On 3/16/23 11:00, Marc Zyngier wrote:
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On 2023-03-16 15:10, Sudeep Holla wrote:
On Wed, Mar 15, 2023 at 07:27:14AM -0500, Shanker Donthineni wrote:
Hi Marc,
On 3/15/23 03:34, Marc Zyngier wrote:
> Please don't duplicate existing code. There is already the required
> infrastructure in drivers/firmware/smccc/soc_id.c. All you need to do
> is:
>
> - disassociate the SMCCC probing from the device registration
>
> - probe the SOC_ID early
>
> - add accessors for the relevant data
>
> - select ARM_SMCCC_SOD_ID/ARM_SMCCC_DISCOVERY from the GICv3 Kconfig
I have not modified soc_id.c as it expects to be loaded as a module
with
the use of module_init() and module_exit() functions. The exported
symbols
in soc_id driver cannot be accessed from the built-in code.
Agree, the SOD-ID discovery code was duplicated.
Please guide me if the below approach is okay?
1) Probe the SOC-ID in arm_smccc_version_init() and export two
functions
arm_smccc_get_soc_id_version() and arm_smccc_get_soc_id_revision().
--- a/drivers/firmware/smccc/smccc.c
+++ b/drivers/firmware/smccc/smccc.c
@@ -17,9 +17,13 @@ static enum arm_smccc_conduit smccc_conduit =
SMCCC_CONDUIT_NONE;
bool __ro_after_init smccc_trng_available = false;
u64 __ro_after_init smccc_has_sve_hint = false;
+s32 __ro_after_init smccc_soc_id_version = SMCCC_RET_NOT_SUPPORTED;
+s32 __ro_after_init smccc_soc_id_revision = SMCCC_RET_NOT_SUPPORTED;
void __init arm_smccc_version_init(u32 version, enum
arm_smccc_conduit conduit)
{
+ struct arm_smccc_res res;
+
smccc_version = version;
smccc_conduit = conduit;
@@ -27,6 +31,18 @@ void __init arm_smccc_version_init(u32 version,
enum arm_smccc_conduit conduit)
if (IS_ENABLED(CONFIG_ARM64_SVE) &&
smccc_version >= ARM_SMCCC_VERSION_1_3)
smccc_has_sve_hint = true;
+
+ if ((smccc_version >= ARM_SMCCC_VERSION_1_2) &&
+ (smccc_conduit != SMCCC_CONDUIT_NONE)) {
+ arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+ ARM_SMCCC_ARCH_SOC_ID, &res);
+ if ((s32)res.a0 >= 0) {
+ arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 0,
&res);
+ smccc_soc_id_version = (s32)res.a0;
+ arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 1,
&res);
+ smccc_soc_id_revision = (s32)res.a0;
+ }
+ }
}
+s32 arm_smccc_get_soc_id_version(void)
+{
+ return smccc_soc_id_version;
+}
+EXPORT_SYMBOL_GPL(arm_smccc_get_soc_id_version);
+
+s32 arm_smccc_get_soc_id_revision(void)
+{
+ return smccc_soc_id_revision;
+}
+EXPORT_SYMBOL_GPL(arm_smccc_get_soc_id_revision);
Overall, it looks OK to me. However I see neither the gic nor the
soc_id
can be build as module atm. So do we really need the export symbols if
no
other modules are using it ?
It really shouldn't be exported. Having accessors should be enough.
Thanks, I'll remove in v3 patch.
-Shanker
