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

[Sunil V L <sunilvl@xxxxxxxxxxxxxxxx>]

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@xxxxxxxxxxxxxxxx>
---
 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