提交 b4416a1b 编写于 作者: I Ingo Molnar

x86: clean up arch/x86/mm/pageattr_64.c

clean up arch/x86/mm/pageattr_64.c.

no code changed:

   text    data     bss     dec     hex filename
   1751      16       0    1767     6e7 pageattr_64.o.before
   1751      16       0    1767     6e7 pageattr_64.o.after
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
上级 9f4c815c
/* /*
* Copyright 2002 Andi Kleen, SuSE Labs. * Copyright 2002 Andi Kleen, SuSE Labs.
* Thanks to Ben LaHaise for precious feedback. * Thanks to Ben LaHaise for precious feedback.
*/ */
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/highmem.h> #include <linux/highmem.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h> #include <linux/slab.h>
#include <asm/uaccess.h> #include <linux/mm.h>
#include <asm/processor.h> #include <asm/processor.h>
#include <asm/tlbflush.h> #include <asm/tlbflush.h>
#include <asm/uaccess.h>
#include <asm/io.h> #include <asm/io.h>
pte_t *lookup_address(unsigned long address) pte_t *lookup_address(unsigned long address)
{ {
pgd_t *pgd = pgd_offset_k(address); pgd_t *pgd = pgd_offset_k(address);
pud_t *pud; pud_t *pud;
pmd_t *pmd; pmd_t *pmd;
pte_t *pte; pte_t *pte;
if (pgd_none(*pgd)) if (pgd_none(*pgd))
return NULL; return NULL;
pud = pud_offset(pgd, address); pud = pud_offset(pgd, address);
if (!pud_present(*pud)) if (!pud_present(*pud))
return NULL; return NULL;
pmd = pmd_offset(pud, address); pmd = pmd_offset(pud, address);
if (!pmd_present(*pmd)) if (!pmd_present(*pmd))
return NULL; return NULL;
if (pmd_large(*pmd)) if (pmd_large(*pmd))
return (pte_t *)pmd; return (pte_t *)pmd;
pte = pte_offset_kernel(pmd, address); pte = pte_offset_kernel(pmd, address);
if (pte && !pte_present(*pte)) if (pte && !pte_present(*pte))
pte = NULL; pte = NULL;
return pte; return pte;
} }
static struct page *split_large_page(unsigned long address, pgprot_t prot, static struct page *
pgprot_t ref_prot) split_large_page(unsigned long address, pgprot_t prot, pgprot_t ref_prot)
{ {
int i;
unsigned long addr; unsigned long addr;
struct page *base = alloc_pages(GFP_KERNEL, 0); struct page *base;
pte_t *pbase; pte_t *pbase;
if (!base) int i;
base = alloc_pages(GFP_KERNEL, 0);
if (!base)
return NULL; return NULL;
/* /*
* page_private is used to track the number of entries in * page_private is used to track the number of entries in
...@@ -52,20 +58,21 @@ static struct page *split_large_page(unsigned long address, pgprot_t prot, ...@@ -52,20 +58,21 @@ static struct page *split_large_page(unsigned long address, pgprot_t prot,
page_private(base) = 0; page_private(base) = 0;
address = __pa(address); address = __pa(address);
addr = address & LARGE_PAGE_MASK; addr = address & LARGE_PAGE_MASK;
pbase = (pte_t *)page_address(base); pbase = (pte_t *)page_address(base);
for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) { for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) {
pbase[i] = pfn_pte(addr >> PAGE_SHIFT, pbase[i] = pfn_pte(addr >> PAGE_SHIFT,
addr == address ? prot : ref_prot); addr == address ? prot : ref_prot);
} }
return base; return base;
} }
void clflush_cache_range(void *adr, int size) void clflush_cache_range(void *addr, int size)
{ {
int i; int i;
for (i = 0; i < size; i += boot_cpu_data.x86_clflush_size) for (i = 0; i < size; i += boot_cpu_data.x86_clflush_size)
clflush(adr+i); clflush(addr+i);
} }
static void flush_kernel_map(void *arg) static void flush_kernel_map(void *arg)
...@@ -76,17 +83,20 @@ static void flush_kernel_map(void *arg) ...@@ -76,17 +83,20 @@ static void flush_kernel_map(void *arg)
/* When clflush is available always use it because it is /* When clflush is available always use it because it is
much cheaper than WBINVD. */ much cheaper than WBINVD. */
/* clflush is still broken. Disable for now. */ /* clflush is still broken. Disable for now. */
if (1 || !cpu_has_clflush) if (1 || !cpu_has_clflush) {
asm volatile("wbinvd" ::: "memory"); asm volatile("wbinvd" ::: "memory");
else list_for_each_entry(pg, l, lru) { } else {
void *adr = page_address(pg); list_for_each_entry(pg, l, lru) {
clflush_cache_range(adr, PAGE_SIZE); void *addr = page_address(pg);
clflush_cache_range(addr, PAGE_SIZE);
}
} }
__flush_tlb_all(); __flush_tlb_all();
} }
static inline void flush_map(struct list_head *l) static inline void flush_map(struct list_head *l)
{ {
on_each_cpu(flush_kernel_map, l, 1, 1); on_each_cpu(flush_kernel_map, l, 1, 1);
} }
...@@ -98,52 +108,56 @@ static inline void save_page(struct page *fpage) ...@@ -98,52 +108,56 @@ static inline void save_page(struct page *fpage)
list_add(&fpage->lru, &deferred_pages); list_add(&fpage->lru, &deferred_pages);
} }
/* /*
* No more special protections in this 2/4MB area - revert to a * No more special protections in this 2/4MB area - revert to a
* large page again. * large page again.
