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1  /*
2   * SS1000/SC2000 interrupt handling.
3   *
4   *  Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
5   *  Heavily based on arch/sparc/kernel/irq.c.
6   */
7  
8  #include <linux/kernel_stat.h>
9  #include <linux/slab.h>
10  #include <linux/seq_file.h>
11  
12  #include <asm/timer.h>
13  #include <asm/traps.h>
14  #include <asm/irq.h>
15  #include <asm/io.h>
16  #include <asm/sbi.h>
17  #include <asm/cacheflush.h>
18  #include <asm/setup.h>
19  #include <asm/oplib.h>
20  
21  #include "kernel.h"
22  #include "irq.h"
23  
24  /* Sun4d interrupts fall roughly into two categories.  SBUS and
25   * cpu local.  CPU local interrupts cover the timer interrupts
26   * and whatnot, and we encode those as normal PILs between
27   * 0 and 15.
28   * SBUS interrupts are encodes as a combination of board, level and slot.
29   */
30  
31  struct sun4d_handler_data {
32  	unsigned int cpuid;    /* target cpu */
33  	unsigned int real_irq; /* interrupt level */
34  };
35  
36  
sun4d_encode_irq(int board,int lvl,int slot)37  static unsigned int sun4d_encode_irq(int board, int lvl, int slot)
38  {
39  	return (board + 1) << 5 | (lvl << 2) | slot;
40  }
41  
42  struct sun4d_timer_regs {
43  	u32	l10_timer_limit;
44  	u32	l10_cur_countx;
45  	u32	l10_limit_noclear;
46  	u32	ctrl;
47  	u32	l10_cur_count;
48  };
49  
50  static struct sun4d_timer_regs __iomem *sun4d_timers;
51  
52  #define SUN4D_TIMER_IRQ        10
53  
54  /* Specify which cpu handle interrupts from which board.
55   * Index is board - value is cpu.
56   */
57  static unsigned char board_to_cpu[32];
58  
59  static int pil_to_sbus[] = {
60  	0,
61  	0,
62  	1,
63  	2,
64  	0,
65  	3,
66  	0,
67  	4,
68  	0,
69  	5,
70  	0,
71  	6,
72  	0,
73  	7,
74  	0,
75  	0,
76  };
77  
78  /* Exported for sun4d_smp.c */
79  DEFINE_SPINLOCK(sun4d_imsk_lock);
80  
81  /* SBUS interrupts are encoded integers including the board number
82   * (plus one), the SBUS level, and the SBUS slot number.  Sun4D
83   * IRQ dispatch is done by:
84   *
85   * 1) Reading the BW local interrupt table in order to get the bus
86   *    interrupt mask.
87   *
88   *    This table is indexed by SBUS interrupt level which can be
89   *    derived from the PIL we got interrupted on.
90   *
91   * 2) For each bus showing interrupt pending from #1, read the
92   *    SBI interrupt state register.  This will indicate which slots
93   *    have interrupts pending for that SBUS interrupt level.
94   *
95   * 3) Call the genreric IRQ support.
96   */
sun4d_sbus_handler_irq(int sbusl)97  static void sun4d_sbus_handler_irq(int sbusl)
98  {
99  	unsigned int bus_mask;
100  	unsigned int sbino, slot;
101  	unsigned int sbil;
102  
103  	bus_mask = bw_get_intr_mask(sbusl) & 0x3ffff;
104  	bw_clear_intr_mask(sbusl, bus_mask);
105  
106  	sbil = (sbusl << 2);
107  	/* Loop for each pending SBI */
108  	for (sbino = 0; bus_mask; sbino++, bus_mask >>= 1) {
109  		unsigned int idx, mask;
110  
111  		if (!(bus_mask & 1))
112  			continue;
113  		/* XXX This seems to ACK the irq twice.  acquire_sbi()
114  		 * XXX uses swap, therefore this writes 0xf << sbil,
115  		 * XXX then later release_sbi() will write the individual
116  		 * XXX bits which were set again.
117  		 */
118  		mask = acquire_sbi(SBI2DEVID(sbino), 0xf << sbil);
119  		mask &= (0xf << sbil);
120  
121  		/* Loop for each pending SBI slot */
122  		slot = (1 << sbil);
123  		for (idx = 0; mask != 0; idx++, slot <<= 1) {
124  			unsigned int pil;
125  			struct irq_bucket *p;
126  
127  			if (!(mask & slot))
128  				continue;
129  
130  			mask &= ~slot;
131  			pil = sun4d_encode_irq(sbino, sbusl, idx);
132  
133  			p = irq_map[pil];
134  			while (p) {
135  				struct irq_bucket *next;
136  
137  				next = p->next;
138  				generic_handle_irq(p->irq);
139  				p = next;
140  			}
141  			release_sbi(SBI2DEVID(sbino), slot);
142  		}
143  	}
144  }
145  
sun4d_handler_irq(unsigned int pil,struct pt_regs * regs)146  void sun4d_handler_irq(unsigned int pil, struct pt_regs *regs)
147  {
148  	struct pt_regs *old_regs;
149  	/* SBUS IRQ level (1 - 7) */
150  	int sbusl = pil_to_sbus[pil];
151  
152  	/* FIXME: Is this necessary?? */
153  	cc_get_ipen();
154  
155  	cc_set_iclr(1 << pil);
156  
157  #ifdef CONFIG_SMP
158  	/*
159  	 * Check IPI data structures after IRQ has been cleared. Hard and Soft
160  	 * IRQ can happen at the same time, so both cases are always handled.
