Commit 82bcd087 authored by Andy Gross's avatar Andy Gross Committed by Will Deacon

firmware: qcom: scm: Fix interrupted SCM calls

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/2016/9/28/272Signed-off-by: default avatarAndy Gross <andy.gross@linaro.org>
Reviewed-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 680a0873
...@@ -12,6 +12,7 @@ ...@@ -12,6 +12,7 @@
* *
*/ */
#include <linux/linkage.h> #include <linux/linkage.h>
#include <linux/arm-smccc.h>
#include <asm/asm-offsets.h> #include <asm/asm-offsets.h>
.macro SMCCC instr .macro SMCCC instr
...@@ -20,7 +21,13 @@ ...@@ -20,7 +21,13 @@
ldr x4, [sp] ldr x4, [sp]
stp x0, x1, [x4, #ARM_SMCCC_RES_X0_OFFS] stp x0, x1, [x4, #ARM_SMCCC_RES_X0_OFFS]
stp x2, x3, [x4, #ARM_SMCCC_RES_X2_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 .cfi_endproc
.endm .endm
......
...@@ -91,6 +91,7 @@ static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id, ...@@ -91,6 +91,7 @@ static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id,
dma_addr_t args_phys = 0; dma_addr_t args_phys = 0;
void *args_virt = NULL; void *args_virt = NULL;
size_t alloc_len; size_t alloc_len;
struct arm_smccc_quirk quirk = {.id = ARM_SMCCC_QUIRK_QCOM_A6};
if (unlikely(arglen > N_REGISTER_ARGS)) { if (unlikely(arglen > N_REGISTER_ARGS)) {
alloc_len = N_EXT_QCOM_SCM_ARGS * sizeof(u64); alloc_len = N_EXT_QCOM_SCM_ARGS * sizeof(u64);
...@@ -131,10 +132,16 @@ static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id, ...@@ -131,10 +132,16 @@ static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id,
qcom_smccc_convention, qcom_smccc_convention,
ARM_SMCCC_OWNER_SIP, fn_id); ARM_SMCCC_OWNER_SIP, fn_id);
quirk.state.a6 = 0;
do { do {
arm_smccc_smc(cmd, desc->arginfo, desc->args[0], arm_smccc_smc_quirk(cmd, desc->arginfo, desc->args[0],
desc->args[1], desc->args[2], x5, 0, 0, desc->args[1], desc->args[2], x5,
res); quirk.state.a6, 0, res, &quirk);
if (res->a0 == QCOM_SCM_INTERRUPTED)
cmd = res->a0;
} while (res->a0 == QCOM_SCM_INTERRUPTED); } while (res->a0 == QCOM_SCM_INTERRUPTED);
mutex_unlock(&qcom_scm_lock); mutex_unlock(&qcom_scm_lock);
......
...@@ -14,9 +14,6 @@ ...@@ -14,9 +14,6 @@
#ifndef __LINUX_ARM_SMCCC_H #ifndef __LINUX_ARM_SMCCC_H
#define __LINUX_ARM_SMCCC_H #define __LINUX_ARM_SMCCC_H
#include <linux/linkage.h>
#include <linux/types.h>
/* /*
* This file provides common defines for ARM SMC Calling Convention as * This file provides common defines for ARM SMC Calling Convention as
* specified in * specified in
...@@ -60,6 +57,13 @@ ...@@ -60,6 +57,13 @@
#define ARM_SMCCC_OWNER_TRUSTED_OS 50 #define ARM_SMCCC_OWNER_TRUSTED_OS 50
#define ARM_SMCCC_OWNER_TRUSTED_OS_END 63 #define ARM_SMCCC_OWNER_TRUSTED_OS_END 63
#define ARM_SMCCC_QUIRK_NONE 0
#define ARM_SMCCC_QUIRK_QCOM_A6 1 /* Save/restore register a6 */
#ifndef __ASSEMBLY__
#include <linux/linkage.h>
#include <linux/types.h>
/** /**
* struct arm_smccc_res - Result from SMC/HVC call * struct arm_smccc_res - Result from SMC/HVC call
* @a0-a3 result values from registers 0 to 3 * @a0-a3 result values from registers 0 to 3
...@@ -125,4 +129,5 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1, ...@@ -125,4 +129,5 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
#define arm_smccc_hvc_quirk(...) __arm_smccc_hvc(__VA_ARGS__) #define arm_smccc_hvc_quirk(...) __arm_smccc_hvc(__VA_ARGS__)
#endif /*__ASSEMBLY__*/
#endif /*__LINUX_ARM_SMCCC_H*/ #endif /*__LINUX_ARM_SMCCC_H*/
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