[PATCH kernel-3.0] arm:cache-l2x0: Fix L2 Cache size calculation.

Srinivas Kandagatla srinivas.kandagatla at st.com
Fri Aug 12 05:21:58 EDT 2011


This patch fixes L2 Cache size calculations for L2C-210, L2C-310 and
PL310, by changing the L2X0_AUX_CTRL_WAY_SIZE_MASK from 2 bits to 3
bits.

The Auxiliary Control Register for L2C-210, L2C-310 and PL310 has 3bits
[19:17] for Way size, however the existing code only uses 2 bits to
get this value. This results in incorrect cachesize calculations.

It also results in performing operations on the whole cache when we
erroneously decide that the range is big enough (due to l2x0_size being
too small) and also prints incorrect cachesize.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla at st.com>
Acked-by: Will Deacon <will.deacon at arm.com>
Cc: stable at kernel.org

---

adding stable in CC..

Hi All,

I found an bug in L2 Cache size calculation in cache-l2x0 code.

According to ARM TRM for L2C-210, L2C-310 and PL310, the Auxiliary
Control Register has 3bits [19:17] allocated for Way size,however
the existing code only uses 2 bits to get this value from Aux 
control register. This results in incorrect cache size calculations.


It also results in performing operations on the whole cache when we
erroneously decide that the range is big enough (due to l2x0_size being
too small).

thanks, 
srini


 arch/arm/include/asm/hardware/cache-l2x0.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/arm/include/asm/hardware/cache-l2x0.h b/arch/arm/include/asm/hardware/cache-l2x0.h
index 16bd480..bfa706f 100644
--- a/arch/arm/include/asm/hardware/cache-l2x0.h
+++ b/arch/arm/include/asm/hardware/cache-l2x0.h
@@ -64,7 +64,7 @@
 #define L2X0_AUX_CTRL_MASK			0xc0000fff
 #define L2X0_AUX_CTRL_ASSOCIATIVITY_SHIFT	16
 #define L2X0_AUX_CTRL_WAY_SIZE_SHIFT		17
-#define L2X0_AUX_CTRL_WAY_SIZE_MASK		(0x3 << 17)
+#define L2X0_AUX_CTRL_WAY_SIZE_MASK		(0x7 << 17)
 #define L2X0_AUX_CTRL_SHARE_OVERRIDE_SHIFT	22
 #define L2X0_AUX_CTRL_NS_LOCKDOWN_SHIFT		26
 #define L2X0_AUX_CTRL_NS_INT_CTRL_SHIFT		27
-- 
1.6.3.3


--------------070305060106060500050607--



More information about the linux-arm-kernel mailing list