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| author | Catalin Marinas <catalin.marinas@arm.com> | 2011-08-15 11:04:41 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2011-08-15 11:58:59 +0100 |
| commit | 145e10e173c8adf4804334fb0dd10028300a7a7a (patch) | |
| tree | 37409358acf86db952e0216fa528d289eef4fc4d /arch/arm | |
| parent | 43c734be5571a4daad9f0a3e0b3229a1c0049917 (diff) | |
| download | linux-145e10e173c8adf4804334fb0dd10028300a7a7a.tar.gz linux-145e10e173c8adf4804334fb0dd10028300a7a7a.tar.bz2 linux-145e10e173c8adf4804334fb0dd10028300a7a7a.zip | |
ARM: 7015/1: ARM errata: Possible cache data corruption with hit-under-miss enabled
This patch is a workaround for the 364296 ARM1136 r0p2 erratum (possible
cache data corruption with hit-under-miss enabled). It sets the
undocumented bit 31 in the auxiliary control register and the FI bit in
the control register, thus disabling hit-under-miss without putting the
processor into full low interrupt latency mode.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/Kconfig | 12 | ||||
| -rw-r--r-- | arch/arm/mm/proc-v6.S | 16 |
2 files changed, 28 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 5ebc5d922ea1..3269576dbfa8 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1271,6 +1271,18 @@ config ARM_ERRATA_754327 This workaround defines cpu_relax() as smp_mb(), preventing correctly written polling loops from denying visibility of updates to memory. +config ARM_ERRATA_364296 + bool "ARM errata: Possible cache data corruption with hit-under-miss enabled" + depends on CPU_V6 && !SMP + help + This options enables the workaround for the 364296 ARM1136 + r0p2 erratum (possible cache data corruption with + hit-under-miss enabled). It sets the undocumented bit 31 in + the auxiliary control register and the FI bit in the control + register, thus disabling hit-under-miss without putting the + processor into full low interrupt latency mode. ARM11MPCore + is not affected. + endmenu source "arch/arm/common/Kconfig" diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S index 219138d2f158..a923aa0fd00d 100644 --- a/arch/arm/mm/proc-v6.S +++ b/arch/arm/mm/proc-v6.S @@ -223,6 +223,22 @@ __v6_setup: mrc p15, 0, r0, c1, c0, 0 @ read control register bic r0, r0, r5 @ clear bits them orr r0, r0, r6 @ set them +#ifdef CONFIG_ARM_ERRATA_364296 + /* + * Workaround for the 364296 ARM1136 r0p2 erratum (possible cache data + * corruption with hit-under-miss enabled). The conditional code below + * (setting the undocumented bit 31 in the auxiliary control register + * and the FI bit in the control register) disables hit-under-miss + * without putting the processor into full low interrupt latency mode. + */ + ldr r6, =0x4107b362 @ id for ARM1136 r0p2 + mrc p15, 0, r5, c0, c0, 0 @ get processor id + teq r5, r6 @ check for the faulty core + mrceq p15, 0, r5, c1, c0, 1 @ load aux control reg + orreq r5, r5, #(1 << 31) @ set the undocumented bit 31 + mcreq p15, 0, r5, c1, c0, 1 @ write aux control reg + orreq r0, r0, #(1 << 21) @ low interrupt latency configuration +#endif mov pc, lr @ return to head.S:__ret /* |