Commit 872fec16 authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds

[PATCH] mm: init_mm without ptlock

First step in pushing down the page_table_lock.  init_mm.page_table_lock has
been used throughout the architectures (usually for ioremap): not to serialize
kernel address space allocation (that's usually vmlist_lock), but because
pud_alloc,pmd_alloc,pte_alloc_kernel expect caller holds it.

Reverse that: don't lock or unlock init_mm.page_table_lock in any of the
architectures; instead rely on pud_alloc,pmd_alloc,pte_alloc_kernel to take
and drop it when allocating a new one, to check lest a racing task already
did.  Similarly no page_table_lock in vmalloc's map_vm_area.

Some temporary ugliness in __pud_alloc and __pmd_alloc: since they also handle
user mms, which are converted only by a later patch, for now they have to lock
differently according to whether or not it's init_mm.

If sources get muddled, there's a danger that an arch source taking
init_mm.page_table_lock will be mixed with common source also taking it (or
neither take it).  So break the rules and make another change, which should
break the build for such a mismatch: remove the redundant mm arg from
pte_alloc_kernel (ppc64 scrapped its distinct ioremap_mm in 2.6.13).

Exceptions: arm26 used pte_alloc_kernel on user mm, now pte_alloc_map; ia64
used pte_alloc_map on init_mm, now pte_alloc_kernel; parisc had bad args to
pmd_alloc and pte_alloc_kernel in unused USE_HPPA_IOREMAP code; ppc64
map_io_page forgot to unlock on failure; ppc mmu_mapin_ram and ppc64 im_free
took page_table_lock for no good reason.
Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 46dea3d0
......@@ -2,7 +2,6 @@
#include <asm/pgalloc.h>
#include <asm/cacheflush.h>
/* called with the page_table_lock held */
static inline void
remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
unsigned long phys_addr, unsigned long flags)
......@@ -31,7 +30,6 @@ remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
} while (address && (address < end));
}
/* called with the page_table_lock held */
static inline int
remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
unsigned long phys_addr, unsigned long flags)
......@@ -46,7 +44,7 @@ remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
if (address >= end)
BUG();
do {
pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
pte_t * pte = pte_alloc_kernel(pmd, address);
if (!pte)
return -ENOMEM;
remap_area_pte(pte, address, end - address,
......@@ -70,7 +68,6 @@ __alpha_remap_area_pages(unsigned long address, unsigned long phys_addr,
flush_cache_all();
if (address >= end)
BUG();
spin_lock(&init_mm.page_table_lock);
do {
pmd_t *pmd;
pmd = pmd_alloc(&init_mm, dir, address);
......@@ -84,7 +81,6 @@ __alpha_remap_area_pages(unsigned long address, unsigned long phys_addr,
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
} while (address && (address < end));
spin_unlock(&init_mm.page_table_lock);
return error;
}
......@@ -397,8 +397,6 @@ static int __init consistent_init(void)
pte_t *pte;
int ret = 0;
spin_lock(&init_mm.page_table_lock);
do {
pgd = pgd_offset(&init_mm, CONSISTENT_BASE);
pmd = pmd_alloc(&init_mm, pgd, CONSISTENT_BASE);
......@@ -409,7 +407,7 @@ static int __init consistent_init(void)
}
WARN_ON(!pmd_none(*pmd));
pte = pte_alloc_kernel(&init_mm, pmd, CONSISTENT_BASE);
pte = pte_alloc_kernel(pmd, CONSISTENT_BASE);
if (!pte) {
printk(KERN_ERR "%s: no pte tables\n", __func__);
ret = -ENOMEM;
......@@ -419,8 +417,6 @@ static int __init consistent_init(void)
consistent_pte = pte;
} while (0);
spin_unlock(&init_mm.page_table_lock);
return ret;
}
......
......@@ -75,7 +75,7 @@ remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
pgprot = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_WRITE | flags);
do {
pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
pte_t * pte = pte_alloc_kernel(pmd, address);
if (!pte)
return -ENOMEM;
remap_area_pte(pte, address, end - address, address + phys_addr, pgprot);
......@@ -97,7 +97,6 @@ remap_area_pages(unsigned long start, unsigned long phys_addr,
phys_addr -= address;
dir = pgd_offset(&init_mm, address);
BUG_ON(address >= end);
spin_lock(&init_mm.page_table_lock);
do {
pmd_t *pmd = pmd_alloc(&init_mm, dir, address);
if (!pmd) {
......@@ -114,7 +113,6 @@ remap_area_pages(unsigned long start, unsigned long phys_addr,
dir++;
} while (address && (address < end));
spin_unlock(&init_mm.page_table_lock);
flush_cache_vmap(start, end);
return err;
}
......
