4.4-stable review patch. If anyone has any objections, please let me know.
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From: Paul Burton paul.burton@mips.com
commit 6a6cba1d945a7511cdfaf338526871195e420762 upstream.
The default CM target field in the GCR_BASE register is encoded with 0 meaning memory & 1 being reserved. However the definitions we use for those bits effectively get these two values backwards - likely because they were copied from the definitions for the CM regions where the target is encoded differently. This results in use setting up GCR_BASE with the reserved target value by default, rather than targeting memory as intended. Although we currently seem to get away with this it's not a great idea to rely upon.
Fix this by changing our macros to match the documentated target values.
The incorrect encoding became used as of commit 9f98f3dd0c51 ("MIPS: Add generic CM probe & access code") in the Linux v3.15 cycle, and was likely carried forwards from older but unused code introduced by commit 39b8d5254246 ("[MIPS] Add support for MIPS CMP platform.") in the v2.6.26 cycle.
Fixes: 9f98f3dd0c51 ("MIPS: Add generic CM probe & access code") Signed-off-by: Paul Burton paul.burton@mips.com Reported-by: Matt Redfearn matt.redfearn@mips.com Reviewed-by: James Hogan jhogan@kernel.org Cc: Matt Redfearn matt.redfearn@mips.com Cc: Ralf Baechle ralf@linux-mips.org Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17562/ Signed-off-by: James Hogan jhogan@kernel.org [jhogan@kernel.org: Backported 3.15..4.13] Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/mips/include/asm/mips-cm.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/mips/include/asm/mips-cm.h +++ b/arch/mips/include/asm/mips-cm.h @@ -238,8 +238,8 @@ BUILD_CM_Cx_R_(tcid_8_priority, 0x80) #define CM_GCR_BASE_GCRBASE_MSK (_ULCAST_(0x1ffff) << 15) #define CM_GCR_BASE_CMDEFTGT_SHF 0 #define CM_GCR_BASE_CMDEFTGT_MSK (_ULCAST_(0x3) << 0) -#define CM_GCR_BASE_CMDEFTGT_DISABLED 0 -#define CM_GCR_BASE_CMDEFTGT_MEM 1 +#define CM_GCR_BASE_CMDEFTGT_MEM 0 +#define CM_GCR_BASE_CMDEFTGT_RESERVED 1 #define CM_GCR_BASE_CMDEFTGT_IOCU0 2 #define CM_GCR_BASE_CMDEFTGT_IOCU1 3