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irq_32.c
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1 /*
2  * Interrupt request handling routines. On the
3  * Sparc the IRQs are basically 'cast in stone'
4  * and you are supposed to probe the prom's device
5  * node trees to find out who's got which IRQ.
6  *
7  * Copyright (C) 1995 David S. Miller ([email protected])
8  * Copyright (C) 1995 Miguel de Icaza ([email protected])
9  * Copyright (C) 1995,2002 Pete A. Zaitcev ([email protected])
10  * Copyright (C) 1996 Dave Redman ([email protected])
11  * Copyright (C) 1998-2000 Anton Blanchard ([email protected])
12  */
13 
14 #include <linux/kernel_stat.h>
15 #include <linux/seq_file.h>
16 #include <linux/export.h>
17 
18 #include <asm/cacheflush.h>
19 #include <asm/cpudata.h>
20 #include <asm/pcic.h>
21 #include <asm/leon.h>
22 
23 #include "kernel.h"
24 #include "irq.h"
25 
26 /* platform specific irq setup */
28 
29 unsigned long arch_local_irq_save(void)
30 {
31  unsigned long retval;
32  unsigned long tmp;
33 
34  __asm__ __volatile__(
35  "rd %%psr, %0\n\t"
36  "or %0, %2, %1\n\t"
37  "wr %1, 0, %%psr\n\t"
38  "nop; nop; nop\n"
39  : "=&r" (retval), "=r" (tmp)
40  : "i" (PSR_PIL)
41  : "memory");
42 
43  return retval;
44 }
46 
48 {
49  unsigned long tmp;
50 
51  __asm__ __volatile__(
52  "rd %%psr, %0\n\t"
53  "andn %0, %1, %0\n\t"
54  "wr %0, 0, %%psr\n\t"
55  "nop; nop; nop\n"
56  : "=&r" (tmp)
57  : "i" (PSR_PIL)
58  : "memory");
59 }
61 
62 void arch_local_irq_restore(unsigned long old_psr)
63 {
64  unsigned long tmp;
65 
66  __asm__ __volatile__(
67  "rd %%psr, %0\n\t"
68  "and %2, %1, %2\n\t"
69  "andn %0, %1, %0\n\t"
70  "wr %0, %2, %%psr\n\t"
71  "nop; nop; nop\n"
72  : "=&r" (tmp)
73  : "i" (PSR_PIL), "r" (old_psr)
74  : "memory");
75 }
77 
78 /*
79  * Dave Redman ([email protected])
80  *
81  * IRQ numbers.. These are no longer restricted to 15..
82  *
83  * this is done to enable SBUS cards and onboard IO to be masked
84  * correctly. using the interrupt level isn't good enough.
85  *
86  * For example:
87  * A device interrupting at sbus level6 and the Floppy both come in
88  * at IRQ11, but enabling and disabling them requires writing to
89  * different bits in the SLAVIO/SEC.
90  *
91  * As a result of these changes sun4m machines could now support
92  * directed CPU interrupts using the existing enable/disable irq code
93  * with tweaks.
94  *
95  * Sun4d complicates things even further. IRQ numbers are arbitrary
96  * 32-bit values in that case. Since this is similar to sparc64,
97  * we adopt a virtual IRQ numbering scheme as is done there.
98  * Virutal interrupt numbers are allocated by build_irq(). So NR_IRQS
99  * just becomes a limit of how many interrupt sources we can handle in
100  * a single system. Even fully loaded SS2000 machines top off at
101  * about 32 interrupt sources or so, therefore a NR_IRQS value of 64
102  * is more than enough.
103  *
104  * We keep a map of per-PIL enable interrupts. These get wired
105  * up via the irq_chip->startup() method which gets invoked by
106  * the generic IRQ layer during request_irq().
