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authorDoug Anderson <armlinux@m.disordat.com>2019-04-27 00:35:46 +0200
committerRussell King <rmk+kernel@armlinux.org.uk>2019-06-20 23:29:55 +0200
commit304009a182b9fc6eff74060b415c8240380501cb (patch)
treefe9743b44dfbd5907a9a614151bfaf776946a5c6
parentARM: 8860/1: VDSO: Drop implicit common-page-size linker flag (diff)
downloadlinux-304009a182b9fc6eff74060b415c8240380501cb.tar.xz
linux-304009a182b9fc6eff74060b415c8240380501cb.zip
ARM: 8861/1: errata: Workaround errata A12 857271 / A17 857272
This adds support for working around errata A12 857271 / A17 857272. These errata were causing hangs on rk3288-based Chromebooks and it was confirmed that this workaround fixed the problems. In the Chrome OS 3.14 kernel this was treated as two errata: ERRATA_FOOBAR [1] and ERRATA_CR711784 [2]. Apparently the two errata got lumped together at some point in time. Let's actually get the workaround landed. [1] https://crrev.com/c/342753 [2] https://crbug.com/711784 Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Sonny Rao <sonnyrao@chromium.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
-rw-r--r--arch/arm/Kconfig18
-rw-r--r--arch/arm/mm/proc-v7.S10
2 files changed, 28 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 8869742a85df..96377e3cd3d8 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1175,6 +1175,14 @@ config ARM_ERRATA_825619
DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
and Device/Strongly-Ordered loads and stores might cause deadlock
+config ARM_ERRATA_857271
+ bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 857271 Cortex-A12
+ (all revs) erratum. Under very rare timing conditions, the CPU might
+ hang. The workaround is expected to have a < 1% performance impact.
+
config ARM_ERRATA_852421
bool "ARM errata: A17: DMB ST might fail to create order between stores"
depends on CPU_V7
@@ -1196,6 +1204,16 @@ config ARM_ERRATA_852423
config option from the A12 erratum due to the way errata are checked
for and handled.
+config ARM_ERRATA_857272
+ bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 857272 Cortex-A17 erratum.
+ This erratum is not known to be fixed in any A17 revision.
+ This is identical to Cortex-A12 erratum 857271. It is a separate
+ config option from the A12 erratum due to the way errata are checked
+ for and handled.
+
endmenu
source "arch/arm/common/Kconfig"
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 339eb17c9808..2966086d8a45 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -392,6 +392,11 @@ __ca12_errata:
orr r10, r10, #1 << 24 @ set bit #24
mcr p15, 0, r10, c15, c0, 1 @ write diagnostic register
#endif
+#ifdef CONFIG_ARM_ERRATA_857271
+ mrc p15, 0, r10, c15, c0, 1 @ read diagnostic register
+ orr r10, r10, #3 << 10 @ set bits #10 and #11
+ mcr p15, 0, r10, c15, c0, 1 @ write diagnostic register
+#endif
b __errata_finish
__ca17_errata:
@@ -407,6 +412,11 @@ __ca17_errata:
orrle r10, r10, #1 << 12 @ set bit #12
mcrle p15, 0, r10, c15, c0, 1 @ write diagnostic register
#endif
+#ifdef CONFIG_ARM_ERRATA_857272
+ mrc p15, 0, r10, c15, c0, 1 @ read diagnostic register
+ orr r10, r10, #3 << 10 @ set bits #10 and #11
+ mcr p15, 0, r10, c15, c0, 1 @ write diagnostic register
+#endif
b __errata_finish
__v7_pj4b_setup: