ACPI: processor_core: RISC-V: Enable mapping processor to the hartid

processor_core needs arch-specific functions to map the ACPI ID
to the physical ID. In RISC-V platforms, hartid is the physical id
and RINTC structure in MADT provides this mapping. Add arch-specific
function to get this mapping from RINTC.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230515054928.2079268-8-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/arch/riscv/include/asm/acpi.h b/arch/riscv/include/asm/acpi.h
index bcade255bd6e067d82e2546bb2d262033a2837b8..9be52b6ffae105de18b0d426a60ad751894109f6 100644 (file)
--- a/arch/riscv/include/asm/acpi.h
+++ b/arch/riscv/include/asm/acpi.h
@@ -15,6 +15,9 @@
 /* Basic configuration for ACPI */
 #ifdef CONFIG_ACPI
 
+typedef u64 phys_cpuid_t;
+#define PHYS_CPUID_INVALID INVALID_HARTID
+
 /* ACPI table mapping after acpi_permanent_mmap is set */
 void *acpi_os_ioremap(acpi_physical_address phys, acpi_size size);
 #define acpi_os_ioremap acpi_os_ioremap

diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index 2ac48cda5b2014ad8494a170d3175f3586a76db4..d6606a9f2da664a4cf1b87183133d6f0591db7ee 100644 (file)
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -106,6 +106,32 @@ static int map_gicc_mpidr(struct acpi_subtable_header *entry,
        return -EINVAL;
 }
 
+/*
+ * Retrieve the RISC-V hartid for the processor
+ */
+static int map_rintc_hartid(struct acpi_subtable_header *entry,
+                           int device_declaration, u32 acpi_id,
+                           phys_cpuid_t *hartid)
+{
+       struct acpi_madt_rintc *rintc =
+           container_of(entry, struct acpi_madt_rintc, header);
+
+       if (!(rintc->flags & ACPI_MADT_ENABLED))
+               return -ENODEV;
+
+       /* device_declaration means Device object in DSDT, in the
+        * RISC-V, logical processors are required to
+        * have a Processor Device object in the DSDT, so we should
+        * check device_declaration here
+        */
+       if (device_declaration && rintc->uid == acpi_id) {
+               *hartid = rintc->hart_id;
+               return 0;
+       }
+
+       return -EINVAL;
+}
+
 static phys_cpuid_t map_madt_entry(struct acpi_table_madt *madt,
                                   int type, u32 acpi_id)
 {
@@ -136,6 +162,9 @@ static phys_cpuid_t map_madt_entry(struct acpi_table_madt *madt,
                } else if (header->type == ACPI_MADT_TYPE_GENERIC_INTERRUPT) {
                        if (!map_gicc_mpidr(header, type, acpi_id, &phys_id))
                                break;
+               } else if (header->type == ACPI_MADT_TYPE_RINTC) {
+                       if (!map_rintc_hartid(header, type, acpi_id, &phys_id))
+                               break;
                }
                entry += header->length;
        }