1 files changed, 90 insertions, 41 deletions

diff --git a/arch/powerpc/mm/8xx_mmu.c b/arch/powerpc/mm/8xx_mmu.c
index 949100577db5..6c5025e81236 100644
--- a/arch/powerpc/mm/8xx_mmu.c
+++ b/arch/powerpc/mm/8xx_mmu.c
@@ -13,62 +13,115 @@
  */
 
 #include <linux/memblock.h>
+#include <asm/fixmap.h>
+#include <asm/code-patching.h>
 
 #include "mmu_decl.h"
 
+#define IMMR_SIZE (FIX_IMMR_SIZE << PAGE_SHIFT)
+
 extern int __map_without_ltlbs;
+
 /*
- * MMU_init_hw does the chip-specific initialization of the MMU hardware.
+ * Return PA for this VA if it is in IMMR area, or 0
  */
-void __init MMU_init_hw(void)
+phys_addr_t v_block_mapped(unsigned long va)
 {
-	/* Nothing to do for the time being but keep it similar to other PPC */
+	unsigned long p = PHYS_IMMR_BASE;
+
+	if (__map_without_ltlbs)
+		return 0;
+	if (va >= VIRT_IMMR_BASE && va < VIRT_IMMR_BASE + IMMR_SIZE)
+		return p + va - VIRT_IMMR_BASE;
+	return 0;
+}
+
+/*
+ * Return VA for a given PA or 0 if not mapped
+ */
+unsigned long p_block_mapped(phys_addr_t pa)
+{
+	unsigned long p = PHYS_IMMR_BASE;
+
+	if (__map_without_ltlbs)
+		return 0;
+	if (pa >= p && pa < p + IMMR_SIZE)
+		return VIRT_IMMR_BASE + pa - p;
+	return 0;
 }
 
-#define LARGE_PAGE_SIZE_4M	(1<<22)
 #define LARGE_PAGE_SIZE_8M	(1<<23)
-#define LARGE_PAGE_SIZE_64M	(1<<26)
 
-unsigned long __init mmu_mapin_ram(unsigned long top)
+/*
+ * MMU_init_hw does the chip-specific initialization of the MMU hardware.
+ */
+void __init MMU_init_hw(void)
 {
-	unsigned long v, s, mapped;
-	phys_addr_t p;
+	/* PIN up to the 3 first 8Mb after IMMR in DTLB table */
+#ifdef CONFIG_PIN_TLB
+	unsigned long ctr = mfspr(SPRN_MD_CTR) & 0xfe000000;
+	unsigned long flags = 0xf0 | MD_SPS16K | _PAGE_SHARED | _PAGE_DIRTY;
+#ifdef CONFIG_PIN_TLB_IMMR
+	int i = 29;
+#else
+	int i = 28;
+#endif
+	unsigned long addr = 0;
+	unsigned long mem = total_lowmem;
+
+	for (; i < 32 && mem >= LARGE_PAGE_SIZE_8M; i++) {
+		mtspr(SPRN_MD_CTR, ctr | (i << 8));
+		mtspr(SPRN_MD_EPN, (unsigned long)__va(addr) | MD_EVALID);
+		mtspr(SPRN_MD_TWC, MD_PS8MEG | MD_SVALID);
+		mtspr(SPRN_MD_RPN, addr | flags | _PAGE_PRESENT);
+		addr += LARGE_PAGE_SIZE_8M;
+		mem -= LARGE_PAGE_SIZE_8M;
+	}
+#endif
+}
 
-	v = KERNELBASE;
-	p = 0;
-	s = top;
+static void mmu_mapin_immr(void)
+{
+	unsigned long p = PHYS_IMMR_BASE;
+	unsigned long v = VIRT_IMMR_BASE;
+	unsigned long f = pgprot_val(PAGE_KERNEL_NCG);
+	int offset;
 
-	if (__map_without_ltlbs)
-		return 0;
+	for (offset = 0; offset < IMMR_SIZE; offset += PAGE_SIZE)
+		map_page(v + offset, p + offset, f);
+}
 
-#ifdef CONFIG_PPC_4K_PAGES
-	while (s >= LARGE_PAGE_SIZE_8M) {
-		pmd_t *pmdp;
-		unsigned long val = p | MD_PS8MEG;
+/* Address of instructions to patch */
+#ifndef CONFIG_PIN_TLB_IMMR
+extern unsigned int DTLBMiss_jmp;
+#endif
+extern unsigned int DTLBMiss_cmp, FixupDAR_cmp;
 
-		pmdp = pmd_offset(pud_offset(pgd_offset_k(v), v), v);
-		*pmdp++ = __pmd(val);
-		*pmdp++ = __pmd(val + LARGE_PAGE_SIZE_4M);
+void mmu_patch_cmp_limit(unsigned int *addr, unsigned long mapped)
+{
+	unsigned int instr = *addr;
 
-		v += LARGE_PAGE_SIZE_8M;
-		p += LARGE_PAGE_SIZE_8M;
-		s -= LARGE_PAGE_SIZE_8M;
-	}
-#else /* CONFIG_PPC_16K_PAGES */
-	while (s >= LARGE_PAGE_SIZE_64M) {
-		pmd_t *pmdp;
-		unsigned long val = p | MD_PS8MEG;
+	instr &= 0xffff0000;
+	instr |= (unsigned long)__va(mapped) >> 16;
+	patch_instruction(addr, instr);
+}
 
-		pmdp = pmd_offset(pud_offset(pgd_offset_k(v), v), v);
-		*pmdp++ = __pmd(val);
+unsigned long __init mmu_mapin_ram(unsigned long top)
+{
+	unsigned long mapped;
 
-		v += LARGE_PAGE_SIZE_64M;
-		p += LARGE_PAGE_SIZE_64M;
-		s -= LARGE_PAGE_SIZE_64M;
-	}
+	if (__map_without_ltlbs) {
+		mapped = 0;
+		mmu_mapin_immr();
+#ifndef CONFIG_PIN_TLB_IMMR
+		patch_instruction(&DTLBMiss_jmp, PPC_INST_NOP);
 #endif
+	} else {
+		mapped = top & ~(LARGE_PAGE_SIZE_8M - 1);
+	}
 
-	mapped = top - s;
+	mmu_patch_cmp_limit(&DTLBMiss_cmp, mapped);
+	mmu_patch_cmp_limit(&FixupDAR_cmp, mapped);
 
 	/* If the size of RAM is not an exact power of two, we may not
 	 * have covered RAM in its entirety with 8 MiB
@@ -77,7 +130,8 @@ unsigned long __init mmu_mapin_ram(unsigned long top)
 	 * coverage with normal-sized pages (or other reasons) do not
 	 * attempt to allocate outside the allowed range.
 	 */
-	memblock_set_current_limit(mapped);
+	if (mapped)
+		memblock_set_current_limit(mapped);
 
 	return mapped;
 }
@@ -90,13 +144,8 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 	 */
 	BUG_ON(first_memblock_base != 0);
 
-#ifdef CONFIG_PIN_TLB
 	/* 8xx can only access 24MB at the moment */
 	memblock_set_current_limit(min_t(u64, first_memblock_size, 0x01800000));
-#else
-	/* 8xx can only access 8MB at the moment */
-	memblock_set_current_limit(min_t(u64, first_memblock_size, 0x00800000));
-#endif
 }
 
 /*