[Xen-devel] [RFC PATCH 36/49] ARM: new VGIC: Add SGIR register handler

[Andre Przywara <andre.przywara@xxxxxxxxxx>]

Triggering an IPI via this register is v2 specific, so the
implementation lives entirely in vgic-mmio-v2.c.

This is based on Linux commit 55cc01fb9004, written by Andre Przywara.

Signed-off-by: Andre Przywara <andre.przywara@xxxxxxxxxx>
---
 xen/arch/arm/vgic/vgic-mmio-v2.c | 47 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 46 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/vgic/vgic-mmio-v2.c b/xen/arch/arm/vgic/vgic-mmio-v2.c
index c59f2c1ba7..3f67b4659a 100644
--- a/xen/arch/arm/vgic/vgic-mmio-v2.c
+++ b/xen/arch/arm/vgic/vgic-mmio-v2.c
@@ -66,6 +66,51 @@ static void vgic_mmio_write_v2_misc(struct vcpu *vcpu,
     }
 }
 
+static void vgic_mmio_write_sgir(struct vcpu *source_vcpu,
+                 paddr_t addr, unsigned int len,
+                 unsigned long val)
+{
+    struct domain *d = source_vcpu->domain;
+    int nr_vcpus = d->max_vcpus;
+    int intid = val & 0xf;
+    int targets = (val >> 16) & 0xff;
+    int mode = (val >> 24) & 0x03;
+    struct vcpu *vcpu;
+    unsigned long flags;
+
+    switch (mode)
+    {
+    case 0x0:       /* as specified by targets */
+        break;
+    case 0x1:
+        targets = (1U << nr_vcpus) - 1;         /* all, ... */
+        targets &= ~(1U << source_vcpu->vcpu_id);   /* but self */
+        break;
+    case 0x2:       /* this very vCPU only */
+        targets = (1U << source_vcpu->vcpu_id);
+        break;
+    case 0x3:       /* reserved */
+        return;
+    }
+
+    for_each_vcpu(d, vcpu)
+    {
+        struct vgic_irq *irq;
+
+        if ( !(targets & (1U << vcpu->vcpu_id)) )
+            continue;
+
+        irq = vgic_get_irq(d, vcpu, intid);
+
+        spin_lock_irqsave(&irq->irq_lock, flags);
+        irq->pending_latch = true;
+        irq->source |= 1U << source_vcpu->vcpu_id;
+
+        vgic_queue_irq_unlock(d, irq, flags);
+        vgic_put_irq(d, irq);
+    }
+}
+
 static unsigned long vgic_mmio_read_target(struct vcpu *vcpu,
                        paddr_t addr, unsigned int len)
 {
@@ -151,7 +196,7 @@ static const struct vgic_register_region 
vgic_v2_dist_registers[] = {
         vgic_mmio_read_config, vgic_mmio_write_config, NULL, NULL, 2,
         VGIC_ACCESS_32bit),
     REGISTER_DESC_WITH_LENGTH(GICD_SGIR,
-        vgic_mmio_read_raz, vgic_mmio_write_wi, 4,
+        vgic_mmio_read_raz, vgic_mmio_write_sgir, 4,
         VGIC_ACCESS_32bit),
     REGISTER_DESC_WITH_LENGTH(GICD_CPENDSGIR,
         vgic_mmio_read_raz, vgic_mmio_write_wi, 16,
-- 
2.14.1


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