irqchip/gic-v4.1: Move doorbell management to the GICv4 abstraction layer

In order to hide some of the differences between v4.0 and v4.1, move
the doorbell management out of the KVM code, and into the GICv4-specific
layer. This allows the calling code to ask for the doorbell when blocking,
and otherwise to leave the doorbell permanently disabled.

This matches the v4.1 code perfectly, and only results in a minor
refactoring of the v4.0 code.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/r/20200304203330.4967-14-maz@kernel.org

1 files changed, 41 insertions, 4 deletions

diff --git a/drivers/irqchip/irq-gic-v4.c b/drivers/irqchip/irq-gic-v4.c
index c01910d53f9e..117ba6db023d 100644
--- a/drivers/irqchip/irq-gic-v4.c
+++ b/drivers/irqchip/irq-gic-v4.c
@@ -87,6 +87,11 @@ static struct irq_domain *gic_domain;
 static const struct irq_domain_ops *vpe_domain_ops;
 static const struct irq_domain_ops *sgi_domain_ops;
 
+static bool has_v4_1(void)
+{
+	return !!sgi_domain_ops;
+}
+
 int its_alloc_vcpu_irqs(struct its_vm *vm)
 {
 	int vpe_base_irq, i;
@@ -139,18 +144,50 @@ static int its_send_vpe_cmd(struct its_vpe *vpe, struct its_cmd_info *info)
 	return irq_set_vcpu_affinity(vpe->irq, info);
 }
 
-int its_schedule_vpe(struct its_vpe *vpe, bool on)
+int its_make_vpe_non_resident(struct its_vpe *vpe, bool db)
 {
-	struct its_cmd_info info;
+	struct irq_desc *desc = irq_to_desc(vpe->irq);
+	struct its_cmd_info info = { };
 	int ret;
 
 	WARN_ON(preemptible());
 
-	info.cmd_type = on ? SCHEDULE_VPE : DESCHEDULE_VPE;
+	info.cmd_type = DESCHEDULE_VPE;
+	if (has_v4_1()) {
+		/* GICv4.1 can directly deal with doorbells */
+		info.req_db = db;
+	} else {
+		/* Undo the nested disable_irq() calls... */
+		while (db && irqd_irq_disabled(&desc->irq_data))
+			enable_irq(vpe->irq);
+	}
+
+	ret = its_send_vpe_cmd(vpe, &info);
+	if (!ret)
+		vpe->resident = false;
+
+	return ret;
+}
+
+int its_make_vpe_resident(struct its_vpe *vpe, bool g0en, bool g1en)
+{
+	struct its_cmd_info info = { };
+	int ret;
+
+	WARN_ON(preemptible());
+
+	info.cmd_type = SCHEDULE_VPE;
+	if (has_v4_1()) {
+		info.g0en = g0en;
+		info.g1en = g1en;
+	} else {
+		/* Disabled the doorbell, as we're about to enter the guest */
+		disable_irq_nosync(vpe->irq);
+	}
 
 	ret = its_send_vpe_cmd(vpe, &info);
 	if (!ret)
-		vpe->resident = on;
+		vpe->resident = true;
 
 	return ret;
 }