There are two GICs (GICv2 and GICv3) supported by KVM. So it is necessary
to find out GIC version before calling ACPI probing functions defined
in vgic-v2.c and vgic-v3.c.
This patch detects GIC version by checking gic_version field of GIC
distributor, which was defined since ACPI 6.0. In case of ACPI 5.1,
we use manual hardware discovery to find out GIC version.
NOTE: This patch is based on a recent patch by Hanjun Guo.
Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Signed-off-by: Wei Huang <wei@xxxxxxxxxx>
---
include/kvm/arm_vgic.h | 18 +++++++++
virt/kvm/arm/vgic-v2.c | 10 +++++
virt/kvm/arm/vgic-v3.c | 10 +++++
virt/kvm/arm/vgic.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++-
4 files changed, 137 insertions(+), 1 deletion(-)
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 3ee732a..7a44b08 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -24,6 +24,7 @@
#include <linux/irqreturn.h>
#include <linux/spinlock.h>
#include <linux/types.h>
+#include <linux/acpi.h>
#include <kvm/iodev.h>
#define VGIC_NR_IRQS_LEGACY 256
@@ -335,10 +336,18 @@ int kvm_vgic_vcpu_active_irq(struct kvm_vcpu *vcpu);
int vgic_v2_dt_probe(struct device_node *vgic_node,
const struct vgic_ops **ops,
const struct vgic_params **params);
+#ifdef CONFIG_ACPI
+int vgic_v2_acpi_probe(struct acpi_madt_generic_interrupt *,
+ const struct vgic_ops **ops,
+ const struct vgic_params **params);
+#endif /* CONFIG_ACPI */
#ifdef CONFIG_ARM_GIC_V3
int vgic_v3_dt_probe(struct device_node *vgic_node,
const struct vgic_ops **ops,
const struct vgic_params **params);
+int vgic_v3_acpi_probe(struct acpi_madt_generic_interrupt *,
+ const struct vgic_ops **ops,
+ const struct vgic_params **params);
#else
static inline int vgic_v3_dt_probe(struct device_node *vgic_node,
const struct vgic_ops **ops,
@@ -346,6 +355,15 @@ static inline int vgic_v3_dt_probe(struct device_node *vgic_node,
{
return -ENODEV;
}
+
+#ifdef CONFIG_ACPI
+int vgic_v3_acpi_probe(struct acpi_madt_generic_interrupt *,
+ const struct vgic_ops **ops,
+ const struct vgic_params **params)
+{
+ return -ENODEV;
+}
+#endif /* CONFIG_ACPI */
#endif
#endif
diff --git a/virt/kvm/arm/vgic-v2.c b/virt/kvm/arm/vgic-v2.c
index 295996f..711de82 100644
--- a/virt/kvm/arm/vgic-v2.c
+++ b/virt/kvm/arm/vgic-v2.c
@@ -23,6 +23,7 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
+#include <linux/acpi.h>
#include <linux/irqchip/arm-gic.h>
@@ -257,3 +258,12 @@ out:
of_node_put(vgic_node);
return ret;
}
+
+#ifdef CONFIG_ACPI
+int vgic_v2_acpi_probe(struct acpi_madt_generic_interrupt *vgic_acpi,
+ const struct vgic_ops **ops,
+ const struct vgic_params **params)
+{
+ return -EINVAL;
+}
+#endif /* CONFIG_ACPI */
diff --git a/virt/kvm/arm/vgic-v3.c b/virt/kvm/arm/vgic-v3.c
index 91814e2..99d0f9f 100644
--- a/virt/kvm/arm/vgic-v3.c
+++ b/virt/kvm/arm/vgic-v3.c
@@ -23,6 +23,7 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
+#include <linux/acpi.h>
#include <linux/irqchip/arm-gic-v3.h>
@@ -285,3 +286,12 @@ out:
of_node_put(vgic_node);
return ret;
}
+
+#ifdef CONFIG_ACPI
