1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2000, 2001, 2002, 2003 Broadcom Corporation
4 */
5 #include <linux/kernel.h>
6 #include <linux/init.h>
7 #include <linux/linkage.h>
8 #include <linux/interrupt.h>
9 #include <linux/spinlock.h>
10 #include <linux/smp.h>
11 #include <linux/mm.h>
12 #include <linux/kernel_stat.h>
13
14 #include <asm/errno.h>
15 #include <asm/signal.h>
16 #include <asm/time.h>
17 #include <asm/io.h>
18
19 #include <asm/sibyte/sb1250_regs.h>
20 #include <asm/sibyte/sb1250_int.h>
21 #include <asm/sibyte/sb1250_uart.h>
22 #include <asm/sibyte/sb1250_scd.h>
23 #include <asm/sibyte/sb1250.h>
24
25 /*
26 * These are the routines that handle all the low level interrupt stuff.
27 * Actions handled here are: initialization of the interrupt map, requesting of
28 * interrupt lines by handlers, dispatching if interrupts to handlers, probing
29 * for interrupt lines
30 */
31
32 #ifdef CONFIG_SIBYTE_HAS_LDT
33 extern unsigned long ldt_eoi_space;
34 #endif
35
36 /* Store the CPU id (not the logical number) */
37 int sb1250_irq_owner[SB1250_NR_IRQS];
38
39 static DEFINE_RAW_SPINLOCK(sb1250_imr_lock);
40
sb1250_mask_irq(int cpu,int irq)41 void sb1250_mask_irq(int cpu, int irq)
42 {
43 unsigned long flags;
44 u64 cur_ints;
45
46 raw_spin_lock_irqsave(&sb1250_imr_lock, flags);
47 cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) +
48 R_IMR_INTERRUPT_MASK));
49 cur_ints |= (((u64) 1) << irq);
50 ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
51 R_IMR_INTERRUPT_MASK));
52 raw_spin_unlock_irqrestore(&sb1250_imr_lock, flags);
53 }
54
sb1250_unmask_irq(int cpu,int irq)55 void sb1250_unmask_irq(int cpu, int irq)
56 {
57 unsigned long flags;
58 u64 cur_ints;
59
60 raw_spin_lock_irqsave(&sb1250_imr_lock, flags);
61 cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) +
62 R_IMR_INTERRUPT_MASK));
63 cur_ints &= ~(((u64) 1) << irq);
64 ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
65 R_IMR_INTERRUPT_MASK));
66 raw_spin_unlock_irqrestore(&sb1250_imr_lock, flags);
67 }
68
69 #ifdef CONFIG_SMP
sb1250_set_affinity(struct irq_data * d,const struct cpumask * mask,bool force)70 static int sb1250_set_affinity(struct irq_data *d, const struct cpumask *mask,
71 bool force)
72 {
73 int i = 0, old_cpu, cpu, int_on;
74 unsigned int irq = d->irq;
75 u64 cur_ints;
76 unsigned long flags;
77
78 i = cpumask_first_and(mask, cpu_online_mask);
79
80 /* Convert logical CPU to physical CPU */
81 cpu = cpu_logical_map(i);
82
83 /* Protect against other affinity changers and IMR manipulation */
84 raw_spin_lock_irqsave(&sb1250_imr_lock, flags);
85
86 /* Swizzle each CPU's IMR (but leave the IP selection alone) */
87 old_cpu = sb1250_irq_owner[irq];
88 cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(old_cpu) +
89 R_IMR_INTERRUPT_MASK));
90 int_on = !(cur_ints & (((u64) 1) << irq));
91 if (int_on) {
92 /* If it was on, mask it */
93 cur_ints |= (((u64) 1) << irq);
94 ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(old_cpu) +
95 R_IMR_INTERRUPT_MASK));
96 }
97 sb1250_irq_owner[irq] = cpu;
98 if (int_on) {
99 /* unmask for the new CPU */
