_data)], %o2
-	sethi		%hi(0x400000), %o3
-	add		%o2, %o3, %o2
-	mov		HV_MMU_IMMU, %o3
-	ta		HV_FAST_TRAP
-
-	mov		HV_FAST_MMU_MAP_PERM_ADDR, %o5
-	sethi		%hi(KERNBASE + 0x400000), %o0
-	clr		%o1
-	sethi		%hi(kern_locked_tte_data), %o2
-	ldx		[%o2 + %lo(kern_locked_tte_data)], %o2
-	sethi		%hi(0x400000), %o3
-	add		%o2, %o3, %o2
-	mov		HV_MMU_DMMU, %o3
-	ta		HV_FAST_TRAP
-
 after_lock_tlb:
 	wrpr		%g0, (PSTATE_PRIV | PSTATE_PEF), %pstate
 	wr		%g0, 0, %fprs

arch/sparc64/mm/init.c

@@ -166,7 +166,7 @@ unsigned long sparc64_kern_pri_context __read_mostly;
 unsigned long sparc64_kern_pri_nuc_bits __read_mostly;
 unsigned long sparc64_kern_sec_context __read_mostly;
 
-int bigkernel = 0;
+int num_kernel_image_mappings;
 
 #ifdef CONFIG_DEBUG_DCFLUSH
 atomic_t dcpage_flushes = ATOMIC_INIT(0);
@@ -572,7 +572,7 @@ static unsigned long kern_large_tte(unsigned long paddr);
 static void __init remap_kernel(void)
 {
 	unsigned long phys_page, tte_vaddr, tte_data;
-	int tlb_ent = sparc64_highest_locked_tlbent();
+	int i, tlb_ent = sparc64_highest_locked_tlbent();
 
 	tte_vaddr = (unsigned long) KERNBASE;
 	phys_page = (prom_boot_mapping_phys_low >> 22UL) << 22UL;
@@ -582,27 +582,20 @@ static void __init remap_kernel(void)
 
 	/* Now lock us into the TLBs via Hypervisor or OBP. */
 	if (tlb_type == hypervisor) {
-		hypervisor_tlb_lock(tte_vaddr, tte_data, HV_MMU_DMMU);
-		hypervisor_tlb_lock(tte_vaddr, tte_data, HV_MMU_IMMU);
-		if (bigkernel) {
-			tte_vaddr += 0x400000;
-			tte_data += 0x400000;
+		for (i = 0; i < num_kernel_image_mappings; i++) {
 			hypervisor_tlb_lock(tte_vaddr, tte_data, HV_MMU_DMMU);
 			hypervisor_tlb_lock(tte_vaddr, tte_data, HV_MMU_IMMU);
+			tte_vaddr += 0x400000;
+			tte_data += 0x400000;
 		}
 	} else {
-		prom_dtlb_load(tlb_ent, tte_data, tte_vaddr);
-		prom_itlb_load(tlb_ent, tte_data, tte_vaddr);
-		if (bigkernel) {
-			tlb_ent -= 1;
-			prom_dtlb_load(tlb_ent,
-				       tte_data + 0x400000, 
-				       tte_vaddr + 0x400000);
-			prom_itlb_load(tlb_ent,
-				       tte_data + 0x400000, 
-				       tte_vaddr + 0x400000);
+		for (i = 0; i < num_kernel_image_mappings; i++) {
+			prom_dtlb_load(tlb_ent - i, tte_data, tte_vaddr);
+			prom_itlb_load(tlb_ent - i, tte_data, tte_vaddr);
+			tte_vaddr += 0x400000;
+			tte_data += 0x400000;
 		}
-		sparc64_highest_unlocked_tlb_ent = tlb_ent - 1;
+		sparc64_highest_unlocked_tlb_ent = tlb_ent - i;
 	}
 	if (tlb_type == cheetah_plus) {
 		sparc64_kern_pri_context = (CTX_CHEETAH_PLUS_CTX0 |
@@ -1352,12 +1345,9 @@ void __init paging_init(void)
 	shift = kern_base + PAGE_OFFSET - ((unsigned long)KERNBASE);
 
 	real_end = (unsigned long)_end;
-	if ((real_end > ((unsigned long)KERNBASE + 0x400000)))
-		bigkernel = 1;
-	if ((real_end > ((unsigned long)KERNBASE + 0x800000))) {
-		prom_printf("paging_init: Kernel > 8MB, too large.\n");
-		prom_halt();
-	}
+	num_kernel_image_mappings = DIV_ROUND_UP(real_end - KERNBASE, 1 << 22);
+	printk("Kernel: Using %d locked TLB entries for main kernel image.\n",
+	       num_kernel_image_mappings);
 
 	/* Set kernel pgd to upper alias so physical page computations
 	 * work.

include/asm-sparc64/hvtramp.h

@@ -16,7 +16,7 @@ struct hvtramp_descr {
 	__u64			fault_info_va;
 	__u64			fault_info_pa;
 	__u64			thread_reg;
-	struct hvtramp_mapping	maps[2];
+	struct hvtramp_mapping	maps[1];
 };
 
 extern void hv_cpu_startup(unsigned long hvdescr_pa);

include/asm-sparc64/spitfire.h

@@ -63,6 +63,8 @@ extern void cheetah_enable_pcache(void);
 	 SPITFIRE_HIGHEST_LOCKED_TLBENT : \
 	 CHEETAH_HIGHEST_LOCKED_TLBENT)
 
+extern int num_kernel_image_mappings;
+
 /* The data cache is write through, so this just invalidates the
  * specified line.
  */