forked from luck/tmp_suning_uos_patched
ea7322decb
CLFLUSH is a lot faster than WBINVD so avoid the later if at all possible. Always pass the complete list of pages to other CPUs to cut down the number of IPIs. Minor other cleanup and sync with i386 version. Signed-off-by: Andi Kleen <ak@suse.de>
233 lines
5.8 KiB
C
233 lines
5.8 KiB
C
/*
|
|
* Copyright 2002 Andi Kleen, SuSE Labs.
|
|
* Thanks to Ben LaHaise for precious feedback.
|
|
*/
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/highmem.h>
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/io.h>
|
|
|
|
static inline pte_t *lookup_address(unsigned long address)
|
|
{
|
|
pgd_t *pgd = pgd_offset_k(address);
|
|
pud_t *pud;
|
|
pmd_t *pmd;
|
|
pte_t *pte;
|
|
if (pgd_none(*pgd))
|
|
return NULL;
|
|
pud = pud_offset(pgd, address);
|
|
if (!pud_present(*pud))
|
|
return NULL;
|
|
pmd = pmd_offset(pud, address);
|
|
if (!pmd_present(*pmd))
|
|
return NULL;
|
|
if (pmd_large(*pmd))
|
|
return (pte_t *)pmd;
|
|
pte = pte_offset_kernel(pmd, address);
|
|
if (pte && !pte_present(*pte))
|
|
pte = NULL;
|
|
return pte;
|
|
}
|
|
|
|
static struct page *split_large_page(unsigned long address, pgprot_t prot,
|
|
pgprot_t ref_prot)
|
|
{
|
|
int i;
|
|
unsigned long addr;
|
|
struct page *base = alloc_pages(GFP_KERNEL, 0);
|
|
pte_t *pbase;
|
|
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;
|
|
pbase = (pte_t *)page_address(base);
|
|
for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) {
|
|
pbase[i] = pfn_pte(addr >> PAGE_SHIFT,
|
|
addr == address ? prot : ref_prot);
|
|
}
|
|
return base;
|
|
}
|
|
|
|
static void cache_flush_page(void *adr)
|
|
{
|
|
int i;
|
|
for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
|
|
asm volatile("clflush (%0)" :: "r" (adr + i));
|
|
}
|
|
|
|
static void flush_kernel_map(void *arg)
|
|
{
|
|
struct list_head *l = (struct list_head *)arg;
|
|
struct page *pg;
|
|
|
|
/* When clflush is available always use it because it is
|
|
much cheaper than WBINVD */
|
|
if (!cpu_has_clflush)
|
|
asm volatile("wbinvd" ::: "memory");
|
|
list_for_each_entry(pg, l, lru) {
|
|
void *adr = page_address(pg);
|
|
if (cpu_has_clflush)
|
|
cache_flush_page(adr);
|
|
__flush_tlb_one(adr);
|
|
}
|
|
}
|
|
|
|
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)
|
|
{
|
|
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)
|
|
{
|
|
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);
|
|
large_pte = mk_pte_phys(__pa(address) & LARGE_PAGE_MASK, 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)
|
|
{
|
|
pte_t *kpte;
|
|
struct page *kpte_page;
|
|
pgprot_t ref_prot2;
|
|
kpte = lookup_address(address);
|
|
if (!kpte) return 0;
|
|
kpte_page = virt_to_page(((unsigned long)kpte) & PAGE_MASK);
|
|
if (pgprot_val(prot) != pgprot_val(ref_prot)) {
|
|
if (!pte_huge(*kpte)) {
|
|
set_pte(kpte, pfn_pte(pfn, prot));
|
|
} else {
|
|
/*
|
|
* split_large_page will take the reference for this
|
|
* change_page_attr on the split page.
|
|
*/
|
|
struct page *split;
|
|
ref_prot2 = pte_pgprot(pte_clrhuge(*kpte));
|
|
split = split_large_page(address, prot, ref_prot2);
|
|
if (!split)
|
|
return -ENOMEM;
|
|
set_pte(kpte, mk_pte(split, ref_prot2));
|
|
kpte_page = split;
|
|
}
|
|
page_private(kpte_page)++;
|
|
} else if (!pte_huge(*kpte)) {
|
|
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));
|
|
|
|
if (page_private(kpte_page) == 0) {
|
|
save_page(kpte_page);
|
|
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.
|
|
*
|
|
* The caller needs to ensure that there are no conflicting mappings elsewhere.
|
|
* This function only deals with the kernel linear map.
|
|
*
|
|
* Caller must call global_flush_tlb() after this.
|
|
*/
|
|
int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
|
|
{
|
|
int err = 0;
|
|
int i;
|
|
|
|
down_write(&init_mm.mmap_sem);
|
|
for (i = 0; i < numpages; i++, address += PAGE_SIZE) {
|
|
unsigned long pfn = __pa(address) >> PAGE_SHIFT;
|
|
|
|
err = __change_page_attr(address, pfn, prot, PAGE_KERNEL);
|
|
if (err)
|
|
break;
|
|
/* Handle kernel mapping too which aliases part of the
|
|
* lowmem */
|
|
if (__pa(address) < KERNEL_TEXT_SIZE) {
|
|
unsigned long addr2;
|
|
pgprot_t prot2;
|
|
addr2 = __START_KERNEL_map + __pa(address);
|
|
/* Make sure the kernel mappings stay executable */
|
|
prot2 = pte_pgprot(pte_mkexec(pfn_pte(0, prot)));
|
|
err = __change_page_attr(addr2, pfn, prot2,
|
|
PAGE_KERNEL_EXEC);
|
|
}
|
|
}
|
|
up_write(&init_mm.mmap_sem);
|
|
return err;
|
|
}
|
|
|
|
/* Don't call this for MMIO areas that may not have a mem_map entry */
|
|
int change_page_attr(struct page *page, int numpages, pgprot_t prot)
|
|
{
|
|
unsigned long addr = (unsigned long)page_address(page);
|
|
return change_page_attr_addr(addr, numpages, prot);
|
|
}
|
|
|
|
void global_flush_tlb(void)
|
|
{
|
|
struct page *pg, *next;
|
|
struct list_head l;
|
|
|
|
down_read(&init_mm.mmap_sem);
|
|
list_replace_init(&deferred_pages, &l);
|
|
up_read(&init_mm.mmap_sem);
|
|
|
|
flush_map(&l);
|
|
|
|
list_for_each_entry_safe(pg, next, &l, lru) {
|
|
ClearPagePrivate(pg);
|
|
__free_page(pg);
|
|
}
|
|
}
|
|
|
|
EXPORT_SYMBOL(change_page_attr);
|
|
EXPORT_SYMBOL(global_flush_tlb);
|