[kvm-unit-tests PATCH v3 11/27] arm/arm64: Add support for gic initialization through ACPI

Nikos Nikoleris
2022-06-30T10:04:08Z

In systems with ACPI support and when a DT is not provided, we can use
the MADTs to figure out if it implements a GICv2 or a GICv3 and
discover the GIC parameters. This change implements this but retains
the default behavior; we check if a valid DT is provided, if not, we
try to discover the cores in the system using ACPI.

Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
---
lib/acpi.h | 44 +++++++++++++++++
lib/libcflat.h | 1 +
lib/arm/gic.c | 127 ++++++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 171 insertions(+), 1 deletion(-)

diff --git a/lib/acpi.h b/lib/acpi.h
index 160bfbe..9f6fbe4 100644
--- a/lib/acpi.h
+++ b/lib/acpi.h
@@ -187,6 +187,50 @@ struct acpi_madt_generic_interrupt {
u16 spe_interrupt; /* ACPI 6.3 */
};

+#define ACPI_MADT_ENABLED (1) /* 00: Processor is usable if set */
+
+/* 12: Generic Distributor (ACPI 5.0 + ACPI 6.0 changes) */
+
+struct acpi_madt_generic_distributor {
+ struct acpi_subtable_header header;
+ u16 reserved; /* reserved - must be zero */
+ u32 gic_id;
+ u64 base_address;
+ u32 global_irq_base;
+ u8 version;
+ u8 reserved2[3]; /* reserved - must be zero */
+};
+
+/* Values for Version field above */
+
+enum acpi_madt_gic_version {
+ ACPI_MADT_GIC_VERSION_NONE = 0,
+ ACPI_MADT_GIC_VERSION_V1 = 1,
+ ACPI_MADT_GIC_VERSION_V2 = 2,
+ ACPI_MADT_GIC_VERSION_V3 = 3,
+ ACPI_MADT_GIC_VERSION_V4 = 4,
+ ACPI_MADT_GIC_VERSION_RESERVED = 5 /* 5 and greater are reserved */
+};
+
+/* 14: Generic Redistributor (ACPI 5.1) */
+
+struct acpi_madt_generic_redistributor {
+ struct acpi_subtable_header header;
+ u16 reserved; /* reserved - must be zero */
+ u64 base_address;
+ u32 length;
+};
+
+/* 15: Generic Translator (ACPI 6.0) */
+
+struct acpi_madt_generic_translator {
+ struct acpi_subtable_header header;
+ u16 reserved; /* reserved - must be zero */
+ u32 translation_id;
+ u64 base_address;
+ u32 reserved2;
+};
+
/* Values for MADT subtable type in struct acpi_subtable_header */

enum acpi_madt_type {
diff --git a/lib/libcflat.h b/lib/libcflat.h
index c1fd31f..700f435 100644
--- a/lib/libcflat.h
+++ b/lib/libcflat.h
@@ -161,6 +161,7 @@ extern void setup_vm(void);
#define SZ_8K (1 << 13)
#define SZ_16K (1 << 14)
#define SZ_64K (1 << 16)
+#define SZ_128K (1 << 17)
#define SZ_1M (1 << 20)
#define SZ_2M (1 << 21)
#define SZ_1G (1 << 30)
diff --git a/lib/arm/gic.c b/lib/arm/gic.c
index 1bfcfcf..c346d1f 100644
--- a/lib/arm/gic.c
+++ b/lib/arm/gic.c
@@ -3,6 +3,7 @@
*
* This work is licensed under the terms of the GNU LGPL, version 2.
*/
+#include <acpi.h>
#include <devicetree.h>
#include <asm/gic.h>
#include <asm/io.h>
@@ -120,7 +121,7 @@ int gic_version(void)
return 0;
}

-int gic_init(void)
+static int gic_init_fdt(void)
{
if (gicv2_init()) {
gic_common_ops = &gicv2_common_ops;
@@ -133,6 +134,130 @@ int gic_init(void)
return gic_version();
}

