[PATCH 4.4 100/117] crypto: caam - make write transactions bufferable on PPC platforms

From: Greg Kroah-Hartman
Date: Sun Feb 14 2016 - 19:23:21 EST


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

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

From: Horia Geant? <horia.geanta@xxxxxxx>

commit e7a7104e432c0db8469ca3568daf4f1d1afe3e73 upstream.

Previous change (see "Fixes" tag) to the MCFGR register
clears AWCACHE[0] ("bufferable" AXI3 attribute) (which is "1" at POR).

This makes all writes non-bufferable, causing a ~ 5% performance drop
for PPC-based platforms.

Rework previous change such that MCFGR[AWCACHE]=4'b0011
(bufferable + cacheable) for all platforms.
Note: For ARM-based platforms, AWCACHE[0] is ignored
by the interconnect IP.

Fixes: f10967495144 ("crypto: caam - fix snooping for write transactions")
Signed-off-by: Horia Geant? <horia.geanta@xxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/crypto/caam/ctrl.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -534,8 +534,8 @@ static int caam_probe(struct platform_de
* long pointers in master configuration register
*/
clrsetbits_32(&ctrl->mcr, MCFGR_AWCACHE_MASK, MCFGR_AWCACHE_CACH |
- MCFGR_WDENABLE | (sizeof(dma_addr_t) == sizeof(u64) ?
- MCFGR_LONG_PTR : 0));
+ MCFGR_AWCACHE_BUFF | MCFGR_WDENABLE |
+ (sizeof(dma_addr_t) == sizeof(u64) ? MCFGR_LONG_PTR : 0));

/*
* Read the Compile Time paramters and SCFGR to determine