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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
63047ea3 JH |
2 | /* |
3 | * Linux/Meta general interrupt handling code | |
4 | * | |
5 | */ | |
6 | ||
7 | #include <linux/kernel.h> | |
8 | #include <linux/interrupt.h> | |
9 | #include <linux/init.h> | |
5698c50d JH |
10 | #include <linux/irqchip/metag-ext.h> |
11 | #include <linux/irqchip/metag.h> | |
63047ea3 JH |
12 | #include <linux/irqdomain.h> |
13 | #include <linux/ratelimit.h> | |
14 | ||
15 | #include <asm/core_reg.h> | |
16 | #include <asm/mach/arch.h> | |
7c0f6ba6 | 17 | #include <linux/uaccess.h> |
63047ea3 JH |
18 | |
19 | #ifdef CONFIG_4KSTACKS | |
20 | union irq_ctx { | |
21 | struct thread_info tinfo; | |
22 | u32 stack[THREAD_SIZE/sizeof(u32)]; | |
23 | }; | |
24 | ||
25 | static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; | |
26 | static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; | |
27 | #endif | |
28 | ||
32580ae7 | 29 | static struct irq_domain *root_domain; |
63047ea3 JH |
30 | |
31 | static unsigned int startup_meta_irq(struct irq_data *data) | |
32 | { | |
33 | tbi_startup_interrupt(data->hwirq); | |
34 | return 0; | |
35 | } | |
36 | ||
37 | static void shutdown_meta_irq(struct irq_data *data) | |
38 | { | |
39 | tbi_shutdown_interrupt(data->hwirq); | |
40 | } | |
41 | ||
42 | void do_IRQ(int irq, struct pt_regs *regs) | |
43 | { | |
44 | struct pt_regs *old_regs = set_irq_regs(regs); | |
45 | #ifdef CONFIG_4KSTACKS | |
46 | struct irq_desc *desc; | |
47 | union irq_ctx *curctx, *irqctx; | |
48 | u32 *isp; | |
49 | #endif | |
50 | ||
51 | irq_enter(); | |
52 | ||
53 | irq = irq_linear_revmap(root_domain, irq); | |
54 | ||
55 | #ifdef CONFIG_DEBUG_STACKOVERFLOW | |
56 | /* Debugging check for stack overflow: is there less than 1KB free? */ | |
57 | { | |
58 | unsigned long sp; | |
59 | ||
60 | sp = __core_reg_get(A0StP); | |
61 | sp &= THREAD_SIZE - 1; | |
62 | ||
63 | if (unlikely(sp > (THREAD_SIZE - 1024))) | |
64 | pr_err("Stack overflow in do_IRQ: %ld\n", sp); | |
65 | } | |
66 | #endif | |
67 | ||
68 | ||
69 | #ifdef CONFIG_4KSTACKS | |
70 | curctx = (union irq_ctx *) current_thread_info(); | |
71 | irqctx = hardirq_ctx[smp_processor_id()]; | |
72 | ||
73 | /* | |
74 | * this is where we switch to the IRQ stack. However, if we are | |
75 | * already using the IRQ stack (because we interrupted a hardirq | |
76 | * handler) we can't do that and just have to keep using the | |
77 | * current stack (which is the irq stack already after all) | |
78 | */ | |
79 | if (curctx != irqctx) { | |
80 | /* build the stack frame on the IRQ stack */ | |
81 | isp = (u32 *) ((char *)irqctx + sizeof(struct thread_info)); | |
82 | irqctx->tinfo.task = curctx->tinfo.task; | |
83 | ||
84 | /* | |
85 | * Copy the softirq bits in preempt_count so that the | |
86 | * softirq checks work in the hardirq context. | |
87 | */ | |
88 | irqctx->tinfo.preempt_count = | |
89 | (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | | |
90 | (curctx->tinfo.preempt_count & SOFTIRQ_MASK); | |
91 | ||
92 | desc = irq_to_desc(irq); | |
93 | ||
94 | asm volatile ( | |
95 | "MOV D0.5,%0\n" | |
96 | "MOV D1Ar1,%1\n" | |