......@@ -92,7 +92,7 @@ pgd_t *get_pgd_slow(struct mm_struct *mm)
if (!new_pmd)
goto no_pmd;
new_pte = pte_alloc_kernel(mm, new_pmd, 0);
new_pte = pte_alloc_map(mm, new_pmd, 0);
if (!new_pte)
goto no_pte;
......@@ -101,6 +101,7 @@ pgd_t *get_pgd_slow(struct mm_struct *mm)
init_pte = pte_offset(init_pmd, 0);
set_pte(new_pte, *init_pte);
pte_unmap(new_pte);
/*
* the page table entries are zeroed
......
......@@ -52,7 +52,7 @@ static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned lo
if (address >= end)
BUG();
do {
pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
pte_t * pte = pte_alloc_kernel(pmd, address);
if (!pte)
return -ENOMEM;
remap_area_pte(pte, address, end - address, address + phys_addr, prot);
......@@ -74,7 +74,6 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
flush_cache_all();
if (address >= end)
BUG();
spin_lock(&init_mm.page_table_lock);
do {
pud_t *pud;
pmd_t *pmd;
......@@ -94,7 +93,6 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
} while (address && (address < end));
spin_unlock(&init_mm.page_table_lock);
flush_tlb_all();
return error;
}
......
......@@ -55,21 +55,18 @@ static int map_page(unsigned long va, unsigned long pa, pgprot_t prot)
pte_t *pte;
int err = -ENOMEM;
spin_lock(&init_mm.page_table_lock);
/* Use upper 10 bits of VA to index the first level map */
pge = pgd_offset_k(va);
pue = pud_offset(pge, va);
pme = pmd_offset(pue, va);
/* Use middle 10 bits of VA to index the second-level map */
pte = pte_alloc_kernel(&init_mm, pme, va);
pte = pte_alloc_kernel(pme, va);
if (pte != 0) {
err = 0;
set_pte(pte, mk_pte_phys(pa & PAGE_MASK, prot));
}
spin_unlock(&init_mm.page_table_lock);
return err;
}
......
......@@ -28,7 +28,7 @@ static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
unsigned long pfn;
pfn = phys_addr >> PAGE_SHIFT;
pte = pte_alloc_kernel(&init_mm, pmd, addr);
pte = pte_alloc_kernel(pmd, addr);
if (!pte)
return -ENOMEM;
do {
......@@ -87,14 +87,12 @@ static int ioremap_page_range(unsigned long addr,
flush_cache_all();
phys_addr -= addr;
pgd = pgd_offset_k(addr);
spin_lock(&init_mm.page_table_lock);
do {
next = pgd_addr_end(addr, end);
err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, flags);
if (err)
break;
} while (pgd++, addr = next, addr != end);
spin_unlock(&init_mm.page_table_lock);
flush_tlb_all();
return err;
}
......
......@@ -275,26 +275,21 @@ put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
pgd = pgd_offset_k(address); /* note: this is NOT pgd_offset()! */
spin_lock(&init_mm.page_table_lock);
{
pud = pud_alloc(&init_mm, pgd, address);
if (!pud)
goto out;
pmd = pmd_alloc(&init_mm, pud, address);
if (!pmd)
goto out;
pte = pte_alloc_map(&init_mm, pmd, address);
pte = pte_alloc_kernel(pmd, address);
if (!pte)
goto out;
if (!pte_none(*pte)) {
pte_unmap(pte);
if (!pte_none(*pte))
goto out;
}
set_pte(pte, mk_pte(page, pgprot));
pte_unmap(pte);
}
out: spin_unlock(&init_mm.page_table_lock);
out:
/* no need for flush_tlb */
return page;
}
......
......@@ -67,7 +67,7 @@ remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
if (address >= end)
BUG();
do {
pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
pte_t * pte = pte_alloc_kernel(pmd, address);
if (!pte)
return -ENOMEM;
remap_area_pte(pte, address, end - address, address + phys_addr, flags);
......@@ -90,7 +90,6 @@ remap_area_pages(unsigned long address, unsigned long phys_addr,
flush_cache_all();
if (address >= end)
BUG();
spin_lock(&init_mm.page_table_lock);
do {
pmd_t *pmd;
pmd = pmd_alloc(&init_mm, dir, address);
......@@ -104,7 +103,6 @@ remap_area_pages(unsigned long address, unsigned long phys_addr,
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
} while (address && (address < end));
spin_unlock(&init_mm.page_table_lock);
flush_tlb_all();
return error;
}
......
