Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1548417 > unrolled thread
| Started by | Andy Gross <andy.gross@linaro.org> |
|---|---|
| First post | 2016-12-30 00:30 +0100 |
| Last post | 2016-12-30 00:30 +0100 |
| Articles | 2 — 1 participant |
Back to article view | Back to linux.kernel
[Patch v2 0/2] Support ARM SMCC SoC vendor quirks Andy Gross <andy.gross@linaro.org> - 2016-12-30 00:30 +0100
[Patch v2 2/2] firmware: qcom: scm: Fix interrupted SCM calls Andy Gross <andy.gross@linaro.org> - 2016-12-30 00:30 +0100
| From | Andy Gross <andy.gross@linaro.org> |
|---|---|
| Date | 2016-12-30 00:30 +0100 |
| Subject | [Patch v2 0/2] Support ARM SMCC SoC vendor quirks |
| Message-ID | <sTSj0-4Jr-5@gated-at.bofh.it> |
At least one SoC vendor (Qualcomm) requires additional processing done during ARM SMCCC calls. As such, an additional parameter to the arm_smccc_smc is required to be able to handle SoC specific quirks. The Qualcomm quirk is necessary due to the fact that the scm call can be interrupted on Qualcomm ARM64 platforms. When this occurs, the call must be restarted using information that was passed back during the original smc call. The first patch in this series adds a quirk structure and also adds a quirk paramter to arm_smccc_smc calls. I added macros to allow users to choose the API they need. This keeps all of the current users who do not need quirks from having to change anything. The second patch adds the Qualcomm quirk and also implements the Qualcomm firmware changes required to handle the restarting of the interrupted SMC call. The original patch set for the SMCCC session ID is located at: https://lkml.org/lkml/2016/8/20/7 Changes from v1: - Add macros to handle both use cases per review comments Andy Gross (2): arm: kernel: Add SMC structure parameter firmware: qcom: scm: Fix interrupted SCM calls arch/arm/kernel/armksyms.c | 2 +- arch/arm/kernel/smccc-call.S | 7 ++++--- arch/arm64/kernel/arm64ksyms.c | 2 +- arch/arm64/kernel/asm-offsets.c | 7 +++++-- arch/arm64/kernel/smccc-call.S | 16 ++++++++++++---- drivers/firmware/qcom_scm-64.c | 13 ++++++++++--- include/linux/arm-smccc.h | 39 ++++++++++++++++++++++++++++++++------- 7 files changed, 65 insertions(+), 21 deletions(-) -- 1.9.1
[toc] | [next] | [standalone]
| From | Andy Gross <andy.gross@linaro.org> |
|---|---|
| Date | 2016-12-30 00:30 +0100 |
| Subject | [Patch v2 2/2] firmware: qcom: scm: Fix interrupted SCM calls |
| Message-ID | <sTSj0-4Jr-7@gated-at.bofh.it> |
| In reply to | #1548417 |
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>
---
arch/arm64/kernel/smccc-call.S | 9 ++++++++-
drivers/firmware/qcom_scm-64.c | 13 ++++++++++---
include/linux/arm-smccc.h | 11 ++++++++---
3 files changed, 26 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/kernel/smccc-call.S b/arch/arm64/kernel/smccc-call.S
index 6290696..72ecdca 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
diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c
index 4a0f5ea..1e2e519 100644
--- a/drivers/firmware/qcom_scm-64.c
+++ b/drivers/firmware/qcom_scm-64.c
@@ -91,6 +91,7 @@ static int qcom_scm_call(struct device *dev, u32 svc_id, u32 cmd_id,
dma_addr_t args_phys = 0;
void *args_virt = NULL;
size_t alloc_len;
+ struct arm_smccc_quirk quirk = {.id = ARM_SMCCC_QUIRK_QCOM_A6};
if (unlikely(arglen > N_REGISTER_ARGS)) {
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,
qcom_smccc_convention,
ARM_SMCCC_OWNER_SIP, fn_id);
+ quirk.state.a6 = 0;
+
do {
- arm_smccc_smc(cmd, desc->arginfo, desc->args[0],
- desc->args[1], desc->args[2], x5, 0, 0,
- res);
+ arm_smccc_smc_quirk(cmd, desc->arginfo, desc->args[0],
+ desc->args[1], desc->args[2], x5,
+ quirk.state.a6, 0, res, &quirk);
+
+ if (res->a0 == QCOM_SCM_INTERRUPTED)
+ cmd = res->a0;
+
} while (res->a0 == QCOM_SCM_INTERRUPTED);
mutex_unlock(&qcom_scm_lock);
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index cde4f1f..64d0454 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -14,9 +14,6 @@
#ifndef __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
* specified in
@@ -60,6 +57,13 @@
#define ARM_SMCCC_OWNER_TRUSTED_OS 50
#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
* @a0-a3 result values from registers 0 to 3
@@ -121,4 +125,5 @@ asmlinkage void arm_smccc_hvc(unsigned long a0, unsigned long a1,
#define arm_smccc_smc_quirk(a0, a1, a2, a3, a4, a5, a6, a7, res, quirk) \
__arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res, quirk)
+#endif /*__ASSEMBLY__*/
#endif /*__LINUX_ARM_SMCCC_H*/
--
1.9.1
[toc] | [prev] | [standalone]
Back to top | Article view | linux.kernel
csiph-web