summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorSuzuki K Poulose <suzuki.poulose@arm.com>2018-03-26 15:12:49 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-05-09 09:53:04 +0200
commit41fd9f89c01f9063fc97e3de3bd12968a6b60824 (patch)
tree7b0355341410f4234de085fa83502b0bd8b7e296
parent3fe89843c710603e79d23090b9b1a00c0cce3254 (diff)
arm64: Add work around for Arm Cortex-A55 Erratum 1024718
commit ece1397cbc89c51914fae1aec729539cfd8bd62b upstream. Some variants of the Arm Cortex-55 cores (r0p0, r0p1, r1p0) suffer from an erratum 1024718, which causes incorrect updates when DBM/AP bits in a page table entry is modified without a break-before-make sequence. The work around is to skip enabling the hardware DBM feature on the affected cores. The hardware Access Flag management features is not affected. There are some other cores suffering from this errata, which could be added to the midr_list to trigger the work around. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: ckadabi@codeaurora.org Reviewed-by: Dave Martin <dave.martin@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--Documentation/arm64/silicon-errata.txt1
-rw-r--r--arch/arm64/Kconfig14
-rw-r--r--arch/arm64/include/asm/assembler.h40
-rw-r--r--arch/arm64/include/asm/cputype.h2
-rw-r--r--arch/arm64/mm/proc.S5
5 files changed, 62 insertions, 0 deletions
diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
index c1d520de6dfe..3b2f2dd82225 100644
--- a/Documentation/arm64/silicon-errata.txt
+++ b/Documentation/arm64/silicon-errata.txt
@@ -55,6 +55,7 @@ stable kernels.
| ARM | Cortex-A57 | #834220 | ARM64_ERRATUM_834220 |
| ARM | Cortex-A72 | #853709 | N/A |
| ARM | Cortex-A73 | #858921 | ARM64_ERRATUM_858921 |
+| ARM | Cortex-A55 | #1024718 | ARM64_ERRATUM_1024718 |
| ARM | MMU-500 | #841119,#826419 | N/A |
| | | | |
| Cavium | ThunderX ITS | #22375, #24313 | CAVIUM_ERRATUM_22375 |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7381eeb7ef8e..be665760f2bd 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -464,6 +464,20 @@ config ARM64_ERRATUM_843419
If unsure, say Y.
+config ARM64_ERRATUM_1024718
+ bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update"
+ default y
+ help
+ This option adds work around for Arm Cortex-A55 Erratum 1024718.
+
+ Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect
+ update of the hardware dirty bit when the DBM/AP bits are updated
+ without a break-before-make. The work around is to disable the usage
+ of hardware DBM locally on the affected cores. CPUs not affected by
+ erratum will continue to use the feature.
+
+ If unsure, say Y.
+
config CAVIUM_ERRATUM_22375
bool "Cavium erratum 22375, 24313"
default y
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 3c78835bba94..a3ca19e68b73 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -25,6 +25,7 @@
#include <asm/asm-offsets.h>
#include <asm/cpufeature.h>
+#include <asm/cputype.h>
#include <asm/debug-monitors.h>
#include <asm/page.h>
#include <asm/pgtable-hwdef.h>
@@ -595,4 +596,43 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU
#endif
.endm
+/*
+ * Check the MIDR_EL1 of the current CPU for a given model and a range of
+ * variant/revision. See asm/cputype.h for the macros used below.
+ *
+ * model: MIDR_CPU_MODEL of CPU
+ * rv_min: Minimum of MIDR_CPU_VAR_REV()
+ * rv_max: Maximum of MIDR_CPU_VAR_REV()
+ * res: Result register.
+ * tmp1, tmp2, tmp3: Temporary registers
+ *
+ * Corrupts: res, tmp1, tmp2, tmp3
+ * Returns: 0, if the CPU id doesn't match. Non-zero otherwise
+ */
+ .macro cpu_midr_match model, rv_min, rv_max, res, tmp1, tmp2, tmp3
+ mrs \res, midr_el1
+ mov_q \tmp1, (MIDR_REVISION_MASK | MIDR_VARIANT_MASK)
+ mov_q \tmp2, MIDR_CPU_MODEL_MASK
+ and \tmp3, \res, \tmp2 // Extract model
+ and \tmp1, \res, \tmp1 // rev & variant
+ mov_q \tmp2, \model
+ cmp \tmp3, \tmp2
+ cset \res, eq
+ cbz \res, .Ldone\@ // Model matches ?
+
+ .if (\rv_min != 0) // Skip min check if rv_min == 0
+ mov_q \tmp3, \rv_min
+ cmp \tmp1, \tmp3
+ cset \res, ge
+ .endif // \rv_min != 0
+ /* Skip rv_max check if rv_min == rv_max && rv_min != 0 */
+ .if ((\rv_min != \rv_max) || \rv_min == 0)
+ mov_q \tmp2, \rv_max
+ cmp \tmp1, \tmp2
+ cset \tmp2, le
+ and \res, \res, \tmp2
+ .endif
+.Ldone\@:
+ .endm
+
#endif /* __ASM_ASSEMBLER_H */
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 350c76a1d15b..8e32a6f28f00 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -83,6 +83,7 @@
#define ARM_CPU_PART_CORTEX_A53 0xD03
#define ARM_CPU_PART_CORTEX_A73 0xD09
#define ARM_CPU_PART_CORTEX_A75 0xD0A
+#define ARM_CPU_PART_CORTEX_A55 0xD05
#define APM_CPU_PART_POTENZA 0x000
@@ -102,6 +103,7 @@
#define MIDR_CORTEX_A72 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A72)
#define MIDR_CORTEX_A73 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A73)
#define MIDR_CORTEX_A75 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A75)
+#define MIDR_CORTEX_A55 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A55)
#define MIDR_THUNDERX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX)
#define MIDR_THUNDERX_81XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_81XX)
#define MIDR_THUNDERX_83XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_83XX)
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index c0af47617299..5244440baea4 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -448,6 +448,11 @@ ENTRY(__cpu_setup)
cbz x9, 2f
cmp x9, #2
b.lt 1f
+#ifdef CONFIG_ARM64_ERRATUM_1024718
+ /* Disable hardware DBM on Cortex-A55 r0p0, r0p1 & r1p0 */
+ cpu_midr_match MIDR_CORTEX_A55, MIDR_CPU_VAR_REV(0, 0), MIDR_CPU_VAR_REV(1, 0), x1, x2, x3, x4
+ cbnz x1, 1f
+#endif
orr x10, x10, #TCR_HD // hardware Dirty flag update
1: orr x10, x10, #TCR_HA // hardware Access flag update
2: