[PATCH 7/10] hot-add-mem x86_64: x86_64 kernel mapping fix

From: Keith Mannthey
Date: Fri Aug 04 2006 - 09:14:14 EST


From: Keith Mannthey <kmannth@xxxxxxxxxx>

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@xxxxxxxxxx>
---
init.c | 51 ++++++++++++++++++++++++++-------------------------
1 files changed, 26 insertions(+), 25 deletions(-)

diff -urN linux-2.6.17-stock/arch/x86_64/mm/init.c linux-2.6.17/arch/x86_64/mm/init.c
--- linux-2.6.17-stock/arch/x86_64/mm/init.c 2006-08-04 08:01:57.000000000 -0400
+++ linux-2.6.17/arch/x86_64/mm/init.c 2006-08-04 08:01:01.000000000 -0400
@@ -250,12 +250,13 @@
}

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 @@
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 @@
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);
+ int i = pud_index(addr);

- pud = pud + i;

- 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);
}
-
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