diff options
Diffstat (limited to 'arch/riscv')
| -rw-r--r-- | arch/riscv/include/asm/processor.h | 2 | ||||
| -rw-r--r-- | arch/riscv/include/asm/smp.h | 47 | ||||
| -rw-r--r-- | arch/riscv/include/asm/tlbflush.h | 16 | ||||
| -rw-r--r-- | arch/riscv/kernel/cpu.c | 87 | ||||
| -rw-r--r-- | arch/riscv/kernel/entry.S | 1 | ||||
| -rw-r--r-- | arch/riscv/kernel/head.S | 4 | ||||
| -rw-r--r-- | arch/riscv/kernel/irq.c | 12 | ||||
| -rw-r--r-- | arch/riscv/kernel/setup.c | 10 | ||||
| -rw-r--r-- | arch/riscv/kernel/smp.c | 82 | ||||
| -rw-r--r-- | arch/riscv/kernel/smpboot.c | 46 |
10 files changed, 245 insertions, 62 deletions
diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index 3fe4af8147d2..50de774d827a 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -88,7 +88,7 @@ static inline void wait_for_interrupt(void) } struct device_node; -extern int riscv_of_processor_hart(struct device_node *node); +int riscv_of_processor_hartid(struct device_node *node); extern void riscv_fill_hwcap(void); diff --git a/arch/riscv/include/asm/smp.h b/arch/riscv/include/asm/smp.h index 36016845461d..41aa73b476f4 100644 --- a/arch/riscv/include/asm/smp.h +++ b/arch/riscv/include/asm/smp.h @@ -14,16 +14,24 @@ #ifndef _ASM_RISCV_SMP_H #define _ASM_RISCV_SMP_H -/* This both needs asm-offsets.h and is used when generating it. */ -#ifndef GENERATING_ASM_OFFSETS -#include <asm/asm-offsets.h> -#endif - #include <linux/cpumask.h> #include <linux/irqreturn.h> +#include <linux/thread_info.h> + +#define INVALID_HARTID ULONG_MAX +/* + * Mapping between linux logical cpu index and hartid. + */ +extern unsigned long __cpuid_to_hartid_map[NR_CPUS]; +#define cpuid_to_hartid_map(cpu) __cpuid_to_hartid_map[cpu] + +struct seq_file; #ifdef CONFIG_SMP +/* print IPI stats */ +void show_ipi_stats(struct seq_file *p, int prec); + /* SMP initialization hook for setup_arch */ void __init setup_smp(void); @@ -33,14 +41,31 @@ void arch_send_call_function_ipi_mask(struct cpumask *mask); /* Hook for the generic smp_call_function_single() routine. */ void arch_send_call_function_single_ipi(int cpu); +int riscv_hartid_to_cpuid(int hartid); +void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out); + /* - * This is particularly ugly: it appears we can't actually get the definition - * of task_struct here, but we need access to the CPU this task is running on. - * Instead of using C we're using asm-offsets.h to get the current processor - * ID. + * Obtains the hart ID of the currently executing task. This relies on + * THREAD_INFO_IN_TASK, but we define that unconditionally. */ -#define raw_smp_processor_id() (*((int*)((char*)get_current() + TASK_TI_CPU))) +#define raw_smp_processor_id() (current_thread_info()->cpu) -#endif /* CONFIG_SMP */ +#else + +static inline void show_ipi_stats(struct seq_file *p, int prec) +{ +} +static inline int riscv_hartid_to_cpuid(int hartid) +{ + return 0; +} + +static inline void riscv_cpuid_to_hartid_mask(const struct cpumask *in, + struct cpumask *out) +{ + cpumask_set_cpu(cpuid_to_hartid_map(0), out); +} + +#endif /* CONFIG_SMP */ #endif /* _ASM_RISCV_SMP_H */ diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h index 85c2d8bae957..54fee0cadb1e 100644 --- a/arch/riscv/include/asm/tlbflush.h +++ b/arch/riscv/include/asm/tlbflush.h @@ -16,6 +16,7 @@ #define _ASM_RISCV_TLBFLUSH_H #include <linux/mm_types.h> +#include <asm/smp.h> /* * Flush entire local TLB. 