872fec16d9
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: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
86 lines
1.9 KiB
C
86 lines
1.9 KiB
C
#include <linux/vmalloc.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/cacheflush.h>
|
|
|
|
static inline void
|
|
remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
|
|
unsigned long phys_addr, unsigned long flags)
|
|
{
|
|
unsigned long end;
|
|
unsigned long pfn;
|
|
|
|
address &= ~PMD_MASK;
|
|
end = address + size;
|
|
if (end > PMD_SIZE)
|
|
end = PMD_SIZE;
|
|
if (address >= end)
|
|
BUG();
|
|
pfn = phys_addr >> PAGE_SHIFT;
|
|
do {
|
|
if (!pte_none(*pte)) {
|
|
printk("remap_area_pte: page already exists\n");
|
|
BUG();
|
|
}
|
|
set_pte(pte, pfn_pte(pfn,
|
|
__pgprot(_PAGE_VALID | _PAGE_ASM |
|
|
_PAGE_KRE | _PAGE_KWE | flags)));
|
|
address += PAGE_SIZE;
|
|
pfn++;
|
|
pte++;
|
|
} while (address && (address < end));
|
|
}
|
|
|
|
static inline int
|
|
remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
|
|
unsigned long phys_addr, unsigned long flags)
|
|
{
|
|
unsigned long end;
|
|
|
|
address &= ~PGDIR_MASK;
|
|
end = address + size;
|
|
if (end > PGDIR_SIZE)
|
|
end = PGDIR_SIZE;
|
|
phys_addr -= address;
|
|
if (address >= end)
|
|
BUG();
|
|
do {
|
|
pte_t * pte = pte_alloc_kernel(pmd, address);
|
|
if (!pte)
|
|
return -ENOMEM;
|
|
remap_area_pte(pte, address, end - address,
|
|
address + phys_addr, flags);
|
|
address = (address + PMD_SIZE) & PMD_MASK;
|
|
pmd++;
|
|
} while (address && (address < end));
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
__alpha_remap_area_pages(unsigned long address, unsigned long phys_addr,
|
|
unsigned long size, unsigned long flags)
|
|
{
|
|
pgd_t * dir;
|
|
int error = 0;
|
|
unsigned long end = address + size;
|
|
|
|
phys_addr -= address;
|
|
dir = pgd_offset(&init_mm, address);
|
|
flush_cache_all();
|
|
if (address >= end)
|
|
BUG();
|
|
do {
|
|
pmd_t *pmd;
|
|
pmd = pmd_alloc(&init_mm, dir, address);
|
|
error = -ENOMEM;
|
|
if (!pmd)
|
|
break;
|
|
if (remap_area_pmd(pmd, address, end - address,
|
|
phys_addr + address, flags))
|
|
break;
|
|
error = 0;
|
|
address = (address + PGDIR_SIZE) & PGDIR_MASK;
|
|
dir++;
|
|
} while (address && (address < end));
|
|
return error;
|
|
}
|
|
|