kernel_optimize_test/include/asm-parisc/cacheflush.h
Hugh Dickins 92dc6fcc84 [PATCH] mm: parisc pte atomicity
There's a worrying function translation_exists in parisc cacheflush.h,
unaffected by split ptlock since flush_dcache_page is using it on some other
mm, without any relevant lock.  Oh well, make it a slightly more robust by
factoring the pfn check within it.  And it looked liable to confuse a
camouflaged swap or file entry with a good pte: fix that too.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29 21:40:42 -07:00

187 lines
5.0 KiB
C

#ifndef _PARISC_CACHEFLUSH_H
#define _PARISC_CACHEFLUSH_H
#include <linux/config.h>
#include <linux/mm.h>
#include <asm/cache.h> /* for flush_user_dcache_range_asm() proto */
/* The usual comment is "Caches aren't brain-dead on the <architecture>".
* Unfortunately, that doesn't apply to PA-RISC. */
/* Cache flush operations */
#ifdef CONFIG_SMP
#define flush_cache_mm(mm) flush_cache_all()
#else
#define flush_cache_mm(mm) flush_cache_all_local()
#endif
#define flush_kernel_dcache_range(start,size) \
flush_kernel_dcache_range_asm((start), (start)+(size));
extern void flush_cache_all_local(void);
static inline void cacheflush_h_tmp_function(void *dummy)
{
flush_cache_all_local();
}
static inline void flush_cache_all(void)
{
on_each_cpu(cacheflush_h_tmp_function, NULL, 1, 1);
}
#define flush_cache_vmap(start, end) flush_cache_all()
#define flush_cache_vunmap(start, end) flush_cache_all()
extern int parisc_cache_flush_threshold;
void parisc_setup_cache_timing(void);
static inline void
flush_user_dcache_range(unsigned long start, unsigned long end)
{
if ((end - start) < parisc_cache_flush_threshold)
flush_user_dcache_range_asm(start,end);
else
flush_data_cache();
}
static inline void
flush_user_icache_range(unsigned long start, unsigned long end)
{
if ((end - start) < parisc_cache_flush_threshold)
flush_user_icache_range_asm(start,end);
else
flush_instruction_cache();
}
extern void flush_dcache_page(struct page *page);
#define flush_dcache_mmap_lock(mapping) \
write_lock_irq(&(mapping)->tree_lock)
#define flush_dcache_mmap_unlock(mapping) \
write_unlock_irq(&(mapping)->tree_lock)
#define flush_icache_page(vma,page) do { flush_kernel_dcache_page(page_address(page)); flush_kernel_icache_page(page_address(page)); } while (0)
#define flush_icache_range(s,e) do { flush_kernel_dcache_range_asm(s,e); flush_kernel_icache_range_asm(s,e); } while (0)
#define copy_to_user_page(vma, page, vaddr, dst, src, len) \
do { \
flush_cache_page(vma, vaddr, page_to_pfn(page)); \
memcpy(dst, src, len); \
flush_kernel_dcache_range_asm((unsigned long)dst, (unsigned long)dst + len); \
} while (0)
#define copy_from_user_page(vma, page, vaddr, dst, src, len) \
do { \
flush_cache_page(vma, vaddr, page_to_pfn(page)); \
memcpy(dst, src, len); \
} while (0)
static inline void flush_cache_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
int sr3;
if (!vma->vm_mm->context) {
BUG();
return;
}
sr3 = mfsp(3);
if (vma->vm_mm->context == sr3) {
flush_user_dcache_range(start,end);
flush_user_icache_range(start,end);
} else {
flush_cache_all();
}
}
/* Simple function to work out if we have an existing address translation
* for a user space vma. */
static inline int translation_exists(struct vm_area_struct *vma,
unsigned long addr, unsigned long pfn)
{
pgd_t *pgd = pgd_offset(vma->vm_mm, addr);
pmd_t *pmd;
pte_t pte;
if(pgd_none(*pgd))
return 0;
pmd = pmd_offset(pgd, addr);
if(pmd_none(*pmd) || pmd_bad(*pmd))
return 0;
/* We cannot take the pte lock here: flush_cache_page is usually
* called with pte lock already held. Whereas flush_dcache_page
* takes flush_dcache_mmap_lock, which is lower in the hierarchy:
* the vma itself is secure, but the pte might come or go racily.
*/
pte = *pte_offset_map(pmd, addr);
/* But pte_unmap() does nothing on this architecture */
/* Filter out coincidental file entries and swap entries */
if (!(pte_val(pte) & (_PAGE_FLUSH|_PAGE_PRESENT)))
return 0;
return pte_pfn(pte) == pfn;
}
/* Private function to flush a page from the cache of a non-current
* process. cr25 contains the Page Directory of the current user
* process; we're going to hijack both it and the user space %sr3 to
* temporarily make the non-current process current. We have to do
* this because cache flushing may cause a non-access tlb miss which
* the handlers have to fill in from the pgd of the non-current
* process. */
static inline void
flush_user_cache_page_non_current(struct vm_area_struct *vma,
unsigned long vmaddr)
{
/* save the current process space and pgd */
unsigned long space = mfsp(3), pgd = mfctl(25);
/* we don't mind taking interrups since they may not
* do anything with user space, but we can't
* be preempted here */
preempt_disable();
/* make us current */
mtctl(__pa(vma->vm_mm->pgd), 25);
mtsp(vma->vm_mm->context, 3);
flush_user_dcache_page(vmaddr);
if(vma->vm_flags & VM_EXEC)
flush_user_icache_page(vmaddr);
/* put the old current process back */
mtsp(space, 3);
mtctl(pgd, 25);
preempt_enable();
}
static inline void
__flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr)
{
if (likely(vma->vm_mm->context == mfsp(3))) {
flush_user_dcache_page(vmaddr);
if (vma->vm_flags & VM_EXEC)
flush_user_icache_page(vmaddr);
} else {
flush_user_cache_page_non_current(vma, vmaddr);
}
}
static inline void
flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn)
{
BUG_ON(!vma->vm_mm->context);
if (likely(translation_exists(vma, vmaddr, pfn)))
__flush_cache_page(vma, vmaddr);
}
#endif