4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Paul Burton <paul.burton@xxxxxxxx>
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@xxxxxxxx>
Reported-by: Matt Redfearn <matt.redfearn@xxxxxxxx>
Reviewed-by: James Hogan <jhogan@xxxxxxxxxx>
Cc: Matt Redfearn <matt.redfearn@xxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx> # v3.15+
Patchwork: https://patchwork.linux-mips.org/patch/17562/
Signed-off-by: James Hogan <jhogan@xxxxxxxxxx>
[jhogan@xxxxxxxxxx: Backported 3.15..4.13]
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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