| Message ID | 20210326182237.47048-1-manivannan.sadhasivam@linaro.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [v3] ARM: kernel: Fix interrupted SMC calls | expand |
On Fri 26 Mar 13:22 CDT 2021, Manivannan Sadhasivam wrote: > 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@linaro.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Regards, Bjorn > --- > > Changes in v3: > > * Rebased on top of v5.12-rc2 > * Sent to SoC list since there was no review so far apart from initial one > by Russel > > Changes in v2: > > * Preserved callee saved registers and used the registers r4, r5 which > are getting pushed onto the stack. > > arch/arm/kernel/asm-offsets.c | 3 +++ > arch/arm/kernel/smccc-call.S | 11 ++++++++++- > 2 files changed, 13 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c > index be8050b0c3df..70993af22d80 100644 > --- a/arch/arm/kernel/asm-offsets.c > +++ b/arch/arm/kernel/asm-offsets.c > @@ -24,6 +24,7 @@ > #include <asm/vdso_datapage.h> > #include <asm/hardware/cache-l2x0.h> > #include <linux/kbuild.h> > +#include <linux/arm-smccc.h> > #include "signal.h" > > /* > @@ -148,6 +149,8 @@ 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 > -- > 2.25.1 >
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c index be8050b0c3df..70993af22d80 100644 --- a/arch/arm/kernel/asm-offsets.c +++ b/arch/arm/kernel/asm-offsets.c @@ -24,6 +24,7 @@ #include <asm/vdso_datapage.h> #include <asm/hardware/cache-l2x0.h> #include <linux/kbuild.h> +#include <linux/arm-smccc.h> #include "signal.h" /* @@ -148,6 +149,8 @@ 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
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@linaro.org> --- Changes in v3: * Rebased on top of v5.12-rc2 * Sent to SoC list since there was no review so far apart from initial one by Russel Changes in v2: * Preserved callee saved registers and used the registers r4, r5 which are getting pushed onto the stack. arch/arm/kernel/asm-offsets.c | 3 +++ arch/arm/kernel/smccc-call.S | 11 ++++++++++- 2 files changed, 13 insertions(+), 1 deletion(-)