James Hogan | 63047ea | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Linux/Meta general interrupt handling code |
| 3 | * |
| 4 | */ |
| 5 | |
| 6 | #include <linux/kernel.h> |
| 7 | #include <linux/interrupt.h> |
| 8 | #include <linux/init.h> |
James Hogan | 5698c50 | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 9 | #include <linux/irqchip/metag-ext.h> |
| 10 | #include <linux/irqchip/metag.h> |
James Hogan | 63047ea | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 11 | #include <linux/irqdomain.h> |
| 12 | #include <linux/ratelimit.h> |
| 13 | |
| 14 | #include <asm/core_reg.h> |
| 15 | #include <asm/mach/arch.h> |
| 16 | #include <asm/uaccess.h> |
| 17 | |
| 18 | #ifdef CONFIG_4KSTACKS |
| 19 | union irq_ctx { |
| 20 | struct thread_info tinfo; |
| 21 | u32 stack[THREAD_SIZE/sizeof(u32)]; |
| 22 | }; |
| 23 | |
| 24 | static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; |
| 25 | static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; |
| 26 | #endif |
| 27 | |
Markos Chandras | 32580ae | 2013-05-07 16:48:21 +0100 | [diff] [blame] | 28 | static struct irq_domain *root_domain; |
James Hogan | 63047ea | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 29 | |
| 30 | static unsigned int startup_meta_irq(struct irq_data *data) |
| 31 | { |
| 32 | tbi_startup_interrupt(data->hwirq); |
| 33 | return 0; |
| 34 | } |
| 35 | |
| 36 | static void shutdown_meta_irq(struct irq_data *data) |
| 37 | { |
| 38 | tbi_shutdown_interrupt(data->hwirq); |
| 39 | } |
| 40 | |
| 41 | void do_IRQ(int irq, struct pt_regs *regs) |
| 42 | { |
| 43 | struct pt_regs *old_regs = set_irq_regs(regs); |
| 44 | #ifdef CONFIG_4KSTACKS |
| 45 | struct irq_desc *desc; |
| 46 | union irq_ctx *curctx, *irqctx; |
| 47 | u32 *isp; |
| 48 | #endif |
| 49 | |
| 50 | irq_enter(); |
| 51 | |
| 52 | irq = irq_linear_revmap(root_domain, irq); |
| 53 | |
| 54 | #ifdef CONFIG_DEBUG_STACKOVERFLOW |
| 55 | /* Debugging check for stack overflow: is there less than 1KB free? */ |
| 56 | { |
| 57 | unsigned long sp; |
| 58 | |
| 59 | sp = __core_reg_get(A0StP); |
| 60 | sp &= THREAD_SIZE - 1; |
| 61 | |
| 62 | if (unlikely(sp > (THREAD_SIZE - 1024))) |
| 63 | pr_err("Stack overflow in do_IRQ: %ld\n", sp); |
| 64 | } |
| 65 | #endif |
| 66 | |
| 67 | |
| 68 | #ifdef CONFIG_4KSTACKS |
| 69 | curctx = (union irq_ctx *) current_thread_info(); |
| 70 | irqctx = hardirq_ctx[smp_processor_id()]; |
| 71 | |
| 72 | /* |
| 73 | * this is where we switch to the IRQ stack. However, if we are |
| 74 | * already using the IRQ stack (because we interrupted a hardirq |
| 75 | * handler) we can't do that and just have to keep using the |
| 76 | * current stack (which is the irq stack already after all) |
| 77 | */ |
| 78 | if (curctx != irqctx) { |
| 79 | /* build the stack frame on the IRQ stack */ |
| 80 | isp = (u32 *) ((char *)irqctx + sizeof(struct thread_info)); |
| 81 | irqctx->tinfo.task = curctx->tinfo.task; |
| 82 | |
| 83 | /* |
| 84 | * Copy the softirq bits in preempt_count so that the |
| 85 | * softirq checks work in the hardirq context. |
| 86 | */ |
| 87 | irqctx->tinfo.preempt_count = |
| 88 | (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | |
| 89 | (curctx->tinfo.preempt_count & SOFTIRQ_MASK); |
| 90 | |
| 91 | desc = irq_to_desc(irq); |
| 92 | |
| 93 | asm volatile ( |
| 94 | "MOV D0.5,%0\n" |
| 95 | "MOV D1Ar1,%1\n" |
| 96 | "MOV D1RtP,%2\n" |
| 97 | "MOV D0Ar2,%3\n" |
| 98 | "SWAP A0StP,D0.5\n" |
| 99 | "SWAP PC,D1RtP\n" |
| 100 | "MOV A0StP,D0.5\n" |
| 101 | : |
| 102 | : "r" (isp), "r" (irq), "r" (desc->handle_irq), |
| 103 | "r" (desc) |
| 104 | : "memory", "cc", "D1Ar1", "D0Ar2", "D1Ar3", "D0Ar4", |
| 105 | "D1Ar5", "D0Ar6", "D0Re0", "D1Re0", "D0.4", "D1RtP", |
| 106 | "D0.5" |
| 107 | ); |
| 108 | } else |
| 109 | #endif |
| 110 | generic_handle_irq(irq); |
