c08ff582da6f05144535cf3c04615ab640b5e805
[linux-2.6.git] / arch / mips / sibyte / sb1250 / irq.c
1 /*
2  * Copyright (C) 2000, 2001, 2002, 2003 Broadcom Corporation
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
17  */
18 #include <linux/kernel.h>
19 #include <linux/init.h>
20 #include <linux/linkage.h>
21 #include <linux/interrupt.h>
22 #include <linux/spinlock.h>
23 #include <linux/smp.h>
24 #include <linux/mm.h>
25 #include <linux/slab.h>
26 #include <linux/kernel_stat.h>
27
28 #include <asm/errno.h>
29 #include <asm/signal.h>
30 #include <asm/system.h>
31 #include <asm/time.h>
32 #include <asm/io.h>
33
34 #include <asm/sibyte/sb1250_regs.h>
35 #include <asm/sibyte/sb1250_int.h>
36 #include <asm/sibyte/sb1250_uart.h>
37 #include <asm/sibyte/sb1250_scd.h>
38 #include <asm/sibyte/sb1250.h>
39
40 /*
41  * These are the routines that handle all the low level interrupt stuff.
42  * Actions handled here are: initialization of the interrupt map, requesting of
43  * interrupt lines by handlers, dispatching if interrupts to handlers, probing
44  * for interrupt lines
45  */
46
47
48 static void end_sb1250_irq(unsigned int irq);
49 static void enable_sb1250_irq(unsigned int irq);
50 static void disable_sb1250_irq(unsigned int irq);
51 static void ack_sb1250_irq(unsigned int irq);
52 #ifdef CONFIG_SMP
53 static void sb1250_set_affinity(unsigned int irq, const struct cpumask *mask);
54 #endif
55
56 #ifdef CONFIG_SIBYTE_HAS_LDT
57 extern unsigned long ldt_eoi_space;
58 #endif
59
60 static struct irq_chip sb1250_irq_type = {
61         .name = "SB1250-IMR",
62         .ack = ack_sb1250_irq,
63         .mask = disable_sb1250_irq,
64         .mask_ack = ack_sb1250_irq,
65         .unmask = enable_sb1250_irq,
66         .end = end_sb1250_irq,
67 #ifdef CONFIG_SMP
68         .set_affinity = sb1250_set_affinity
69 #endif
70 };
71
72 /* Store the CPU id (not the logical number) */
73 int sb1250_irq_owner[SB1250_NR_IRQS];
74
75 DEFINE_SPINLOCK(sb1250_imr_lock);
76
77 void sb1250_mask_irq(int cpu, int irq)
78 {
79         unsigned long flags;
80         u64 cur_ints;
81
82         spin_lock_irqsave(&sb1250_imr_lock, flags);
83         cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) +
84                                         R_IMR_INTERRUPT_MASK));
85         cur_ints |= (((u64) 1) << irq);
86         ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
87                                         R_IMR_INTERRUPT_MASK));
88         spin_unlock_irqrestore(&sb1250_imr_lock, flags);
89 }
90
91 void sb1250_unmask_irq(int cpu, int irq)
92 {
93         unsigned long flags;
94         u64 cur_ints;
95
96         spin_lock_irqsave(&sb1250_imr_lock, flags);
97         cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) +
98                                         R_IMR_INTERRUPT_MASK));
99         cur_ints &= ~(((u64) 1) << irq);
100         ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
101                                         R_IMR_INTERRUPT_MASK));
102         spin_unlock_irqrestore(&sb1250_imr_lock, flags);
103 }
104
105 #ifdef CONFIG_SMP
106 static void sb1250_set_affinity(unsigned int irq, const struct cpumask *mask)
107 {
108         int i = 0, old_cpu, cpu, int_on;
109         u64 cur_ints;
110         struct irq_desc *desc = irq_desc + irq;
111         unsigned long flags;
112
113         i = cpumask_first(mask);
114
115         if (cpumask_weight(mask) > 1) {
116                 printk("attempted to set irq affinity for irq %d to multiple CPUs\n", irq);
117                 return;
118         }
119
120         /* Convert logical CPU to physical CPU */
121         cpu = cpu_logical_map(i);
122
123         /* Protect against other affinity changers and IMR manipulation */
124         spin_lock_irqsave(&desc->lock, flags);
125         spin_lock(&sb1250_imr_lock);
126
127         /* Swizzle each CPU's IMR (but leave the IP selection alone) */
128         old_cpu = sb1250_irq_owner[irq];
129         cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(old_cpu) +
130                                         R_IMR_INTERRUPT_MASK));
131         int_on = !(cur_ints & (((u64) 1) << irq));
