diff options
author | Sunil V L <sunilvl@ventanamicro.com> | 2023-05-15 07:49:19 +0200 |
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committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-06-01 17:45:06 +0200 |
commit | ce92546cd63779445d205e3153defedacf8b08c6 (patch) | |
tree | 2109c0476036837804118e593ce860558c58d623 /arch/riscv/kernel/smpboot.c | |
parent | RISC-V: smpboot: Create wrapper setup_smp() (diff) | |
download | linux-ce92546cd63779445d205e3153defedacf8b08c6.tar.xz linux-ce92546cd63779445d205e3153defedacf8b08c6.zip |
RISC-V: smpboot: Add ACPI support in setup_smp()
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>
Diffstat (limited to 'arch/riscv/kernel/smpboot.c')
-rw-r--r-- | arch/riscv/kernel/smpboot.c | 72 |
1 files changed, 71 insertions, 1 deletions
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index a2e66126b733..67bc5ef3e8b2 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -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) |