| 111 | |
| 112 | irq_exit(); |
| 113 | |
| 114 | set_irq_regs(old_regs); |
| 115 | } |
| 116 | |
| 117 | #ifdef CONFIG_4KSTACKS |
| 118 | |
| 119 | static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; |
| 120 | |
| 121 | static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; |
| 122 | |
| 123 | /* |
| 124 | * allocate per-cpu stacks for hardirq and for softirq processing |
| 125 | */ |
| 126 | void irq_ctx_init(int cpu) |
| 127 | { |
| 128 | union irq_ctx *irqctx; |
| 129 | |
| 130 | if (hardirq_ctx[cpu]) |
| 131 | return; |
| 132 | |
| 133 | irqctx = (union irq_ctx *) &hardirq_stack[cpu * THREAD_SIZE]; |
| 134 | irqctx->tinfo.task = NULL; |
| 135 | irqctx->tinfo.exec_domain = NULL; |
| 136 | irqctx->tinfo.cpu = cpu; |
| 137 | irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; |
| 138 | irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); |
| 139 | |
| 140 | hardirq_ctx[cpu] = irqctx; |
| 141 | |
| 142 | irqctx = (union irq_ctx *) &softirq_stack[cpu * THREAD_SIZE]; |
| 143 | irqctx->tinfo.task = NULL; |
| 144 | irqctx->tinfo.exec_domain = NULL; |
| 145 | irqctx->tinfo.cpu = cpu; |
| 146 | irqctx->tinfo.preempt_count = 0; |
| 147 | irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); |
| 148 | |
| 149 | softirq_ctx[cpu] = irqctx; |
| 150 | |
| 151 | pr_info("CPU %u irqstacks, hard=%p soft=%p\n", |
| 152 | cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); |
| 153 | } |
| 154 | |
| 155 | void irq_ctx_exit(int cpu) |
| 156 | { |
| 157 | hardirq_ctx[smp_processor_id()] = NULL; |
| 158 | } |
| 159 | |
| 160 | extern asmlinkage void __do_softirq(void); |
| 161 | |
Frederic Weisbecker | 7d65f4a | 2013-09-05 15:49:45 +0200 | [diff] [blame] | 162 | void do_softirq_own_stack(void) |
James Hogan | 63047ea | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 163 | { |
James Hogan | 63047ea | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 164 | struct thread_info *curctx; |
| 165 | union irq_ctx *irqctx; |
| 166 | u32 *isp; |
| 167 | |
Frederic Weisbecker | 7d65f4a | 2013-09-05 15:49:45 +0200 | [diff] [blame] | 168 | curctx = current_thread_info(); |
| 169 | irqctx = softirq_ctx[smp_processor_id()]; |
| 170 | irqctx->tinfo.task = curctx->task; |
James Hogan | 63047ea | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 171 | |
Frederic Weisbecker | 7d65f4a | 2013-09-05 15:49:45 +0200 | [diff] [blame] | 172 | /* build the stack frame on the softirq stack */ |
| 173 | isp = (u32 *) ((char *)irqctx + sizeof(struct thread_info)); |
James Hogan | 63047ea | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 174 | |
Frederic Weisbecker | 7d65f4a | 2013-09-05 15:49:45 +0200 | [diff] [blame] | 175 | asm volatile ( |
| 176 | "MOV D0.5,%0\n" |
| 177 | "SWAP A0StP,D0.5\n" |
| 178 | "CALLR D1RtP,___do_softirq\n" |
| 179 | "MOV A0StP,D0.5\n" |
| 180 | : |
| 181 | : "r" (isp) |
| 182 | : "memory", "cc", "D1Ar1", "D0Ar2", "D1Ar3", "D0Ar4", |
| 183 | "D1Ar5", "D0Ar6", "D0Re0", "D1Re0", "D0.4", "D1RtP", |
| 184 | "D0.5" |
| 185 | ); |
James Hogan | 63047ea | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 186 | } |
| 187 | #endif |
| 188 | |
| 189 | static struct irq_chip meta_irq_type = { |
| 190 | .name = "META-IRQ", |
| 191 | .irq_startup = startup_meta_irq, |
| 192 | .irq_shutdown = shutdown_meta_irq, |
| 193 | }; |
| 194 | |
| 195 | /** |
| 196 | * tbisig_map() - Map a TBI signal number to a virtual IRQ number. |
| 197 | * @hw: Number of the TBI signal. Must be in range. |
| 198 | * |
| 199 | * Returns: The virtual IRQ number of the TBI signal number IRQ specified by |
| 200 | * @hw. |
| 201 | */ |
| 202 | int tbisig_map(unsigned int hw) |
| 203 | { |
| 204 | return irq_create_mapping(root_domain, hw); |
| 205 | } |
| 206 | |
| 207 | /** |
| 208 | * metag_tbisig_map() - map a tbi signal to a Linux virtual IRQ number |
| 209 | * @d: root irq domain |
