[PATCH 4.2 018/134] MIPS: CPS: use 32b accesses to GCRs

From: Greg Kroah-Hartman
Date: Sat Sep 26 2015 - 18:17:12 EST


4.2-stable review patch. If anyone has any objections, please let me know.

------------------

From: Paul Burton <paul.burton@xxxxxxxxxx>

commit 90996511187d6282db6d02d3f97006b4dbb5c457 upstream.

Commit b677bc03d757 ("MIPS: cps-vec: Use macros for various arithmetics
and memory operations") replaced various load & store instructions
through cps-vec.S with the PTR_L & PTR_S macros. However it was somewhat
overzealous in doing so for CM GCR accesses, since the bit width of the
CM doesn't necessarily match that of the CPU. The registers accessed
(GCR_CL_COHERENCE & GCR_CL_ID) should be safe to simply always access
using 32b instructions, so do so in order to avoid issues when using a
32b CM with a 64b CPU.

Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: Markos Chandras <markos.chandras@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: James Hogan <james.hogan@xxxxxxxxxx>
Patchwork: https://patchwork.linux-mips.org/patch/10864/
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/mips/kernel/cps-vec.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/mips/kernel/cps-vec.S
+++ b/arch/mips/kernel/cps-vec.S
@@ -152,7 +152,7 @@ dcache_done:

/* Enter the coherent domain */
li t0, 0xff
- PTR_S t0, GCR_CL_COHERENCE_OFS(v1)
+ sw t0, GCR_CL_COHERENCE_OFS(v1)
ehb

/* Jump to kseg0 */
@@ -302,7 +302,7 @@ LEAF(mips_cps_boot_vpes)
PTR_L t0, 0(t0)

/* Calculate a pointer to this cores struct core_boot_config */
- PTR_L t0, GCR_CL_ID_OFS(t0)
+ lw t0, GCR_CL_ID_OFS(t0)
li t1, COREBOOTCFG_SIZE
mul t0, t0, t1
PTR_LA t1, mips_cps_core_bootcfg


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