'sfence.vma' implicitly fences with the instruction @@ -49,13 +50,22 @@ static inline void flush_tlb_range(struct vm_area_struct *vma, #include <asm/sbi.h> +static inline void remote_sfence_vma(struct cpumask *cmask, unsigned long start, + unsigned long size) +{ + struct cpumask hmask; + + cpumask_clear(&hmask); + riscv_cpuid_to_hartid_mask(cmask, &hmask); + sbi_remote_sfence_vma(hmask.bits, start, size); +} + #define flush_tlb_all() sbi_remote_sfence_vma(NULL, 0, -1) #define flush_tlb_page(vma, addr) flush_tlb_range(vma, addr, 0) #define flush_tlb_range(vma, start, end) \ - sbi_remote_sfence_vma(mm_cpumask((vma)->vm_mm)->bits, \ - start, (end) - (start)) + remote_sfence_vma(mm_cpumask((vma)->vm_mm), start, (end) - (start)) #define flush_tlb_mm(mm) \ - sbi_remote_sfence_vma(mm_cpumask(mm)->bits, 0, -1) + remote_sfence_vma(mm_cpumask(mm), 0, -1) #endif /* CONFIG_SMP */ diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index ca6c81e54e37..3a5a2ee31547 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -14,9 +14,13 @@ #include <linux/init.h> #include <linux/seq_file.h> #include <linux/of.h> +#include <asm/smp.h> -/* Return -1 if not a valid hart */ -int riscv_of_processor_hart(struct device_node *node) +/* + * Returns the hart ID of the given device tree node, or -1 if the device tree + * node isn't a RISC-V hart. + */ +int riscv_of_processor_hartid(struct device_node *node) { const char *isa, *status; u32 hart; @@ -58,6 +62,64 @@ int riscv_of_processor_hart(struct device_node *node) #ifdef CONFIG_PROC_FS +static void print_isa(struct seq_file *f, const char *orig_isa) +{ + static const char *ext = "mafdc"; + const char *isa = orig_isa; + const char *e; + + /* + * Linux doesn't support rv32e or rv128i, and we only support booting + * kernels on harts with the same ISA that the kernel is compiled for. + */ +#if defined(CONFIG_32BIT) + if (strncmp(isa, "rv32i", 5) != 0) + return; +#elif defined(CONFIG_64BIT) + if (strncmp(isa, "rv64i", 5) != 0) + return; +#endif + + /* Print the base ISA, as we already know it's legal. */ + seq_puts(f, "isa\t\t: "); + seq_write(f, isa, 5); + isa += 5; + + /* + * Check the rest of the ISA string for valid extensions, printing those + * we find. RISC-V ISA strings define an order, so we only print the + * extension bits when they're in order. + */ + for (e = ext; *e != '\0'; ++e) { + if (isa[0] == e[0]) { + seq_write(f, isa, 1); + isa++; + } + } + seq_puts(f, "\n"); + + /* + * If we were given an unsupported ISA in the device tree then print + * a bit of info describing what went wrong. + */ + if (isa[0] != '\0') + pr_info("unsupported ISA \"%s\" in device tree", orig_isa); +} + +static void print_mmu(struct seq_file *f, const char *mmu_type) +{ +#if defined(CONFIG_32BIT) + if (strcmp(mmu_type, "riscv,sv32") != 0) + return; +#elif defined(CONFIG_64BIT) + if (strcmp(mmu_type, "riscv,sv39") != 0 && + strcmp(mmu_type, "riscv,sv48") != 0) + return; +#endif + + seq_printf(f, "mmu\t\t: %s\n", mmu_type+6); +} + static void *c_start(struct seq_file *m, loff_t *pos) { *pos = cpumask_next(*pos - 1, cpu_online_mask); @@ -78,21 +140,20 @@ static void c_stop(struct seq_file *m, void *v) static int c_show(struct seq_file *m, void *v) { - unsigned long hart_id = (unsigned long)v - 1; - struct device_node *node = of_get_cpu_node(hart_id, NULL); + unsigned long cpu_id = (unsigned long)v - 1; + struct device_node *node = of_get_cpu_node(cpuid_to_hartid_map(cpu_id), + NULL); const char *compat, *isa, *mmu; - seq_printf(m, "hart\t: %lu\n", hart_id); - if (!of_property_read_string(node, "riscv,isa", &isa) - && isa[0] == 'r' - && isa[1] == 'v') - seq_printf(m, "isa\t: %s\n", isa); - if (!of_property_read_string(node, "mmu-type", &mmu) - && !strncmp(mmu, "riscv,", 6)) - seq_printf(m, "mmu\t: %s\n", mmu+6); + seq_printf(m, "processor\t: %lu\n", cpu_id); + seq_printf(m, "hart\t\t: %lu\n", cpuid_to_hartid_map(cpu_id)); + if (!of_property_read_string(node, "riscv,isa", &isa)) + print_isa(m, isa); + if (!of_property_read_string(node, "mmu-type", &mmu)) + print_mmu(m, mmu); if (!of_property_read_string(node, "compatible", &compat) && strcmp(compat, "riscv")) - seq_printf(m, "uarch\t: %s\n", compat); + seq_printf(m, "uarch\t\t: %s\n", compat); seq_puts(m, "\n"); return 0; diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 59c02e2bf739..13d4826ab2a1 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -168,7 +168,6 @@ ENTRY(handle_exception) /* Handle interrupts */ move a0, sp /* pt_regs */ - move a1, s4 /* scause */ tail do_IRQ 1: /* Exceptions run with interrupts enabled */ diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index c4d2c63f9a29..711190d473d4 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -47,6 +47,8 @@ ENTRY(_start) /* Save hart ID and DTB physical address */ mv s0, a0 mv s1, a1 + la a2, boot_cpu_hartid + REG_S a0, (a2) /* Initialize page tables and relocate to virtual addresses */ la sp, init_thread_union + THREAD_SIZE @@ -55,7 +57,7 @@ ENTRY(_start) /* Restore C environment */ la tp, init_task - sw s0, TASK_TI_CPU(tp) + sw zero, TASK_TI_CPU(tp) la sp, init_thread_union li a0, ASM_THREAD_SIZE diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c index 0cfac48a1272..48e6b7db83a1 100644 --- a/arch/riscv/kernel/irq.c +++ b/arch/riscv/kernel/irq.c @@ -8,6 +8,8 @@ #include <linux/interrupt.h> #include <linux/irqchip.h> #include <linux/irqdomain.h> +#include <linux/seq_file.h> +#include <asm/smp.h> /* * Possible interrupt causes: @@ -24,12 +26,18 @@ */ #define INTERRUPT_CAUSE_FLAG (1UL << (__riscv_xlen - 1)) -asmlinkage void __irq_entry do_IRQ(struct pt_regs *regs, unsigned long cause) +int arch_show_interrupts(struct seq_file *p, int prec) +{ + show_ipi_stats(p, prec); + return 0; +} + +asmlinkage void __irq_entry do_IRQ(struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); irq_enter(); - switch (cause & ~INTERRUPT_CAUSE_FLAG) { + switch (regs->scause & ~INTERRUPT_CAUSE_FLAG) { case INTERRUPT_CAUSE_TIMER: riscv_timer_interrupt(); break; diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index c9461985db7e..2c290e6aaa6e 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -81,6 +81,16 @@ EXPORT_SYMBOL(empty_zero_page); /* The lucky hart to first increment this variable will boot the other cores */ atomic_t hart_lottery; +unsigned long