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Subject[PATCH] Remove ARM errata Workarounds 458693 and 460075
Date
According to ARM, these errata exist only in a version of Cortex-A8
(r2p0) which was never built. Therefore, I believe there are no platforms
where this workaround should be enabled.
link :http://infocenter.arm.com/help/index.jsp?topic=
/com.arm.doc.faqs/ka15634.html

Signed-off-by: Nisal Menuka <nisalmenuka23@gmail.com>
---
arch/arm/Kconfig | 27 ---------------------------
arch/arm/mm/proc-v7.S | 14 --------------
2 files changed, 41 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 0d4e71b..d527963 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1005,33 +1005,6 @@ config ARM_ERRATA_430973
Note that setting specific bits in the ACTLR register may not be
available in non-secure mode.

-config ARM_ERRATA_458693
- bool "ARM errata: Processor deadlock when a false hazard is created"
- depends on CPU_V7
- depends on !ARCH_MULTIPLATFORM
- help
- This option enables the workaround for the 458693 Cortex-A8 (r2p0)
- erratum. For very specific sequences of memory operations, it is
- possible for a hazard condition intended for a cache line to instead
- be incorrectly associated with a different cache line. This false
- hazard might then cause a processor deadlock. The workaround enables
- the L1 caching of the NEON accesses and disables the PLD instruction
- in the ACTLR register. Note that setting specific bits in the ACTLR
- register may not be available in non-secure mode.
-
-config ARM_ERRATA_460075
- bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
- depends on CPU_V7
- depends on !ARCH_MULTIPLATFORM
- help
- This option enables the workaround for the 460075 Cortex-A8 (r2p0)
- erratum. Any asynchronous access to the L2 cache may encounter a
- situation in which recent store transactions to the L2 cache are lost
- and overwritten with stale memory contents from external memory. The
- workaround disables the write-allocate mode for the L2 cache via the
- ACTLR register. Note that setting specific bits in the ACTLR register
- may not be available in non-secure mode.
-
config ARM_ERRATA_742230
bool "ARM errata: DMB operation may be faulty"
depends on CPU_V7 && SMP
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index d00d52c..43a4a12 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -306,20 +306,6 @@ __ca8_errata:
orreq r0, r0, #(1 << 6) @ set IBE to 1
mcreq p15, 0, r0, c1, c0, 1 @ write aux control register
#endif
-#ifdef CONFIG_ARM_ERRATA_458693
- teq r6, #0x20 @ only present in r2p0
- mrceq p15, 0, r0, c1, c0, 1 @ read aux control register
- orreq r0, r0, #(1 << 5) @ set L1NEON to 1
- orreq r0, r0, #(1 << 9) @ set PLDNOP to 1
- mcreq p15, 0, r0, c1, c0, 1 @ write aux control register
-#endif
-#ifdef CONFIG_ARM_ERRATA_460075
- teq r6, #0x20 @ only present in r2p0
- mrceq p15, 1, r0, c9, c0, 2 @ read L2 cache aux ctrl register
- tsteq r0, #1 << 22
- orreq r0, r0, #(1 << 22) @ set the Write Allocate disable bit
- mcreq p15, 1, r0, c9, c0, 2 @ write the L2 cache aux ctrl register
-#endif
b __errata_finish

__ca9_errata:
--
2.7.4
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