132         if (int_on) {
133                 /* If it was on, mask it */
134                 cur_ints |= (((u64) 1) << irq);
135                 ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(old_cpu) +
136                                         R_IMR_INTERRUPT_MASK));
137         }
138         sb1250_irq_owner[irq] = cpu;
139         if (int_on) {
140                 /* unmask for the new CPU */
141                 cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) +
142                                         R_IMR_INTERRUPT_MASK));
143                 cur_ints &= ~(((u64) 1) << irq);
144                 ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
145                                         R_IMR_INTERRUPT_MASK));
146         }
147         spin_unlock(&sb1250_imr_lock);
148         spin_unlock_irqrestore(&desc->lock, flags);
149 }
150 #endif
151
152 /*****************************************************************************/
153
154 static void disable_sb1250_irq(unsigned int irq)
155 {
156         sb1250_mask_irq(sb1250_irq_owner[irq], irq);
157 }
158
159 static void enable_sb1250_irq(unsigned int irq)
160 {
161         sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
162 }
163
164
165 static void ack_sb1250_irq(unsigned int irq)
166 {
167 #ifdef CONFIG_SIBYTE_HAS_LDT
168         u64 pending;
169
170         /*
171          * If the interrupt was an HT interrupt, now is the time to
172          * clear it.  NOTE: we assume the HT bridge was set up to
173          * deliver the interrupts to all CPUs (which makes affinity
174          * changing easier for us)
175          */
176         pending = __raw_readq(IOADDR(A_IMR_REGISTER(sb1250_irq_owner[irq],
177                                                     R_IMR_LDT_INTERRUPT)));
178         pending &= ((u64)1 << (irq));
179         if (pending) {
180                 int i;
181                 for (i=0; i<NR_CPUS; i++) {
182                         int cpu;
183 #ifdef CONFIG_SMP
184                         cpu = cpu_logical_map(i);
185 #else
186                         cpu = i;
187 #endif
188                         /*
189                          * Clear for all CPUs so an affinity switch
190                          * doesn't find an old status
191                          */
192                         __raw_writeq(pending,
193                                      IOADDR(A_IMR_REGISTER(cpu,
194                                                 R_IMR_LDT_INTERRUPT_CLR)));
195                 }
196
197                 /*
198                  * Generate EOI.  For Pass 1 parts, EOI is a nop.  For
199                  * Pass 2, the LDT world may be edge-triggered, but
200                  * this EOI shouldn't hurt.  If they are
201                  * level-sensitive, the EOI is required.
202                  */
203                 *(uint32_t *)(ldt_eoi_space+(irq<<16)+(7<<2)) = 0;
204         }
205 #endif
206         sb1250_mask_irq(sb1250_irq_owner[irq], irq);
207 }
208
209
210 static void end_sb1250_irq(unsigned int irq)
211 {
212         if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
213                 sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
214         }
215 }
216
217
218 void __init init_sb1250_irqs(void)
219 {
220         int i;
221
222         for (i = 0; i < SB1250_NR_IRQS; i++) {
223                 set_irq_chip_and_handler(i, &sb1250_irq_type, handle_level_irq);
224                 sb1250_irq_owner[i] = 0;
225         }
226 }
227
228
229 /*
230  *  arch_init_irq is called early in the boot sequence from init/main.c via
231  *  init_IRQ.  It is responsible for setting up the interrupt mapper and
232  *  installing the handler that will be responsible for dispatching interrupts
233  *  to the "right" place.
234  */
235 /*
236  * For now, map all interrupts to IP[2].  We could save
237  * some cycles by parceling out system interrupts to different
238  * IP lines, but keep it simple for bringup.  We'll also direct
239  * all interrupts to a single CPU; we should probably route
240  * PCI and LDT to one cpu and everything else to the other
241  * to balance the load a bit.
