3.11.10.4 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Helge Deller <[email protected]> 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 <[email protected]> Signed-off-by: John David Anglin <[email protected]> Signed-off-by: Helge Deller <[email protected]> Signed-off-by: Luis Henriques <[email protected]> --- arch/parisc/include/asm/cacheflush.h | 2 -- arch/parisc/include/asm/page.h | 3 ++- 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 2f9b751..de65f66 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 c53fc63..637fe03 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 a725455..ac87a40 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; -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
