ARM: LPAE: MMU setup for the 3-level page table format
This patch adds the MMU initialisation for the LPAE page table format.
The swapper_pg_dir size with LPAE is 5 rather than 4 pages. A new
proc-v7-3level.S file contains the TTB initialisation, context switch
and PTE setting code with the LPAE. The TTBRx split is based on the
PAGE_OFFSET with TTBR1 used for the kernel mappings. The 36-bit mappings
(supersections) and a few other memory types in mmu.c are conditionally
compiled.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index dc8c550..1935311 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -150,6 +150,7 @@
}
early_param("nowb", early_nowrite);
+#ifndef CONFIG_ARM_LPAE
static int __init early_ecc(char *p)
{
if (memcmp(p, "on", 2) == 0)
@@ -159,6 +160,7 @@
return 0;
}
early_param("ecc", early_ecc);
+#endif
static int __init noalign_setup(char *__unused)
{
@@ -228,10 +230,12 @@
.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
.domain = DOMAIN_KERNEL,
},
+#ifndef CONFIG_ARM_LPAE
[MT_MINICLEAN] = {
.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN | PMD_SECT_MINICACHE,
.domain = DOMAIN_KERNEL,
},
+#endif
[MT_LOW_VECTORS] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
L_PTE_RDONLY,
@@ -429,6 +433,7 @@
* ARMv6 and above have extended page tables.
*/
if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) {
+#ifndef CONFIG_ARM_LPAE
/*
* Mark cache clean areas and XIP ROM read only
* from SVC mode and no access from userspace.
@@ -436,6 +441,7 @@
mem_types[MT_ROM].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
+#endif
if (is_smp()) {
/*
@@ -474,6 +480,18 @@
mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_BUFFERABLE;
}
+#ifdef CONFIG_ARM_LPAE
+ /*
+ * Do not generate access flag faults for the kernel mappings.
+ */
+ for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
+ mem_types[i].prot_pte |= PTE_EXT_AF;
+ mem_types[i].prot_sect |= PMD_SECT_AF;
+ }
+ kern_pgprot |= PTE_EXT_AF;
+ vecs_pgprot |= PTE_EXT_AF;
+#endif
+
for (i = 0; i < 16; i++) {
unsigned long v = pgprot_val(protection_map[i]);
protection_map[i] = __pgprot(v | user_pgprot);
@@ -572,8 +590,10 @@
if (((addr | end | phys) & ~SECTION_MASK) == 0) {
pmd_t *p = pmd;
+#ifndef CONFIG_ARM_LPAE
if (addr & SECTION_SIZE)
pmd++;
+#endif
do {
*pmd = __pmd(phys | type->prot_sect);
@@ -603,6 +623,7 @@
} while (pud++, addr = next, addr != end);
}
+#ifndef CONFIG_ARM_LPAE
static void __init create_36bit_mapping(struct map_desc *md,
const struct mem_type *type)
{
@@ -662,6 +683,7 @@
pgd += SUPERSECTION_SIZE >> PGDIR_SHIFT;
} while (addr != end);
}
+#endif /* !CONFIG_ARM_LPAE */
/*
* Create the page directory entries and any necessary
@@ -693,6 +715,7 @@
type = &mem_types[md->type];
+#ifndef CONFIG_ARM_LPAE
/*
* Catch 36-bit addresses
*/
@@ -700,6 +723,7 @@
create_36bit_mapping(md, type);
return;
}
+#endif
addr = md->virtual & PAGE_MASK;
phys = __pfn_to_phys(md->pfn);
@@ -897,7 +921,13 @@
pmd_clear(pmd_off_k(addr));
}
+#ifdef CONFIG_ARM_LPAE
+/* the first page is reserved for pgd */
+#define SWAPPER_PG_DIR_SIZE (PAGE_SIZE + \
+ PTRS_PER_PGD * PTRS_PER_PMD * sizeof(pmd_t))
+#else
#define SWAPPER_PG_DIR_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
+#endif
/*
* Reserve the special regions of memory