Messages in this thread Patch in this message | | | From | Yinghai Lu <> | Subject | [PATCH 1/3] x86: get early page table from BRK | Date | Sat, 6 Oct 2012 00:44:27 -0700 |
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set pgt_buf early from BRK, and use it to map page table at first.
also use the left at first, then use new extend one.
-v2: extra xen call back for that new range.
Signed-off-by: Yinghai Lu <yinghai@kernel.org> --- arch/x86/include/asm/init.h | 4 ++++ arch/x86/include/asm/pgtable.h | 1 + arch/x86/kernel/setup.c | 2 ++ arch/x86/mm/init.c | 25 +++++++++++++++++++++++++ arch/x86/mm/init_32.c | 8 ++++++-- arch/x86/mm/init_64.c | 8 ++++++-- 6 files changed, 44 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/init.h b/arch/x86/include/asm/init.h index 4f13998..2f32eea 100644 --- a/arch/x86/include/asm/init.h +++ b/arch/x86/include/asm/init.h @@ -16,4 +16,8 @@ extern unsigned long __initdata pgt_buf_start; extern unsigned long __meminitdata pgt_buf_end; extern unsigned long __meminitdata pgt_buf_top; +extern unsigned long __initdata early_pgt_buf_start; +extern unsigned long __meminitdata early_pgt_buf_end; +extern unsigned long __meminitdata early_pgt_buf_top; + #endif /* _ASM_X86_INIT_32_H */ diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 52d40a1..25fa5bb 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -599,6 +599,7 @@ static inline int pgd_none(pgd_t pgd) extern int direct_gbpages; void init_mem_mapping(void); +void early_alloc_pgt_buf(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 4989f80..7eb6855 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -896,6 +896,8 @@ void __init setup_arch(char **cmdline_p) reserve_ibft_region(); + early_alloc_pgt_buf(); + /* * Need to conclude brk, before memblock_x86_fill() * it could use memblock_find_in_range, could overlap with diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index cf662ba..c32eed1 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -21,6 +21,10 @@ unsigned long __initdata pgt_buf_start; unsigned long __meminitdata pgt_buf_end; unsigned long __meminitdata pgt_buf_top; +unsigned long __initdata early_pgt_buf_start; +unsigned long __meminitdata early_pgt_buf_end; +unsigned long __meminitdata early_pgt_buf_top; + int after_bootmem; int direct_gbpages @@ -291,6 +295,11 @@ static void __init find_early_table_space(unsigned long start, if (!base) panic("Cannot find space for the kernel page tables"); + init_memory_mapping(base, base + tables); + printk(KERN_DEBUG "kernel direct mapping tables from %#llx to %#llx @ [mem %#010lx-%#010lx]\n", + base, base + tables - 1, early_pgt_buf_start << PAGE_SHIFT, + (early_pgt_buf_end << PAGE_SHIFT) - 1); + pgt_buf_start = base >> PAGE_SHIFT; pgt_buf_end = pgt_buf_start; pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT); @@ -430,6 +439,8 @@ void __init init_mem_mapping(void) x86_init.mapping.pagetable_reserve(PFN_PHYS(pgt_buf_start), PFN_PHYS(pgt_buf_end)); } + x86_init.mapping.pagetable_reserve(PFN_PHYS(early_pgt_buf_start), + PFN_PHYS(early_pgt_buf_end)); /* stop the wrong using */ pgt_buf_top = 0; @@ -437,6 +448,20 @@ void __init init_mem_mapping(void) early_memtest(0, max_pfn_mapped << PAGE_SHIFT); } +RESERVE_BRK(early_pgt_alloc, 16384); + +void __init early_alloc_pgt_buf(void) +{ + unsigned long tables = 16384; + phys_addr_t base; + + base = __pa(extend_brk(tables, PAGE_SIZE)); + + early_pgt_buf_start = base >> PAGE_SHIFT; + early_pgt_buf_end = early_pgt_buf_start; + early_pgt_buf_top = early_pgt_buf_start + (tables >> PAGE_SHIFT); +} + /* * devmem_is_allowed() checks to see if /dev/mem access to a certain address * is valid. The argument is a physical page number. diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index 11a5800..92c0f12 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -61,10 +61,14 @@ bool __read_mostly __vmalloc_start_set = false; static __init void *alloc_low_page(void) { - unsigned long pfn = pgt_buf_end++; + unsigned long pfn; void *adr; - if (pfn >= pgt_buf_top) + if (early_pgt_buf_end < early_pgt_buf_top) + pfn = early_pgt_buf_end++; + else if (pgt_buf_end < pgt_buf_top) + pfn = pgt_buf_end++; + else panic("alloc_low_page: ran out of memory"); adr = __va(pfn * PAGE_SIZE); diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index ab558eb..5375cf0 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -316,7 +316,7 @@ void __init cleanup_highmap(void) static __ref void *alloc_low_page(unsigned long *phys) { - unsigned long pfn = pgt_buf_end++; + unsigned long pfn; void *adr; if (after_bootmem) { @@ -326,7 +326,11 @@ static __ref void *alloc_low_page(unsigned long *phys) return adr; } - if (pfn >= pgt_buf_top) + if (early_pgt_buf_end < early_pgt_buf_top) + pfn = early_pgt_buf_end++; + else if (pgt_buf_end < pgt_buf_top) + pfn = pgt_buf_end++; + else panic("alloc_low_page: ran out of memory"); adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE); -- 1.7.7
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