irqchip: mips-gic: Provide VP ID accessor

Provide a gic_read_local_vp_id() function to read the VCNUM field of the
GICs local VP_IDENT register. This will be used by a further patch to
check that the value reported by the GIC matches up with the kernels
calculation.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12334/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index e28311f..c089f49 100644 (file)
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -246,6 +246,14 @@ void gic_stop_count(void)
 
 #endif
 
+unsigned gic_read_local_vp_id(void)
+{
+       unsigned long ident;
+
+       ident = gic_read(GIC_REG(VPE_LOCAL, GIC_VP_IDENT));
+       return ident & GIC_VP_IDENT_VCNUM_MSK;
+}
+
 static bool gic_local_irq_is_routable(int intr)
 {
        u32 vpe_ctl;

diff --git a/include/linux/irqchip/mips-gic.h b/include/linux/irqchip/mips-gic.h
index 80f89e4..81f930b 100644 (file)
--- a/include/linux/irqchip/mips-gic.h
+++ b/include/linux/irqchip/mips-gic.h
@@ -103,6 +103,7 @@
 #define GIC_VPE_SWINT0_MAP_OFS         0x0054
 #define GIC_VPE_SWINT1_MAP_OFS         0x0058
 #define GIC_VPE_OTHER_ADDR_OFS         0x0080
+#define GIC_VP_IDENT_OFS               0x0088
 #define GIC_VPE_WD_CONFIG0_OFS         0x0090
 #define GIC_VPE_WD_COUNT0_OFS          0x0094
 #define GIC_VPE_WD_INITIAL0_OFS                0x0098
@@ -211,6 +212,10 @@
 #define GIC_VPE_SMASK_FDC_SHF          6
 #define GIC_VPE_SMASK_FDC_MSK          (MSK(1) << GIC_VPE_SMASK_FDC_SHF)
 
+/* GIC_VP_IDENT fields */
+#define GIC_VP_IDENT_VCNUM_SHF         0
+#define GIC_VP_IDENT_VCNUM_MSK         (MSK(6) << GIC_VP_IDENT_VCNUM_SHF)
+
 /* GIC nomenclature for Core Interrupt Pins. */
 #define GIC_CPU_INT0           0 /* Core Interrupt 2 */
 #define GIC_CPU_INT1           1 /* .                */
@@ -278,4 +283,16 @@ static inline int gic_get_usm_range(struct resource *gic_usm_res)
 
 #endif /* CONFIG_MIPS_GIC */
 
+/**
+ * gic_read_local_vp_id() - read the local VPs VCNUM
+ *
+ * Read the VCNUM of the local VP from the GIC_VP_IDENT register and
+ * return it to the caller. This ID should be used to refer to the VP
+ * via the GICs VP-other region, or when calculating an offset to a
+ * bit representing the VP in interrupt masks.
+ *
+ * Return: The VCNUM value for the local VP.
+ */
+extern unsigned gic_read_local_vp_id(void);
+
 #endif /* __LINUX_IRQCHIP_MIPS_GIC_H */