107  */
108 
109 
110 /* Table of allocated irqs. Unused entries has irq == 0 */
111 static struct irq_bucket irq_table[NR_IRQS];
112 /* Protect access to irq_table */
113 static DEFINE_SPINLOCK(irq_table_lock);
114 
115 /* Map between the irq identifier used in hw to the irq_bucket. */
117 /* Protect access to irq_map */
118 static DEFINE_SPINLOCK(irq_map_lock);
119 
120 /* Allocate a new irq from the irq_table */
121 unsigned int irq_alloc(unsigned int real_irq, unsigned int pil)
122 {
123  unsigned long flags;
124  unsigned int i;
125 
126  spin_lock_irqsave(&irq_table_lock, flags);
127  for (i = 1; i < NR_IRQS; i++) {
128  if (irq_table[i].real_irq == real_irq && irq_table[i].pil == pil)
129  goto found;
130  }
131 
132  for (i = 1; i < NR_IRQS; i++) {
133  if (!irq_table[i].irq)
134  break;
135  }
136 
137  if (i < NR_IRQS) {
138  irq_table[i].real_irq = real_irq;
139  irq_table[i].irq = i;
140  irq_table[i].pil = pil;
141  } else {
142  printk(KERN_ERR "IRQ: Out of virtual IRQs.\n");
143  i = 0;
144  }
145 found:
146  spin_unlock_irqrestore(&irq_table_lock, flags);
147 
148  return i;
149 }
150 
151 /* Based on a single pil handler_irq may need to call several
152  * interrupt handlers. Use irq_map as entry to irq_table,
153  * and let each entry in irq_table point to the next entry.
154  */
155 void irq_link(unsigned int irq)
156 {
157  struct irq_bucket *p;
158  unsigned long flags;
159  unsigned int pil;
160 
161  BUG_ON(irq >= NR_IRQS);
162 
163  spin_lock_irqsave(&irq_map_lock, flags);
164 
165  p = &irq_table[irq];
166  pil = p->pil;
167  BUG_ON(pil > SUN4D_MAX_IRQ);
168  p->next = irq_map[pil];
169  irq_map[pil] = p;
170 
171  spin_unlock_irqrestore(&irq_map_lock, flags);
172 }
173 
174 void irq_unlink(unsigned int irq)
175 {
176  struct irq_bucket *p, **pnext;
177  unsigned long flags;
178 
179  BUG_ON(irq >= NR_IRQS);
180 
181  spin_lock_irqsave(&irq_map_lock, flags);
182 
183  p = &irq_table[irq];
184  BUG_ON(p->pil > SUN4D_MAX_IRQ);
185  pnext = &irq_map[p->pil];
186  while (*pnext != p)
187  pnext = &(*pnext)->next;
188  *pnext = p->next;
189 
190  spin_unlock_irqrestore(&irq_map_lock, flags);
191 }
192 
193 
194 /* /proc/interrupts printing */
195 int arch_show_interrupts(struct seq_file *p, int prec)
196 {
197  int j;
198 
199 #ifdef CONFIG_SMP
200  seq_printf(p, "RES: ");
202  seq_printf(p, "%10u ", cpu_data(j).irq_resched_count);
203  seq_printf(p, " IPI rescheduling interrupts\n");
204  seq_printf(p, "CAL: ");
206  seq_printf(p, "%10u ", cpu_data(j).irq_call_count);
207  seq_printf(p, " IPI function call interrupts\n");
208 #endif
209  seq_printf(p, "NMI: ");
211  seq_printf(p, "%10u ", cpu_data(j).counter);
212  seq_printf(p, " Non-maskable interrupts\n");
213  return 0;
214 }
215 
216 void handler_irq(unsigned int pil, struct pt_regs *regs)
217 {
218  struct pt_regs *old_regs;
219  struct irq_bucket *p;
220 
221  BUG_ON(pil > 15);
222  old_regs = set_irq_regs(regs);
223  irq_enter();
224 
225  p = irq_map[pil];
226  while (p) {
227  struct irq_bucket *next = p->next;
228 
230  p = next;
231  }
232  irq_exit();
233  set_irq_regs(old_regs);
234 }
235 
236 #if defined(CONFIG_BLK_DEV_FD) || defined(CONFIG_BLK_DEV_FD_MODULE)
237 static unsigned int floppy_irq;
238 
240 {
241  unsigned int cpu_irq;
242  int err;
243 
244 