......@@ -201,7 +201,7 @@ void *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
virtaddr += PTRTREESIZE;
size -= PTRTREESIZE;
} else {
pte_dir = pte_alloc_kernel(&init_mm, pmd_dir, virtaddr);
pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
if (!pte_dir) {
printk("ioremap: no mem for pte_dir\n");
return NULL;
......
......@@ -116,7 +116,7 @@ inline int dvma_map_cpu(unsigned long kaddr,
pte_t *pte;
unsigned long end3;
if((pte = pte_alloc_kernel(&init_mm, pmd, vaddr)) == NULL) {
if((pte = pte_alloc_kernel(pmd, vaddr)) == NULL) {
ret = -ENOMEM;
goto out;
}
......
......@@ -55,7 +55,7 @@ static inline int remap_area_pmd(pmd_t * pmd, unsigned long address,
if (address >= end)
BUG();
do {
pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
pte_t * pte = pte_alloc_kernel(pmd, address);
if (!pte)
return -ENOMEM;
remap_area_pte(pte, address, end - address, address + phys_addr, flags);
......@@ -77,7 +77,6 @@ static int remap_area_pages(unsigned long address, phys_t phys_addr,
flush_cache_all();
if (address >= end)
BUG();
spin_lock(&init_mm.page_table_lock);
do {
pud_t *pud;
pmd_t *pmd;
......@@ -96,7 +95,6 @@ static int remap_area_pages(unsigned long address, phys_t phys_addr,
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
} while (address && (address < end));
spin_unlock(&init_mm.page_table_lock);
flush_tlb_all();
return error;
}
......
......@@ -114,7 +114,7 @@ static inline int map_pmd_uncached(pmd_t * pmd, unsigned long vaddr,
if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
do {
pte_t * pte = pte_alloc_kernel(&init_mm, pmd, vaddr);
pte_t * pte = pte_alloc_kernel(pmd, vaddr);
if (!pte)
return -ENOMEM;
if (map_pte_uncached(pte, orig_vaddr, end - vaddr, paddr_ptr))
......
......@@ -52,7 +52,7 @@ static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned lo
if (address >= end)
BUG();
do {
pte_t * pte = pte_alloc_kernel(NULL, pmd, address);
pte_t * pte = pte_alloc_kernel(pmd, address);
if (!pte)
return -ENOMEM;
remap_area_pte(pte, address, end - address, address + phys_addr, flags);
......@@ -75,10 +75,9 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
flush_cache_all();
if (address >= end)
BUG();
spin_lock(&init_mm.page_table_lock);
do {
pmd_t *pmd;
pmd = pmd_alloc(dir, address);
pmd = pmd_alloc(&init_mm, dir, address);
error = -ENOMEM;
if (!pmd)
break;
......@@ -89,7 +88,6 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
} while (address && (address < end));
spin_unlock(&init_mm.page_table_lock);
flush_tlb_all();
return error;
}
......
......@@ -335,8 +335,6 @@ static int __init dma_alloc_init(void)
pte_t *pte;
int ret = 0;
spin_lock(&init_mm.page_table_lock);
do {
pgd = pgd_offset(&init_mm, CONSISTENT_BASE);
pmd = pmd_alloc(&init_mm, pgd, CONSISTENT_BASE);
......@@ -347,7 +345,7 @@ static int __init dma_alloc_init(void)
}
WARN_ON(!pmd_none(*pmd));
pte = pte_alloc_kernel(&init_mm, pmd, CONSISTENT_BASE);
pte = pte_alloc_kernel(pmd, CONSISTENT_BASE);
if (!pte) {
printk(KERN_ERR "%s: no pte tables\n", __func__);
ret = -ENOMEM;
......@@ -357,8 +355,6 @@ static int __init dma_alloc_init(void)
consistent_pte = pte;
} while (0);
spin_unlock(&init_mm.page_table_lock);
return ret;
}
......
