This is a note to let you know that I've just added the patch titled
ARM: 9075/1: kernel: Fix interrupted SMC calls
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm-9075-1-kernel-fix-interrupted-smc-calls.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8c9d370c4668c116ef1b9e0d9f654e9bb5d1228d
Author: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Date: Wed Apr 14 04:41:16 2021 +0100
ARM: 9075/1: kernel: Fix interrupted SMC calls
[ Upstream commit 57ac51667d8cd62731223d687e5fe7b41c502f89 ]
On Qualcomm ARM32 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 ARM32 SMCC code already has the provision to add platform specific
quirks for things like this. So let's make use of it and add the
Qualcomm specific quirk (ARM_SMCCC_QUIRK_QCOM_A6) used by the QCOM_SCM
driver.
This change is similar to the below one added for ARM64 a while ago:
commit 82bcd087029f ("firmware: qcom: scm: Fix interrupted SCM calls")
Without this change, the Qualcomm ARM32 platforms like SDX55 will return
-EINVAL for SMC calls used for modem firmware loading and validation.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index bfb05c93494d..4ce2e29da14d 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -27,6 +27,7 @@
#include <asm/vdso_datapage.h>
#include <asm/hardware/cache-l2x0.h>
#include <linux/kbuild.h>
+#include <linux/arm-smccc.h>
#include "signal.h"
/*
@@ -160,6 +161,8 @@ int main(void)
DEFINE(SLEEP_SAVE_SP_PHYS, offsetof(struct sleep_save_sp, save_ptr_stash_phys));
DEFINE(SLEEP_SAVE_SP_VIRT, offsetof(struct sleep_save_sp, save_ptr_stash));
#endif
+ DEFINE(ARM_SMCCC_QUIRK_ID_OFFS, offsetof(struct arm_smccc_quirk, id));
+ DEFINE(ARM_SMCCC_QUIRK_STATE_OFFS, offsetof(struct arm_smccc_quirk, state));
BLANK();
DEFINE(DMA_BIDIRECTIONAL, DMA_BIDIRECTIONAL);
DEFINE(DMA_TO_DEVICE, DMA_TO_DEVICE);
diff --git a/arch/arm/kernel/smccc-call.S b/arch/arm/kernel/smccc-call.S
index 00664c78faca..931df62a7831 100644
--- a/arch/arm/kernel/smccc-call.S
+++ b/arch/arm/kernel/smccc-call.S
@@ -3,7 +3,9 @@
* Copyright (c) 2015, Linaro Limited
*/
#include <linux/linkage.h>
+#include <linux/arm-smccc.h>
+#include <asm/asm-offsets.h>
#include <asm/opcodes-sec.h>
#include <asm/opcodes-virt.h>
#include <asm/unwind.h>
@@ -27,7 +29,14 @@ UNWIND( .fnstart)
UNWIND( .save {r4-r7})
ldm r12, {r4-r7}
\instr
- pop {r4-r7}
+ ldr r4, [sp, #36]
+ cmp r4, #0
+ beq 1f // No quirk structure
+ ldr r5, [r4, #ARM_SMCCC_QUIRK_ID_OFFS]
+ cmp r5, #ARM_SMCCC_QUIRK_QCOM_A6
+ bne 1f // No quirk present
+ str r6, [r4, #ARM_SMCCC_QUIRK_STATE_OFFS]
+1: pop {r4-r7}
ldr r12, [sp, #(4 * 4)]
stm r12, {r0-r3}
bx lr
