+++ /dev/null
-From 4b239f458c229de044d6905c2b0f9fe16ed9e01e Mon Sep 17 00:00:00 2001
-From: Yinghai Lu <yinghai@kernel.org>
-Date: Fri, 17 Dec 2010 16:58:28 -0800
-Subject: x86-64, mm: Put early page table high
-
-From: Yinghai Lu <yinghai@kernel.org>
-
-commit 4b239f458c229de044d6905c2b0f9fe16ed9e01e upstream.
-
-While dubug kdump, found current kernel will have problem with crashkernel=512M.
-
-It turns out that initial mapping is to 512M, and later initial mapping to 4G
-(acutally is 2040M in my platform), will put page table near 512M.
-then initial mapping to 128g will be near 2g.
-
-before this patch:
-[ 0.000000] initial memory mapped : 0 - 20000000
-[ 0.000000] init_memory_mapping: [0x00000000000000-0x0000007f74ffff]
-[ 0.000000] 0000000000 - 007f600000 page 2M
-[ 0.000000] 007f600000 - 007f750000 page 4k
-[ 0.000000] kernel direct mapping tables up to 7f750000 @ [0x1fffc000-0x1fffffff]
-[ 0.000000] memblock_x86_reserve_range: [0x1fffc000-0x1fffdfff] PGTABLE
-[ 0.000000] init_memory_mapping: [0x00000100000000-0x0000207fffffff]
-[ 0.000000] 0100000000 - 2080000000 page 2M
-[ 0.000000] kernel direct mapping tables up to 2080000000 @ [0x7bc01000-0x7bc83fff]
-[ 0.000000] memblock_x86_reserve_range: [0x7bc01000-0x7bc7efff] PGTABLE
-[ 0.000000] RAMDISK: 7bc84000 - 7f745000
-[ 0.000000] crashkernel reservation failed - No suitable area found.
-
-after patch:
-[ 0.000000] initial memory mapped : 0 - 20000000
-[ 0.000000] init_memory_mapping: [0x00000000000000-0x0000007f74ffff]
-[ 0.000000] 0000000000 - 007f600000 page 2M
-[ 0.000000] 007f600000 - 007f750000 page 4k
-[ 0.000000] kernel direct mapping tables up to 7f750000 @ [0x7f74c000-0x7f74ffff]
-[ 0.000000] memblock_x86_reserve_range: [0x7f74c000-0x7f74dfff] PGTABLE
-[ 0.000000] init_memory_mapping: [0x00000100000000-0x0000207fffffff]
-[ 0.000000] 0100000000 - 2080000000 page 2M
-[ 0.000000] kernel direct mapping tables up to 2080000000 @ [0x207ff7d000-0x207fffffff]
-[ 0.000000] memblock_x86_reserve_range: [0x207ff7d000-0x207fffafff] PGTABLE
-[ 0.000000] RAMDISK: 7bc84000 - 7f745000
-[ 0.000000] memblock_x86_reserve_range: [0x17000000-0x36ffffff] CRASH KERNEL
-[ 0.000000] Reserving 512MB of memory at 368MB for crashkernel (System RAM: 133120MB)
-
-It means with the patch, page table for [0, 2g) will need 2g, instead of under 512M,
-page table for [4g, 128g) will be near 128g, instead of under 2g.
-
-That would good, if we have lots of memory above 4g, like 1024g, or 2048g or 16T, will not put
-related page table under 2g. that would be have chance to fill the under 2g if 1G or 2M page is
-not used.
-
-the code change will use add map_low_page() and update unmap_low_page() for 64bit, and use them
-to get access the corresponding high memory for page table setting.
-
-Signed-off-by: Yinghai Lu <yinghai@kernel.org>
-LKML-Reference: <4D0C0734.7060900@kernel.org>
-Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
-Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-
----
- arch/x86/mm/init.c | 9 ++-----
- arch/x86/mm/init_64.c | 63 +++++++++++++++++++++-----------------------------
- 2 files changed, 30 insertions(+), 42 deletions(-)
-
---- a/arch/x86/mm/init.c
-+++ b/arch/x86/mm/init.c
-@@ -33,7 +33,7 @@ int direct_gbpages
- static void __init find_early_table_space(unsigned long end, int use_pse,
- int use_gbpages)
- {
-- unsigned long puds, pmds, ptes, tables, start;
-+ unsigned long puds, pmds, ptes, tables, start = 0, good_end = end;
- phys_addr_t base;
-
- puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
-@@ -73,12 +73,9 @@ static void __init find_early_table_spac
- * need roughly 0.5KB per GB.