......@@ -110,13 +110,11 @@ unsigned long __init mmu_mapin_ram(void)
pmd_t *pmdp;
unsigned long val = p | _PMD_SIZE_16M | _PAGE_HWEXEC | _PAGE_HWWRITE;
spin_lock(&init_mm.page_table_lock);
pmdp = pmd_offset(pgd_offset_k(v), v);
pmd_val(*pmdp++) = val;
pmd_val(*pmdp++) = val;
pmd_val(*pmdp++) = val;
pmd_val(*pmdp++) = val;
spin_unlock(&init_mm.page_table_lock);
v += LARGE_PAGE_SIZE_16M;
p += LARGE_PAGE_SIZE_16M;
......@@ -127,10 +125,8 @@ unsigned long __init mmu_mapin_ram(void)
pmd_t *pmdp;
unsigned long val = p | _PMD_SIZE_4M | _PAGE_HWEXEC | _PAGE_HWWRITE;
spin_lock(&init_mm.page_table_lock);
pmdp = pmd_offset(pgd_offset_k(v), v);
pmd_val(*pmdp) = val;
spin_unlock(&init_mm.page_table_lock);
v += LARGE_PAGE_SIZE_4M;
p += LARGE_PAGE_SIZE_4M;
......
......@@ -280,18 +280,16 @@ map_page(unsigned long va, phys_addr_t pa, int flags)
pte_t *pg;
int err = -ENOMEM;
spin_lock(&init_mm.page_table_lock);
/* Use upper 10 bits of VA to index the first level map */
pd = pmd_offset(pgd_offset_k(va), va);
/* Use middle 10 bits of VA to index the second-level map */
pg = pte_alloc_kernel(&init_mm, pd, va);
pg = pte_alloc_kernel(pd, va);
if (pg != 0) {
err = 0;
set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags)));
if (mem_init_done)
flush_HPTE(0, va, pmd_val(*pd));
}
spin_unlock(&init_mm.page_table_lock);
return err;
}
......
......@@ -300,12 +300,7 @@ void im_free(void * addr)
for (p = &imlist ; (tmp = *p) ; p = &tmp->next) {
if (tmp->addr == addr) {
*p = tmp->next;
/* XXX: do we need the lock? */
spin_lock(&init_mm.page_table_lock);
unmap_vm_area(tmp);
spin_unlock(&init_mm.page_table_lock);
kfree(tmp);
up(&imlist_sem);
return;
......
......@@ -155,7 +155,6 @@ static int map_io_page(unsigned long ea, unsigned long pa, int flags)
unsigned long vsid;
if (mem_init_done) {
spin_lock(&init_mm.page_table_lock);
pgdp = pgd_offset_k(ea);
pudp = pud_alloc(&init_mm, pgdp, ea);
if (!pudp)
......@@ -163,12 +162,11 @@ static int map_io_page(unsigned long ea, unsigned long pa, int flags)
pmdp = pmd_alloc(&init_mm, pudp, ea);
if (!pmdp)
return -ENOMEM;
ptep = pte_alloc_kernel(&init_mm, pmdp, ea);
ptep = pte_alloc_kernel(pmdp, ea);
if (!ptep)
return -ENOMEM;
set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
__pgprot(flags)));
spin_unlock(&init_mm.page_table_lock);
} else {
unsigned long va, vpn, hash, hpteg;
......
......@@ -58,7 +58,7 @@ static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned lo
if (address >= end)
BUG();
do {
pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
pte_t * pte = pte_alloc_kernel(pmd, address);
if (!pte)
return -ENOMEM;
remap_area_pte(pte, address, end - address, address + phys_addr, flags);
......@@ -80,7 +80,6 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
flush_cache_all();
if (address >= end)
BUG();
spin_lock(&init_mm.page_table_lock);
do {
pmd_t *pmd;
pmd = pmd_alloc(&init_mm, dir, address);
......@@ -94,7 +93,6 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
} while (address && (address < end));
spin_unlock(&init_mm.page_table_lock);
flush_tlb_all();
return 0;
}
......
......@@ -57,7 +57,7 @@ static inline int remap_area_pmd(pmd_t * pmd, unsigned long address,
if (address >= end)
BUG();
do {
pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
pte_t * pte = pte_alloc_kernel(pmd, address);
if (!pte)
return -ENOMEM;
remap_area_pte(pte, address, end - address, address + phys_addr, flags);
......@@ -79,7 +79,6 @@ int remap_area_pages(unsigned long address, unsigned long phys_addr,
flush_cache_all();
if (address >= end)
BUG();
spin_lock(&init_mm.page_table_lock);
do {
pmd_t *pmd;
pmd = pmd_alloc(&init_mm, dir, address);
......@@ -93,7 +92,6 @@ int remap_area_pages(unsigned long address, unsigned long phys_addr,
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
} while (address && (address < end));
spin_unlock(&init_mm.page_table_lock);
flush_tlb_all();
return error;
}
......