97 | "MOV D1RtP,%2\n" | |
63047ea3 JH |
98 | "SWAP A0StP,D0.5\n" |
99 | "SWAP PC,D1RtP\n" | |
100 | "MOV A0StP,D0.5\n" | |
101 | : | |
bd0b9ac4 | 102 | : "r" (isp), "r" (desc), "r" (desc->handle_irq) |
63047ea3 JH |
103 | : "memory", "cc", "D1Ar1", "D0Ar2", "D1Ar3", "D0Ar4", |
104 | "D1Ar5", "D0Ar6", "D0Re0", "D1Re0", "D0.4", "D1RtP", | |
105 | "D0.5" | |
106 | ); | |
107 | } else | |
108 | #endif | |
109 | generic_handle_irq(irq); | |
110 | ||
111 | irq_exit(); | |
112 | ||
113 | set_irq_regs(old_regs); | |
114 | } | |
115 | ||
116 | #ifdef CONFIG_4KSTACKS | |
117 | ||
118 | static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; | |
119 | ||
120 | static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; | |
121 | ||
122 | /* | |
123 | * allocate per-cpu stacks for hardirq and for softirq processing | |
124 | */ | |
125 | void irq_ctx_init(int cpu) | |
126 | { | |
127 | union irq_ctx *irqctx; | |
128 | ||
129 | if (hardirq_ctx[cpu]) | |
130 | return; | |
131 | ||
132 | irqctx = (union irq_ctx *) &hardirq_stack[cpu * THREAD_SIZE]; | |
133 | irqctx->tinfo.task = NULL; | |
63047ea3 JH |
134 | irqctx->tinfo.cpu = cpu; |
135 | irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; | |
136 | irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); | |
137 | ||
138 | hardirq_ctx[cpu] = irqctx; | |
139 | ||
140 | irqctx = (union irq_ctx *) &softirq_stack[cpu * THREAD_SIZE]; | |
141 | irqctx->tinfo.task = NULL; | |
63047ea3 JH |
142 | irqctx->tinfo.cpu = cpu; |
143 | irqctx->tinfo.preempt_count = 0; | |
144 | irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); | |
145 | ||
146 | softirq_ctx[cpu] = irqctx; | |
147 | ||
148 | pr_info("CPU %u irqstacks, hard=%p soft=%p\n", | |
149 | cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); | |
150 | } | |
151 | ||
152 | void irq_ctx_exit(int cpu) | |
153 | { | |
154 | hardirq_ctx[smp_processor_id()] = NULL; | |
155 | } | |
156 | ||
157 | extern asmlinkage void __do_softirq(void); | |
158 | ||
7d65f4a6 | 159 | void do_softirq_own_stack(void) |
63047ea3 | 160 | { |
63047ea3 JH |
161 | struct thread_info *curctx; |
162 | union irq_ctx *irqctx; | |
163 | u32 *isp; | |
164 | ||
7d65f4a6 FW |
165 | curctx = current_thread_info(); |
166 | irqctx = softirq_ctx[smp_processor_id()]; | |
167 | irqctx->tinfo.task = curctx->task; | |
168 | ||
169 | /* build the stack frame on the softirq stack */ | |
170 | isp = (u32 *) ((char *)irqctx + sizeof(struct thread_info)); | |
171 | ||
172 | asm volatile ( | |
173 | "MOV D0.5,%0\n" | |
174 | "SWAP A0StP,D0.5\n" | |
175 | "CALLR D1RtP,___do_softirq\n" | |
176 | "MOV A0StP,D0.5\n" | |
177 | : | |
178 | : "r" (isp) | |
179 | : "memory", "cc", "D1Ar1", "D0Ar2", "D1Ar3", "D0Ar4", | |
180 | "D1Ar5", "D0Ar6", "D0Re0", "D1Re0", "D0.4", "D1RtP", | |
181 | "D0.5" | |
182 | ); | |
63047ea3 JH |
183 | } |
184 | #endif | |
185 | ||
186 | static struct irq_chip meta_irq_type = { | |
187 | .name = "META-IRQ", | |
188 | .irq_startup = startup_meta_irq, | |
189 | .irq_shutdown = shutdown_meta_irq, | |
190 | }; | |
191 | ||
192 | /** | |
193 | * tbisig_map() - Map a TBI signal number to a virtual IRQ number. | |
194 | * @hw: Number of the TBI signal. Must be in range. | |
195 | * | |
