| From foo@baz Sun Jun 17 12:07:33 CEST 2018 |
| From: Sinan Kaya <okaya@codeaurora.org> |
| Date: Thu, 12 Apr 2018 22:30:44 -0400 |
| Subject: MIPS: io: Add barrier after register read in readX() |
| |
| From: Sinan Kaya <okaya@codeaurora.org> |
| |
| [ Upstream commit a1cc7034e33d12dc17d13fbcd7d597d552889097 ] |
| |
| While a barrier is present in the writeX() functions before the register |
| write, a similar barrier is missing in the readX() functions after the |
| register read. This could allow memory accesses following readX() to |
| observe stale data. |
| |
| Signed-off-by: Sinan Kaya <okaya@codeaurora.org> |
| Reported-by: Arnd Bergmann <arnd@arndb.de> |
| Cc: Ralf Baechle <ralf@linux-mips.org> |
| Cc: Paul Burton <paul.burton@mips.com> |
| Cc: linux-mips@linux-mips.org |
| Patchwork: https://patchwork.linux-mips.org/patch/19069/ |
| [jhogan@kernel.org: Tidy commit message] |
| Signed-off-by: James Hogan <jhogan@kernel.org> |
| Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| arch/mips/include/asm/io.h | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/arch/mips/include/asm/io.h |
| +++ b/arch/mips/include/asm/io.h |
| @@ -377,6 +377,8 @@ static inline type pfx##read##bwlq(const |
| BUG(); \ |
| } \ |
| \ |
| + /* prevent prefetching of coherent DMA data prematurely */ \ |
| + rmb(); \ |
| return pfx##ioswab##bwlq(__mem, __val); \ |
| } |
| |