[PATCH v2] irqchip: gic-v3: fix unmet dependency on ARM_PSCI_FW

ARM_GIC_V3 currently selects HAVE_ARM_SMCCC_DISCOVERY without ensuring its
dependency, ARM_PSCI_FW, is met. However, ARM_PSCI_FW is always enabled on
for arm64, and the GICv3 driver only uses HAVE_ARM_SMCCC_DISCOVERY to
identify the NVIDIA T241, which is arm64 anyway.

Also adds fallbacks for callers to avoid needing #ifdef guards when
HAVE_ARM_SMCCC_DISCOVERY is disabled (32bit arm).

This unmet dependency was found by kconfirm, a static analysis tool for
Kconfig.

Fixes: 35727af2b15d ("irqchip/gicv3: Workaround for NVIDIA erratum T241-FABRIC-4")
Suggested-by: Marc Zyngier <[email protected]>
Signed-off-by: Julian Braha <[email protected]>
---
Changes since v1:
- remove select and dependency on ARM_PSCI_FW, 
- make the HAVE_ARM_SMCCC_DISCOVERY 'select' conditional on arm64
Link to v1: https://lore.kernel.org/all/[email protected]/
---
 drivers/irqchip/Kconfig   | 2 +-
 include/linux/arm-smccc.h | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 20b77fbc51ee..dae023fed7d6 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -37,7 +37,7 @@ config ARM_GIC_V3
 	bool
 	select IRQ_DOMAIN_HIERARCHY
 	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
-	select HAVE_ARM_SMCCC_DISCOVERY
+	select HAVE_ARM_SMCCC_DISCOVERY if ARM64
 	select IRQ_MSI_IOMMU
 
 config ARM_GIC_ITS_PARENT
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index 4de81848fe2e..248624c1af7c 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -324,6 +324,7 @@ enum arm_smccc_conduit {
 	SMCCC_CONDUIT_HVC,
 };
 
+#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
 /**
  * arm_smccc_1_1_get_conduit()
  *
@@ -363,6 +364,12 @@ s32 arm_smccc_get_soc_id_version(void);
  * When ARM_SMCCC_ARCH_SOC_ID is not present, returns SMCCC_RET_NOT_SUPPORTED.
  */
 s32 arm_smccc_get_soc_id_revision(void);
+#else   /* CONFIG_HAVE_ARM_SMCCC_DISCOVERY */
+#define arm_smccc_1_1_get_conduit()	SMCCC_CONDUIT_NONE
+#define arm_smccc_get_version()		0
+#define arm_smccc_get_soc_id_version()	SMCCC_RET_NOT_SUPPORTED
+#define arm_smccc_get_soc_id_revision()	SMCCC_RET_NOT_SUPPORTED
+#endif	/* CONFIG_HAVE_ARM_SMCCC_DISCOVERY */
 
 #ifndef __ASSEMBLY__
 
-- 
2.55.0