196 | * Returns: The virtual IRQ number of the TBI signal number IRQ specified by | |
197 | * @hw. | |
198 | */ | |
199 | int tbisig_map(unsigned int hw) | |
200 | { | |
201 | return irq_create_mapping(root_domain, hw); | |
202 | } | |
203 | ||
204 | /** | |
205 | * metag_tbisig_map() - map a tbi signal to a Linux virtual IRQ number | |
206 | * @d: root irq domain | |
207 | * @irq: virtual irq number | |
208 | * @hw: hardware irq number (TBI signal number) | |
209 | * | |
210 | * This sets up a virtual irq for a specified TBI signal number. | |
211 | */ | |
212 | static int metag_tbisig_map(struct irq_domain *d, unsigned int irq, | |
213 | irq_hw_number_t hw) | |
214 | { | |
215 | #ifdef CONFIG_SMP | |
216 | irq_set_chip_and_handler(irq, &meta_irq_type, handle_percpu_irq); | |
217 | #else | |
218 | irq_set_chip_and_handler(irq, &meta_irq_type, handle_simple_irq); | |
219 | #endif | |
220 | return 0; | |
221 | } | |
222 | ||
223 | static const struct irq_domain_ops metag_tbisig_domain_ops = { | |
224 | .map = metag_tbisig_map, | |
225 | }; | |
226 | ||
227 | /* | |
228 | * void init_IRQ(void) | |
229 | * | |
230 | * Parameters: None | |
231 | * | |
232 | * Returns: Nothing | |
233 | * | |
234 | * This function should be called during kernel startup to initialize | |
235 | * the IRQ handling routines. | |
236 | */ | |
237 | void __init init_IRQ(void) | |
238 | { | |
239 | root_domain = irq_domain_add_linear(NULL, 32, | |
240 | &metag_tbisig_domain_ops, NULL); | |
241 | if (unlikely(!root_domain)) | |
242 | panic("init_IRQ: cannot add root IRQ domain"); | |
243 | ||
244 | irq_ctx_init(smp_processor_id()); | |
245 | ||
5698c50d JH |
246 | init_internal_IRQ(); |
247 | init_external_IRQ(); | |
248 | ||
63047ea3 JH |
249 | if (machine_desc->init_irq) |
250 | machine_desc->init_irq(); | |
251 | } | |
252 | ||
253 | int __init arch_probe_nr_irqs(void) | |
254 | { | |
255 | if (machine_desc->nr_irqs) | |
256 | nr_irqs = machine_desc->nr_irqs; | |
257 | return 0; | |
258 | } | |
259 | ||
260 | #ifdef CONFIG_HOTPLUG_CPU | |
63047ea3 JH |
261 | /* |
262 | * The CPU has been marked offline. Migrate IRQs off this CPU. If | |
263 | * the affinity settings do not allow other CPUs, force them onto any | |
264 | * available CPU. | |
265 | */ | |
266 | void migrate_irqs(void) | |
267 | { | |
268 | unsigned int i, cpu = smp_processor_id(); | |
63047ea3 | 269 | |
48ce8e3f TG |
270 | for_each_active_irq(i) { |
271 | struct irq_data *data = irq_get_irq_data(i); | |
7ce0c22b | 272 | struct cpumask *mask; |
63047ea3 JH |
273 | unsigned int newcpu; |
274 | ||
275 | if (irqd_is_per_cpu(data)) | |
276 | continue; | |
277 | ||
7ce0c22b JL |
278 | mask = irq_data_get_affinity_mask(data); |
279 | if (!cpumask_test_cpu(cpu, mask)) | |
63047ea3 JH |
280 | continue; |
281 | ||
7ce0c22b | 282 | newcpu = cpumask_any_and(mask, cpu_online_mask); |
63047ea3 JH |
283 | |
284 | if (newcpu >= nr_cpu_ids) { | |
285 | pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n", | |
286 | i, cpu); | |
287 | ||
7ce0c22b | 288 | cpumask_setall(mask); |
63047ea3 | 289 | } |
7ce0c22b | 290 | irq_set_affinity(i, mask); |
63047ea3 JH |
291 | } |
292 | } | |
293 | #endif /* CONFIG_HOTPLUG_CPU */ |