+#define ACPI_GICV2_DIST_MEM_SIZE (SZ_4K)
+#define ACPI_GIC_CPU_IF_MEM_SIZE (SZ_8K)
+#define ACPI_GICV3_DIST_MEM_SIZE (SZ_64K)
+#define ACPI_GICV3_ITS_MEM_SIZE (SZ_128K)
+
+static int gic_acpi_version(struct acpi_subtable_header *header)
+{
+ struct acpi_madt_generic_distributor *dist = (void *)header;
+ int version = dist->version;
+
+ if (version == 2)
+ gic_common_ops = &gicv2_common_ops;
+ else if (version == 3)
+ gic_common_ops = &gicv3_common_ops;
+
+ return version;
+}
+
+static int gicv2_acpi_parse_madt_cpu(struct acpi_subtable_header *header)
+{
+ struct acpi_madt_generic_interrupt *gicc = (void *)header;
+ static phys_addr_t gicc_base_address;
+
+ if (!(gicc->flags & ACPI_MADT_ENABLED))
+ return 0;
+
+ if (!gicc_base_address) {
+ gicc_base_address = gicc->base_address;
+ gicv2_data.cpu_base = ioremap(gicc_base_address, ACPI_GIC_CPU_IF_MEM_SIZE);
+ }
+ assert(gicc_base_address == gicc->base_address);
+
+ return 0;
+}
+
+static int gicv2_acpi_parse_madt_dist(struct acpi_subtable_header *header)
+{
+ struct acpi_madt_generic_distributor *dist = (void *)header;
+
+ gicv2_data.dist_base = ioremap(dist->base_address, ACPI_GICV2_DIST_MEM_SIZE);
+
+ return 0;
+}
+
+static int gicv3_acpi_parse_madt_gicc(struct acpi_subtable_header *header)
+{
+ struct acpi_madt_generic_interrupt *gicc = (void *)header;
+ static phys_addr_t gicr_base_address;
+
+ if (!(gicc->flags & ACPI_MADT_ENABLED))
+ return 0;
+
+ if (!gicr_base_address) {
+ gicr_base_address = gicc->gicr_base_address;
+ gicv3_data.redist_bases[0] = ioremap(gicr_base_address, SZ_64K * 2);
+ }
+ assert(gicr_base_address == gicc->gicr_base_address);
+
+ return 0;
+}
+
+static int gicv3_acpi_parse_madt_dist(struct acpi_subtable_header *header)
+{
+ struct acpi_madt_generic_distributor *dist = (void *)header;
+
+ gicv3_data.dist_base = ioremap(dist->base_address, ACPI_GICV3_DIST_MEM_SIZE);
+
+ return 0;
+}
+
+static int gicv3_acpi_parse_madt_redist(struct acpi_subtable_header *header)
+{
+ static int i;
+ struct acpi_madt_generic_redistributor *redist = (void *)header;
+
+ gicv3_data.redist_bases[i++] = ioremap(redist->base_address, redist->length);
+
+ return 0;
+}
+
+static int gicv3_acpi_parse_madt_its(struct acpi_subtable_header *header)
+{
+ struct acpi_madt_generic_translator *its_entry = (void *)header;
+
+ its_data.base = ioremap(its_entry->base_address, ACPI_GICV3_ITS_MEM_SIZE - 1);
+
+ return 0;
+}
+
+static int gic_init_acpi(void)
+{
+ acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,
+ gic_acpi_version);
+ if (gic_version() == 2) {
+ acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
+ gicv2_acpi_parse_madt_cpu);
+ acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,
+ gicv2_acpi_parse_madt_dist);
+ } else if (gic_version() == 3) {
+ acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,
+ gicv3_acpi_parse_madt_dist);
+ acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR,
+ gicv3_acpi_parse_madt_redist);
+ if (!gicv3_data.redist_base)
+ acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR,
+ gicv3_acpi_parse_madt_gicc);
+ acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
+ gicv3_acpi_parse_madt_its);
+#ifdef __aarch64__
+ its_init();
+#endif
+ }
+
+ return gic_version();
+}
+
+int gic_init(void)
+{
+ if (dt_available())
+ return gic_init_fdt();
+ else
+ return gic_init_acpi();
+}
+
void gic_enable_defaults(void)
{
if (!gic_common_ops) {
--
2.25.1