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author | Helge Deller <deller@gmx.de> | 2014-01-31 21:33:17 +0100 |
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committer | Helge Deller <deller@gmx.de> | 2014-02-02 20:57:16 +0100 |
commit | 57737c49dd72c96cfbcd4f66559f3ffc399aeb4f (patch) | |
tree | 390ecd631d941babf6f7390bbac4f7c6187f957a /arch/parisc/kernel | |
parent | parisc/sti_console: prefer Linux fonts over built-in ROM fonts (diff) | |
download | linux-57737c49dd72c96cfbcd4f66559f3ffc399aeb4f.tar.xz linux-57737c49dd72c96cfbcd4f66559f3ffc399aeb4f.zip |
parisc: fix cache-flushing
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>
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to '')
-rw-r--r-- | arch/parisc/kernel/cache.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c index a72545554a31..ac87a40502e6 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; |