245  err = request_irq(irq, irq_handler, 0, "floppy", NULL);
246  if (err)
247  return -1;
248 
249  /* Save for later use in floppy interrupt handler */
250  floppy_irq = irq;
251 
252  cpu_irq = (irq & (NR_IRQS - 1));
253 
254  /* Dork with trap table if we get this far. */
255 #define INSTANTIATE(table) \
256  table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_one = SPARC_RD_PSR_L0; \
257  table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_two = \
258  SPARC_BRANCH((unsigned long) floppy_hardint, \
259  (unsigned long) &table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_two);\
260  table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_three = SPARC_RD_WIM_L3; \
261  table[SP_TRAP_IRQ1+(cpu_irq-1)].inst_four = SPARC_NOP;
262 
263  INSTANTIATE(sparc_ttable)
264 
265 #if defined CONFIG_SMP
266  if (sparc_cpu_model != sparc_leon) {
267  struct tt_entry *trap_table;
268 
269  trap_table = &trapbase_cpu1;
270  INSTANTIATE(trap_table)
271  trap_table = &trapbase_cpu2;
272  INSTANTIATE(trap_table)
273  trap_table = &trapbase_cpu3;
274  INSTANTIATE(trap_table)
275  }
276 #endif
277 #undef INSTANTIATE
278  /*
279  * XXX Correct thing whould be to flush only I- and D-cache lines
280  * which contain the handler in question. But as of time of the
281  * writing we have no CPU-neutral interface to fine-grained flushes.
282  */
283  flush_cache_all();
284  return 0;
285 }
287 
288 /*
289  * These variables are used to access state from the assembler
290  * interrupt handler, floppy_hardint, so we cannot put these in
291  * the floppy driver image because that would not work in the
292  * modular case.
293  */
294 volatile unsigned char *fdc_status;
295 EXPORT_SYMBOL(fdc_status);
296 
297 char *pdma_vaddr;
298 EXPORT_SYMBOL(pdma_vaddr);
299 
300 unsigned long pdma_size;
301 EXPORT_SYMBOL(pdma_size);
302 
303 volatile int doing_pdma;
304 EXPORT_SYMBOL(doing_pdma);
305 
306 char *pdma_base;
307 EXPORT_SYMBOL(pdma_base);
308 
309 unsigned long pdma_areasize;
310 EXPORT_SYMBOL(pdma_areasize);
311 
312 /* Use the generic irq support to call floppy_interrupt
313  * which was setup using request_irq() in sparc_floppy_request_irq().
314  * We only have one floppy interrupt so we do not need to check
315  * for additional handlers being wired up by irq_link()
316  */
317 void sparc_floppy_irq(int irq, void *dev_id, struct pt_regs *regs)
318 {
319  struct pt_regs *old_regs;
320 
321  old_regs = set_irq_regs(regs);
322  irq_enter();
323  generic_handle_irq(floppy_irq);
324  irq_exit();
325  set_irq_regs(old_regs);
326 }
327 #endif
328 
329 /* djhr
330  * This could probably be made indirect too and assigned in the CPU
331  * bits of the code. That would be much nicer I think and would also
332  * fit in with the idea of being able to tune your kernel for your machine
333  * by removing unrequired machine and device support.
334  *
335  */
336 
337 void __init init_IRQ(void)
338 {
339  switch (sparc_cpu_model) {
340  case sun4m:
341  pcic_probe();
342  if (pcic_present())
344  else
345  sun4m_init_IRQ();
346  break;
347 
348  case sun4d:
349  sun4d_init_IRQ();
350  break;
351 
352  case sparc_leon:
353  leon_init_IRQ();
354  break;
355 
356  default:
357  prom_printf("Cannot initialize IRQs on this Sun machine...");
358  break;
359  }
360 }
361