boot_cpu_hartid; + +unsigned long __cpuid_to_hartid_map[NR_CPUS] = { + [0 ... NR_CPUS-1] = INVALID_HARTID +}; + +void __init smp_setup_processor_id(void) +{ + cpuid_to_hartid_map(0) = boot_cpu_hartid; +} #ifdef CONFIG_BLK_DEV_INITRD static void __init setup_initrd(void) diff --git a/arch/riscv/kernel/smp.c b/arch/riscv/kernel/smp.c index 906fe21ea21b..57b1383e5ef7 100644 --- a/arch/riscv/kernel/smp.c +++ b/arch/riscv/kernel/smp.c @@ -22,23 +22,44 @@ #include <linux/interrupt.h> #include <linux/smp.h> #include <linux/sched.h> +#include <linux/seq_file.h> #include <asm/sbi.h> #include <asm/tlbflush.h> #include <asm/cacheflush.h> -/* A collection of single bit ipi messages. */ -static struct { - unsigned long bits ____cacheline_aligned; -} ipi_data[NR_CPUS] __cacheline_aligned; - enum ipi_message_type { IPI_RESCHEDULE, IPI_CALL_FUNC, IPI_MAX }; +/* A collection of single bit ipi messages. */ +static struct { + unsigned long stats[IPI_MAX] ____cacheline_aligned; + unsigned long bits ____cacheline_aligned; +} ipi_data[NR_CPUS] __cacheline_aligned; + +int riscv_hartid_to_cpuid(int hartid) +{ + int i = -1; + + for (i = 0; i < NR_CPUS; i++) + if (cpuid_to_hartid_map(i) == hartid) + return i; + pr_err("Couldn't find cpu id for hartid [%d]\n", hartid); + BUG(); + return i; +} + +void riscv_cpuid_to_hartid_mask(const struct cpumask *in, struct cpumask *out) +{ + int cpu; + + for_each_cpu(cpu, in) + cpumask_set_cpu(cpuid_to_hartid_map(cpu), out); +} /* Unsupported */ int setup_profiling_timer(unsigned int multiplier) { @@ -48,6 +69,7 @@ int setup_profiling_timer(unsigned int multiplier) void riscv_software_interrupt(void) { unsigned long *pending_ipis = &ipi_data[smp_processor_id()].bits; + unsigned long *stats = ipi_data[smp_processor_id()].stats; /* Clear pending IPI */ csr_clear(sip, SIE_SSIE); @@ -62,11 +84,15 @@ void riscv_software_interrupt(void) if (ops == 0) return; - if (ops & (1 << IPI_RESCHEDULE)) + if (ops & (1 << IPI_RESCHEDULE)) { + stats[IPI_RESCHEDULE]++; scheduler_ipi(); + } - if (ops & (1 << IPI_CALL_FUNC)) + if (ops & (1 << IPI_CALL_FUNC)) { + stats[IPI_CALL_FUNC]++; generic_smp_call_function_interrupt(); + } BUG_ON((ops >> IPI_MAX) != 0); @@ -78,14 +104,36 @@ void riscv_software_interrupt(void) static void send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation) { - int i; + int cpuid, hartid; + struct cpumask hartid_mask; + cpumask_clear(&hartid_mask); mb(); - for_each_cpu(i, to_whom) - set_bit(operation, &ipi_data[i].bits); - + for_each_cpu(cpuid, to_whom) { + set_bit(operation, &ipi_data[cpuid].bits); + hartid = cpuid_to_hartid_map(cpuid); + cpumask_set_cpu(hartid, &hartid_mask); + } mb(); - sbi_send_ipi(cpumask_bits(to_whom)); + sbi_send_ipi(cpumask_bits(&hartid_mask)); +} + +static const char * const ipi_names[] = { + [IPI_RESCHEDULE] = "Rescheduling interrupts", + [IPI_CALL_FUNC] = "Function call interrupts", +}; + +void show_ipi_stats(struct seq_file *p, int prec) +{ + unsigned int cpu, i; + + for (i = 0; i < IPI_MAX; i++) { + seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i, + prec >= 4 ? " " : ""); + for_each_online_cpu(cpu) + seq_printf(p, "%10lu ", ipi_data[cpu].stats[i]); + seq_printf(p, " %s\n", ipi_names[i]); + } } void arch_send_call_function_ipi_mask(struct