arm/gic-v2: Add ACPI boot support for GICv2

ACPI on Xen hypervisor uses MADT table for proper GIC initialization.
First get the GIC version from GIC Distributor. Then parse GIC related
subtables, collect CPU interface and distributor addresses and call
driver initialization function (which is hardware abstraction agnostic).
In a similar way, FDT initialize GICv2.

Signed-off-by: Parth Dixit <parth.dixit@linaro.org>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

diff --git a/xen/arch/arm/gic-v2.c b/xen/arch/arm/gic-v2.c
index 668b86353bd5b24a318acaa24896b934ae105964..0fcb89400ff27927e3fa60ddfcad9d2c974c9c6b 100644 (file)
--- a/xen/arch/arm/gic-v2.c
+++ b/xen/arch/arm/gic-v2.c
@@ -29,6 +29,8 @@
 #include <xen/device_tree.h>
 #include <xen/libfdt/libfdt.h>
 #include <xen/sizes.h>
+#include <xen/acpi.h>
+#include <acpi/actables.h>
 #include <asm/p2m.h>
 #include <asm/domain.h>
 #include <asm/platform.h>
@@ -36,6 +38,7 @@
 
 #include <asm/io.h>
 #include <asm/gic.h>
+#include <asm/acpi.h>
 
 /*
  * LR register definitions are GIC v2 specific.
@@ -681,11 +684,108 @@ static void __init gicv2_dt_init(void)
                csize, vsize);
 }
 
+#ifdef CONFIG_ACPI
+static int __init
+gic_acpi_parse_madt_cpu(struct acpi_subtable_header *header,
+                        const unsigned long end)
+{
+    static int cpu_base_assigned = 0;
+    struct acpi_madt_generic_interrupt *processor =
+               container_of(header, struct acpi_madt_generic_interrupt, header);
+
+    if ( BAD_MADT_ENTRY(processor, end) )
+        return -EINVAL;
+
+    /* Read from APIC table and fill up the GIC variables */
+    if ( cpu_base_assigned == 0 )
+    {
+        cbase = processor->base_address;
+        csize = SZ_8K;
+        hbase = processor->gich_base_address;
+        vbase = processor->gicv_base_address;
+        gicv2_info.maintenance_irq = processor->vgic_interrupt;
+
+        if ( processor->flags & ACPI_MADT_VGIC_IRQ_MODE )
+            irq_set_type(gicv2_info.maintenance_irq, IRQ_TYPE_EDGE_BOTH);
+        else
+            irq_set_type(gicv2_info.maintenance_irq, IRQ_TYPE_LEVEL_MASK);
+
+        cpu_base_assigned = 1;
+    }
+    else
+    {
+        if ( cbase != processor->base_address
+             || hbase != processor->gich_base_address
+             || vbase != processor->gicv_base_address
+             || gicv2_info.maintenance_irq != processor->vgic_interrupt )
+        {
+            printk("GICv2: GICC entries are not same in MADT table\n");
+            return -EINVAL;
+        }
+    }
+
+    return 0;
+}
+
+static int __init
+gic_acpi_parse_madt_distributor(struct acpi_subtable_header *header,
+                                const unsigned long end)
+{
+    struct acpi_madt_generic_distributor *dist =
+             container_of(header, struct acpi_madt_generic_distributor, header);
+
+    if ( BAD_MADT_ENTRY(dist, end) )
+        return -EINVAL;
+
+    dbase = dist->base_address;
+
+    return 0;
+}
+
+static void __init gicv2_acpi_init(void)
+{
+    acpi_status status;
+    struct acpi_table_header *table;
+    int count;
+
+    status = acpi_get_table(ACPI_SIG_MADT, 0, &table);
+
+    if ( ACPI_FAILURE(status) )
+    {
+        const char *msg = acpi_format_exception(status);
+
+        panic("GICv2: Failed to get MADT table, %s", msg);
+    }
+
+    /* Collect CPU base addresses */
+    count = acpi_parse_entries(ACPI_SIG_MADT, sizeof(struct acpi_table_madt),
+                               gic_acpi_parse_madt_cpu, table,
+                               ACPI_MADT_TYPE_GENERIC_INTERRUPT, 0);
+    if ( count <= 0 )
+        panic("GICv2: No valid GICC entries exists");
+
+    /*
+     * Find distributor base address. We expect one distributor entry since
+     * ACPI 5.0 spec neither support multi-GIC instances nor GIC cascade.
+     */
+    count = acpi_parse_entries(ACPI_SIG_MADT, sizeof(struct acpi_table_madt),
+                               gic_acpi_parse_madt_distributor, table,
+                               ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR, 0);
+    if ( count <= 0 )
+        panic("GICv2: No valid GICD entries exists");
+}
+#else
+static void __init gicv2_acpi_init(void) { }
+#endif
+
 static int __init gicv2_init(void)
 {
     uint32_t aliased_offset = 0;
 
-    gicv2_dt_init();
+    if ( acpi_disabled )
+        gicv2_dt_init();
+    else
+        gicv2_acpi_init();
 
     printk("GICv2 initialization:\n"
               "        gic_dist_addr=%"PRIpaddr"\n"
@@ -793,6 +893,21 @@ DT_DEVICE_START(gicv2, "GICv2", DEVICE_GIC)
         .init = gicv2_dt_preinit,
 DT_DEVICE_END
 
+#ifdef CONFIG_ACPI
+/* Set up the GIC */
+static int __init gicv2_acpi_preinit(const void *data)
+{
+    gicv2_info.hw_version = GIC_V2;
+    register_gic_ops(&gicv2_ops);
+
+    return 0;
+}
+
+ACPI_DEVICE_START(agicv2, "GICv2", DEVICE_GIC)
+        .class_type = ACPI_MADT_GIC_VERSION_V2,
+        .init = gicv2_acpi_preinit,
+ACPI_DEVICE_END
+#endif
 /*
  * Local variables:
  * mode: C