| 210 | * @irq: virtual irq number |
| 211 | * @hw: hardware irq number (TBI signal number) |
| 212 | * |
| 213 | * This sets up a virtual irq for a specified TBI signal number. |
| 214 | */ |
| 215 | static int metag_tbisig_map(struct irq_domain *d, unsigned int irq, |
| 216 | irq_hw_number_t hw) |
| 217 | { |
| 218 | #ifdef CONFIG_SMP |
| 219 | irq_set_chip_and_handler(irq, &meta_irq_type, handle_percpu_irq); |
| 220 | #else |
| 221 | irq_set_chip_and_handler(irq, &meta_irq_type, handle_simple_irq); |
| 222 | #endif |
| 223 | return 0; |
| 224 | } |
| 225 | |
| 226 | static const struct irq_domain_ops metag_tbisig_domain_ops = { |
| 227 | .map = metag_tbisig_map, |
| 228 | }; |
| 229 | |
| 230 | /* |
| 231 | * void init_IRQ(void) |
| 232 | * |
| 233 | * Parameters: None |
| 234 | * |
| 235 | * Returns: Nothing |
| 236 | * |
| 237 | * This function should be called during kernel startup to initialize |
| 238 | * the IRQ handling routines. |
| 239 | */ |
| 240 | void __init init_IRQ(void) |
| 241 | { |
| 242 | root_domain = irq_domain_add_linear(NULL, 32, |
| 243 | &metag_tbisig_domain_ops, NULL); |
| 244 | if (unlikely(!root_domain)) |
| 245 | panic("init_IRQ: cannot add root IRQ domain"); |
| 246 | |
| 247 | irq_ctx_init(smp_processor_id()); |
| 248 | |
James Hogan | 5698c50 | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 249 | init_internal_IRQ(); |
| 250 | init_external_IRQ(); |
| 251 | |
James Hogan | 63047ea | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 252 | if (machine_desc->init_irq) |
| 253 | machine_desc->init_irq(); |
| 254 | } |
| 255 | |
| 256 | int __init arch_probe_nr_irqs(void) |
| 257 | { |
| 258 | if (machine_desc->nr_irqs) |
| 259 | nr_irqs = machine_desc->nr_irqs; |
| 260 | return 0; |
| 261 | } |
| 262 | |
| 263 | #ifdef CONFIG_HOTPLUG_CPU |
| 264 | static void route_irq(struct irq_data *data, unsigned int irq, unsigned int cpu) |
| 265 | { |
| 266 | struct irq_desc *desc = irq_to_desc(irq); |
| 267 | struct irq_chip *chip = irq_data_get_irq_chip(data); |
James Hogan | 8b8b241 | 2013-07-01 15:36:38 +0100 | [diff] [blame] | 268 | unsigned long flags; |
James Hogan | 63047ea | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 269 | |
James Hogan | 8b8b241 | 2013-07-01 15:36:38 +0100 | [diff] [blame] | 270 | raw_spin_lock_irqsave(&desc->lock, flags); |
James Hogan | 63047ea | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 271 | if (chip->irq_set_affinity) |
| 272 | chip->irq_set_affinity(data, cpumask_of(cpu), false); |
James Hogan | 8b8b241 | 2013-07-01 15:36:38 +0100 | [diff] [blame] | 273 | raw_spin_unlock_irqrestore(&desc->lock, flags); |
James Hogan | 63047ea | 2012-10-09 10:54:47 +0100 | [diff] [blame] | 274 | } |
| 275 | |
| 276 | /* |
| 277 | * The CPU has been marked offline. Migrate IRQs off this CPU. If |
| 278 | * the affinity settings do not allow other CPUs, force them onto any |
| 279 | * available CPU. |
| 280 | */ |
| 281 | void migrate_irqs(void) |
| 282 | { |
| 283 | unsigned int i, cpu = smp_processor_id(); |
| 284 | struct irq_desc *desc; |
| 285 | |
| 286 | for_each_irq_desc(i, desc) { |
| 287 | struct irq_data *data = irq_desc_get_irq_data(desc); |
| 288 | unsigned int newcpu; |
| 289 | |
| 290 | if (irqd_is_per_cpu(data)) |
| 291 | continue; |
| 292 | |
| 293 | if (!cpumask_test_cpu(cpu, data->affinity)) |
| 294 | continue; |
| 295 | |
| 296 | newcpu = cpumask_any_and(data->affinity, cpu_online_mask); |
| 297 | |
| 298 | if (newcpu >= nr_cpu_ids) { |
| 299 | pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n", |
| 300 | i, cpu); |
| 301 | |
| 302 | cpumask_setall(data->affinity); |
| 303 | newcpu = cpumask_any_and(data->affinity, |
| 304 | cpu_online_mask); |
| 305 | } |
| 306 | |
| 307 | route_irq(data, i, newcpu); |
| 308 | } |
| 309 | } |
| 310 | #endif /* CONFIG_HOTPLUG_CPU */ |