On Wed, Jan 31, 2024 at 8:27 PM Heinrich Schuchardt <xypron.g...@gmx.de> wrote: > > On 31.01.24 12:12, Weizhao Ouyang wrote: > > According to PSCI specification DEN0022F, PSCI_FEATURES is used to check > > whether the SMCCC is implemented by discovering SMCCC_VERSION. > > > > Signed-off-by: Weizhao Ouyang <o451686...@gmail.com> > > --- > > v2: check SMCCC_ARCH_FEATURES > > --- > > drivers/firmware/psci.c | 9 ++++++++- > > include/linux/arm-smccc.h | 6 ++++++ > > 2 files changed, 14 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c > > index c6b9efab41..ed701cd1e4 100644 > > --- a/drivers/firmware/psci.c > > +++ b/drivers/firmware/psci.c > > @@ -135,7 +135,7 @@ static int bind_smccc_features(struct udevice *dev, int > > psci_method) > > PSCI_VERSION_MAJOR(psci_0_2_get_version()) == 0) > > return 0; > > > > - if (request_psci_features(ARM_SMCCC_ARCH_FEATURES) == > > + if (request_psci_features(ARM_SMCCC_VERSION) == > > PSCI_RET_NOT_SUPPORTED) > > return 0; > > > > @@ -144,6 +144,13 @@ static int bind_smccc_features(struct udevice *dev, > > int psci_method) > > else > > pdata->invoke_fn = smccc_invoke_smc; > > > > + /* > > + * SMCCC_ARCH_FEATURES is MANDATORY from SMCCC v1.1, but we still > > remain > > + * the invoke_fn() even the SMCCC version is v1.0. > > This sentence is a bit hard to understand. Did you mean, > > "but we keep calling invoke_fn() even if the SMCC version is v1.0" ? > > > + */ > > + if (invoke_psci_fn(ARM_SMCCC_VERSION, 0, 0, 0) < > > ARM_SMCCC_VERSION_1_1) > > + return 0; > > > Why do we leave the function for > invoke_psci_fn(ARM_SMCCC_VERSION, 0, 0, 0) == ARM_SMCCC_VERSION_1_0 > despite the comment above? >
Previously I was trying to leave the driver a fallback SMC call for SMCCC v1.0, but since the arm-ffa driver not use the legacy SMC invoke function and also we can directly call invoke_psci_fn(), so maybe we can drop this fallback function. Will update in v3. BR, Weizhao > Best regards > > Heinrich > > > + > > feature_cnt = ll_entry_count(struct arm_smccc_feature, > > arm_smccc_feature); > > feature = ll_entry_start(struct arm_smccc_feature, arm_smccc_feature); > > > > diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h > > index f44e9e8f93..da3d29aabe 100644 > > --- a/include/linux/arm-smccc.h > > +++ b/include/linux/arm-smccc.h > > @@ -55,8 +55,14 @@ > > #define ARM_SMCCC_QUIRK_NONE 0 > > #define ARM_SMCCC_QUIRK_QCOM_A6 1 /* Save/restore register a6 > > */ > > > > +#define ARM_SMCCC_VERSION 0x80000000 > > #define ARM_SMCCC_ARCH_FEATURES 0x80000001 > > > > +#define ARM_SMCCC_VERSION_1_0 0x10000 > > +#define ARM_SMCCC_VERSION_1_1 0x10001 > > +#define ARM_SMCCC_VERSION_1_2 0x10002 > > +#define ARM_SMCCC_VERSION_1_3 0x10003 > > + > > #define ARM_SMCCC_RET_NOT_SUPPORTED ((unsigned long)-1) > > > > #ifndef __ASSEMBLY__ >
