Commit d6ee09a2 authored by Ingo Molnar's avatar Ingo Molnar

x86: simplify pageattr_64.c

simplify pageattr_64.c.
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent a5f55035
......@@ -9,6 +9,14 @@
#include <linux/slab.h>
#include <linux/mm.h>
void clflush_cache_range(void *addr, int size)
{
int i;
for (i = 0; i < size; i += boot_cpu_data.x86_clflush_size)
clflush(addr+i);
}
#include <asm/processor.h>
#include <asm/tlbflush.h>
#include <asm/uaccess.h>
......@@ -47,12 +55,6 @@ split_large_page(unsigned long address, pgprot_t prot, pgprot_t ref_prot)
base = alloc_pages(GFP_KERNEL, 0);
if (!base)
return NULL;
/*
* page_private is used to track the number of entries in
* the page table page have non standard attributes.
*/
SetPagePrivate(base);
page_private(base) = 0;
address = __pa(address);
addr = address & LARGE_PAGE_MASK;
......@@ -64,80 +66,13 @@ split_large_page(unsigned long address, pgprot_t prot, pgprot_t ref_prot)
return base;
}
void clflush_cache_range(void *addr, int size)
{
int i;
for (i = 0; i < size; i += boot_cpu_data.x86_clflush_size)
clflush(addr+i);
}
static void flush_kernel_map(void *arg)
{
struct list_head *l = (struct list_head *)arg;
struct page *pg;
__flush_tlb_all();
/* When clflush is available always use it because it is
much cheaper than WBINVD. */
/* clflush is still broken. Disable for now. */
if (1 || !cpu_has_clflush) {
wbinvd();
} else {
list_for_each_entry(pg, l, lru) {
void *addr = page_address(pg);
clflush_cache_range(addr, PAGE_SIZE);
}
}
}
static inline void flush_map(struct list_head *l)
{
on_each_cpu(flush_kernel_map, l, 1, 1);
}
static LIST_HEAD(deferred_pages); /* protected by init_mm.mmap_sem */
static inline void save_page(struct page *fpage)
{
if (!test_and_set_bit(PG_arch_1, &fpage->flags))
list_add(&fpage->lru, &deferred_pages);
}
/*
* No more special protections in this 2/4MB area - revert to a
* large page again.
*/
static void revert_page(unsigned long address, pgprot_t ref_prot)
{
unsigned long pfn;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t large_pte;
pgd = pgd_offset_k(address);
BUG_ON(pgd_none(*pgd));
pud = pud_offset(pgd, address);
BUG_ON(pud_none(*pud));
pmd = pmd_offset(pud, address);
BUG_ON(pmd_val(*pmd) & _PAGE_PSE);
pfn = (__pa(address) & LARGE_PAGE_MASK) >> PAGE_SHIFT;
large_pte = pfn_pte(pfn, ref_prot);
large_pte = pte_mkhuge(large_pte);
set_pte((pte_t *)pmd, large_pte);
}
static int
__change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
pgprot_t ref_prot)
{
struct page *kpte_page;
pgprot_t ref_prot2;
pte_t *kpte;
pgprot_t ref_prot2, oldprot;
int level;
kpte = lookup_address(address, &level);
......@@ -145,8 +80,12 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
return 0;
kpte_page = virt_to_page(kpte);
oldprot = pte_pgprot(*kpte);
BUG_ON(PageLRU(kpte_page));
BUG_ON(PageCompound(kpte_page));
ref_prot = canon_pgprot(ref_prot);
prot = canon_pgprot(prot);
if (pgprot_val(prot) != pgprot_val(ref_prot)) {
if (level == 4) {
set_pte(kpte, pfn_pte(pfn, prot));
......@@ -165,38 +104,29 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
set_pte(kpte, mk_pte(split, ref_prot2));
kpte_page = split;
}
page_private(kpte_page)++;
} else {
if (level == 4) {
set_pte(kpte, pfn_pte(pfn, ref_prot));
BUG_ON(page_private(kpte_page) == 0);
page_private(kpte_page)--;
} else
BUG();
}
/* on x86-64 the direct mapping set at boot is not using 4k pages */
BUG_ON(PageReserved(kpte_page));
save_page(kpte_page);
if (page_private(kpte_page) == 0)
revert_page(address, ref_prot);
return 0;
}
/*
* Change the page attributes of an page in the linear mapping.
*
* This should be used when a page is mapped with a different caching policy
* than write-back somewhere - some CPUs do not like it when mappings with
* different caching policies exist. This changes the page attributes of the
* in kernel linear mapping too.
/**
* change_page_attr_addr - Change page table attributes in linear mapping
* @address: Virtual address in linear mapping.
* @numpages: Number of pages to change
* @prot: New page table attribute (PAGE_*)
*
* The caller needs to ensure that there are no conflicting mappings elsewhere.
* This function only deals with the kernel linear map.
* Change page attributes of a page in the direct mapping. This is a variant
* of change_page_attr() that also works on memory holes that do not have
* mem_map entry (pfn_valid() is false).
*
* Caller must call global_flush_tlb() after this.
* See change_page_attr() documentation for more details.
*/
int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
{
int err = 0, kernel_map = 0, i;
......@@ -236,7 +166,26 @@ int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
return err;
}
/* Don't call this for MMIO areas that may not have a mem_map entry */
/**
* change_page_attr - Change page table attributes in the linear mapping.
* @page: First page to change
* @numpages: Number of pages to change
* @prot: New protection/caching type (PAGE_*)
*
* Returns 0 on success, otherwise a negated errno.
*
* This should be used when a page is mapped with a different caching policy
* than write-back somewhere - some CPUs do not like it when mappings with
* different caching policies exist. This changes the page attributes of the
* in kernel linear mapping too.
*
* Caller must call global_flush_tlb() later to make the changes active.
*
* The caller needs to ensure that there are no conflicting mappings elsewhere
* (e.g. in user space) * This function only deals with the kernel linear map.
*
* For MMIO areas without mem_map use change_page_attr_addr() instead.
*/
int change_page_attr(struct page *page, int numpages, pgprot_t prot)
{
unsigned long addr = (unsigned long)page_address(page);
......@@ -245,29 +194,22 @@ int change_page_attr(struct page *page, int numpages, pgprot_t prot)
}
EXPORT_SYMBOL(change_page_attr);
void global_flush_tlb(void)
static void flush_kernel_map(void *arg)
{
struct page *pg, *next;
struct list_head l;
/*
* Write-protect the semaphore, to exclude two contexts
* doing a list_replace_init() call in parallel and to
* exclude new additions to the deferred_pages list:
* Flush all to work around Errata in early athlons regarding
* large page flushing.
*/
down_write(&init_mm.mmap_sem);
list_replace_init(&deferred_pages, &l);
up_write(&init_mm.mmap_sem);
__flush_tlb_all();
flush_map(&l);
if (boot_cpu_data.x86_model >= 4)
wbinvd();
}
list_for_each_entry_safe(pg, next, &l, lru) {
list_del(&pg->lru);
clear_bit(PG_arch_1, &pg->flags);
if (page_private(pg) != 0)
continue;
ClearPagePrivate(pg);
__free_page(pg);
}
void global_flush_tlb(void)
{
BUG_ON(irqs_disabled());
on_each_cpu(flush_kernel_map, NULL, 1, 1);
}
EXPORT_SYMBOL(global_flush_tlb);
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