279 lines
6.8 KiB
C
279 lines
6.8 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/pgalloc.h>
|
|
#include <asm/sections.h>
|
|
|
|
static DEFINE_SPINLOCK(cpa_lock);
|
|
static struct list_head df_list = LIST_HEAD_INIT(df_list);
|
|
|
|
|
|
pte_t *lookup_address(unsigned long address)
|
|
{
|
|
pgd_t *pgd = pgd_offset_k(address);
|
|
pud_t *pud;
|
|
pmd_t *pmd;
|
|
if (pgd_none(*pgd))
|
|
return NULL;
|
|
pud = pud_offset(pgd, address);
|
|
if (pud_none(*pud))
|
|
return NULL;
|
|
pmd = pmd_offset(pud, address);
|
|
if (pmd_none(*pmd))
|
|
return NULL;
|
|
if (pmd_large(*pmd))
|
|
return (pte_t *)pmd;
|
|
return pte_offset_kernel(pmd, address);
|
|
}
|
|
|
|
static struct page *split_large_page(unsigned long address, pgprot_t prot,
|
|
pgprot_t ref_prot)
|
|
{
|
|
int i;
|
|
unsigned long addr;
|
|
struct page *base;
|
|
pte_t *pbase;
|
|
|
|
spin_unlock_irq(&cpa_lock);
|
|
base = alloc_pages(GFP_KERNEL, 0);
|
|
spin_lock_irq(&cpa_lock);
|
|
if (!base)
|
|
return NULL;
|
|
|
|
/*
|
|
* page_private is used to track the number of entries in
|
|
* the page table page that have non standard attributes.
|
|
*/
|
|
SetPagePrivate(base);
|
|
page_private(base) = 0;
|
|
|
|
address = __pa(address);
|
|
addr = address & LARGE_PAGE_MASK;
|
|
pbase = (pte_t *)page_address(base);
|
|
paravirt_alloc_pt(&init_mm, page_to_pfn(base));
|
|
for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) {
|
|
set_pte(&pbase[i], pfn_pte(addr >> PAGE_SHIFT,
|
|
addr == address ? prot : ref_prot));
|
|
}
|
|
return base;
|
|
}
|
|
|
|
static void cache_flush_page(struct page *p)
|
|
{
|
|
void *adr = page_address(p);
|
|
int i;
|
|
for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
|
|
clflush(adr+i);
|
|
}
|
|
|
|
static void flush_kernel_map(void *arg)
|
|
{
|
|
struct list_head *lh = (struct list_head *)arg;
|
|
struct page *p;
|
|
|
|
/* High level code is not ready for clflush yet */
|
|
if (0 && cpu_has_clflush) {
|
|
list_for_each_entry (p, lh, lru)
|
|
cache_flush_page(p);
|
|
} else if (boot_cpu_data.x86_model >= 4)
|
|
wbinvd();
|
|
|
|
/* Flush all to work around Errata in early athlons regarding
|
|
* large page flushing.
|
|
*/
|
|
__flush_tlb_all();
|
|
}
|
|
|
|
static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
|
|
{
|
|
struct page *page;
|
|
unsigned long flags;
|
|
|
|
set_pte_atomic(kpte, pte); /* change init_mm */
|
|
if (SHARED_KERNEL_PMD)
|
|
return;
|
|
|
|
spin_lock_irqsave(&pgd_lock, flags);
|
|
for (page = pgd_list; page; page = (struct page *)page->index) {
|
|
pgd_t *pgd;
|
|
pud_t *pud;
|
|
pmd_t *pmd;
|
|
pgd = (pgd_t *)page_address(page) + pgd_index(address);
|
|
pud = pud_offset(pgd, address);
|
|
pmd = pmd_offset(pud, address);
|
|
set_pte_atomic((pte_t *)pmd, pte);
|
|
}
|
|
spin_unlock_irqrestore(&pgd_lock, flags);
|
|
}
|
|
|
|
/*
|
|
* No more special protections in this 2/4MB area - revert to a
|
|
* large page again.