*/ */
static void revert_page(unsigned long address, pgprot_t ref_prot) static void revert_page(unsigned long address, pgprot_t ref_prot)
{ {
unsigned long pfn;
pgd_t *pgd; pgd_t *pgd;
pud_t *pud; pud_t *pud;
pmd_t *pmd; pmd_t *pmd;
pte_t large_pte; pte_t large_pte;
unsigned long pfn;
pgd = pgd_offset_k(address); pgd = pgd_offset_k(address);
BUG_ON(pgd_none(*pgd)); BUG_ON(pgd_none(*pgd));
pud = pud_offset(pgd,address); pud = pud_offset(pgd, address);
BUG_ON(pud_none(*pud)); BUG_ON(pud_none(*pud));
pmd = pmd_offset(pud, address); pmd = pmd_offset(pud, address);
BUG_ON(pmd_val(*pmd) & _PAGE_PSE); BUG_ON(pmd_val(*pmd) & _PAGE_PSE);
pfn = (__pa(address) & LARGE_PAGE_MASK) >> PAGE_SHIFT; pfn = (__pa(address) & LARGE_PAGE_MASK) >> PAGE_SHIFT;
large_pte = pfn_pte(pfn, ref_prot); large_pte = pfn_pte(pfn, ref_prot);
large_pte = pte_mkhuge(large_pte); large_pte = pte_mkhuge(large_pte);
set_pte((pte_t *)pmd, large_pte); set_pte((pte_t *)pmd, large_pte);
} }
static int static int
__change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot, __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
pgprot_t ref_prot) pgprot_t ref_prot)
{ {
pte_t *kpte;
struct page *kpte_page; struct page *kpte_page;
pgprot_t ref_prot2; pgprot_t ref_prot2;
pte_t *kpte;
kpte = lookup_address(address); kpte = lookup_address(address);
if (!kpte) return 0; if (!kpte)
return 0;
kpte_page = virt_to_page(((unsigned long)kpte) & PAGE_MASK); kpte_page = virt_to_page(((unsigned long)kpte) & PAGE_MASK);
BUG_ON(PageLRU(kpte_page)); BUG_ON(PageLRU(kpte_page));
BUG_ON(PageCompound(kpte_page)); BUG_ON(PageCompound(kpte_page));
if (pgprot_val(prot) != pgprot_val(ref_prot)) { if (pgprot_val(prot) != pgprot_val(ref_prot)) {
if (!pte_huge(*kpte)) { if (!pte_huge(*kpte)) {
set_pte(kpte, pfn_pte(pfn, prot)); set_pte(kpte, pfn_pte(pfn, prot));
} else { } else {
/* /*
* split_large_page will take the reference for this * split_large_page will take the reference for this
* change_page_attr on the split page. * change_page_attr on the split page.
*/ */
struct page *split; struct page *split;
ref_prot2 = pte_pgprot(pte_clrhuge(*kpte)); ref_prot2 = pte_pgprot(pte_clrhuge(*kpte));
split = split_large_page(address, prot, ref_prot2); split = split_large_page(address, prot, ref_prot2);
if (!split) if (!split)
...@@ -153,21 +167,23 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot, ...@@ -153,21 +167,23 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
kpte_page = split; kpte_page = split;
} }
page_private(kpte_page)++; page_private(kpte_page)++;
} else if (!pte_huge(*kpte)) { } else {
set_pte(kpte, pfn_pte(pfn, ref_prot)); if (!pte_huge(*kpte)) {
BUG_ON(page_private(kpte_page) == 0); set_pte(kpte, pfn_pte(pfn, ref_prot));
page_private(kpte_page)--; BUG_ON(page_private(kpte_page) == 0);
} else page_private(kpte_page)--;
BUG(); } else
BUG();
}
/* on x86-64 the direct mapping set at boot is not using 4k pages */ /* on x86-64 the direct mapping set at boot is not using 4k pages */
BUG_ON(PageReserved(kpte_page)); BUG_ON(PageReserved(kpte_page));
save_page(kpte_page); save_page(kpte_page);
if (page_private(kpte_page) == 0) if (page_private(kpte_page) == 0)
revert_page(address, ref_prot); revert_page(address, ref_prot);
return 0; return 0;
} }
/* /*
* Change the page attributes of an page in the linear mapping. * Change the page attributes of an page in the linear mapping.
