[PATCH 14/24] RISC-V: ACPI: smpboot: Add function to retrieve the hartid

Sunil V L
2023-01-30T18:25:19Z

hartid is in RINTC structuire in MADT table. Instead of parsing
the ACPI table every time we need for a cpu, cache it and provide
a function to read it.

This is similar to acpi_get_madt_gicc() in arm64.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
---
arch/riscv/include/asm/acpi.h | 14 +++++++++++++-
arch/riscv/kernel/smpboot.c | 21 +++++++++++++++++++++
2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/acpi.h b/arch/riscv/include/asm/acpi.h
index d1f1e53ec657..69a880b7257a 100644
--- a/arch/riscv/include/asm/acpi.h
+++ b/arch/riscv/include/asm/acpi.h
@@ -65,6 +65,18 @@ int acpi_numa_get_nid(unsigned int cpu);
static inline int acpi_numa_get_nid(unsigned int cpu) { return NUMA_NO_NODE; }
#endif /* CONFIG_ACPI_NUMA */

-#endif
+struct acpi_madt_rintc *acpi_get_madt_rintc(int cpu);
+struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu);
+static inline u32 get_acpi_id_for_cpu(int cpu)
+{
+ return acpi_cpu_get_madt_rintc(cpu)->uid;
+}
+#else
+static inline u32 get_acpi_id_for_cpu(int cpu)
+{
+ return -1;
+}
+
+#endif /* CONFIG_ACPI */

#endif /*_ASM_ACPI_H*/
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index e48cf88d0bc1..3a8b7a9eb5ac 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -73,6 +73,25 @@ void __init smp_prepare_cpus(unsigned int max_cpus)

#ifdef CONFIG_ACPI
static unsigned int cpu_count = 1;
+static unsigned int intc_count;
+static struct acpi_madt_rintc cpu_madt_rintc[NR_CPUS];
+
+struct acpi_madt_rintc *acpi_get_madt_rintc(int cpu)
+{
+ return &cpu_madt_rintc[cpu];
+}
+
+struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu)
+{
+ int i;
+
+ for (i = 0; i < NR_CPUS; i++) {
+ if (riscv_hartid_to_cpuid(cpu_madt_rintc[i].hart_id) == cpu)
+ return &cpu_madt_rintc[i];
+ }
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(acpi_cpu_get_madt_rintc);

static int __init
acpi_parse_rintc(union acpi_subtable_headers *header,
@@ -92,6 +111,8 @@ acpi_parse_rintc(union acpi_subtable_headers *header,
hart = processor->hart_id;
if (hart < 0)
return 0;
+
+ cpu_madt_rintc[intc_count++] = *processor;
if (hart == cpuid_to_hartid_map(0)) {
BUG_ON(found_boot_cpu);
found_boot_cpu = 1;
--
2.38.0