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RISC-V: smpboot: Add ACPI support in setup_smp()

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Enable SMP boot on ACPI based platforms by using the RINTC
structures in the MADT table.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230515054928.2079268-13-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Sunil V L 2023-05-15 11:19:19 +05:30 committed by Palmer Dabbelt
parent 61946127ab
commit ce92546cd6
No known key found for this signature in database
GPG Key ID: 2E1319F35FBB1889
2 changed files with 73 additions and 1 deletions
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2
arch/riscv/include/asm/acpi.h
View File

@ -64,6 +64,8 @@ struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu);
u32 get_acpi_id_for_cpu(int cpu);
int acpi_get_riscv_isa(struct acpi_table_header *table,
unsigned int cpu, const char **isa);
static inline int acpi_numa_get_nid(unsigned int cpu) { return NUMA_NO_NODE; }
#else
static inline void acpi_init_rintc_map(void) { }
static inline struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu)

72
arch/riscv/kernel/smpboot.c
View File

@ -8,6 +8,7 @@
* Copyright (C) 2017 SiFive
*/
#include <linux/acpi.h>
#include <linux/arch_topology.h>
#include <linux/module.h>
#include <linux/init.h>
@ -70,6 +71,72 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
}
}
#ifdef CONFIG_ACPI
static unsigned int cpu_count = 1;
static int __init acpi_parse_rintc(union acpi_subtable_headers *header, const unsigned long end)
{
unsigned long hart;
static bool found_boot_cpu;
struct acpi_madt_rintc *processor = (struct acpi_madt_rintc *)header;
/*
* Each RINTC structure in MADT will have a flag. If ACPI_MADT_ENABLED
* bit in the flag is not enabled, it means OS should not try to enable
* the cpu to which RINTC belongs.
*/
if (!(processor->flags & ACPI_MADT_ENABLED))
return 0;
if (BAD_MADT_ENTRY(processor, end))
return -EINVAL;
acpi_table_print_madt_entry(&header->common);
hart = processor->hart_id;
if (hart == INVALID_HARTID) {
pr_warn("Invalid hartid\n");
return 0;
}
if (hart == cpuid_to_hartid_map(0)) {
BUG_ON(found_boot_cpu);
found_boot_cpu = true;
early_map_cpu_to_node(0, acpi_numa_get_nid(cpu_count));
return 0;
}
if (cpu_count >= NR_CPUS) {
pr_warn("NR_CPUS is too small for the number of ACPI tables.\n");
return 0;
}
cpuid_to_hartid_map(cpu_count) = hart;
early_map_cpu_to_node(cpu_count, acpi_numa_get_nid(cpu_count));
cpu_count++;
return 0;
}
static void __init acpi_parse_and_init_cpus(void)
{
int cpuid;
cpu_set_ops(0);
acpi_table_parse_madt(ACPI_MADT_TYPE_RINTC, acpi_parse_rintc, 0);
for (cpuid = 1; cpuid < nr_cpu_ids; cpuid++) {
if (cpuid_to_hartid_map(cpuid) != INVALID_HARTID) {
cpu_set_ops(cpuid);
set_cpu_possible(cpuid, true);
}
}
}
#else
#define acpi_parse_and_init_cpus(...) do { } while (0)
#endif
static void __init of_parse_and_init_cpus(void)
{
struct device_node *dn;
@ -118,7 +185,10 @@ static void __init of_parse_and_init_cpus(void)
void __init setup_smp(void)
{
of_parse_and_init_cpus();
if (acpi_disabled)
of_parse_and_init_cpus();
else
acpi_parse_and_init_cpus();
}
static int start_secondary_cpu(int cpu, struct task_struct *tidle)