1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/arch/sh/kernel/irq.c 4 * 5 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar 6 * 7 * 8 * SuperH version: Copyright (C) 1999 Niibe Yutaka 9 */ 10 #include <linux/irq.h> 11 #include <linux/interrupt.h> 12 #include <linux/module.h> 13 #include <linux/kernel_stat.h> 14 #include <linux/seq_file.h> 15 #include <linux/ftrace.h> 16 #include <linux/delay.h> 17 #include <linux/ratelimit.h> 18 #include <asm/processor.h> 19 #include <asm/machvec.h> 20 #include <linux/uaccess.h> 21 #include <asm/thread_info.h> 22 #include <cpu/mmu_context.h> 23 #include <asm/softirq_stack.h> 24 25 atomic_t irq_err_count; 26 27 /* 28 * 'what should we do if we get a hw irq event on an illegal vector'. 29 * each architecture has to answer this themselves, it doesn't deserve 30 * a generic callback i think. 31 */ 32 void ack_bad_irq(unsigned int irq) 33 { 34 atomic_inc(&irq_err_count); 35 printk("unexpected IRQ trap at vector %02x\n", irq); 36 } 37 38 #if defined(CONFIG_PROC_FS) 39 /* 40 * /proc/interrupts printing for arch specific interrupts 41 */ 42 int arch_show_interrupts(struct seq_file *p, int prec) 43 { 44 int j; 45 46 seq_printf(p, "%*s: ", prec, "NMI"); 47 for_each_online_cpu(j) 48 seq_printf(p, "%10u ", per_cpu(irq_stat.__nmi_count, j)); 49 seq_printf(p, " Non-maskable interrupts\n"); 50 51 seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count)); 52 53 return 0; 54 } 55 #endif 56 57 #ifdef CONFIG_IRQSTACKS 58 /* 59 * per-CPU IRQ handling contexts (thread information and stack) 60 */ 61 union irq_ctx { 62 struct thread_info tinfo; 63 u32 stack[THREAD_SIZE/sizeof(u32)]; 64 }; 65 66 static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; 67 static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; 68 69 static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; 70 static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; 71 72 static inline void handle_one_irq(unsigned int irq) 73 { 74 union irq_ctx *curctx, *irqctx; 75 76 curctx = (union irq_ctx *)current_thread_info(); 77 irqctx = hardirq_ctx[smp_processor_id()]; 78 79 /* 80 * this is where we switch to the IRQ stack. However, if we are 81 * already using the IRQ stack (because we interrupted a hardirq 82 * handler) we can't do that and just have to keep using the 83 * current stack (which is the irq stack already after all) 84 */ 85 if (curctx != irqctx) { 86 u32 *isp; 87 88 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 89 irqctx->tinfo.task = curctx->tinfo.task; 90 irqctx->tinfo.previous_sp = current_stack_pointer; 91 92 /* 93 * Copy the softirq bits in preempt_count so that the 94 * softirq checks work in the hardirq context. 95 */ 96 irqctx->tinfo.preempt_count = 97 (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | 98 (curctx->tinfo.preempt_count & SOFTIRQ_MASK); 99 100 __asm__ __volatile__ ( 101 "mov %0, r4 \n" 102 "mov r15, r8 \n" 103 "jsr @%1 \n" 104 /* switch to the irq stack */ 105 " mov %2, r15 \n" 106 /* restore the stack (ring zero) */ 107 "mov r8, r15 \n" 108 : /* no outputs */ 109 : "r" (irq), "r" (generic_handle_irq), "r" (isp) 110 : "memory", "r0", "r1", "r2", "r3", "r4", 111 "r5", "r6", "r7", "r8", "t", "pr" 112 ); 113 } else 114 generic_handle_irq(irq); 115 } 116 117 /* 118 * allocate per-cpu stacks for hardirq and for softirq processing 119 */ 120 void irq_ctx_init(int cpu) 121 { 122 union irq_ctx *irqctx; 123 124 if (hardirq_ctx[cpu]) 125 return; 126 127 irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE]; 128 irqctx->tinfo.task = NULL; 129 irqctx->tinfo.cpu = cpu; 130 irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; 131 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 132 133 hardirq_ctx[cpu] = irqctx; 134 135 irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE]; 136 irqctx->tinfo.task = NULL; 137 irqctx->tinfo.cpu = cpu; 138 irqctx->tinfo.preempt_count = 0; 139 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 140 141 softirq_ctx[cpu] = irqctx; 142 143 printk("CPU %u irqstacks, hard=%p soft=%p\n", 144 cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); 145 } 146 147 void irq_ctx_exit(int cpu) 148 { 149 hardirq_ctx[cpu] = NULL; 150 } 151 152 void do_softirq_own_stack(void) 153 { 154 struct thread_info *curctx; 155 union irq_ctx *irqctx; 156 u32 *isp; 157 158 curctx = current_thread_info(); 159 irqctx = softirq_ctx[smp_processor_id()]; 160 irqctx->tinfo.task = curctx->task; 161 irqctx->tinfo.previous_sp = current_stack_pointer; 162 163 /* build the stack frame on the softirq stack */ 164 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 165 166 __asm__ __volatile__ ( 167 "mov r15, r9 \n" 168 "jsr @%0 \n" 169 /* switch to the softirq stack */ 170 " mov %1, r15 \n" 171 /* restore the thread stack */ 172 "mov r9, r15 \n" 173 : /* no outputs */ 174 : "r" (__do_softirq), "r" (isp) 175 : "memory", "r0", "r1", "r2", "r3", "r4", 176 "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" 177 ); 178 } 179 #else 180 static inline void handle_one_irq(unsigned int irq) 181 { 182 generic_handle_irq(irq); 183 } 184 #endif 185 186 asmlinkage __irq_entry int do_IRQ(unsigned int irq, struct pt_regs *regs) 187 { 188 struct pt_regs *old_regs = set_irq_regs(regs); 189 190 irq_enter(); 191 192 irq = irq_demux(irq_lookup(irq)); 193 194 if (irq != NO_IRQ_IGNORE) { 195 handle_one_irq(irq); 196 irq_finish(irq); 197 } 198 199 irq_exit(); 200 201 set_irq_regs(old_regs); 202 203 return IRQ_HANDLED; 204 } 205 206 void __init init_IRQ(void) 207 { 208 plat_irq_setup(); 209 210 /* Perform the machine specific initialisation */ 211 if (sh_mv.mv_init_irq) 212 sh_mv.mv_init_irq(); 213 214 intc_finalize(); 215 216 irq_ctx_init(smp_processor_id()); 217 } 218 219 #ifdef CONFIG_HOTPLUG_CPU 220 /* 221 * The CPU has been marked offline. Migrate IRQs off this CPU. If 222 * the affinity settings do not allow other CPUs, force them onto any 223 * available CPU. 224 */ 225 void migrate_irqs(void) 226 { 227 unsigned int irq, cpu = smp_processor_id(); 228 229 for_each_active_irq(irq) { 230 struct irq_data *data = irq_get_irq_data(irq); 231 232 if (irq_data_get_node(data) == cpu) { 233 struct cpumask *mask = irq_data_get_affinity_mask(data); 234 unsigned int newcpu = cpumask_any_and(mask, 235 cpu_online_mask); 236 if (newcpu >= nr_cpu_ids) { 237 pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n", 238 irq, cpu); 239 240 cpumask_setall(mask); 241 } 242 irq_set_affinity(irq, mask); 243 } 244 } 245 } 246 #endif 247