Commit 57737c49 authored by Helge Deller's avatar Helge Deller

parisc: fix cache-flushing

This commit:
f8dae006: parisc: Ensure full cache coherency for kmap/kunmap
caused negative caching side-effects, e.g. hanging processes with expect and
too many inequivalent alias messages from flush_dcache_page() on Debian 5 systems.

This patch now partly reverts it and has been in production use on our debian buildd
makeservers since a week without any major problems.
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
Signed-off-by: default avatarJohn David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
parent 8a10bc9d
...@@ -132,7 +132,6 @@ void mark_rodata_ro(void); ...@@ -132,7 +132,6 @@ void mark_rodata_ro(void);
static inline void *kmap(struct page *page) static inline void *kmap(struct page *page)
{ {
might_sleep(); might_sleep();
flush_dcache_page(page);
return page_address(page); return page_address(page);
} }
...@@ -144,7 +143,6 @@ static inline void kunmap(struct page *page) ...@@ -144,7 +143,6 @@ static inline void kunmap(struct page *page)
static inline void *kmap_atomic(struct page *page) static inline void *kmap_atomic(struct page *page)
{ {
pagefault_disable(); pagefault_disable();
flush_dcache_page(page);
return page_address(page); return page_address(page);
} }
......
...@@ -29,7 +29,8 @@ struct page; ...@@ -29,7 +29,8 @@ struct page;
void clear_page_asm(void *page); void clear_page_asm(void *page);
void copy_page_asm(void *to, void *from); void copy_page_asm(void *to, void *from);
#define clear_user_page(vto, vaddr, page) clear_page_asm(vto) #define clear_user_page(vto, vaddr, page) clear_page_asm(vto)
#define copy_user_page(vto, vfrom, vaddr, page) copy_page_asm(vto, vfrom) void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
struct page *pg);
/* #define CONFIG_PARISC_TMPALIAS */ /* #define CONFIG_PARISC_TMPALIAS */
......
...@@ -388,6 +388,20 @@ void flush_kernel_dcache_page_addr(void *addr) ...@@ -388,6 +388,20 @@ void flush_kernel_dcache_page_addr(void *addr)
} }
EXPORT_SYMBOL(flush_kernel_dcache_page_addr); EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
struct page *pg)
{
/* Copy using kernel mapping. No coherency is needed (all in
kunmap) for the `to' page. However, the `from' page needs to
be flushed through a mapping equivalent to the user mapping
before it can be accessed through the kernel mapping. */
preempt_disable();
flush_dcache_page_asm(__pa(vfrom), vaddr);
preempt_enable();
copy_page_asm(vto, vfrom);
}
EXPORT_SYMBOL(copy_user_page);
void purge_tlb_entries(struct mm_struct *mm, unsigned long addr) void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
{ {
unsigned long flags; unsigned long flags;
......
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