[PATCH 3/3] x86, mm: Remove early_memremap workaround for page table accessing

From: Yinghai Lu
Date: Sat Oct 06 2012 - 03:45:21 EST


Not needed anymore after premaping page table buf and not clear initial page
table wrongly.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
arch/x86/mm/init_64.c | 38 ++++----------------------------------
1 files changed, 4 insertions(+), 34 deletions(-)

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 0348a02..e59c94f 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -333,36 +333,12 @@ static __ref void *alloc_low_page(unsigned long *phys)
else
panic("alloc_low_page: ran out of memory");

- adr = early_memremap(pfn * PAGE_SIZE, PAGE_SIZE);
+ adr = __va(pfn * PAGE_SIZE);
clear_page(adr);
*phys = pfn * PAGE_SIZE;
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((void *)((unsigned long)adr & PAGE_MASK), PAGE_SIZE);
-}
-
static unsigned long __meminit
phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end,
pgprot_t prot)
@@ -435,10 +411,9 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
if (pmd_val(*pmd)) {
if (!pmd_large(*pmd)) {
spin_lock(&init_mm.page_table_lock);
- pte = map_low_page((pte_t *)pmd_page_vaddr(*pmd));
+ pte = (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;
}
@@ -474,7 +449,6 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,

pte = alloc_low_page(&pte_phys);
last_map_addr = phys_pte_init(pte, address, end, new_prot);
- unmap_low_page(pte);

spin_lock(&init_mm.page_table_lock);
pmd_populate_kernel(&init_mm, pmd, __va(pte_phys));
@@ -509,10 +483,9 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,

if (pud_val(*pud)) {
if (!pud_large(*pud)) {
- pmd = map_low_page(pmd_offset(pud, 0));
+ pmd = 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;
}
@@ -548,7 +521,6 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
pmd = alloc_low_page(&pmd_phys);
last_map_addr = phys_pmd_init(pmd, addr, end, page_size_mask,
prot);
- unmap_low_page(pmd);

spin_lock(&init_mm.page_table_lock);
pud_populate(&init_mm, pud, __va(pmd_phys));
@@ -584,17 +556,15 @@ kernel_physical_mapping_init(unsigned long start,
next = end;

if (pgd_val(*pgd)) {
- pud = map_low_page((pud_t *)pgd_page_vaddr(*pgd));
+ pud = (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;
}

pud = alloc_low_page(&pud_phys);
last_map_addr = phys_pud_init(pud, __pa(start), __pa(next),
page_size_mask);
- unmap_low_page(pud);

spin_lock(&init_mm.page_table_lock);
pgd_populate(&init_mm, pgd, __va(pud_phys));
--
1.7.7

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