mirror of https://gitee.com/openkylin/linux.git
x86: mm: Remove x86 version of huge_pmd_share.
The huge_pmd_share code has been copied over to mm/hugetlb.c to make it accessible to other architectures. Remove the x86 copy of the huge_pmd_share code and enable the ARCH_WANT_HUGE_PMD_SHARE config flag. That way we reference the general one. Signed-off-by: Steve Capper <steve.capper@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Steve Capper
parent
3212b535f2
commit
cfe28c5d63
|
|
@ -207,6 +207,9 @@ config ARCH_HIBERNATION_POSSIBLE
|
|||
config ARCH_SUSPEND_POSSIBLE
|
||||
def_bool y
|
||||
|
||||
config ARCH_WANT_HUGE_PMD_SHARE
|
||||
def_bool y
|
||||
|
||||
config ZONE_DMA32
|
||||
bool
|
||||
default X86_64
|
||||
|
|
|
|||
|
|
@ -16,126 +16,6 @@
|
|||
#include <asm/tlbflush.h>
|
||||
#include <asm/pgalloc.h>
|
||||
|
||||
static unsigned long page_table_shareable(struct vm_area_struct *svma,
|
||||
struct vm_area_struct *vma,
|
||||
unsigned long addr, pgoff_t idx)
|
||||
{
|
||||
unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) +
|
||||
svma->vm_start;
|
||||
unsigned long sbase = saddr & PUD_MASK;
|
||||
unsigned long s_end = sbase + PUD_SIZE;
|
||||
|
||||
/* Allow segments to share if only one is marked locked */
|
||||
unsigned long vm_flags = vma->vm_flags & ~VM_LOCKED;
|
||||
unsigned long svm_flags = svma->vm_flags & ~VM_LOCKED;
|
||||
|
||||
/*
|
||||
* match the virtual addresses, permission and the alignment of the
|
||||
* page table page.
|
||||
*/
|
||||
if (pmd_index(addr) != pmd_index(saddr) ||
|
||||
vm_flags != svm_flags ||
|
||||
sbase < svma->vm_start || svma->vm_end < s_end)
|
||||
return 0;
|
||||
|
||||
return saddr;
|
||||
}
|
||||
|
||||
static int vma_shareable(struct vm_area_struct *vma, unsigned long addr)
|
||||
{
|
||||
unsigned long base = addr & PUD_MASK;
|
||||
unsigned long end = base + PUD_SIZE;
|
||||
|
||||
/*
|
||||
* check on proper vm_flags and page table alignment
|
||||
*/
|
||||
if (vma->vm_flags & VM_MAYSHARE &&
|
||||
vma->vm_start <= base && end <= vma->vm_end)
|
||||
return 1;
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
|
||||
* and returns the corresponding pte. While this is not necessary for the
|
||||
* !shared pmd case because we can allocate the pmd later as well, it makes the
|
||||
* code much cleaner. pmd allocation is essential for the shared case because
|
||||
* pud has to be populated inside the same i_mmap_mutex section - otherwise
|
||||
* racing tasks could either miss the sharing (see huge_pte_offset) or select a
|
||||
* bad pmd for sharing.
|
||||
*/
|
||||
static pte_t *
|
||||
huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
|
||||
{
|
||||
struct vm_area_struct *vma = find_vma(mm, addr);
|
||||
struct address_space *mapping = vma->vm_file->f_mapping;
|
||||
pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) +
|
||||
vma->vm_pgoff;
|
||||
struct vm_area_struct *svma;
|
||||
unsigned long saddr;
|
||||
pte_t *spte = NULL;
|
||||
pte_t *pte;
|
||||
|
||||
if (!vma_shareable(vma, addr))
|
||||
return (pte_t *)pmd_alloc(mm, pud, addr);
|
||||
|
||||
mutex_lock(&mapping->i_mmap_mutex);
|
||||
vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) {
|
||||
if (svma == vma)
|
||||
continue;
|
||||
|
||||
saddr = page_table_shareable(svma, vma, addr, idx);
|
||||
if (saddr) {
|
||||
spte = huge_pte_offset(svma->vm_mm, saddr);
|
||||
if (spte) {
|
||||
get_page(virt_to_page(spte));
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (!spte)
|
||||
goto out;
|
||||
|
||||
spin_lock(&mm->page_table_lock);
|
||||
if (pud_none(*pud))
|
||||
pud_populate(mm, pud, (pmd_t *)((unsigned long)spte & PAGE_MASK));
|
||||
else
|
||||
put_page(virt_to_page(spte));
|
||||
spin_unlock(&mm->page_table_lock);
|
||||
out:
|
||||
pte = (pte_t *)pmd_alloc(mm, pud, addr);
|
||||
mutex_unlock(&mapping->i_mmap_mutex);
|
||||
return pte;
|
||||
}
|
||||
|
||||
/*
|
||||
* unmap huge page backed by shared pte.
|
||||
*
|
||||
* Hugetlb pte page is ref counted at the time of mapping. If pte is shared
|
||||
* indicated by page_count > 1, unmap is achieved by clearing pud and
|
||||
* decrementing the ref count. If count == 1, the pte page is not shared.
|
||||
*
|
||||
* called with vma->vm_mm->page_table_lock held.
|
||||
*
|
||||
* returns: 1 successfully unmapped a shared pte page
|
||||
* 0 the underlying pte page is not shared, or it is the last user
|
||||
*/
|
||||
int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
|
||||
{
|
||||
pgd_t *pgd = pgd_offset(mm, *addr);
|
||||
pud_t *pud = pud_offset(pgd, *addr);
|
||||
|
||||
BUG_ON(page_count(virt_to_page(ptep)) == 0);
|
||||
if (page_count(virt_to_page(ptep)) == 1)
|
||||
return 0;
|
||||
|
||||
pud_clear(pud);
|
||||
put_page(virt_to_page(ptep));
|
||||
*addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE;
|
||||
return 1;
|
||||
}
|
||||
|
||||
pte_t *huge_pte_alloc(struct mm_struct *mm,
|
||||
unsigned long addr, unsigned long sz)
|
||||
{
|
||||
|
|
|
|||
Loading…
Reference in New Issue