Messages in this thread Patch in this message | | | From | Yinghai Lu <> | Subject | [PATCH 03/10] x86, mm: get early page table from BRK | Date | Mon, 8 Oct 2012 21:39:11 -0700 |
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Get pgt_buf early from BRK, and use it to map page table at first.
also use the left at first, then use new one.
-v2: extra xen call back for that new range. -v3: fix compiling about #llx in print out that is reported by Fengguang -v4: remove the early_pgt_buf_* stuff, because xen interface is ready yet. still need to run x86_init.mapping.pagetable_reserve separately. so we will waste some pages in BRK, will address that later.
Signed-off-by: Yinghai Lu <yinghai@kernel.org> --- arch/x86/include/asm/pgtable.h | 1 + arch/x86/kernel/setup.c | 2 ++ arch/x86/mm/init.c | 26 +++++++++++++++++++++++++- 3 files changed, 28 insertions(+), 1 deletions(-)
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 0c58f2d..a89f485 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -317,12 +317,22 @@ static void __init find_early_table_space(unsigned long start, unsigned long good_end, unsigned long tables) { - phys_addr_t base; + unsigned long base; base = memblock_find_in_range(start, good_end, tables, PAGE_SIZE); if (!base) panic("Cannot find space for the kernel page tables"); + init_memory_mapping(base, base + tables); + if (pgt_buf_end > pgt_buf_start) { + printk(KERN_DEBUG "kernel direct mapping tables from %#lx to %#lx @ [mem %#010lx-%#010lx]\n", + base, base + tables - 1, pgt_buf_start << PAGE_SHIFT, + (pgt_buf_end << PAGE_SHIFT) - 1); + + x86_init.mapping.pagetable_reserve(PFN_PHYS(pgt_buf_start), + PFN_PHYS(pgt_buf_end)); + } + pgt_buf_start = base >> PAGE_SHIFT; pgt_buf_end = pgt_buf_start; pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT); @@ -469,6 +479,20 @@ 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)); + + pgt_buf_start = base >> PAGE_SHIFT; + pgt_buf_end = pgt_buf_start; + pgt_buf_top = 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. -- 1.7.7
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