[PATCH] x86_64 kernel mapping fix

Fix for the x86_64 kernel mapping code.  Without this patch the update path
only inits one pmd_page worth of memory and tramples any entries on it.  now
the calling convention to phys_pmd_init and phys_init is to always pass a
[pmd/pud] page not an offset within a page.

Signed-off-by: Keith Mannthey<kmannth@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>

1 files changed, 26 insertions, 25 deletions

diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c
index d40134bd6399..984155b75e4c 100644
--- a/arch/x86_64/mm/init.c
+++ b/arch/x86_64/mm/init.c
@@ -250,12 +250,13 @@ __init void early_iounmap(void *addr, unsigned long size)
 }
 
 static void __meminit
-phys_pmd_init(pmd_t *pmd, unsigned long address, unsigned long end)
+phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
 {
-        int i;
+        int i = pmd_index(address);
 
-        for (i = 0; i < PTRS_PER_PMD; pmd++, i++, address += PMD_SIZE) {
+        for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
                 unsigned long entry;
+                pmd_t *pmd = pmd_page + pmd_index(address);
 
                 if (address >= end) {
                         if (!after_bootmem)
@@ -263,6 +264,10 @@ phys_pmd_init(pmd_t *pmd, unsigned long address, unsigned long end)
                                         set_pmd(pmd, __pmd(0));
                         break;
                 }
+
+                if (pmd_val(*pmd))
+                        continue;
+
                 entry = _PAGE_NX|_PAGE_PSE|_KERNPG_TABLE|_PAGE_GLOBAL|address;
                 entry &= __supported_pte_mask;
                 set_pmd(pmd, __pmd(entry));
@@ -272,45 +277,41 @@ phys_pmd_init(pmd_t *pmd, unsigned long address, unsigned long end)
 static void __meminit
 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
 {
-        pmd_t *pmd = pmd_offset(pud, (unsigned long)__va(address));
-
-        if (pmd_none(*pmd)) {
-                spin_lock(&init_mm.page_table_lock);
-                phys_pmd_init(pmd, address, end);
-                spin_unlock(&init_mm.page_table_lock);
-                __flush_tlb_all();
-        }
+        pmd_t *pmd = pmd_offset(pud,0);
+        spin_lock(&init_mm.page_table_lock);
+        phys_pmd_init(pmd, address, end);
+        spin_unlock(&init_mm.page_table_lock);
+        __flush_tlb_all();
 }
 
-static void __meminit phys_pud_init(pud_t *pud, unsigned long address, unsigned long end)
+static void __meminit phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
 { 
-        long i = pud_index(address);
-
-        pud = pud + i;
+        int i = pud_index(addr);
 
-        if (after_bootmem && pud_val(*pud)) {
-                phys_pmd_update(pud, address, end);
-                return;
-        }
 
-        for (; i < PTRS_PER_PUD; pud++, i++) {
+        for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE ) {
                 int map; 
-                unsigned long paddr, pmd_phys;
+                unsigned long pmd_phys;
+                pud_t *pud = pud_page + pud_index(addr);
                 pmd_t *pmd;
 
-                paddr = (address & PGDIR_MASK) + i*PUD_SIZE;
-                if (paddr >= end)
+                if (addr >= end)
                         break;
 
-                if (!after_bootmem && !e820_any_mapped(paddr, paddr+PUD_SIZE, 0)) {
+                if (!after_bootmem && !e820_any_mapped(addr,addr+PUD_SIZE,0)) {
                         set_pud(pud, __pud(0)); 
                         continue;
                 } 
 
+                if (pud_val(*pud)) {
+                        phys_pmd_update(pud, addr, end);
+                        continue;
+                }
+
                 pmd = alloc_low_page(&map, &pmd_phys);
                 spin_lock(&init_mm.page_table_lock);
                 set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
-                phys_pmd_init(pmd, paddr, end);
+                phys_pmd_init(pmd, addr, end);
                 spin_unlock(&init_mm.page_table_lock);
                 unmap_low_page(map);
         }