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From: Yinghai Lu <yinghai@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
	"H. Peter Anvin" <hpa@zytor.com>, Jacob Shin <jacob.shin@amd.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	linux-kernel@vger.kernel.org, Yinghai Lu <yinghai@kernel.org>
Subject: [PATCH v8 19/46] x86, mm: Don't clear page table if range is ram
Date: Fri, 16 Nov 2012 19:38:56 -0800
Message-ID: <1353123563-3103-20-git-send-email-yinghai@kernel.org> (raw)
In-Reply-To: <1353123563-3103-1-git-send-email-yinghai@kernel.org>

After we add code use buffer in BRK to pre-map buf for page table in
following patch:
	x86, mm: setup page table in top-down
it should be safe to remove early_memmap for page table accessing.
Instead we get panic with that.

It turns out that we clear the initial page table wrongly for next range
that is separated by holes.
And it only happens when we are trying to map ram range one by one.

We need to check if the range is ram before clearing page table.

We change the loop structure to remove the extra little loop and use
one loop only, and in that loop will caculate next at first, and check if
[addr,next) is covered by E820_RAM.

-v2: E820_RESERVED_KERN is treated as E820_RAM. EFI one change some E820_RAM
     to that, so next kernel by kexec will know that range is used already.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
 arch/x86/mm/init_64.c |   40 +++++++++++++++++++---------------------
 1 files changed, 19 insertions(+), 21 deletions(-)

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 869372a..fa28e3e 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -363,20 +363,20 @@ static unsigned long __meminit
 phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
 	      pgprot_t prot)
 {
-	unsigned pages = 0;
+	unsigned long pages = 0, next;
 	unsigned long last_map_addr = end;
 	int i;
 
 	pte_t *pte = pte_page + pte_index(addr);
 
-	for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) {
-
+	for (i = pte_index(addr); i < PTRS_PER_PTE; i++, addr = next, pte++) {
+		next = (addr & PAGE_MASK) + PAGE_SIZE;
 		if (addr >= end) {
-			if (!after_bootmem) {
-				for(; i < PTRS_PER_PTE; i++, pte++)
-					set_pte(pte, __pte(0));
-			}
-			break;
+			if (!after_bootmem &&
+			    !e820_any_mapped(addr & PAGE_MASK, next, E820_RAM) &&
+			    !e820_any_mapped(addr & PAGE_MASK, next, E820_RESERVED_KERN))
+				set_pte(pte, __pte(0));
+			continue;
 		}
 
 		/*
@@ -419,16 +419,15 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
 		pte_t *pte;
 		pgprot_t new_prot = prot;
 
+		next = (address & PMD_MASK) + PMD_SIZE;
 		if (address >= end) {
-			if (!after_bootmem) {
-				for (; i < PTRS_PER_PMD; i++, pmd++)
-					set_pmd(pmd, __pmd(0));
-			}
-			break;
+			if (!after_bootmem &&
+			    !e820_any_mapped(address & PMD_MASK, next, E820_RAM) &&
+			    !e820_any_mapped(address & PMD_MASK, next, E820_RESERVED_KERN))
+				set_pmd(pmd, __pmd(0));
+			continue;
 		}
 
-		next = (address & PMD_MASK) + PMD_SIZE;
-
 		if (pmd_val(*pmd)) {
 			if (!pmd_large(*pmd)) {
 				spin_lock(&init_mm.page_table_lock);
@@ -497,13 +496,12 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
 		pmd_t *pmd;
 		pgprot_t prot = PAGE_KERNEL;
 
-		if (addr >= end)
-			break;
-
 		next = (addr & PUD_MASK) + PUD_SIZE;
-
-		if (!after_bootmem && !e820_any_mapped(addr, next, 0)) {
-			set_pud(pud, __pud(0));
+		if (addr >= end) {
+			if (!after_bootmem &&
+			    !e820_any_mapped(addr & PUD_MASK, next, E820_RAM) &&
+			    !e820_any_mapped(addr & PUD_MASK, next, E820_RESERVED_KERN))
+				set_pud(pud, __pud(0));
 			continue;
 		}
 