242  *
243  * On the second cpu, everything is set to IP5, which is
244  * ignored, EXCEPT the mailbox interrupt.  That one is
245  * set to IP[2] so it is handled.  This is needed so we
246  * can do cross-cpu function calls, as requred by SMP
247  */
248
249 #define IMR_IP2_VAL     K_INT_MAP_I0
250 #define IMR_IP3_VAL     K_INT_MAP_I1
251 #define IMR_IP4_VAL     K_INT_MAP_I2
252 #define IMR_IP5_VAL     K_INT_MAP_I3
253 #define IMR_IP6_VAL     K_INT_MAP_I4
254
255 void __init arch_init_irq(void)
256 {
257
258         unsigned int i;
259         u64 tmp;
260         unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
261                 STATUSF_IP1 | STATUSF_IP0;
262
263         /* Default everything to IP2 */
264         for (i = 0; i < SB1250_NR_IRQS; i++) {  /* was I0 */
265                 __raw_writeq(IMR_IP2_VAL,
266                              IOADDR(A_IMR_REGISTER(0,
267                                                    R_IMR_INTERRUPT_MAP_BASE) +
268                                     (i << 3)));
269                 __raw_writeq(IMR_IP2_VAL,
270                              IOADDR(A_IMR_REGISTER(1,
271                                                    R_IMR_INTERRUPT_MAP_BASE) +
272                                     (i << 3)));
273         }
274
275         init_sb1250_irqs();
276
277         /*
278          * Map the high 16 bits of the mailbox registers to IP[3], for
279          * inter-cpu messages
280          */
281         /* Was I1 */
282         __raw_writeq(IMR_IP3_VAL,
283                      IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) +
284                             (K_INT_MBOX_0 << 3)));
285         __raw_writeq(IMR_IP3_VAL,
286                      IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MAP_BASE) +
287                             (K_INT_MBOX_0 << 3)));
288
289         /* Clear the mailboxes.  The firmware may leave them dirty */
290         __raw_writeq(0xffffffffffffffffULL,
291                      IOADDR(A_IMR_REGISTER(0, R_IMR_MAILBOX_CLR_CPU)));
292         __raw_writeq(0xffffffffffffffffULL,
293                      IOADDR(A_IMR_REGISTER(1, R_IMR_MAILBOX_CLR_CPU)));
294
295         /* Mask everything except the mailbox registers for both cpus */
296         tmp = ~((u64) 0) ^ (((u64) 1) << K_INT_MBOX_0);
297         __raw_writeq(tmp, IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MASK)));
298         __raw_writeq(tmp, IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MASK)));
299
300         /*
301          * Note that the timer interrupts are also mapped, but this is
302          * done in sb1250_time_init().  Also, the profiling driver
303          * does its own management of IP7.
304          */
305
306         /* Enable necessary IPs, disable the rest */
307         change_c0_status(ST0_IM, imask);
308 }
309
310 extern void sb1250_mailbox_interrupt(void);
311
312 static inline void dispatch_ip2(void)
313 {
314         unsigned int cpu = smp_processor_id();
315         unsigned long long mask;
316
317         /*
318          * Default...we've hit an IP[2] interrupt, which means we've got to
319          * check the 1250 interrupt registers to figure out what to do.  Need
320          * to detect which CPU we're on, now that smp_affinity is supported.
321          */
322         mask = __raw_readq(IOADDR(A_IMR_REGISTER(cpu,
323                                   R_IMR_INTERRUPT_STATUS_BASE)));
324         if (mask)
325                 do_IRQ(fls64(mask) - 1);
326 }
327
328 asmlinkage void plat_irq_dispatch(void)
329 {
330         unsigned int cpu = smp_processor_id();
331         unsigned int pending;
332
333         /*
334          * What a pain. We have to be really careful saving the upper 32 bits
335          * of any * register across function calls if we don't want them
336          * trashed--since were running in -o32, the calling routing never saves
337          * the full 64 bits of a register across a function call.  Being the
338          * interrupt handler, we're guaranteed that interrupts are disabled
339          * during this code so we don't have to worry about random interrupts
340          * blasting the high 32 bits.
341          */
342
343         pending = read_c0_cause() & read_c0_status() & ST0_IM;
344
345         if (pending & CAUSEF_IP7) /* CPU performance counter interrupt */
346                 do_IRQ(MIPS_CPU_IRQ_BASE + 7);
347         else if (pending & CAUSEF_IP4)
348                 do_IRQ(K_INT_TIMER_0 + cpu);    /* sb1250_timer_interrupt() */
349
350 #ifdef CONFIG_SMP
351         else if (pending & CAUSEF_IP3)
352                 sb1250_mailbox_interrupt();
353 #endif
354
355         else if (pending & CAUSEF_IP2)
356                 dispatch_ip2();
357         else
358                 spurious_interrupt();
359 }