cpumask *mask) @@ -127,7 +175,7 @@ void smp_send_reschedule(int cpu) void flush_icache_mm(struct mm_struct *mm, bool local) { unsigned int cpu; - cpumask_t others, *mask; + cpumask_t others, hmask, *mask; preempt_disable(); @@ -145,9 +193,11 @@ void flush_icache_mm(struct mm_struct *mm, bool local) */ cpumask_andnot(&others, mm_cpumask(mm), cpumask_of(cpu)); local |= cpumask_empty(&others); - if (mm != current->active_mm || !local) - sbi_remote_fence_i(others.bits); - else { + if (mm != current->active_mm || !local) { + cpumask_clear(&hmask); + riscv_cpuid_to_hartid_mask(&others, &hmask); + sbi_remote_fence_i(hmask.bits); + } else { /* * It's assumed that at least one strongly ordered operation is * performed on this hart between setting a hart's cpumask bit diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 56abab6a9812..18cda0e8cf94 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -30,6 +30,7 @@ #include <linux/irq.h> #include <linux/of.h> #include <linux/sched/task_stack.h> +#include <linux/sched/mm.h> #include <asm/irq.h> #include <asm/mmu_context.h> #include <asm/tlbflush.h> @@ -50,25 +51,33 @@ void __init smp_prepare_cpus(unsigned int max_cpus) void __init setup_smp(void) { struct device_node *dn = NULL; - int hart, im_okay_therefore_i_am = 0; + int hart; + bool found_boot_cpu = false; + int cpuid = 1; while ((dn = of_find_node_by_type(dn, "cpu"))) { - hart = riscv_of_processor_hart(dn); - if (hart >= 0) { - set_cpu_possible(hart, true); - set_cpu_present(hart, true); - if (hart == smp_processor_id()) { - BUG_ON(im_okay_therefore_i_am); - im_okay_therefore_i_am = 1; - } + hart = riscv_of_processor_hartid(dn); + if (hart < 0) + continue; + + if (hart == cpuid_to_hartid_map(0)) { + BUG_ON(found_boot_cpu); + found_boot_cpu = 1; + continue; } + + cpuid_to_hartid_map(cpuid) = hart; + set_cpu_possible(cpuid, true); + set_cpu_present(cpuid, true); + cpuid++; } - BUG_ON(!im_okay_therefore_i_am); + BUG_ON(!found_boot_cpu); } int __cpu_up(unsigned int cpu, struct task_struct *tidle) { + int hartid = cpuid_to_hartid_map(cpu); tidle->thread_info.cpu = cpu; /* @@ -79,8 +88,9 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle) * the spinning harts that they can continue the boot process. */ smp_mb(); - __cpu_up_stack_pointer[cpu] = task_stack_page(tidle) + THREAD_SIZE; - __cpu_up_task_pointer[cpu] = tidle; + WRITE_ONCE(__cpu_up_stack_pointer[hartid], + task_stack_page(tidle) + THREAD_SIZE); + WRITE_ONCE(__cpu_up_task_pointer[hartid], tidle); while (!cpu_online(cpu)) cpu_relax(); @@ -100,14 +110,22 @@ asmlinkage void __init smp_callin(void) struct mm_struct *mm = &init_mm; /* All kernel threads share the same mm context. */ - atomic_inc(&mm->mm_count); + mmgrab(mm); current->active_mm = mm; trap_init(); notify_cpu_starting(smp_processor_id()); set_cpu_online(smp_processor_id(), 1); + /* + * Remote TLB flushes are ignored while the CPU is offline, so emit + * a local TLB flush right now just in case. + */ local_flush_tlb_all(); - local_irq_enable(); + /* + * Disable preemption before enabling interrupts, so we don't try to + * schedule a CPU that hasn't actually started yet. + */ preempt_disable(); + local_irq_enable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } |
