From f9be0ff96262be81a29e3fc382a3b29ad1a676b4 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Sat, 15 Dec 2012 20:59:08 -0800 Subject: [PATCH v7 08/29] x86, 64bit: #PF handler set page to cover 2M only 1. check if phys address is passed, aka we only handle kernel low mapping. 2. only add one 2M instead of 1G accessing one time for dynamically. 3. switchover only cover kernel space instead of 1G. Signed-off-by: Yinghai Lu --- arch/x86/kernel/head64.c | 44 ++++++++++++++++++++++++++------------------ arch/x86/kernel/head_64.S | 7 +++++-- 2 files changed, 31 insertions(+), 20 deletions(-) diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 4fabebc..014b48d 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -54,14 +54,14 @@ int __init early_make_pgtable(unsigned long address) unsigned long physaddr = address - __PAGE_OFFSET; unsigned long i; pgdval_t pgd, *pgd_p; - pudval_t *pud_p; + pudval_t pud, *pud_p; pmdval_t pmd, *pmd_p; - if (physaddr >= MAXMEM) + if (address < __PAGE_OFFSET || physaddr >= MAXMEM) return -1; /* Invalid address - puke */ - i = (address >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1); - pgd_p = &early_level4_pgt[i].pgd; +again: + pgd_p = &early_level4_pgt[pgd_index(address)].pgd; pgd = *pgd_p; /* @@ -69,29 +69,37 @@ int __init early_make_pgtable(unsigned long address) * critical -- __PAGE_OFFSET would point us back into the dynamic * range and we might end up looping forever... */ - if (pgd && next_early_pgt < EARLY_DYNAMIC_PAGE_TABLES) { + if (pgd) pud_p = (pudval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base); - } else { - if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES-1) + else { + if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) { reset_early_page_tables(); + goto again; + } pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++]; for (i = 0; i < PTRS_PER_PUD; i++) pud_p[i] = 0; - *pgd_p = (pgdval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; } - i = (address >> PUD_SHIFT) & (PTRS_PER_PUD - 1); - pud_p += i; - - pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++]; - pmd = (physaddr & PUD_MASK) + (__PAGE_KERNEL_LARGE & ~_PAGE_GLOBAL); - for (i = 0; i < PTRS_PER_PMD; i++) { - pmd_p[i] = pmd; - pmd += PMD_SIZE; - } + pud_p += pud_index(address); + pud = *pud_p; - *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; + if (pud) + pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base); + else { + if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) { + reset_early_page_tables(); + goto again; + } + + pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++]; + for (i = 0; i < PTRS_PER_PMD; i++) + pmd_p[i] = 0; + *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; + } + pmd = (physaddr & PMD_MASK) + (__PAGE_KERNEL_LARGE & ~_PAGE_GLOBAL); + pmd_p[pmd_index(address)] = pmd; return 0; } diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 5261f37..0ee661c 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -122,14 +122,17 @@ startup_64: movq %rdi, %rax shrq $PMD_SHIFT, %rdi addq $(__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL), %rax - movl $PTRS_PER_PMD, %ecx + leaq (_end - 1)(%rip), %rcx + shrq $PMD_SHIFT, %rcx + subq %rdi, %rcx + incq %rcx 1: andq $(PTRS_PER_PMD - 1), %rdi movq %rax, (%rbx,%rdi,8) incq %rdi addq $PMD_SIZE, %rax - decl %ecx + decq %rcx jnz 1b /* -- 1.7.10.4