-- 
1.7.7


  parent reply index

Thread overview: 119+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-17  3:38 [PATCH v8 00/46] x86, mm: map ram from top-down with BRK and memblock Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 01/46] x86, mm: Add global page_size_mask and probe one time only Yinghai Lu
2012-11-22  1:38   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 02/46] x86, mm: Split out split_mem_range from init_memory_mapping Yinghai Lu
2012-11-22  1:39   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 03/46] x86, mm: Move down find_early_table_space() Yinghai Lu
2012-11-22  1:40   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 16:50   ` [PATCH v8 03/46] " Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 04/46] x86, mm: Move init_memory_mapping calling out of setup.c Yinghai Lu
2012-11-22  1:41   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 16:50   ` [PATCH v8 04/46] " Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 05/46] x86, mm: Revert back good_end setting for 64bit Yinghai Lu
2012-11-22  1:42   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 06/46] x86, mm: Change find_early_table_space() paramters Yinghai Lu
2012-11-22  1:43   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 16:50   ` [PATCH v8 06/46] " Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 07/46] x86, mm: Find early page table buffer together Yinghai Lu
2012-11-22  1:44   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 16:50   ` [PATCH v8 07/46] " Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 08/46] x86, mm: Separate out calculate_table_space_size() Yinghai Lu
2012-11-22  1:45   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 16:59   ` [PATCH v8 08/46] " Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 09/46] x86, mm: Set memblock initial limit to 1M Yinghai Lu
2012-11-22  1:46   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 10/46] x86, mm: if kernel .text .data .bss are not marked as E820_RAM, complain and fix Yinghai Lu
2012-11-22  1:47   ` [tip:x86/mm2] " tip-bot for Jacob Shin
2012-11-17  3:38 ` [PATCH v8 11/46] x86, mm: Fixup code testing if a pfn is direct mapped Yinghai Lu
2012-11-22  1:48   ` [tip:x86/mm2] " tip-bot for Jacob Shin
2012-11-17  3:38 ` [PATCH v8 12/46] x86, mm: use pfn_range_is_mapped() with CPA Yinghai Lu
2012-11-22  1:49   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 17:06   ` [PATCH v8 12/46] " Konrad Rzeszutek Wilk
2012-11-28 19:33     ` Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 13/46] x86, mm: use pfn_range_is_mapped() with gart Yinghai Lu
2012-11-22  1:50   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 17:07   ` [PATCH v8 13/46] " Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 14/46] x86, mm: use pfn_range_is_mapped() with reserve_initrd Yinghai Lu
2012-11-22  1:51   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 17:08   ` [PATCH v8 14/46] " Konrad Rzeszutek Wilk
2012-11-28 19:40     ` Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 15/46] x86, mm: Only direct map addresses that are marked as E820_RAM Yinghai Lu
2012-11-22  1:53   ` [tip:x86/mm2] " tip-bot for Jacob Shin
2012-11-28 17:15   ` [PATCH v8 15/46] " Konrad Rzeszutek Wilk
2012-11-28 19:43     ` Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 16/46] x86, mm: relocate initrd under all mem for 64bit Yinghai Lu
2012-11-22  1:54   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 17/46] x86, mm: Align start address to correct big page size Yinghai Lu
2012-11-22  1:55   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 18/46] x86, mm: Use big page size for small memory range Yinghai Lu
2012-11-22  1:56   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` Yinghai Lu [this message]
2012-11-22  1:57   ` [tip:x86/mm2] x86, mm: Don't clear page table if range is ram tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 20/46] x86, mm: Break down init_all_memory_mapping Yinghai Lu
2012-11-22  1:58   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:38 ` [PATCH v8 21/46] x86, mm: setup page table in top-down Yinghai Lu
2012-11-22  1:59   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 17:50   ` [PATCH v8 21/46] " Konrad Rzeszutek Wilk
2012-11-28 20:16     ` Yinghai Lu
2012-12-05 21:53       ` Konrad Rzeszutek Wilk
2012-11-17  3:38 ` [PATCH v8 22/46] x86, mm: Remove early_memremap workaround for page table accessing on 64bit Yinghai Lu
