1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Derived from arch/i386/kernel/irq.c 4 * Copyright (C) 1992 Linus Torvalds 5 * Adapted from arch/i386 by Gary Thomas 6 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 7 * Updated and modified by Cort Dougan <cort@fsmlabs.com> 8 * Copyright (C) 1996-2001 Cort Dougan 9 * Adapted for Power Macintosh by Paul Mackerras 10 * Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au) 11 * 12 * This file contains the code used by various IRQ handling routines: 13 * asking for different IRQ's should be done through these routines 14 * instead of just grabbing them. Thus setups with different IRQ numbers 15 * shouldn't result in any weird surprises, and installing new handlers 16 * should be easier. 17 * 18 * The MPC8xx has an interrupt mask in the SIU. If a bit is set, the 19 * interrupt is _enabled_. As expected, IRQ0 is bit 0 in the 32-bit 20 * mask register (of which only 16 are defined), hence the weird shifting 21 * and complement of the cached_irq_mask. I want to be able to stuff 22 * this right into the SIU SMASK register. 23 * Many of the prep/chrp functions are conditional compiled on CONFIG_PPC_8xx 24 * to reduce code space and undefined function references. 25 */ 26 27 #undef DEBUG 28 29 #include <linux/export.h> 30 #include <linux/threads.h> 31 #include <linux/kernel_stat.h> 32 #include <linux/signal.h> 33 #include <linux/sched.h> 34 #include <linux/ptrace.h> 35 #include <linux/ioport.h> 36 #include <linux/interrupt.h> 37 #include <linux/timex.h> 38 #include <linux/init.h> 39 #include <linux/slab.h> 40 #include <linux/delay.h> 41 #include <linux/irq.h> 42 #include <linux/seq_file.h> 43 #include <linux/cpumask.h> 44 #include <linux/profile.h> 45 #include <linux/bitops.h> 46 #include <linux/list.h> 47 #include <linux/radix-tree.h> 48 #include <linux/mutex.h> 49 #include <linux/pci.h> 50 #include <linux/debugfs.h> 51 #include <linux/of.h> 52 #include <linux/of_irq.h> 53 #include <linux/vmalloc.h> 54 #include <linux/pgtable.h> 55 #include <linux/static_call.h> 56 57 #include <linux/uaccess.h> 58 #include <asm/interrupt.h> 59 #include <asm/io.h> 60 #include <asm/irq.h> 61 #include <asm/cache.h> 62 #include <asm/ptrace.h> 63 #include <asm/machdep.h> 64 #include <asm/udbg.h> 65 #include <asm/smp.h> 66 #include <asm/hw_irq.h> 67 #include <asm/softirq_stack.h> 68 #include <asm/ppc_asm.h> 69 70 #define CREATE_TRACE_POINTS 71 #include <asm/trace.h> 72 #include <asm/cpu_has_feature.h> 73 74 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat); 75 EXPORT_PER_CPU_SYMBOL(irq_stat); 76 77 #ifdef CONFIG_PPC32 78 atomic_t ppc_n_lost_interrupts; 79 80 #ifdef CONFIG_TAU_INT 81 extern int tau_initialized; 82 u32 tau_interrupts(unsigned long cpu); 83 #endif 84 #endif /* CONFIG_PPC32 */ 85 86 int arch_show_interrupts(struct seq_file *p, int prec) 87 { 88 int j; 89 90 #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT) 91 if (tau_initialized) { 92 seq_printf(p, "%*s: ", prec, "TAU"); 93 for_each_online_cpu(j) 94 seq_printf(p, "%10u ", tau_interrupts(j)); 95 seq_puts(p, " PowerPC Thermal Assist (cpu temp)\n"); 96 } 97 #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */ 98 99 seq_printf(p, "%*s: ", prec, "LOC"); 100 for_each_online_cpu(j) 101 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs_event); 102 seq_printf(p, " Local timer interrupts for timer event device\n"); 103 104 seq_printf(p, "%*s: ", prec, "BCT"); 105 for_each_online_cpu(j) 106 seq_printf(p, "%10u ", per_cpu(irq_stat, j).broadcast_irqs_event); 107 seq_printf(p, " Broadcast timer interrupts for timer event device\n"); 108 109 seq_printf(p, "%*s: ", prec, "LOC"); 110 for_each_online_cpu(j) 111 seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs_others); 112 seq_printf(p, " Local timer interrupts for others\n"); 113 114 seq_printf(p, "%*s: ", prec, "SPU"); 