......@@ -79,7 +79,7 @@ static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned lo
BUG();
do {
pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
pte_t * pte = pte_alloc_kernel(pmd, address);
if (!pte)
return -ENOMEM;
remap_area_pte(pte, address, end - address, address + phys_addr, flags);
......@@ -101,7 +101,6 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
flush_cache_all();
if (address >= end)
BUG();
spin_lock(&init_mm.page_table_lock);
do {
pmd_t *pmd = pmd_alloc(&init_mm, dir, address);
error = -ENOMEM;
......@@ -115,7 +114,6 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
} while (address && (address < end));
spin_unlock(&init_mm.page_table_lock);
flush_tlb_all();
return 0;
}
......
......@@ -60,7 +60,7 @@ static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned lo
if (address >= end)
BUG();
do {
pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
pte_t * pte = pte_alloc_kernel(pmd, address);
if (!pte)
return -ENOMEM;
remap_area_pte(pte, address, end - address, address + phys_addr, flags);
......@@ -105,7 +105,6 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
flush_cache_all();
if (address >= end)
BUG();
spin_lock(&init_mm.page_table_lock);
do {
pud_t *pud;
pud = pud_alloc(&init_mm, pgd, address);
......@@ -119,7 +118,6 @@ static int remap_area_pages(unsigned long address, unsigned long phys_addr,
address = (address + PGDIR_SIZE) & PGDIR_MASK;
pgd++;
} while (address && (address < end));
spin_unlock(&init_mm.page_table_lock);
flush_tlb_all();
return error;
}
......
......@@ -706,7 +706,7 @@ static inline void unmap_shared_mapping_range(struct address_space *mapping,
extern int vmtruncate(struct inode * inode, loff_t offset);
extern pud_t *FASTCALL(__pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address));
extern pmd_t *FASTCALL(__pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address));
extern pte_t *FASTCALL(pte_alloc_kernel(struct mm_struct *mm, pmd_t *pmd, unsigned long address));
extern pte_t *FASTCALL(pte_alloc_kernel(pmd_t *pmd, unsigned long address));
extern pte_t *FASTCALL(pte_alloc_map(struct mm_struct *mm, pmd_t *pmd, unsigned long address));
extern int install_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, struct page *page, pgprot_t prot);
extern int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, unsigned long pgoff, pgprot_t prot);
......
......@@ -307,28 +307,22 @@ out:
return pte_offset_map(pmd, address);
}
pte_t fastcall * pte_alloc_kernel(struct mm_struct *mm, pmd_t *pmd, unsigned long address)
pte_t fastcall * pte_alloc_kernel(pmd_t *pmd, unsigned long address)
{
if (!pmd_present(*pmd)) {
pte_t *new;
spin_unlock(&mm->page_table_lock);
new = pte_alloc_one_kernel(mm, address);
spin_lock(&mm->page_table_lock);
new = pte_alloc_one_kernel(&init_mm, address);
if (!new)
return NULL;
/*
* Because we dropped the lock, we should re-check the
* entry, as somebody else could have populated it..
*/
if (pmd_present(*pmd)) {
spin_lock(&init_mm.page_table_lock);
if (pmd_present(*pmd))
pte_free_kernel(new);
goto out;
}
pmd_populate_kernel(mm, pmd, new);
else
pmd_populate_kernel(&init_mm, pmd, new);
spin_unlock(&init_mm.page_table_lock);
}
out:
return pte_offset_kernel(pmd, address);
}
......@@ -2097,30 +2091,30 @@ int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
#ifndef __PAGETABLE_PUD_FOLDED
/*
* Allocate page upper directory.
*
* We've already handled the fast-path in-line, and we own the
* page table lock.
* We've already handled the fast-path in-line.
*/
pud_t fastcall *__pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
{
pud_t *new;
spin_unlock(&mm->page_table_lock);
if (mm != &init_mm) /* Temporary bridging hack */
spin_unlock(&mm->page_table_lock);
new = pud_alloc_one(mm, address);
spin_lock(&mm->page_table_lock);
if (!new)
if (!new) {
if (mm != &init_mm) /* Temporary bridging hack */
spin_lock(&mm->page_table_lock);
return NULL;
}
/*
* Because we dropped the lock, we should re-check the
* entry, as somebody else could have populated it..
*/
spin_lock(&mm->page_table_lock);
if (pgd_present(*pgd)) {
pud_free(new);
goto out;
}
pgd_populate(mm, pgd, new);
out:
if (mm == &init_mm) /* Temporary bridging hack */
spin_unlock(&mm->page_table_lock);
return pud_offset(pgd, address);