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authorAndy Gross <andy.gross@linaro.org>2017-04-04 19:32:32 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-04-12 12:41:21 +0200
commitbec9918bb4dae2099c37791133403c32aa2738c7 (patch)
tree8bda4c001768c2246736edbd2b833b1d236d6613 /arch
parent007f0a2f2c0fcfa9ecef016c0910aebd0b784fdd (diff)
firmware: qcom: scm: Fix interrupted SCM calls
[ Upstream commit 82bcd087029f6056506ea929f11af02622230901 ] This patch adds a Qualcomm specific quirk to the arm_smccc_smc call. On Qualcomm ARM64 platforms, the SMC call can return before it has completed. If this occurs, the call can be restarted, but it requires using the returned session ID value from the interrupted SMC call. The quirk stores off the session ID from the interrupted call in the quirk structure so that it can be used by the caller. This patch folds in a fix given by Sricharan R: https://lkml.org/lkml/2016/9/28/272 Signed-off-by: Andy Gross <andy.gross@linaro.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/kernel/smccc-call.S9
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/arm64/kernel/smccc-call.S b/arch/arm64/kernel/smccc-call.S
index ba60a8cb07d2..62522342e1e4 100644
--- a/arch/arm64/kernel/smccc-call.S
+++ b/arch/arm64/kernel/smccc-call.S
@@ -12,6 +12,7 @@
*
*/
#include <linux/linkage.h>
+#include <linux/arm-smccc.h>
#include <asm/asm-offsets.h>
.macro SMCCC instr
@@ -20,7 +21,13 @@
ldr x4, [sp]
stp x0, x1, [x4, #ARM_SMCCC_RES_X0_OFFS]
stp x2, x3, [x4, #ARM_SMCCC_RES_X2_OFFS]
- ret
+ ldr x4, [sp, #8]
+ cbz x4, 1f /* no quirk structure */
+ ldr x9, [x4, #ARM_SMCCC_QUIRK_ID_OFFS]
+ cmp x9, #ARM_SMCCC_QUIRK_QCOM_A6
+ b.ne 1f
+ str x6, [x4, ARM_SMCCC_QUIRK_STATE_OFFS]
+1: ret
.cfi_endproc
.endm