115 for_each_online_cpu(j) 116 seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs); 117 seq_printf(p, " Spurious interrupts\n"); 118 119 seq_printf(p, "%*s: ", prec, "PMI"); 120 for_each_online_cpu(j) 121 seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs); 122 seq_printf(p, " Performance monitoring interrupts\n"); 123 124 seq_printf(p, "%*s: ", prec, "MCE"); 125 for_each_online_cpu(j) 126 seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions); 127 seq_printf(p, " Machine check exceptions\n"); 128 129 #ifdef CONFIG_PPC_BOOK3S_64 130 if (cpu_has_feature(CPU_FTR_HVMODE)) { 131 seq_printf(p, "%*s: ", prec, "HMI"); 132 for_each_online_cpu(j) 133 seq_printf(p, "%10u ", paca_ptrs[j]->hmi_irqs); 134 seq_printf(p, " Hypervisor Maintenance Interrupts\n"); 135 } 136 #endif 137 138 seq_printf(p, "%*s: ", prec, "NMI"); 139 for_each_online_cpu(j) 140 seq_printf(p, "%10u ", per_cpu(irq_stat, j).sreset_irqs); 141 seq_printf(p, " System Reset interrupts\n"); 142 143 #ifdef CONFIG_PPC_WATCHDOG 144 seq_printf(p, "%*s: ", prec, "WDG"); 145 for_each_online_cpu(j) 146 seq_printf(p, "%10u ", per_cpu(irq_stat, j).soft_nmi_irqs); 147 seq_printf(p, " Watchdog soft-NMI interrupts\n"); 148 #endif 149 150 #ifdef CONFIG_PPC_DOORBELL 151 if (cpu_has_feature(CPU_FTR_DBELL)) { 152 seq_printf(p, "%*s: ", prec, "DBL"); 153 for_each_online_cpu(j) 154 seq_printf(p, "%10u ", per_cpu(irq_stat, j).doorbell_irqs); 155 seq_printf(p, " Doorbell interrupts\n"); 156 } 157 #endif 158 159 return 0; 160 } 161 162 /* 163 * /proc/stat helpers 164 */ 165 u64 arch_irq_stat_cpu(unsigned int cpu) 166 { 167 u64 sum = per_cpu(irq_stat, cpu).timer_irqs_event; 168 169 sum += per_cpu(irq_stat, cpu).broadcast_irqs_event; 170 sum += per_cpu(irq_stat, cpu).pmu_irqs; 171 sum += per_cpu(irq_stat, cpu).mce_exceptions; 172 sum += per_cpu(irq_stat, cpu).spurious_irqs; 173 sum += per_cpu(irq_stat, cpu).timer_irqs_others; 174 #ifdef CONFIG_PPC_BOOK3S_64 175 sum += paca_ptrs[cpu]->hmi_irqs; 176 #endif 177 sum += per_cpu(irq_stat, cpu).sreset_irqs; 178 #ifdef CONFIG_PPC_WATCHDOG 179 sum += per_cpu(irq_stat, cpu).soft_nmi_irqs; 180 #endif 181 #ifdef CONFIG_PPC_DOORBELL 182 sum += per_cpu(irq_stat, cpu).doorbell_irqs; 183 #endif 184 185 return sum; 186 } 187 188 static inline void check_stack_overflow(unsigned long sp) 189 { 190 if (!IS_ENABLED(CONFIG_DEBUG_STACKOVERFLOW)) 191 return; 192 193 sp &= THREAD_SIZE - 1; 194 195 /* check for stack overflow: is there less than 1/4th free? */ 196 if (unlikely(sp < THREAD_SIZE / 4)) { 197 pr_err("do_IRQ: stack overflow: %ld\n", sp); 198 dump_stack(); 199 } 200 } 201 202 #ifdef CONFIG_SOFTIRQ_ON_OWN_STACK 203 static __always_inline void call_do_softirq(const void *sp) 204 { 205 /* Temporarily switch r1 to sp, call __do_softirq() then restore r1. */ 206 asm volatile ( 207 PPC_STLU " %%r1, %[offset](%[sp]) ;" 208 "mr %%r1, %[sp] ;" 209 #ifdef CONFIG_PPC_KERNEL_PCREL 210 "bl %[callee]@notoc ;" 211 #else 212 "bl %[callee] ;" 213 #endif 214 PPC_LL " %%r1, 0(%%r1) ;" 215 : // Outputs 216 : // Inputs 217 [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_MIN_SIZE), 218 [callee] "i" (__do_softirq) 219 : // Clobbers 220 "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6", 221 "cr7", "r0", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", 222 "r11", "r12" 223 ); 224 } 225 #endif 226 227 DEFINE_STATIC_CALL_RET0(ppc_get_irq, *ppc_md.get_irq); 228 229 static void __do_irq(struct pt_regs *regs, unsigned long oldsp) 230 { 231 unsigned int irq; 232 233 trace_irq_entry(regs); 234 235 check_stack_overflow(oldsp); 236 237 /* 238 * Query the platform PIC for the interrupt & ack it. 239 * 240 * This will typically lower the interrupt line to the CPU 241 */ 242 irq = static_call(ppc_get_irq)(); 243 244 /* We can hard enable interrupts now to allow perf interrupts */ 245 if (should_hard_irq_enable(regs)) 246 do_hard_irq_enable(); 247 248 /* And finally process it */ 249 if (unlikely(!irq)) 250 __this_cpu_inc(irq_stat.spurious_irqs); 251 else 252 generic_handle_irq(irq); 253 254 trace_irq_exit(regs); 255 } 256 257 static __always_inline void call_do_irq(struct pt_regs *regs, void *sp) 258 { 259 register unsigned long r3 asm("r3") = (unsigned long)regs; 260 261 /* Temporarily switch r1 to sp, call __do_irq() then restore r1. */ 262 asm volatile ( 263 PPC_STLU " %%r1, %[offset](%[sp]) ;" 264 "mr %%r4, %%r1 ;" 265 "mr %%r1, %[sp] ;" 266 #ifdef CONFIG_PPC_KERNEL_PCREL 267 "bl %[callee]@notoc ;" 268 #else 269 "bl %[callee] ;" 270 #endif 271 PPC_LL " %%r1, 0(%%r1) ;" 272 : // Outputs 273 "+r" (r3) 274 : // Inputs 275 [sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_MIN_SIZE), 276 [callee] "i" (__do_irq) 277 : // Clobbers 278 "lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6", 279 "cr7", "r0", "r4", "r5", "r6", "r7", "r8", "r9", "r10", 280 "r11", "r12" 281 ); 282 } 283 284 void __do_IRQ(struct pt_regs *regs) 285 { 286 struct pt_regs *old_regs = set_irq_regs(regs); 287 void *cursp, *irqsp, *sirqsp; 288 289 /* Switch to the irq stack to handle this */ 290 cursp = (void *)(current_stack_pointer & ~(THREAD_SIZE - 1)); 291 irqsp = hardirq_ctx[raw_smp_processor_id()]; 292 sirqsp = softirq_ctx[raw_smp_processor_id()]; 293 294 /* Already there ? If not switch stack and call */ 295 if (unlikely(cursp == irqsp || cursp == sirqsp)) 296 __do_irq(regs, current_stack_pointer); 297 else 298 call_do_irq(regs, irqsp); 299 300 set_irq_regs(old_regs); 301 } 302 303 DEFINE_INTERRUPT_HANDLER_ASYNC(do_IRQ) 304 { 305 __do_IRQ(regs); 306 } 307 308 static void *__init alloc_vm_stack(void) 309 { 310 return __vmalloc_node(THREAD_SIZE, THREAD_ALIGN, THREADINFO_GFP, 311 NUMA_NO_NODE, (void *)_RET_IP_); 312 } 313 314 static void __init vmap_irqstack_init(void) 315 { 316 int i; 317 318 for_each_possible_cpu(i) { 319 softirq_ctx[i] = alloc_vm_stack(); 320 hardirq_ctx[i] = alloc_vm_stack(); 321 } 322 } 323 324 325 void __init init_IRQ(void) 326 { 327 if (IS_ENABLED(CONFIG_VMAP_STACK)) 328 vmap_irqstack_init(); 329 330 if (ppc_md.init_IRQ) 331 ppc_md.init_IRQ(); 332 333 if (!WARN_ON(!ppc_md.get_irq)) 334 static_call_update(ppc_get_irq, ppc_md.get_irq); 335 } 336 337 #ifdef CONFIG_BOOKE_OR_40x 338 void *critirq_ctx[NR_CPUS] __read_mostly; 339 void *dbgirq_ctx[NR_CPUS] __read_mostly; 340 void *mcheckirq_ctx[NR_CPUS] __read_mostly; 341 #endif 342 343 void *softirq_ctx[NR_CPUS] __read_mostly; 344 void *hardirq_ctx[NR_CPUS] __read_mostly; 345 346 #ifdef CONFIG_SOFTIRQ_ON_OWN_STACK 347 void do_softirq_own_stack(void) 348 { 349 call_do_softirq(softirq_ctx[smp_processor_id()]); 350 } 351 #endif 352 353 irq_hw_number_t virq_to_hw(unsigned int virq) 354 { 355 struct irq_data *irq_data = irq_get_irq_data(virq); 356 return WARN_ON(!irq_data) ? 0 : irq_data->hwirq; 357 } 358 EXPORT_SYMBOL_GPL(virq_to_hw); 359 360 #ifdef CONFIG_SMP 361 int irq_choose_cpu(const struct cpumask *mask) 362 { 363 int cpuid; 364 365 if (cpumask_equal(mask, cpu_online_mask)) { 366 static int irq_rover; 367 static DEFINE_RAW_SPINLOCK(irq_rover_lock); 368 unsigned long flags; 369 370 /* Round-robin distribution... */ 371 do_round_robin: 372 raw_spin_lock_irqsave(&irq_rover_lock, flags); 373 374 irq_rover = cpumask_next(irq_rover, cpu_online_mask); 375 if (irq_rover >= nr_cpu_ids) 376 irq_rover = cpumask_first(cpu_online_mask); 377 378 cpuid = irq_rover; 379 380 raw_spin_unlock_irqrestore(&irq_rover_lock, flags); 381 } else { 382 cpuid = cpumask_first_and(mask, cpu_online_mask); 383 if (cpuid >= nr_cpu_ids) 384 goto do_round_robin; 385 } 386 387 return get_hard_smp_processor_id(cpuid); 388 } 389 #else 390 int irq_choose_cpu(const struct cpumask *mask) 391 { 392 return hard_smp_processor_id(); 393 } 394 #endif 395