100 cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) +
101 R_IMR_INTERRUPT_MASK));
102 cur_ints &= ~(((u64) 1) << irq);
103 ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
104 R_IMR_INTERRUPT_MASK));
105 }
106 raw_spin_unlock_irqrestore(&sb1250_imr_lock, flags);
107
108 return 0;
109 }
110 #endif
111
disable_sb1250_irq(struct irq_data * d)112 static void disable_sb1250_irq(struct irq_data *d)
113 {
114 unsigned int irq = d->irq;
115
116 sb1250_mask_irq(sb1250_irq_owner[irq], irq);
117 }
118
enable_sb1250_irq(struct irq_data * d)119 static void enable_sb1250_irq(struct irq_data *d)
120 {
121 unsigned int irq = d->irq;
122
123 sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
124 }
125
126
ack_sb1250_irq(struct irq_data * d)127 static void ack_sb1250_irq(struct irq_data *d)
128 {
129 unsigned int irq = d->irq;
130 #ifdef CONFIG_SIBYTE_HAS_LDT
131 u64 pending;
132
133 /*
134 * If the interrupt was an HT interrupt, now is the time to
135 * clear it. NOTE: we assume the HT bridge was set up to
136 * deliver the interrupts to all CPUs (which makes affinity
137 * changing easier for us)
138 */
139 pending = __raw_readq(IOADDR(A_IMR_REGISTER(sb1250_irq_owner[irq],
140 R_IMR_LDT_INTERRUPT)));
141 pending &= ((u64)1 << (irq));
142 if (pending) {
143 int i;
144 for (i=0; i<NR_CPUS; i++) {
145 int cpu;
146 #ifdef CONFIG_SMP
147 cpu = cpu_logical_map(i);
148 #else
149 cpu = i;
150 #endif
151 /*
152 * Clear for all CPUs so an affinity switch
153 * doesn't find an old status
154 */
155 __raw_writeq(pending,
156 IOADDR(A_IMR_REGISTER(cpu,
157 R_IMR_LDT_INTERRUPT_CLR)));
158 }
159
160 /*
161 * Generate EOI. For Pass 1 parts, EOI is a nop. For
162 * Pass 2, the LDT world may be edge-triggered, but
163 * this EOI shouldn't hurt. If they are
164 * level-sensitive, the EOI is required.
165 */
166 *(uint32_t *)(ldt_eoi_space+(irq<<16)+(7<<2)) = 0;
167 }
168 #endif
169 sb1250_mask_irq(sb1250_irq_owner[irq], irq);
170 }
171
172 static struct irq_chip sb1250_irq_type = {
173 .name = "SB1250-IMR",
174 .irq_mask_ack = ack_sb1250_irq,
175 .irq_unmask = enable_sb1250_irq,
176 .irq_mask = disable_sb1250_irq,
177 #ifdef CONFIG_SMP
178 .irq_set_affinity = sb1250_set_affinity
179 #endif
180 };
181
init_sb1250_irqs(void)182 void __init init_sb1250_irqs(void)
183 {
184 int i;
185
186 for (i = 0; i < SB1250_NR_IRQS; i++) {
187 irq_set_chip_and_handler(i, &sb1250_irq_type,
188 handle_level_irq);
189 sb1250_irq_owner[i] = 0;
190 }
191 }
192
193
194 /*
195 * arch_init_irq is called early in the boot sequence from init/main.c via
196 * init_IRQ. It is responsible for setting up the interrupt mapper and
197 * installing the handler that will be responsible for dispatching interrupts
198 * to the "right" place.
199 */
200 /*
201 * For now, map all interrupts to IP[2]. We could save
202 * some cycles by parceling out system interrupts to different
203 * IP lines, but keep it simple for bringup. We'll also direct
204 * all interrupts to a single CPU; we should probably route
205 * PCI and LDT to one cpu and everything else to the other
206 * to balance the load a bit.
