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author | Steve Capper <steve.capper@linaro.org> | 2014-05-06 14:02:27 +0100 |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2014-05-09 16:10:58 +0100 |
commit | 206a2a73a62d37c8b8f6ddd3180c202b2e7298ab (patch) | |
tree | 0d62a75a3e29667792ee37e3c5aed14d1bc03303 /arch/arm64/mm | |
parent | ba6bf8c85cb0d263ca9a98ef6a76ab651a97c60b (diff) | |
download | op-kernel-dev-206a2a73a62d37c8b8f6ddd3180c202b2e7298ab.zip op-kernel-dev-206a2a73a62d37c8b8f6ddd3180c202b2e7298ab.tar.gz |
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/mm')
-rw-r--r-- | arch/arm64/mm/mmu.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 2c0e1dd..3a729de 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; |