From a4166aec11309d24e650e74cf8191a6d25a97fcf Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Tue, 21 Nov 2023 15:47:24 -0800 Subject: [PATCH 1/3] riscv: Deduplicate code in setup_smp() Both the ACPI and DT implementations contain some of the same code. Move it to the calling function so it is not duplicated. Signed-off-by: Samuel Holland Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20231121234736.3489608-2-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/smpboot.c | 33 ++++++++++++--------------------- 1 file changed, 12 insertions(+), 21 deletions(-) diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index d162bf339beb..1c68e61fb852 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -125,18 +125,7 @@ static int __init acpi_parse_rintc(union acpi_subtable_headers *header, const un 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) @@ -150,8 +139,6 @@ static void __init of_parse_and_init_cpus(void) int cpuid = 1; int rc; - cpu_set_ops(0); - for_each_of_cpu_node(dn) { rc = riscv_early_of_processor_hartid(dn, &hart); if (rc < 0) @@ -179,6 +166,18 @@ static void __init of_parse_and_init_cpus(void) if (cpuid > nr_cpu_ids) pr_warn("Total number of cpus [%d] is greater than nr_cpus option value [%d]\n", cpuid, nr_cpu_ids); +} + +void __init setup_smp(void) +{ + int cpuid; + + cpu_set_ops(0); + + if (acpi_disabled) + of_parse_and_init_cpus(); + else + acpi_parse_and_init_cpus(); for (cpuid = 1; cpuid < nr_cpu_ids; cpuid++) { if (cpuid_to_hartid_map(cpuid) != INVALID_HARTID) { @@ -188,14 +187,6 @@ static void __init of_parse_and_init_cpus(void) } } -void __init setup_smp(void) -{ - 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) { if (cpu_ops[cpu]->cpu_start) From 79093f3ec39c90edf4bd1a532d922ee6163441ec Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Tue, 21 Nov 2023 15:47:25 -0800 Subject: [PATCH 2/3] riscv: Remove unused members from struct cpu_operations name is not used anywhere at all. cpu_prepare and cpu_disable do nothing and always return 0 if implemented. Signed-off-by: Samuel Holland Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20231121234736.3489608-3-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/cpu_ops.h | 10 ---------- arch/riscv/kernel/cpu-hotplug.c | 9 +-------- arch/riscv/kernel/cpu_ops.c | 2 -- arch/riscv/kernel/cpu_ops_sbi.c | 19 ------------------- arch/riscv/kernel/cpu_ops_spinwait.c | 11 ----------- arch/riscv/kernel/head.S | 1 - arch/riscv/kernel/setup.c | 1 - arch/riscv/kernel/smpboot.c | 6 ------ 8 files changed, 1 insertion(+), 58 deletions(-) diff --git a/arch/riscv/include/asm/cpu_ops.h b/arch/riscv/include/asm/cpu_ops.h index aa128466c4d4..18af75e6873c 100644 --- a/arch/riscv/include/asm/cpu_ops.h +++ b/arch/riscv/include/asm/cpu_ops.h @@ -13,26 +13,16 @@ /** * struct cpu_operations - Callback operations for hotplugging CPUs. * - * @name: Name of the boot protocol. - * @cpu_prepare: Early one-time preparation step for a cpu. If there - * is a mechanism for doing so, tests whether it is - * possible to boot the given HART. * @cpu_start: Boots a cpu into the kernel. - * @cpu_disable: Prepares a cpu to die. May fail for some - * mechanism-specific reason, which will cause the hot - * unplug to be aborted. Called from the cpu to be killed. * @cpu_stop: Makes a cpu leave the kernel. Must not fail. Called from * the cpu being stopped. * @cpu_is_stopped: Ensures a cpu has left the kernel. Called from another * cpu. */ struct cpu_operations { - const char *name; - int (*cpu_prepare)(unsigned int cpu); int (*cpu_start)(unsigned int cpu, struct task_struct *tidle); #ifdef CONFIG_HOTPLUG_CPU - int (*cpu_disable)(unsigned int cpu); void (*cpu_stop)(void); int (*cpu_is_stopped)(unsigned int cpu); #endif diff --git a/arch/riscv/kernel/cpu-hotplug.c b/arch/riscv/kernel/cpu-hotplug.c index 457a18efcb11..934eb64da0d0 100644 --- a/arch/riscv/kernel/cpu-hotplug.c +++ b/arch/riscv/kernel/cpu-hotplug.c @@ -29,25 +29,18 @@ bool cpu_has_hotplug(unsigned int cpu) */ int __cpu_disable(void) { - int ret = 0; unsigned int cpu = smp_processor_id(); if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_stop) return -EOPNOTSUPP; - if (cpu_ops[cpu]->cpu_disable) - ret = cpu_ops[cpu]->cpu_disable(cpu); - - if (ret) - return ret; - remove_cpu_topology(cpu); numa_remove_cpu(cpu); set_cpu_online(cpu, false); riscv_ipi_disable(); irq_migrate_all_off_this_cpu(); - return ret; + return 0; } #ifdef CONFIG_HOTPLUG_CPU diff --git a/arch/riscv/kernel/cpu_ops.c b/arch/riscv/kernel/cpu_ops.c index eb479a88a954..5540e2880abb 100644 --- a/arch/riscv/kernel/cpu_ops.c +++ b/arch/riscv/kernel/cpu_ops.c @@ -18,8 +18,6 @@ const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init; extern const struct cpu_operations cpu_ops_sbi; #ifndef CONFIG_RISCV_BOOT_SPINWAIT const struct cpu_operations cpu_ops_spinwait = { - .name = "", - .cpu_prepare = NULL, .cpu_start = NULL, }; #endif diff --git a/arch/riscv/kernel/cpu_ops_sbi.c b/arch/riscv/kernel/cpu_ops_sbi.c index efa0f0816634..1cc7df740edd 100644 --- a/arch/riscv/kernel/cpu_ops_sbi.c +++ b/arch/riscv/kernel/cpu_ops_sbi.c @@ -79,23 +79,7 @@ static int sbi_cpu_start(unsigned int cpuid, struct task_struct *tidle) return sbi_hsm_hart_start(hartid, boot_addr, hsm_data); } -static int sbi_cpu_prepare(unsigned int cpuid) -{ - if (!cpu_ops_sbi.cpu_start) { - pr_err("cpu start method not defined for CPU [%d]\n", cpuid); - return -ENODEV; - } - return 0; -} - #ifdef CONFIG_HOTPLUG_CPU -static int sbi_cpu_disable(unsigned int cpuid) -{ - if (!cpu_ops_sbi.cpu_stop) - return -EOPNOTSUPP; - return 0; -} - static void sbi_cpu_stop(void) { int ret; @@ -118,11 +102,8 @@ static int sbi_cpu_is_stopped(unsigned int cpuid) #endif const struct cpu_operations cpu_ops_sbi = { - .name = "sbi", - .cpu_prepare = sbi_cpu_prepare, .cpu_start = sbi_cpu_start, #ifdef CONFIG_HOTPLUG_CPU - .cpu_disable = sbi_cpu_disable, .cpu_stop = sbi_cpu_stop, .cpu_is_stopped = sbi_cpu_is_stopped, #endif diff --git a/arch/riscv/kernel/cpu_ops_spinwait.c b/arch/riscv/kernel/cpu_ops_spinwait.c index d98d19226b5f..613872b0a21a 100644 --- a/arch/riscv/kernel/cpu_ops_spinwait.c +++ b/arch/riscv/kernel/cpu_ops_spinwait.c @@ -39,15 +39,6 @@ static void cpu_update_secondary_bootdata(unsigned int cpuid, WRITE_ONCE(__cpu_spinwait_task_pointer[hartid], tidle); } -static int spinwait_cpu_prepare(unsigned int cpuid) -{ - if (!cpu_ops_spinwait.cpu_start) { - pr_err("cpu start method not defined for CPU [%d]\n", cpuid); - return -ENODEV; - } - return 0; -} - static int spinwait_cpu_start(unsigned int cpuid, struct task_struct *tidle) { /* @@ -64,7 +55,5 @@ static int spinwait_cpu_start(unsigned int cpuid, struct task_struct *tidle) } const struct cpu_operations cpu_ops_spinwait = { - .name = "spinwait", - .cpu_prepare = spinwait_cpu_prepare, .cpu_start = spinwait_cpu_start, }; diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index b77397432403..0349e5cdfe1d 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -11,7 +11,6 @@ #include #include #include -#include #include #include #include diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 535a837de55d..2bf882804624 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -26,7 +26,6 @@ #include #include #include -#include #include #include #include diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 1c68e61fb852..5551945255cd 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -49,7 +49,6 @@ void __init smp_prepare_boot_cpu(void) void __init smp_prepare_cpus(unsigned int max_cpus) { int cpuid; - int ret; unsigned int curr_cpuid; init_cpu_topology(); @@ -66,11 +65,6 @@ void __init smp_prepare_cpus(unsigned int max_cpus) for_each_possible_cpu(cpuid) { if (cpuid == curr_cpuid) continue; - if (cpu_ops[cpuid]->cpu_prepare) { - ret = cpu_ops[cpuid]->cpu_prepare(cpuid); - if (ret) - continue; - } set_cpu_present(cpuid, true); numa_store_cpu_info(cpuid); } From 62ff262227a45bf917fe198885ab7aa19be5a01f Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Tue, 21 Nov 2023 15:47:26 -0800 Subject: [PATCH 3/3] riscv: Use the same CPU operations for all CPUs RISC-V provides no binding (ACPI or DT) to describe per-cpu start/stop operations, so cpu_set_ops() will always detect the same operations for every CPU. Replace the cpu_ops array with a single