[kvm-unit-tests PATCH v3 10/27] arm/arm64: Add support for cpu initialization through ACPI

Nikos Nikoleris
2022-06-30T10:04:07Z

In systems with ACPI support and when a DT is not provided, we can use
the MADTs to discover the number of CPUs and their corresponding MIDR.
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>
Reviewed-by: Andrew Jones <drjones@redhat.com>
---
lib/acpi.h | 63 +++++++++++++++++++++++++++++++++++++++++++++++++
lib/acpi.c | 21 +++++++++++++++++
lib/arm/setup.c | 25 +++++++++++++++++---
3 files changed, 106 insertions(+), 3 deletions(-)

diff --git a/lib/acpi.h b/lib/acpi.h
index 9910c39..160bfbe 100644
--- a/lib/acpi.h
+++ b/lib/acpi.h
@@ -17,6 +17,7 @@
#define XSDT_SIGNATURE ACPI_SIGNATURE('X','S','D','T')
#define FACP_SIGNATURE ACPI_SIGNATURE('F','A','C','P')
#define FACS_SIGNATURE ACPI_SIGNATURE('F','A','C','S')
+#define MADT_SIGNATURE ACPI_SIGNATURE('A','P','I','C')
#define SPCR_SIGNATURE ACPI_SIGNATURE('S','P','C','R')
#define GTDT_SIGNATURE ACPI_SIGNATURE('G','T','D','T')

@@ -150,6 +151,67 @@ struct facs_descriptor_rev1
u8 reserved3 [40]; /* Reserved - must be zero */
};

+struct acpi_table_madt {
+ ACPI_TABLE_HEADER_DEF /* ACPI common table header */
+ u32 address; /* Physical address of local APIC */
+ u32 flags;
+};
+
+struct acpi_subtable_header {
+ u8 type;
+ u8 length;
+};
+
+typedef int (*acpi_table_handler)(struct acpi_subtable_header *header);
+
+/* 11: Generic interrupt - GICC (ACPI 5.0 + ACPI 6.0 + ACPI 6.3 changes) */
+
+struct acpi_madt_generic_interrupt {
+ u8 type;
+ u8 length;
+ u16 reserved; /* reserved - must be zero */
+ u32 cpu_interface_number;
+ u32 uid;
+ u32 flags;
+ u32 parking_version;
+ u32 performance_interrupt;
+ u64 parked_address;
+ u64 base_address;
+ u64 gicv_base_address;
+ u64 gich_base_address;
+ u32 vgic_interrupt;
+ u64 gicr_base_address;
+ u64 arm_mpidr;
+ u8 efficiency_class;
+ u8 reserved2[1];
+ u16 spe_interrupt; /* ACPI 6.3 */
+};
+
+/* Values for MADT subtable type in struct acpi_subtable_header */
+
+enum acpi_madt_type {
+ ACPI_MADT_TYPE_LOCAL_APIC = 0,
+ ACPI_MADT_TYPE_IO_APIC = 1,
+ ACPI_MADT_TYPE_INTERRUPT_OVERRIDE = 2,
+ ACPI_MADT_TYPE_NMI_SOURCE = 3,
+ ACPI_MADT_TYPE_LOCAL_APIC_NMI = 4,
+ ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE = 5,
+ ACPI_MADT_TYPE_IO_SAPIC = 6,
+ ACPI_MADT_TYPE_LOCAL_SAPIC = 7,
+ ACPI_MADT_TYPE_INTERRUPT_SOURCE = 8,
+ ACPI_MADT_TYPE_LOCAL_X2APIC = 9,
+ ACPI_MADT_TYPE_LOCAL_X2APIC_NMI = 10,
+ ACPI_MADT_TYPE_GENERIC_INTERRUPT = 11,
+ ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR = 12,
+ ACPI_MADT_TYPE_GENERIC_MSI_FRAME = 13,
+ ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR = 14,
+ ACPI_MADT_TYPE_GENERIC_TRANSLATOR = 15,
+ ACPI_MADT_TYPE_RESERVED = 16 /* 16 and greater are reserved */
+};
+
+/* MADT Local APIC flags */
+#define ACPI_MADT_ENABLED (1) /* 00: Processor is usable if set */
+
struct spcr_descriptor {
ACPI_TABLE_HEADER_DEF /* ACPI common table header */
u8 interface_type; /* 0=full 16550, 1=subset of 16550 */
@@ -195,5 +257,6 @@ struct acpi_table_gtdt {

void set_efi_rsdp(struct rsdp_descriptor *rsdp);
void* find_acpi_table_addr(u32 sig);
+void acpi_table_parse_madt(enum acpi_madt_type mtype, acpi_table_handler handler);

#endif
diff --git a/lib/acpi.c b/lib/acpi.c
index aeaccb8..b652d18 100644
--- a/lib/acpi.c
+++ b/lib/acpi.c
@@ -104,3 +104,24 @@ void *find_acpi_table_addr(u32 sig)

return NULL;
}
+
+void acpi_table_parse_madt(enum acpi_madt_type mtype,
+ acpi_table_handler handler)
+{
+ struct acpi_table_madt *madt;
+ struct acpi_subtable_header *header;
+ void *end;
+
+ madt = find_acpi_table_addr(MADT_SIGNATURE);
+ assert(madt);
+
+ header = (void *)(ulong)madt + sizeof(struct acpi_table_madt);
+ end = (void *)((ulong)madt + madt->length);
+
+ while ((void *)header < end) {
+ if (header->type == mtype)
+ handler(header);
+
+ header = (void *)(ulong)header + header->length;
+ }
+}
diff --git a/lib/arm/setup.c b/lib/arm/setup.c
index 1572c64..3612991 100644
--- a/lib/arm/setup.c
+++ b/lib/arm/setup.c
@@ -13,6 +13,7 @@
#include <libcflat.h>
#include <libfdt/libfdt.h>
#include <devicetree.h>
+#include <acpi.h>
#include <alloc.h>
#include <alloc_phys.h>
#include <alloc_page.h>
@@ -55,7 +56,7 @@ int mpidr_to_cpu(uint64_t mpidr)
return -1;
}

-static void cpu_set(int fdtnode __unused, u64 regval, void *info __unused)
+static void cpu_set_fdt(int fdtnode __unused, u64 regval, void *info __unused)
{
int cpu = nr_cpus++;

@@ -65,13 +66,31 @@ static void cpu_set(int fdtnode __unused, u64 regval, void *info __unused)
set_cpu_present(cpu, true);
}

+static int cpu_set_acpi(struct acpi_subtable_header *header)
+{
+ int cpu = nr_cpus++;
+ struct acpi_madt_generic_interrupt *gicc = (void *)header;
+
+ assert_msg(cpu < NR_CPUS, "Number cpus exceeds maximum supported (%d).", NR_CPUS);
+
+ cpus[cpu] = gicc->arm_mpidr;
+ set_cpu_present(cpu, true);
+
+ return 0;
+}
+
static void cpu_init(void)
{
int ret;

nr_cpus = 0;
- ret = dt_for_each_cpu_node(cpu_set, NULL);
- assert(ret == 0);
+ if (dt_available()) {
+ ret = dt_for_each_cpu_node(cpu_set_fdt, NULL);
+ assert(ret == 0);
+ } else {
+ acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT, cpu_set_acpi);
+ }
+
set_cpu_online(0, true);
}

--
2.25.1