+int vgic_v3_acpi_probe(struct acpi_madt_generic_interrupt *vgic_acpi,
+ const struct vgic_ops **ops,
+ const struct vgic_params **params)
+{
+ return -EINVAL;
+}
+#endif /* CONFIG_ACPI */
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index b4010f0..cd09877 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -28,6 +28,7 @@
#include <linux/acpi.h>
#include <linux/irqchip/arm-gic.h>
+#include <linux/irqchip/arm-gic-v3.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_arm.h>
@@ -2114,9 +2115,106 @@ static int kvm_vgic_dt_probe(void)
}
#ifdef CONFIG_ACPI
+u8 gic_version = ACPI_MADT_GIC_VER_UNKNOWN;
+phys_addr_t dist_phy_base;
+static struct acpi_madt_generic_interrupt *vgic_acpi;
+
+static void gic_get_acpi_header(struct acpi_subtable_header *header)
+{
+ vgic_acpi = (struct acpi_madt_generic_interrupt *)header;
+}
+
+static int gic_parse_distributor(struct acpi_subtable_header *header,
+ const unsigned long end)
+{
+ struct acpi_madt_generic_distributor *dist;
+
+ dist = (struct acpi_madt_generic_distributor *)header;
+
+ if (BAD_MADT_ENTRY(dist, end))
+ return -EINVAL;
+
+ gic_version = dist->gic_version;
+ dist_phy_base = dist->base_address;
+
+ return 0;
+}
+
+static int gic_match_redist(struct acpi_subtable_header *header,
+ const unsigned long end)
+{
+ return 0;
+}
+
+static bool gic_redist_is_present(void)
+{
+ int count;
+
+ /* scan MADT table to find if we have redistributor entries */
+ count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR,
+ gic_match_redist, 0);
+
+ return (count > 0) ? true : false;
+}
+
static int kvm_vgic_acpi_probe(void)
{
- return -EINVAL;
+ u32 reg;
+ int count;
+ void __iomem *dist_base;
+ int ret;
+
+ /* MADT table */
+ ret = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
+ (acpi_tbl_entry_handler)gic_get_acpi_header, 0);
+ if (!ret) {
+ pr_err("Failed to get MADT VGIC CPU entry\n");
+ return -ENODEV;
+ }
+
+ /* detect GIC version */
+ count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,
+ gic_parse_distributor, 0);
+ if (count <= 0) {
+ pr_err("No valid GIC distributor entry exists\n");
+ return -ENODEV;
+ }
+ if (gic_version >= ACPI_MADT_GIC_VER_RESERVED) {
+ pr_err("Invalid GIC version %d in MADT\n", gic_version);
+ return -EINVAL;
+ }
+
+ /* falls back to manual hardware discovery under ACPI 5.1 */
+ if (gic_version == ACPI_MADT_GIC_VER_UNKNOWN) {
+ if (gic_redist_is_present()) {
+ dist_base = ioremap(dist_phy_base, SZ_64K);
+ if (!dist_base)
+ return -ENOMEM;
+
+ reg = readl_relaxed(dist_base + GICD_PIDR2) & GIC_PIDR2_ARCH_MASK;
+ if (reg == GIC_PIDR2_ARCH_GICv3)
+ gic_version = ACPI_MADT_GIC_VER_V3;
+ else
+ gic_version = ACPI_MADT_GIC_VER_V4;
+
+ iounmap(dist_base);
+ } else {
+ gic_version = ACPI_MADT_GIC_VER_V2;
+ }
+ }
+
+ switch (gic_version) {
+ case ACPI_MADT_GIC_VER_V2:
+ ret = vgic_v2_acpi_probe(vgic_acpi, &vgic_ops, &vgic);
+ break;
+ case ACPI_MADT_GIC_VER_V3:
+ ret = vgic_v3_acpi_probe(vgic_acpi, &vgic_ops, &vgic);
+ break;
+ default:
+ ret = -ENODEV;
+ }
+
+ return ret;
}
#endif /* CONFIG_ACPI */
--
1.8.3.1
--
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