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63047ea3 JH |
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> | |
5698c50d JH |
9 | #include <linux/irqchip/metag-ext.h> |
10 | #include <linux/irqchip/metag.h> | |
63047ea3 JH |
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 | ||
28 | struct irq_domain *root_domain; | |
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 | ||
162 | asmlinkage void do_softirq(void) | |
163 | { | |
164 | unsigned long flags; | |
165 | struct thread_info *curctx; | |
166 | union irq_ctx *irqctx; | |
167 | u32 *isp; | |
168 | ||
169 | if (in_interrupt()) | |
170 | return; | |
171 | ||
172 | local_irq_save(flags); | |
173 | ||
174 | if (local_softirq_pending()) { | |
175 | curctx = current_thread_info(); | |
176 | irqctx = softirq_ctx[smp_processor_id()]; | |
177 | irqctx->tinfo.task = curctx->task; | |
178 | ||
179 | /* build the stack frame on the softirq stack */ | |
180 | isp = (u32 *) ((char *)irqctx + sizeof(struct thread_info)); | |
181 | ||
182 | asm volatile ( | |
183 | "MOV D0.5,%0\n" | |
184 | "SWAP A0StP,D0.5\n" | |
185 | "CALLR D1RtP,___do_softirq\n" | |
186 | "MOV A0StP,D0.5\n" | |
187 | : | |
188 | : "r" (isp) | |
189 | : "memory", "cc", "D1Ar1", "D0Ar2", "D1Ar3", "D0Ar4", | |
190 | "D1Ar5", "D0Ar6", "D0Re0", "D1Re0", "D0.4", "D1RtP", | |
191 | "D0.5" | |
192 | ); | |
193 | /* | |
194 | * Shouldn't happen, we returned above if in_interrupt(): | |
195 | */ | |
196 | WARN_ON_ONCE(softirq_count()); | |
197 | } | |
198 | ||
199 | local_irq_restore(flags); | |
200 | } | |
201 | #endif | |
202 | ||
203 | static struct irq_chip meta_irq_type = { | |
204 | .name = "META-IRQ", | |
205 | .irq_startup = startup_meta_irq, | |
206 | .irq_shutdown = shutdown_meta_irq, | |
207 | }; | |
208 | ||
209 | /** | |
210 | * tbisig_map() - Map a TBI signal number to a virtual IRQ number. | |
211 | * @hw: Number of the TBI signal. Must be in range. | |
212 | * | |
213 | * Returns: The virtual IRQ number of the TBI signal number IRQ specified by | |
214 | * @hw. | |
215 | */ | |
216 | int tbisig_map(unsigned int hw) | |
217 | { | |
218 | return irq_create_mapping(root_domain, hw); | |
219 | } | |
220 | ||
221 | /** | |
222 | * metag_tbisig_map() - map a tbi signal to a Linux virtual IRQ number | |
223 | * @d: root irq domain | |
224 | * @irq: virtual irq number | |
225 | * @hw: hardware irq number (TBI signal number) | |
226 | * | |
227 | * This sets up a virtual irq for a specified TBI signal number. | |
228 | */ | |
229 | static int metag_tbisig_map(struct irq_domain *d, unsigned int irq, | |
230 | irq_hw_number_t hw) | |
231 | { | |
232 | #ifdef CONFIG_SMP | |
233 | irq_set_chip_and_handler(irq, &meta_irq_type, handle_percpu_irq); | |
234 | #else | |
235 | irq_set_chip_and_handler(irq, &meta_irq_type, handle_simple_irq); | |
236 | #endif | |
237 | return 0; | |
238 | } | |
239 | ||
240 | static const struct irq_domain_ops metag_tbisig_domain_ops = { | |
241 | .map = metag_tbisig_map, | |
242 | }; | |
243 | ||
244 | /* | |
245 | * void init_IRQ(void) | |
246 | * | |
247 | * Parameters: None | |
248 | * | |
249 | * Returns: Nothing | |
250 | * | |
251 | * This function should be called during kernel startup to initialize | |
252 | * the IRQ handling routines. | |
253 | */ | |
254 | void __init init_IRQ(void) | |
255 | { | |
256 | root_domain = irq_domain_add_linear(NULL, 32, | |
257 | &metag_tbisig_domain_ops, NULL); | |
258 | if (unlikely(!root_domain)) | |
259 | panic("init_IRQ: cannot add root IRQ domain"); | |
260 | ||
261 | irq_ctx_init(smp_processor_id()); | |
262 | ||
5698c50d JH |
263 | init_internal_IRQ(); |
264 | init_external_IRQ(); | |
265 | ||
63047ea3 JH |
266 | if (machine_desc->init_irq) |
267 | machine_desc->init_irq(); | |
268 | } | |
269 | ||
270 | int __init arch_probe_nr_irqs(void) | |
271 | { | |
272 | if (machine_desc->nr_irqs) | |
273 | nr_irqs = machine_desc->nr_irqs; | |
274 | return 0; | |
275 | } | |
276 | ||
277 | #ifdef CONFIG_HOTPLUG_CPU | |
278 | static void route_irq(struct irq_data *data, unsigned int irq, unsigned int cpu) | |
279 | { | |
280 | struct irq_desc *desc = irq_to_desc(irq); | |
281 | struct irq_chip *chip = irq_data_get_irq_chip(data); | |
282 | ||
283 | raw_spin_lock_irq(&desc->lock); | |
284 | if (chip->irq_set_affinity) | |
285 | chip->irq_set_affinity(data, cpumask_of(cpu), false); | |
286 | raw_spin_unlock_irq(&desc->lock); | |
287 | } | |
288 | ||
289 | /* | |
290 | * The CPU has been marked offline. Migrate IRQs off this CPU. If | |
291 | * the affinity settings do not allow other CPUs, force them onto any | |
292 | * available CPU. | |
293 | */ | |
294 | void migrate_irqs(void) | |
295 | { | |
296 | unsigned int i, cpu = smp_processor_id(); | |
297 | struct irq_desc *desc; | |
298 | ||
299 | for_each_irq_desc(i, desc) { | |
300 | struct irq_data *data = irq_desc_get_irq_data(desc); | |
301 | unsigned int newcpu; | |
302 | ||
303 | if (irqd_is_per_cpu(data)) | |
304 | continue; | |
305 | ||
306 | if (!cpumask_test_cpu(cpu, data->affinity)) | |
307 | continue; | |
308 | ||
309 | newcpu = cpumask_any_and(data->affinity, cpu_online_mask); | |
310 | ||
311 | if (newcpu >= nr_cpu_ids) { | |
312 | pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n", | |
313 | i, cpu); | |
314 | ||
315 | cpumask_setall(data->affinity); | |
316 | newcpu = cpumask_any_and(data->affinity, | |
317 | cpu_online_mask); | |
318 | } | |
319 | ||
320 | route_irq(data, i, newcpu); | |
321 | } | |
322 | } | |
323 | #endif /* CONFIG_HOTPLUG_CPU */ |