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ARM: make_coherent: avoid recalculating the pfn for the modified page

We already know the pfn for the page to be modified in make_coherent,
so let's stop recalculating it unnecessarily.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2009-12-18 16:31:38 +00:00
parent 56dd47098a
commit ed42acaef1

View file

@ -37,7 +37,7 @@ static unsigned long shared_pte_mask = L_PTE_MT_BUFFERABLE;
* without CONFIG_CPU_CACHE_VIPT) cannot support split page_table_lock.
*/
static int do_adjust_pte(struct vm_area_struct *vma, unsigned long address,
pte_t *ptep)
unsigned long pfn, pte_t *ptep)
{
pte_t entry = *ptep;
int ret;
@ -52,7 +52,6 @@ static int do_adjust_pte(struct vm_area_struct *vma, unsigned long address,
* fault (ie, is old), we can safely ignore any issues.
*/
if (ret && (pte_val(entry) & L_PTE_MT_MASK) != shared_pte_mask) {
unsigned long pfn = pte_pfn(entry);
flush_cache_page(vma, address, pfn);
outer_flush_range((pfn << PAGE_SHIFT),
(pfn << PAGE_SHIFT) + PAGE_SIZE);
@ -65,7 +64,8 @@ static int do_adjust_pte(struct vm_area_struct *vma, unsigned long address,
return ret;
}
static int adjust_pte(struct vm_area_struct *vma, unsigned long address)
static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
unsigned long pfn)
{
spinlock_t *ptl;
pgd_t *pgd;
@ -90,7 +90,7 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address)
pte = pte_offset_map_nested(pmd, address);
spin_lock(ptl);
ret = do_adjust_pte(vma, address, pte);
ret = do_adjust_pte(vma, address, pfn, pte);
spin_unlock(ptl);
pte_unmap_nested(pte);
@ -127,11 +127,11 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma, unsigne
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);
}