Messages in this thread Patch in this message | | | From | Yinghai Lu <> | Subject | [PATCH -v2 01/13] x86, mm: Add global page_size_mask | Date | Sun, 2 Sep 2012 00:46:47 -0700 |
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detect if need to use 1G or 2M and store them in page_size_mask.
Only probe them one time.
Suggested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Yinghai Lu <yinghai@kernel.org> --- arch/x86/include/asm/pgtable.h | 1 + arch/x86/kernel/setup.c | 1 + arch/x86/mm/init.c | 66 +++++++++++++++++++--------------------- 3 files changed, 33 insertions(+), 35 deletions(-)
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 49afb3f..e47e4db 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -597,6 +597,7 @@ static inline int pgd_none(pgd_t pgd) #ifndef __ASSEMBLY__ extern int direct_gbpages; +void probe_page_size_mask(void); /* local pte updates need not use xchg for locking */ static inline pte_t native_local_ptep_get_and_clear(pte_t *ptep) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index f4b9b80..d6e8c03 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -912,6 +912,7 @@ void __init setup_arch(char **cmdline_p) setup_real_mode(); init_gbpages(); + probe_page_size_mask(); /* max_pfn_mapped is updated here */ max_low_pfn_mapped = init_memory_mapping(0, max_low_pfn<<PAGE_SHIFT); diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index e0e6990..838e9bc 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -35,8 +35,10 @@ struct map_range { unsigned page_size_mask; }; -static void __init find_early_table_space(struct map_range *mr, unsigned long end, - int use_pse, int use_gbpages) +static int page_size_mask; + +static void __init find_early_table_space(struct map_range *mr, + unsigned long end) { unsigned long puds, pmds, ptes, tables, start = 0, good_end = end; phys_addr_t base; @@ -44,7 +46,7 @@ static void __init find_early_table_space(struct map_range *mr, unsigned long en puds = (end + PUD_SIZE - 1) >> PUD_SHIFT; tables = roundup(puds * sizeof(pud_t), PAGE_SIZE); - if (use_gbpages) { + if (page_size_mask & (1 << PG_LEVEL_1G)) { unsigned long extra; extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT); @@ -54,7 +56,7 @@ static void __init find_early_table_space(struct map_range *mr, unsigned long en tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE); - if (use_pse) { + if (page_size_mask & (1 << PG_LEVEL_2M)) { unsigned long extra; extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT); @@ -90,6 +92,30 @@ static void __init find_early_table_space(struct map_range *mr, unsigned long en (pgt_buf_top << PAGE_SHIFT) - 1); } +void probe_page_size_mask(void) +{ +#if !defined(CONFIG_DEBUG_PAGEALLOC) && !defined(CONFIG_KMEMCHECK) + /* + * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages. + * This will simplify cpa(), which otherwise needs to support splitting + * large pages into small in interrupt context, etc. + */ + if (direct_gbpages) + page_size_mask |= 1 << PG_LEVEL_1G; + if (cpu_has_pse) + page_size_mask |= 1 << PG_LEVEL_2M; +#endif + + /* Enable PSE if available */ + if (cpu_has_pse) + set_in_cr4(X86_CR4_PSE); + + /* Enable PGE if available */ + if (cpu_has_pge) { + set_in_cr4(X86_CR4_PGE); + __supported_pte_mask |= _PAGE_GLOBAL; + } +} void __init native_pagetable_reserve(u64 start, u64 end) { memblock_reserve(start, end - start); @@ -125,45 +151,15 @@ static int __meminit save_mr(struct map_range *mr, int nr_range, unsigned long __init_refok init_memory_mapping(unsigned long start, unsigned long end) { - unsigned long page_size_mask = 0; unsigned long start_pfn, end_pfn; unsigned long ret = 0; unsigned long pos; - struct map_range mr[NR_RANGE_MR]; int nr_range, i; - int use_pse, use_gbpages; printk(KERN_INFO "init_memory_mapping: [mem %#010lx-%#010lx]\n", start, end - 1); -#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK) - /* - * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages. - * This will simplify cpa(), which otherwise needs to support splitting - * large pages into small in interrupt context, etc. - */ - use_pse = use_gbpages = 0; -#else - use_pse = cpu_has_pse; - use_gbpages = direct_gbpages; -#endif - - /* Enable PSE if available */ - if (cpu_has_pse) - set_in_cr4(X86_CR4_PSE); - - /* Enable PGE if available */ - if (cpu_has_pge) { - set_in_cr4(X86_CR4_PGE); - __supported_pte_mask |= _PAGE_GLOBAL; - } - - if (use_gbpages) - page_size_mask |= 1 << PG_LEVEL_1G; - if (use_pse) - page_size_mask |= 1 << PG_LEVEL_2M; - memset(mr, 0, sizeof(mr)); nr_range = 0; @@ -267,7 +263,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, * nodes are discovered. */ if (!after_bootmem) - find_early_table_space(&mr[0], end, use_pse, use_gbpages); + find_early_table_space(&mr[0], end); for (i = 0; i < nr_range; i++) ret = kernel_physical_mapping_init(mr[i].start, mr[i].end, -- 1.7.7
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