...@@ -176,19 +192,19 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot, ...@@ -176,19 +192,19 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
* than write-back somewhere - some CPUs do not like it when mappings with * than write-back somewhere - some CPUs do not like it when mappings with
* different caching policies exist. This changes the page attributes of the * different caching policies exist. This changes the page attributes of the
* in kernel linear mapping too. * in kernel linear mapping too.
* *
* The caller needs to ensure that there are no conflicting mappings elsewhere. * The caller needs to ensure that there are no conflicting mappings elsewhere.
* This function only deals with the kernel linear map. * This function only deals with the kernel linear map.
* *
* Caller must call global_flush_tlb() after this. * Caller must call global_flush_tlb() after this.
*/ */
int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot) int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
{ {
int err = 0, kernel_map = 0; int err = 0, kernel_map = 0, i;
int i;
if (address >= __START_KERNEL_map &&
address < __START_KERNEL_map + KERNEL_TEXT_SIZE) {
if (address >= __START_KERNEL_map
&& address < __START_KERNEL_map + KERNEL_TEXT_SIZE) {
address = (unsigned long)__va(__pa(address)); address = (unsigned long)__va(__pa(address));
kernel_map = 1; kernel_map = 1;
} }
...@@ -198,7 +214,8 @@ int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot) ...@@ -198,7 +214,8 @@ int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
unsigned long pfn = __pa(address) >> PAGE_SHIFT; unsigned long pfn = __pa(address) >> PAGE_SHIFT;
if (!kernel_map || pte_present(pfn_pte(0, prot))) { if (!kernel_map || pte_present(pfn_pte(0, prot))) {
err = __change_page_attr(address, pfn, prot, PAGE_KERNEL); err = __change_page_attr(address, pfn, prot,
PAGE_KERNEL);
if (err) if (err)
break; break;
} }
...@@ -207,14 +224,16 @@ int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot) ...@@ -207,14 +224,16 @@ int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
if (__pa(address) < KERNEL_TEXT_SIZE) { if (__pa(address) < KERNEL_TEXT_SIZE) {
unsigned long addr2; unsigned long addr2;
pgprot_t prot2; pgprot_t prot2;
addr2 = __START_KERNEL_map + __pa(address); addr2 = __START_KERNEL_map + __pa(address);
/* Make sure the kernel mappings stay executable */ /* Make sure the kernel mappings stay executable */
prot2 = pte_pgprot(pte_mkexec(pfn_pte(0, prot))); prot2 = pte_pgprot(pte_mkexec(pfn_pte(0, prot)));
err = __change_page_attr(addr2, pfn, prot2, err = __change_page_attr(addr2, pfn, prot2,
PAGE_KERNEL_EXEC); PAGE_KERNEL_EXEC);
} }
} }
up_write(&init_mm.mmap_sem); up_write(&init_mm.mmap_sem);
return err; return err;
} }
...@@ -222,11 +241,13 @@ int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot) ...@@ -222,11 +241,13 @@ int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
int change_page_attr(struct page *page, int numpages, pgprot_t prot) int change_page_attr(struct page *page, int numpages, pgprot_t prot)
{ {
unsigned long addr = (unsigned long)page_address(page); unsigned long addr = (unsigned long)page_address(page);
return change_page_attr_addr(addr, numpages, prot); return change_page_attr_addr(addr, numpages, prot);
} }
EXPORT_SYMBOL(change_page_attr);
void global_flush_tlb(void) void global_flush_tlb(void)
{ {
struct page *pg, *next; struct page *pg, *next;
struct list_head l; struct list_head l;
...@@ -248,8 +269,6 @@ void global_flush_tlb(void) ...@@ -248,8 +269,6 @@ void global_flush_tlb(void)
continue; continue;
ClearPagePrivate(pg); ClearPagePrivate(pg);
__free_page(pg); __free_page(pg);
} }
} }
EXPORT_SYMBOL(change_page_attr);
EXPORT_SYMBOL(global_flush_tlb); EXPORT_SYMBOL(global_flush_tlb);
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