- */
- #ifdef CONFIG_X86_32
-- start = 0x7000;
--#else
-- start = 0x8000;
-+ good_end = max_pfn_mapped << PAGE_SHIFT;
- #endif
-- base = memblock_find_in_range(start, max_pfn_mapped<<PAGE_SHIFT,
-- tables, PAGE_SIZE);
-+ base = memblock_find_in_range(start, good_end, tables, PAGE_SIZE);
- if (base == MEMBLOCK_ERROR)
- panic("Cannot find space for the kernel page tables");
-
---- a/arch/x86/mm/init_64.c
-+++ b/arch/x86/mm/init_64.c
-@@ -334,12 +334,28 @@ static __ref void *alloc_low_page(unsign
- return adr;
- }
-
-+static __ref void *map_low_page(void *virt)
-+{
-+ void *adr;
-+ unsigned long phys, left;
-+
-+ if (after_bootmem)
-+ return virt;
-+
-+ phys = __pa(virt);
-+ left = phys & (PAGE_SIZE - 1);
-+ adr = early_memremap(phys & PAGE_MASK, PAGE_SIZE);
-+ adr = (void *)(((unsigned long)adr) | left);
-+
-+ return adr;
-+}
-+
- static __ref void unmap_low_page(void *adr)
- {
- if (after_bootmem)
- return;
-
-- early_iounmap(adr, PAGE_SIZE);
-+ early_iounmap((void *)((unsigned long)adr & PAGE_MASK), PAGE_SIZE);
- }
-
- static unsigned long __meminit
-@@ -387,15 +403,6 @@ phys_pte_init(pte_t *pte_page, unsigned
- }
-
- static unsigned long __meminit
--phys_pte_update(pmd_t *pmd, unsigned long address, unsigned long end,
-- pgprot_t prot)
--{
-- pte_t *pte = (pte_t *)pmd_page_vaddr(*pmd);
--
-- return phys_pte_init(pte, address, end, prot);
--}
--
--static unsigned long __meminit
- phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
- unsigned long page_size_mask, pgprot_t prot)
- {
-@@ -421,8 +428,10 @@ phys_pmd_init(pmd_t *pmd_page, unsigned
- if (pmd_val(*pmd)) {
- if (!pmd_large(*pmd)) {
- spin_lock(&init_mm.page_table_lock);
-- last_map_addr = phys_pte_update(pmd, address,
-+ pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd));
-+ last_map_addr = phys_pte_init(pte, address,
- end, prot);
-+ unmap_low_page(pte);
- spin_unlock(&init_mm.page_table_lock);
- continue;
- }
-@@ -469,18 +478,6 @@ phys_pmd_init(pmd_t *pmd_page, unsigned
- }
-
- static unsigned long __meminit
--phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end,
-- unsigned long page_size_mask, pgprot_t prot)
--{
-- pmd_t *pmd = pmd_offset(pud, 0);
-- unsigned long last_map_addr;
--
-- last_map_addr = phys_pmd_init(pmd, address, end, page_size_mask, prot);
-- __flush_tlb_all();
-- return last_map_addr;
--}
--
--static unsigned long __meminit
- phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
- unsigned long page_size_mask)
- {
-@@ -505,8 +502,11 @@ phys_pud_init(pud_t *pud_page, unsigned
-
- if (pud_val(*pud)) {
- if (!pud_large(*pud)) {
-- last_map_addr = phys_pmd_update(pud, addr, end,
-+ pmd = map_low_page(pmd_offset(pud, 0));
-+ last_map_addr = phys_pmd_init(pmd, addr, end,
- page_size_mask, prot);
-+ unmap_low_page(pmd);
-+ __flush_tlb_all();
- continue;
- }
- /*
-@@ -554,17 +554,6 @@ phys_pud_init(pud_t *pud_page, unsigned
- return last_map_addr;
- }
-
--static unsigned long __meminit
--phys_pud_update(pgd_t *pgd, unsigned long addr, unsigned long end,
-- unsigned long page_size_mask)
--{
-- pud_t *pud;
--
-- pud = (pud_t *)pgd_page_vaddr(*pgd);
--
-- return phys_pud_init(pud, addr, end, page_size_mask);
--}
--
- unsigned long __meminit
- kernel_physical_mapping_init(unsigned long start,
- unsigned long end,
-@@ -588,8 +577,10 @@ kernel_physical_mapping_init(unsigned lo
- next = end;
-
- if (pgd_val(*pgd)) {
-- last_map_addr = phys_pud_update(pgd, __pa(start),
-+ pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd));
-+ last_map_addr = phys_pud_init(pud, __pa(start),
- __pa(end), page_size_mask);
-+ unmap_low_page(pud);
- continue;
- }
-
projects / thirdparty / kernel / stable-queue.git / commitdiff