|
|
*/
|
|
static inline void revert_page(struct page *kpte_page, unsigned long address)
|
|
{
|
|
pgprot_t ref_prot;
|
|
pte_t *linear;
|
|
|
|
ref_prot =
|
|
((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
|
|
? PAGE_KERNEL_LARGE_EXEC : PAGE_KERNEL_LARGE;
|
|
|
|
linear = (pte_t *)
|
|
pmd_offset(pud_offset(pgd_offset_k(address), address), address);
|
|
set_pmd_pte(linear, address,
|
|
pfn_pte((__pa(address) & LARGE_PAGE_MASK) >> PAGE_SHIFT,
|
|
ref_prot));
|
|
}
|
|
|
|
static inline void save_page(struct page *kpte_page)
|
|
{
|
|
if (!test_and_set_bit(PG_arch_1, &kpte_page->flags))
|
|
list_add(&kpte_page->lru, &df_list);
|
|
}
|
|
|
|
static int
|
|
__change_page_attr(struct page *page, pgprot_t prot)
|
|
{
|
|
pte_t *kpte;
|
|
unsigned long address;
|
|
struct page *kpte_page;
|
|
|
|
BUG_ON(PageHighMem(page));
|
|
address = (unsigned long)page_address(page);
|
|
|
|
kpte = lookup_address(address);
|
|
if (!kpte)
|
|
return -EINVAL;
|
|
kpte_page = virt_to_page(kpte);
|
|
BUG_ON(PageLRU(kpte_page));
|
|
BUG_ON(PageCompound(kpte_page));
|
|
|
|
if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL)) {
|
|
if (!pte_huge(*kpte)) {
|
|
set_pte_atomic(kpte, mk_pte(page, prot));
|
|
} else {
|
|
pgprot_t ref_prot;
|
|
struct page *split;
|
|
|
|
ref_prot =
|
|
((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
|
|
? PAGE_KERNEL_EXEC : PAGE_KERNEL;
|
|
split = split_large_page(address, prot, ref_prot);
|
|
if (!split)
|
|
return -ENOMEM;
|
|
set_pmd_pte(kpte,address,mk_pte(split, ref_prot));
|
|
kpte_page = split;
|
|
}
|
|
page_private(kpte_page)++;
|
|
} else if (!pte_huge(*kpte)) {
|
|
set_pte_atomic(kpte, mk_pte(page, PAGE_KERNEL));
|
|
BUG_ON(page_private(kpte_page) == 0);
|
|
page_private(kpte_page)--;
|
|
} else
|
|
BUG();
|
|
|
|
/*
|
|
* If the pte was reserved, it means it was created at boot
|
|
* time (not via split_large_page) and in turn we must not
|
|
* replace it with a largepage.
|
|
*/
|
|
|
|
save_page(kpte_page);
|
|
if (!PageReserved(kpte_page)) {
|
|
if (cpu_has_pse && (page_private(kpte_page) == 0)) {
|
|
paravirt_release_pt(page_to_pfn(kpte_page));
|
|
revert_page(kpte_page, address);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static inline void flush_map(struct list_head *l)
|
|
{
|
|
on_each_cpu(flush_kernel_map, l, 1, 1);
|
|
}
|
|
|
|
/*
|
|
* 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(struct page *page, int numpages, pgprot_t prot)
|
|
{
|
|
int err = 0;
|
|
int i;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&cpa_lock, flags);
|
|
for (i = 0; i < numpages; i++, page++) {
|
|
err = __change_page_attr(page, prot);
|
|
if (err)
|
|
break;
|
|
}
|
|
spin_unlock_irqrestore(&cpa_lock, flags);
|
|
return err;
|
|
}
|
|
|
|
void global_flush_tlb(void)
|
|
{
|
|
struct list_head l;
|
|
struct page *pg, *next;
|
|
|
|
BUG_ON(irqs_disabled());
|
|
|
|
spin_lock_irq(&cpa_lock);
|
|
list_replace_init(&df_list, &l);
|
|
spin_unlock_irq(&cpa_lock);
|
|
flush_map(&l);
|
|
list_for_each_entry_safe(pg, next, &l, lru) {
|
|
list_del(&pg->lru);
|
|
clear_bit(PG_arch_1, &pg->flags);
|
|
if (PageReserved(pg) || !cpu_has_pse || page_private(pg) != 0)
|
|
continue;
|
|
ClearPagePrivate(pg);
|
|
__free_page(pg);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_PAGEALLOC
|
|
void kernel_map_pages(struct page *page, int numpages, int enable)
|
|
{
|
|
if (PageHighMem(page))
|
|
return;
|
|
if (!enable)
|
|
debug_check_no_locks_freed(page_address(page),
|
|
numpages * PAGE_SIZE);
|
|
|
|
/* the return value is ignored - the calls cannot fail,
|
|
* large pages are disabled at boot time.
|
|
*/
|
|
change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
|
|
/* we should perform an IPI and flush all tlbs,
|
|
* but that can deadlock->flush only current cpu.
|
|
*/
|
|
__flush_tlb_all();
|
|
}
|
|
#endif
|
|
|
|
EXPORT_SYMBOL(change_page_attr);
|
|
EXPORT_SYMBOL(global_flush_tlb);
|