207 *
208 * On the second cpu, everything is set to IP5, which is
209 * ignored, EXCEPT the mailbox interrupt. That one is
210 * set to IP[2] so it is handled. This is needed so we
211 * can do cross-cpu function calls, as required by SMP
212 */
213
214 #define IMR_IP2_VAL K_INT_MAP_I0
215 #define IMR_IP3_VAL K_INT_MAP_I1
216 #define IMR_IP4_VAL K_INT_MAP_I2
217 #define IMR_IP5_VAL K_INT_MAP_I3
218 #define IMR_IP6_VAL K_INT_MAP_I4
219
arch_init_irq(void)220 void __init arch_init_irq(void)
221 {
222
223 unsigned int i;
224 u64 tmp;
225 unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
226 STATUSF_IP1 | STATUSF_IP0;
227
228 /* Default everything to IP2 */
229 for (i = 0; i < SB1250_NR_IRQS; i++) { /* was I0 */
230 __raw_writeq(IMR_IP2_VAL,
231 IOADDR(A_IMR_REGISTER(0,
232 R_IMR_INTERRUPT_MAP_BASE) +
233 (i << 3)));
234 __raw_writeq(IMR_IP2_VAL,
235 IOADDR(A_IMR_REGISTER(1,
236 R_IMR_INTERRUPT_MAP_BASE) +
237 (i << 3)));
238 }
239
240 init_sb1250_irqs();
241
242 /*
243 * Map the high 16 bits of the mailbox registers to IP[3], for
244 * inter-cpu messages
245 */
246 /* Was I1 */
247 __raw_writeq(IMR_IP3_VAL,
248 IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) +
249 (K_INT_MBOX_0 << 3)));
250 __raw_writeq(IMR_IP3_VAL,
251 IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MAP_BASE) +
252 (K_INT_MBOX_0 << 3)));
253
254 /* Clear the mailboxes. The firmware may leave them dirty */
255 __raw_writeq(0xffffffffffffffffULL,
256 IOADDR(A_IMR_REGISTER(0, R_IMR_MAILBOX_CLR_CPU)));
257 __raw_writeq(0xffffffffffffffffULL,
258 IOADDR(A_IMR_REGISTER(1, R_IMR_MAILBOX_CLR_CPU)));
259
260 /* Mask everything except the mailbox registers for both cpus */
261 tmp = ~((u64) 0) ^ (((u64) 1) << K_INT_MBOX_0);
262 __raw_writeq(tmp, IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MASK)));
263 __raw_writeq(tmp, IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MASK)));
264
265 /* Enable necessary IPs, disable the rest */
266 change_c0_status(ST0_IM, imask);
267 }
268
269 extern void sb1250_mailbox_interrupt(void);
270
dispatch_ip2(void)271 static inline void dispatch_ip2(void)
272 {
273 unsigned int cpu = smp_processor_id();
274 unsigned long long mask;
275
276 /*
277 * Default...we've hit an IP[2] interrupt, which means we've got to
278 * check the 1250 interrupt registers to figure out what to do. Need
279 * to detect which CPU we're on, now that smp_affinity is supported.
280 */
281 mask = __raw_readq(IOADDR(A_IMR_REGISTER(cpu,
282 R_IMR_INTERRUPT_STATUS_BASE)));
283 if (mask)
284 do_IRQ(fls64(mask) - 1);
285 }
286
plat_irq_dispatch(void)287 asmlinkage void plat_irq_dispatch(void)
288 {
289 unsigned int cpu = smp_processor_id();
290 unsigned int pending;
291
292 /*
293 * What a pain. We have to be really careful saving the upper 32 bits
294 * of any * register across function calls if we don't want them
295 * trashed--since were running in -o32, the calling routing never saves
296 * the full 64 bits of a register across a function call. Being the
297 * interrupt handler, we're guaranteed that interrupts are disabled
298 * during this code so we don't have to worry about random interrupts
299 * blasting the high 32 bits.
300 */
301
302 pending = read_c0_cause() & read_c0_status() & ST0_IM;
303
304 if (pending & CAUSEF_IP7) /* CPU performance counter interrupt */
305 do_IRQ(MIPS_CPU_IRQ_BASE + 7);
306 else if (pending & CAUSEF_IP4)
307 do_IRQ(K_INT_TIMER_0 + cpu); /* sb1250_timer_interrupt() */
308
309 #ifdef CONFIG_SMP
310 else if (pending & CAUSEF_IP3)
311 sb1250_mailbox_interrupt();
312 #endif
313
314 else if (pending & CAUSEF_IP2)
315 dispatch_ip2();
316 else
317 spurious_interrupt();
318 }
319