pointer to save space and reduce boot time. Signed-off-by: Samuel Holland Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20231121234736.3489608-4-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/cpu_ops.h | 4 ++-- arch/riscv/kernel/cpu-hotplug.c | 10 +++++----- arch/riscv/kernel/cpu_ops.c | 12 +++++------- arch/riscv/kernel/smp.c | 2 +- arch/riscv/kernel/smpboot.c | 13 +++++-------- 5 files changed, 18 insertions(+), 23 deletions(-) diff --git a/arch/riscv/include/asm/cpu_ops.h b/arch/riscv/include/asm/cpu_ops.h index 18af75e6873c..176b570ef982 100644 --- a/arch/riscv/include/asm/cpu_ops.h +++ b/arch/riscv/include/asm/cpu_ops.h @@ -29,7 +29,7 @@ struct cpu_operations { }; extern const struct cpu_operations cpu_ops_spinwait; -extern const struct cpu_operations *cpu_ops[NR_CPUS]; -void __init cpu_set_ops(int cpu); +extern const struct cpu_operations *cpu_ops; +void __init cpu_set_ops(void); #endif /* ifndef __ASM_CPU_OPS_H */ diff --git a/arch/riscv/kernel/cpu-hotplug.c b/arch/riscv/kernel/cpu-hotplug.c index 934eb64da0d0..28b58fc5ad19 100644 --- a/arch/riscv/kernel/cpu-hotplug.c +++ b/arch/riscv/kernel/cpu-hotplug.c @@ -18,7 +18,7 @@ bool cpu_has_hotplug(unsigned int cpu) { - if (cpu_ops[cpu]->cpu_stop) + if (cpu_ops->cpu_stop) return true; return false; @@ -31,7 +31,7 @@ int __cpu_disable(void) { unsigned int cpu = smp_processor_id(); - if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_stop) + if (!cpu_ops->cpu_stop) return -EOPNOTSUPP; remove_cpu_topology(cpu); @@ -55,8 +55,8 @@ void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) pr_notice("CPU%u: off\n", cpu); /* Verify from the firmware if the cpu is really stopped*/ - if (cpu_ops[cpu]->cpu_is_stopped) - ret = cpu_ops[cpu]->cpu_is_stopped(cpu); + if (cpu_ops->cpu_is_stopped) + ret = cpu_ops->cpu_is_stopped(cpu); if (ret) pr_warn("CPU%d may not have stopped: %d\n", cpu, ret); } @@ -70,7 +70,7 @@ void __noreturn arch_cpu_idle_dead(void) cpuhp_ap_report_dead(); - cpu_ops[smp_processor_id()]->cpu_stop(); + cpu_ops->cpu_stop(); /* It should never reach here */ BUG(); } diff --git a/arch/riscv/kernel/cpu_ops.c b/arch/riscv/kernel/cpu_ops.c index 5540e2880abb..6a8bd8f4db07 100644 --- a/arch/riscv/kernel/cpu_ops.c +++ b/arch/riscv/kernel/cpu_ops.c @@ -13,7 +13,7 @@ #include #include -const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init; +const struct cpu_operations *cpu_ops __ro_after_init = &cpu_ops_spinwait; extern const struct cpu_operations cpu_ops_sbi; #ifndef CONFIG_RISCV_BOOT_SPINWAIT @@ -22,14 +22,12 @@ const struct cpu_operations cpu_ops_spinwait = { }; #endif -void __init cpu_set_ops(int cpuid) +void __init cpu_set_ops(void) { #if IS_ENABLED(CONFIG_RISCV_SBI) if (sbi_probe_extension(SBI_EXT_HSM)) { - if (!cpuid) - pr_info("SBI HSM extension detected\n"); - cpu_ops[cpuid] = &cpu_ops_sbi; - } else + pr_info("SBI HSM extension detected\n"); + cpu_ops = &cpu_ops_sbi; + } #endif - cpu_ops[cpuid] = &cpu_ops_spinwait; } diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c index 40420afbb1a0..45dd4035416e 100644 --- a/arch/riscv/kernel/smp.c +++ b/arch/riscv/kernel/smp.c @@ -81,7 +81,7 @@ static inline void ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs) #ifdef CONFIG_HOTPLUG_CPU if (cpu_has_hotplug(cpu)) - cpu_ops[cpu]->cpu_stop(); + cpu_ops->cpu_stop(); #endif for(;;) diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 5551945255cd..519b6bd946e5 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -166,25 +166,22 @@ void __init setup_smp(void) { int cpuid; - cpu_set_ops(0); + cpu_set_ops(); if (acpi_disabled) of_parse_and_init_cpus(); else acpi_parse_and_init_cpus(); - for (cpuid = 1; cpuid < nr_cpu_ids; cpuid++) { - if (cpuid_to_hartid_map(cpuid) != INVALID_HARTID) { - cpu_set_ops(cpuid); + for (cpuid = 1; cpuid < nr_cpu_ids; cpuid++) + if (cpuid_to_hartid_map(cpuid) != INVALID_HARTID) set_cpu_possible(cpuid, true); - } - } } static int start_secondary_cpu(int cpu, struct task_struct *tidle) { - if (cpu_ops[cpu]->cpu_start) - return cpu_ops[cpu]->cpu_start(cpu, tidle); + if (cpu_ops->cpu_start) + return cpu_ops->cpu_start(cpu, tidle); return -EOPNOTSUPP; }