#include <linux/init.h>
#include <linux/pagemap.h>
+#include <asm/bugs.h>
#include <asm/cacheflush.h>
+#include <asm/cachetype.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
-static unsigned long shared_pte_mask = L_PTE_CACHEABLE;
+#include "mm.h"
+
+static unsigned long shared_pte_mask = L_PTE_MT_BUFFERABLE;
/*
* We take the easy way out of this problem - we make the
* PTE uncacheable. However, we leave the write buffer on.
+ *
+ * Note that the pte lock held when calling update_mmu_cache must also
+ * guard the pte (somewhere else in the same mm) that we modify here.
+ * Therefore those configurations which might call adjust_pte (those
+ * without CONFIG_CPU_CACHE_VIPT) cannot support split page_table_lock.
*/
-static int adjust_pte(struct vm_area_struct *vma, unsigned long address)
+static int do_adjust_pte(struct vm_area_struct *vma, unsigned long address,
+ unsigned long pfn, pte_t *ptep)
{
- pgd_t *pgd;
- pmd_t *pmd;
- pte_t *pte, entry;
- int ret = 0;
+ pte_t entry = *ptep;
+ int ret;
- pgd = pgd_offset(vma->vm_mm, address);
- if (pgd_none(*pgd))
- goto no_pgd;
- if (pgd_bad(*pgd))
- goto bad_pgd;
-
- pmd = pmd_offset(pgd, address);
- if (pmd_none(*pmd))
- goto no_pmd;
- if (pmd_bad(*pmd))
- goto bad_pmd;
-
- pte = pte_offset_map(pmd, address);
- entry = *pte;
+ /*
+ * If this page is present, it's actually being shared.
+ */
+ ret = pte_present(entry);
/*
* If this page isn't present, or is already setup to
* fault (ie, is old), we can safely ignore any issues.
*/
- if (pte_present(entry) && pte_val(entry) & shared_pte_mask) {
- flush_cache_page(vma, address, pte_pfn(entry));
- pte_val(entry) &= ~shared_pte_mask;
- set_pte(pte, entry);
+ if (ret && (pte_val(entry) & L_PTE_MT_MASK) != shared_pte_mask) {
+ flush_cache_page(vma, address, pfn);
+ outer_flush_range((pfn << PAGE_SHIFT),
+ (pfn << PAGE_SHIFT) + PAGE_SIZE);
+ pte_val(entry) &= ~L_PTE_MT_MASK;
+ pte_val(entry) |= shared_pte_mask;
+ set_pte_at(vma->vm_mm, address, ptep, entry);
flush_tlb_page(vma, address);
- ret = 1;
}
- pte_unmap(pte);
+
return ret;
+}
+
+static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
+ unsigned long pfn)
+{
+ spinlock_t *ptl;
+ pgd_t *pgd;
+ pmd_t *pmd;
+ pte_t *pte;
+ int ret;
-bad_pgd:
- pgd_ERROR(*pgd);
- pgd_clear(pgd);
-no_pgd:
- return 0;
-
-bad_pmd:
- pmd_ERROR(*pmd);
- pmd_clear(pmd);
-no_pmd:
- return 0;
+ pgd = pgd_offset(vma->vm_mm, address);
+ if (pgd_none_or_clear_bad(pgd))
+ return 0;
+
+ pmd = pmd_offset(pgd, address);
+ if (pmd_none_or_clear_bad(pmd))
+ return 0;
+
+ /*
+ * This is called while another page table is mapped, so we
+ * must use the nested version. This also means we need to
+ * open-code the spin-locking.
+ */
+ ptl = pte_lockptr(vma->vm_mm, pmd);
+ pte = pte_offset_map_nested(pmd, address);
+ spin_lock(ptl);
+
+ ret = do_adjust_pte(vma, address, pfn, pte);
+
+ spin_unlock(ptl);
+ pte_unmap_nested(pte);
+
+ return ret;
}
static void
if (!(mpnt->vm_flags & VM_MAYSHARE))
continue;
offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
- aliases += adjust_pte(mpnt, mpnt->vm_start + offset);
+ aliases += adjust_pte(mpnt, mpnt->vm_start + offset, pfn);
}
flush_dcache_mmap_unlock(mapping);
if (aliases)
- adjust_pte(vma, addr);
+ adjust_pte(vma, addr, pfn);
else
flush_cache_page(vma, addr, pfn);
}
-void __flush_dcache_page(struct address_space *mapping, struct page *page);
-
/*
* Take care of architecture specific things when placing a new PTE into
* a page table, or changing an existing PTE. Basically, there are two
* 2. If we have multiple shared mappings of the same space in
* an object, we need to deal with the cache aliasing issues.
*
- * Note that the page_table_lock will be held.
+ * Note that the pte lock will be held.
*/
-void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr,
+ pte_t *ptep)
{
- unsigned long pfn = pte_pfn(pte);
+ unsigned long pfn = pte_pfn(*ptep);
struct address_space *mapping;
struct page *page;
if (!pfn_valid(pfn))
return;
+ /*
+ * The zero page is never written to, so never has any dirty
+ * cache lines, and therefore never needs to be flushed.
+ */
page = pfn_to_page(pfn);
+ if (page == ZERO_PAGE(0))
+ return;
+
mapping = page_mapping(page);
+#ifndef CONFIG_SMP
+ if (test_and_clear_bit(PG_dcache_dirty, &page->flags))
+ __flush_dcache_page(mapping, page);
+#endif
if (mapping) {
- int dirty = test_and_clear_bit(PG_dcache_dirty, &page->flags);
-
- if (dirty)
- __flush_dcache_page(mapping, page);
-
if (cache_is_vivt())
make_coherent(mapping, vma, addr, pfn);
+ else if (vma->vm_flags & VM_EXEC)
+ __flush_icache_all();
}
}
page = alloc_page(GFP_KERNEL);
if (page) {
unsigned long *p1, *p2;
- pgprot_t prot = __pgprot(L_PTE_PRESENT|L_PTE_YOUNG|
- L_PTE_DIRTY|L_PTE_WRITE|
- L_PTE_BUFFERABLE);
+ pgprot_t prot = __pgprot_modify(PAGE_KERNEL,
+ L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE);
p1 = vmap(&page, 1, VM_IOREMAP, prot);
p2 = vmap(&page, 1, VM_IOREMAP, prot);
if (v) {
printk("failed, %s\n", reason);
- shared_pte_mask |= L_PTE_BUFFERABLE;
+ shared_pte_mask = L_PTE_MT_UNCACHED;
} else {
printk("ok\n");
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff