From 206a2a73a62d37c8b8f6ddd3180c202b2e7298ab Mon Sep 17 00:00:00 2001 From: Steve Capper Date: Tue, 6 May 2014 14:02:27 +0100 Subject: 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 Tested-by: Jungseok Lee [catalin.marinas@arm.com: s/prot_sect_kernel/PROT_SECT_NORMAL_EXEC/] Signed-off-by: Catalin Marinas --- arch/arm64/mm/mmu.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) (limited to 'arch/arm64/mm/mmu.c') 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; -- cgit v1.2.3