On 06/10/2015 11:43 AM, Marc Zyngier wrote:
> On 10/06/15 05:16, Wei Huang wrote:
>> 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.
>
> Well, this is really a duplicate of Hanjun's patch, and I'd rather have
> some common infrastructure.
>
> Surely it should be possible for the ACPI GIC code to export the
> necessary entry points, or even to provide the required information?
>
I agreed that this is a duplication and should be avoided if possible.
One easy solution is to export from GIC driver to KVM (using
EXPORT_SYMBOL or something similar). Is this acceptable?
Anyway the difficulty is to find a common place to store and share info
between other modules & KVM.
Thanks,
-Wei
> Thanks,
>
> M.
>
>>
>> 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 */
>>
>>
>
>
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