2012-11-22  2:00   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 18:57   ` [PATCH v8 22/46] " Konrad Rzeszutek Wilk
2012-11-17  3:39 ` [PATCH v8 23/46] x86, mm: Remove parameter in alloc_low_page for 64bit Yinghai Lu
2012-11-22  2:01   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 18:57   ` [PATCH v8 23/46] " Konrad Rzeszutek Wilk
2012-11-17  3:39 ` [PATCH v8 24/46] x86, mm: Merge alloc_low_page between 64bit and 32bit Yinghai Lu
2012-11-22  2:02   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 25/46] x86, mm: Move min_pfn_mapped back to mm/init.c Yinghai Lu
2012-11-22  2:03   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 26/46] x86, mm, Xen: Remove mapping_pagetable_reserve() Yinghai Lu
2012-11-22  2:04   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 27/46] x86, mm: Add alloc_low_pages(num) Yinghai Lu
2012-11-22  2:05   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 28/46] x86, mm: Add pointer about Xen mmu requirement for alloc_low_pages Yinghai Lu
2012-11-22  2:06   ` [tip:x86/mm2] " tip-bot for Stefano Stabellini
2012-11-17  3:39 ` [PATCH v8 29/46] x86, mm: only call early_ioremap_page_table_range_init() once Yinghai Lu
2012-11-22  2:07   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 19:02   ` [PATCH v8 29/46] " Konrad Rzeszutek Wilk
2012-11-17  3:39 ` [PATCH v8 30/46] x86, mm: Move back pgt_buf_* to mm/init.c Yinghai Lu
2012-11-22  2:08   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 31/46] x86, mm: Move init_gbpages() out of setup.c Yinghai Lu
2012-11-22  2:09   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 32/46] x86, mm: change low/hignmem_pfn_init to static on 32bit Yinghai Lu
2012-11-22  2:10   ` [tip:x86/mm2] x86, mm: change low/ hignmem_pfn_init " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 33/46] x86, mm: Move function declaration into mm_internal.h Yinghai Lu
2012-11-22  2:11   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 34/46] x86, mm: Add check before clear pte above max_low_pfn on 32bit Yinghai Lu
2012-11-22  2:13   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 19:09   ` [PATCH v8 34/46] " Konrad Rzeszutek Wilk
2012-11-28 20:38     ` Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 35/46] x86, mm: use round_up/down in split_mem_range() Yinghai Lu
2012-11-22  2:14   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 36/46] x86, mm: use PFN_DOWN " Yinghai Lu
2012-11-22  2:15   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 37/46] x86, mm: use pfn instead of pos in split_mem_range Yinghai Lu
2012-11-22  2:16   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 38/46] x86, mm: use limit_pfn for end pfn Yinghai Lu
2012-11-22  2:17   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 39/46] x86, mm: Unifying after_bootmem for 32bit and 64bit Yinghai Lu
2012-11-22  2:18   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 40/46] x86, mm: Move after_bootmem to mm_internel.h Yinghai Lu
2012-11-22  2:19   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 41/46] x86, mm: Use clamp_t() in init_range_memory_mapping Yinghai Lu
2012-11-22  2:20   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 42/46] x86, mm: kill numa_free_all_bootmem() Yinghai Lu
2012-11-22  2:21   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 43/46] x86, mm: kill numa_64.h Yinghai Lu
2012-11-22  2:22   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 44/46] sparc, mm: Remove calling of free_all_bootmem_node() Yinghai Lu
2012-11-22  2:23   ` [tip:x86/mm2] sparc, mm: Remove calling of free_all_bootmem_node( ) tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 45/46] mm: Kill NO_BOOTMEM version free_all_bootmem_node() Yinghai Lu
2012-11-22  2:24   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-17  3:39 ` [PATCH v8 46/46] x86, mm: Let "memmap=" take more entries one time Yinghai Lu
2012-11-22  2:25   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2012-11-28 19:12   ` [PATCH v8 46/46] " Konrad Rzeszutek Wilk
2012-11-27 21:17 ` [PATCH v8 00/46] x86, mm: map ram from top-down with BRK and memblock Konrad Rzeszutek Wilk
2012-11-28 19:35   ` Konrad Rzeszutek Wilk
2012-11-28 19:47     ` Yinghai Lu
2012-11-28 20:57       ` Konrad Rzeszutek Wilk
2012-11-28 21:06         ` Yinghai Lu

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