commit a55c910e0b18aee2f67b129f0046b53cb8c42f21
author Peter Maydell <peter.maydell@linaro.org> Fri Mar 04 11:30:22 2016 +0000
committer Peter Maydell <peter.maydell@linaro.org> Fri Mar 04 11:30:22 2016 +0000
tree 627482362a21b3711881f5be8f2e81caee8cc35e
parent 9776f636455b6f0d9c14dce112242ed653f954b4

hw/intc/arm_gic.c: Implement GICv2 GICC_DIR

The GICv2 introduces a new CPU interface register GICC_DIR, which
allows an OS to split the "priority drop" and "deactivate interrupt"
parts of interrupt completion. Implement this register.
(Note that the register is at offset 0x1000 in the CPU interface,
which means it is on a different 4K page from all the other registers.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Sergey Fedorov <serge.fdrv@gmail.com>
Message-id: 1456854176-7813-1-git-send-email-peter.maydell@linaro.org

hw/cpu/a15mpcore.c

diff --git a/hw/cpu/a15mpcore.c b/hw/cpu/a15mpcore.c
index e9063ad..a221b8f 100644
--- a/hw/cpu/a15mpcore.c
+++ b/hw/cpu/a15mpcore.c
@@ -109,7 +109,7 @@
     /* Memory map (addresses are offsets from PERIPHBASE):
      *  0x0000-0x0fff -- reserved
      *  0x1000-0x1fff -- GIC Distributor
-     *  0x2000-0x2fff -- GIC CPU interface
+     *  0x2000-0x3fff -- GIC CPU interface
      *  0x4000-0x4fff -- GIC virtual interface control (not modelled)
      *  0x5000-0x5fff -- GIC virtual interface control (not modelled)
      *  0x6000-0x7fff -- GIC virtual CPU interface (not modelled)

hw/intc/arm_gic.c

diff --git a/hw/intc/arm_gic.c b/hw/intc/arm_gic.c
index 60ab9b8..0834c2f 100644
--- a/hw/intc/arm_gic.c
+++ b/hw/intc/arm_gic.c
@@ -500,6 +500,41 @@
     }
 }
 
+/* Return true if we should split priority drop and interrupt deactivation,
+ * ie whether the relevant EOIMode bit is set.
+ */
+static bool gic_eoi_split(GICState *s, int cpu, MemTxAttrs attrs)
+{
+    if (s->revision != 2) {
+        /* Before GICv2 prio-drop and deactivate are not separable */
+        return false;
+    }
+    if (s->security_extn && !attrs.secure) {
+        return s->cpu_ctlr[cpu] & GICC_CTLR_EOIMODE_NS;
+    }
+    return s->cpu_ctlr[cpu] & GICC_CTLR_EOIMODE;
+}
+
+static void gic_deactivate_irq(GICState *s, int cpu, int irq, MemTxAttrs attrs)
+{
+    int cm = 1 << cpu;
+    int group = gic_has_groups(s) && GIC_TEST_GROUP(irq, cm);
+
+    if (!gic_eoi_split(s, cpu, attrs)) {
+        /* This is UNPREDICTABLE; we choose to ignore it */
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "gic_deactivate_irq: GICC_DIR write when EOIMode clear");
+        return;
+    }
+
+    if (s->security_extn && !attrs.secure && !group) {
+        DPRINTF("Non-secure DI for Group0 interrupt %d ignored\n", irq);
+        return;
+    }
+
+    GIC_CLEAR_ACTIVE(irq, cm);
+}
+
 void gic_complete_irq(GICState *s, int cpu, int irq, MemTxAttrs attrs)
 {
     int cm = 1 << cpu;
@@ -544,7 +579,11 @@
      */
 
     gic_drop_prio(s, cpu, group);
-    GIC_CLEAR_ACTIVE(irq, cm);
+
+    /* In GICv2 the guest can choose to split priority-drop and deactivate */
+    if (!gic_eoi_split(s, cpu, attrs)) {
+        GIC_CLEAR_ACTIVE(irq, cm);
+    }
     gic_update(s);
 }
 
@@ -1210,6 +1249,10 @@
         s->nsapr[regno][cpu] = value;
         break;
     }
+    case 0x1000:
+        /* GICC_DIR */
+        gic_deactivate_irq(s, cpu, value & 0x3ff, attrs);
+        break;
     default:
         qemu_log_mask(LOG_GUEST_ERROR,
                       "gic_cpu_write: Bad offset %x\n", (int)offset);

hw/intc/arm_gic_common.c

diff --git a/hw/intc/arm_gic_common.c b/hw/intc/arm_gic_common.c
index ac8cf42..707d00d 100644
--- a/hw/intc/arm_gic_common.c
+++ b/hw/intc/arm_gic_common.c
@@ -121,7 +121,7 @@
          * neither it can use KVM.
          */
         memory_region_init_io(&s->cpuiomem[0], OBJECT(s), ops ? &ops[1] : NULL,
-                              s, "gic_cpu", s->revision == 2 ? 0x1000 : 0x100);
+                              s, "gic_cpu", s->revision == 2 ? 0x2000 : 0x100);
         sysbus_init_mmio(sbd, &s->cpuiomem[0]);
     }
 }