irqchip/gic-v4.1: Add VPE residency callback

Making a VPE resident on GICv4.1 is pretty simple, as it is just a
single write to the local redistributor. We just need extra information
about which groups to enable, which the KVM code will have to provide.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/r/20191224111055.11836-12-maz@kernel.org

drivers/irqchip/irq-gic-v3-its.c

@@ -3624,12 +3624,29 @@ static void its_vpe_4_1_unmask_irq(struct irq_data *d)
 	its_vpe_4_1_send_inv(d);
 }
 
+static void its_vpe_4_1_schedule(struct its_vpe *vpe,
+				 struct its_cmd_info *info)
+{
+	void __iomem *vlpi_base = gic_data_rdist_vlpi_base();
+	u64 val = 0;
+
+	/* Schedule the VPE */
+	val |= GICR_VPENDBASER_Valid;
+	val |= info->g0en ? GICR_VPENDBASER_4_1_VGRP0EN : 0;
+	val |= info->g1en ? GICR_VPENDBASER_4_1_VGRP1EN : 0;
+	val |= FIELD_PREP(GICR_VPENDBASER_4_1_VPEID, vpe->vpe_id);
+
+	gits_write_vpendbaser(val, vlpi_base + GICR_VPENDBASER);
+}
+
 static int its_vpe_4_1_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
 {
+	struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
 	struct its_cmd_info *info = vcpu_info;
 
 	switch (info->cmd_type) {
 	case SCHEDULE_VPE:
+		its_vpe_4_1_schedule(vpe, info);
 		return 0;
 
 	case DESCHEDULE_VPE:

include/linux/irqchip/arm-gic-v3.h

@@ -327,6 +327,15 @@
 #define GICR_VPENDBASER_IDAI		(1ULL << 62)
 #define GICR_VPENDBASER_Valid		(1ULL << 63)
 
+/*
+ * GICv4.1 VPENDBASER, used for VPE residency. On top of these fields,
+ * also use the above Valid, PendingLast and Dirty.
+ */
+#define GICR_VPENDBASER_4_1_DB		(1ULL << 62)
+#define GICR_VPENDBASER_4_1_VGRP0EN	(1ULL << 59)
+#define GICR_VPENDBASER_4_1_VGRP1EN	(1ULL << 58)
+#define GICR_VPENDBASER_4_1_VPEID	GENMASK_ULL(15, 0)
+
 /*
  * ITS registers, offsets from ITS_base
  */

include/linux/irqchip/arm-gic-v4.h

@@ -100,6 +100,11 @@ struct its_cmd_info {
 	union {
 		struct its_vlpi_map	*map;
 		u8			config;
+		bool			req_db;
+		struct {
+			bool		g0en;
+			bool		g1en;
+		};
 	};
 };