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authorSteve Capper <steve.capper@linaro.org>2014-05-06 14:02:27 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2014-05-09 16:10:58 +0100
commit206a2a73a62d37c8b8f6ddd3180c202b2e7298ab (patch)
tree0d62a75a3e29667792ee37e3c5aed14d1bc03303 /arch/arm64
parentba6bf8c85cb0d263ca9a98ef6a76ab651a97c60b (diff)
arm64: mm: Create gigabyte kernel logical mappings where possible
We have the capability to map 1GB level 1 blocks when using a 4K granule. This patch adjusts the create_mapping logic s.t. when mapping physical memory on boot, we attempt to use a 1GB block if both the VA and PA start and end are 1GB aligned. This both reduces the levels of lookup required to resolve a kernel logical address, as well as reduces TLB pressure on cores that support 1GB TLB entries. Signed-off-by: Steve Capper <steve.capper@linaro.org> Tested-by: Jungseok Lee <jays.lee@samsung.com> [catalin.marinas@arm.com: s/prot_sect_kernel/PROT_SECT_NORMAL_EXEC/] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/include/asm/pgtable-hwdef.h2
-rw-r--r--arch/arm64/include/asm/pgtable.h7
-rw-r--r--arch/arm64/mm/mmu.c28
3 files changed, 36 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
index 5fc8a66c3924..955e8c5f0afb 100644
--- a/arch/arm64/include/asm/pgtable-hwdef.h
+++ b/arch/arm64/include/asm/pgtable-hwdef.h
@@ -29,6 +29,8 @@
*/
#define PUD_TABLE_BIT (_AT(pgdval_t, 1) << 1)
+#define PUD_TYPE_MASK (_AT(pgdval_t, 3) << 0)
+#define PUD_TYPE_SECT (_AT(pgdval_t, 1) << 0)
/*
* Level 2 descriptor (PMD).
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 752348dbb4f3..3de4ef8bfd82 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -259,6 +259,7 @@ static inline pmd_t pte_pmd(pte_t pte)
#define mk_pmd(page,prot) pfn_pmd(page_to_pfn(page),prot)
#define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
+#define pud_pfn(pud) (((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
#define set_pmd_at(mm, addr, pmdp, pmd) set_pmd(pmdp, pmd)
@@ -292,6 +293,12 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
#define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \
PMD_TYPE_SECT)
+#ifdef ARM64_64K_PAGES
+#define pud_sect(pud) (0)
+#else
+#define pud_sect(pud) ((pud_val(pud) & PUD_TYPE_MASK) == \
+ PUD_TYPE_SECT)
+#endif
static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
{
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 2c0e1dda8163..3a729de96f15 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -195,7 +195,30 @@ static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
do {
next = pud_addr_end(addr, end);
- alloc_init_pmd(pud, addr, next, phys);
+
+ /*
+ * For 4K granule only, attempt to put down a 1GB block
+ */
+ if ((PAGE_SHIFT == 12) &&
+ ((addr | next | phys) & ~PUD_MASK) == 0) {
+ pud_t old_pud = *pud;
+ set_pud(pud, __pud(phys | PROT_SECT_NORMAL_EXEC));
+
+ /*
+ * If we have an old value for a pud, it will
+ * be pointing to a pmd table that we no longer
+ * need (from swapper_pg_dir).
+ *
+ * Look up the old pmd table and free it.
+ */
+ if (!pud_none(old_pud)) {
+ phys_addr_t table = __pa(pmd_offset(&old_pud, 0));
+ memblock_free(table, PAGE_SIZE);
+ flush_tlb_all();
+ }
+ } else {
+ alloc_init_pmd(pud, addr, next, phys);
+ }
phys += next - addr;
} while (pud++, addr = next, addr != end);
}
@@ -338,6 +361,9 @@ int kern_addr_valid(unsigned long addr)
if (pud_none(*pud))
return 0;
+ if (pud_sect(*pud))
+ return pfn_valid(pud_pfn(*pud));
+
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd))
return 0;