diff options
| author | Helge Deller <deller@gmx.de> | 2014-01-31 21:33:17 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-06 11:08:17 -0800 |
| commit | 64a0099626b2ab6403433ef25e458c4d553a81a1 (patch) | |
| tree | 853ef652965d1df5404edbf593d9b887d17287c2 /arch/parisc | |
| parent | 50920a1dd85602169df04e38248fa582d523c039 (diff) | |
parisc: fix cache-flushing
commit 57737c49dd72c96cfbcd4f66559f3ffc399aeb4f upstream.
This commit:
f8dae00684d678afa13041ef170cecfd1297ed40: 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: Helge Deller <deller@gmx.de>
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/parisc')
| -rw-r--r-- | arch/parisc/include/asm/cacheflush.h | 2 | ||||
| -rw-r--r-- | arch/parisc/include/asm/page.h | 3 | ||||
| -rw-r--r-- | arch/parisc/kernel/cache.c | 14 |
3 files changed, 16 insertions, 3 deletions
diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h index 2f9b751878b..de65f66ea64 100644 --- a/arch/parisc/include/asm/cacheflush.h +++ b/arch/parisc/include/asm/cacheflush.h @@ -132,7 +132,6 @@ void mark_rodata_ro(void); static inline void *kmap(struct page *page) { might_sleep(); - flush_dcache_page(page); return page_address(page); } @@ -144,7 +143,6 @@ static inline void kunmap(struct page *page) static inline void *kmap_atomic(struct page *page) { pagefault_disable(); - flush_dcache_page(page); return page_address(page); } diff --git a/arch/parisc/include/asm/page.h b/arch/parisc/include/asm/page.h index c53fc63149e..637fe031aa8 100644 --- a/arch/parisc/include/asm/page.h +++ b/arch/parisc/include/asm/page.h @@ -29,7 +29,8 @@ struct page; void clear_page_asm(void *page); void copy_page_asm(void *to, void *from); #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 */ diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c index a72545554a3..ac87a40502e 100644 --- a/arch/parisc/kernel/cache.c +++ b/arch/parisc/kernel/cache.c @@ -388,6 +388,20 @@ void flush_kernel_dcache_page_addr(void *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) { unsigned long flags; |