161  	 */
162  	if (pil == SUN4D_IPI_IRQ)
163  		sun4d_ipi_interrupt();
164  #endif
165  
166  	old_regs = set_irq_regs(regs);
167  	irq_enter();
168  	if (sbusl == 0) {
169  		/* cpu interrupt */
170  		struct irq_bucket *p;
171  
172  		p = irq_map[pil];
173  		while (p) {
174  			struct irq_bucket *next;
175  
176  			next = p->next;
177  			generic_handle_irq(p->irq);
178  			p = next;
179  		}
180  	} else {
181  		/* SBUS interrupt */
182  		sun4d_sbus_handler_irq(sbusl);
183  	}
184  	irq_exit();
185  	set_irq_regs(old_regs);
186  }
187  
188  
sun4d_mask_irq(struct irq_data * data)189  static void sun4d_mask_irq(struct irq_data *data)
190  {
191  	struct sun4d_handler_data *handler_data = irq_data_get_irq_handler_data(data);
192  	unsigned int real_irq;
193  #ifdef CONFIG_SMP
194  	int cpuid = handler_data->cpuid;
195  	unsigned long flags;
196  #endif
197  	real_irq = handler_data->real_irq;
198  #ifdef CONFIG_SMP
199  	spin_lock_irqsave(&sun4d_imsk_lock, flags);
200  	cc_set_imsk_other(cpuid, cc_get_imsk_other(cpuid) | (1 << real_irq));
201  	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
202  #else
203  	cc_set_imsk(cc_get_imsk() | (1 << real_irq));
204  #endif
205  }
206  
sun4d_unmask_irq(struct irq_data * data)207  static void sun4d_unmask_irq(struct irq_data *data)
208  {
209  	struct sun4d_handler_data *handler_data = irq_data_get_irq_handler_data(data);
210  	unsigned int real_irq;
211  #ifdef CONFIG_SMP
212  	int cpuid = handler_data->cpuid;
213  	unsigned long flags;
214  #endif
215  	real_irq = handler_data->real_irq;
216  
217  #ifdef CONFIG_SMP
218  	spin_lock_irqsave(&sun4d_imsk_lock, flags);
219  	cc_set_imsk_other(cpuid, cc_get_imsk_other(cpuid) & ~(1 << real_irq));
220  	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
221  #else
222  	cc_set_imsk(cc_get_imsk() & ~(1 << real_irq));
223  #endif
224  }
225  
sun4d_startup_irq(struct irq_data * data)226  static unsigned int sun4d_startup_irq(struct irq_data *data)
227  {
228  	irq_link(data->irq);
229  	sun4d_unmask_irq(data);
230  	return 0;
231  }
232  
sun4d_shutdown_irq(struct irq_data * data)233  static void sun4d_shutdown_irq(struct irq_data *data)
234  {
235  	sun4d_mask_irq(data);
236  	irq_unlink(data->irq);
237  }
238  
239  static struct irq_chip sun4d_irq = {
240  	.name		= "sun4d",
241  	.irq_startup	= sun4d_startup_irq,
242  	.irq_shutdown	= sun4d_shutdown_irq,
243  	.irq_unmask	= sun4d_unmask_irq,
244  	.irq_mask	= sun4d_mask_irq,
245  };
246  
247  #ifdef CONFIG_SMP
248  /* Setup IRQ distribution scheme. */
sun4d_distribute_irqs(void)249  void __init sun4d_distribute_irqs(void)
250  {
251  	struct device_node *dp;
252  
253  	int cpuid = cpu_logical_map(1);
254  
255  	if (cpuid == -1)
256  		cpuid = cpu_logical_map(0);
257  	for_each_node_by_name(dp, "sbi") {
258  		int devid = of_getintprop_default(dp, "device-id", 0);
259  		int board = of_getintprop_default(dp, "board#", 0);
260  		board_to_cpu[board] = cpuid;
261  		set_sbi_tid(devid, cpuid << 3);
262  	}
263  	printk(KERN_ERR "All sbus IRQs directed to CPU%d\n", cpuid);
264  }
265  #endif
266  
sun4d_clear_clock_irq(void)267  static void sun4d_clear_clock_irq(void)
268  {
269  	sbus_readl(&sun4d_timers->l10_timer_limit);
270  }
271  
sun4d_load_profile_irq(int cpu,unsigned int limit)272  static void sun4d_load_profile_irq(int cpu, unsigned int limit)
273  {
274  	unsigned int value = limit ? timer_value(limit) : 0;
275  	bw_set_prof_limit(cpu, value);
276  }
277  
sun4d_load_profile_irqs(void)278  static void __init sun4d_load_profile_irqs(void)
279  {
280  	int cpu = 0, mid;
281  
282  	while (!cpu_find_by_instance(cpu, NULL, &mid)) {
283  		sun4d_load_profile_irq(mid >> 3, 0);
284  		cpu++;
285  	}
286  }
287  
_sun4d_build_device_irq(unsigned int real_irq,unsigned int pil,unsigned int board)288  static unsigned int _sun4d_build_device_irq(unsigned int real_irq,
289                                              unsigned int pil,
290                                              unsigned int board)
291  {
292  	struct sun4d_handler_data *handler_data;
293  	unsigned int irq;
294  
295  	irq = irq_alloc(real_irq, pil);
296  	if (irq == 0) {
297  		prom_printf("IRQ: allocate for %d %d %d failed\n",
298  			real_irq, pil, board);
299  		goto err_out;
300  	}
301  
302  	handler_data = irq_get_handler_data(irq);
303  	if (unlikely(handler_data))
304  		goto err_out;
305  
306  	handler_data = kzalloc(sizeof(struct sun4d_handler_data), GFP_ATOMIC);
307  	if (unlikely(!handler_data)) {
308  		prom_printf("IRQ: kzalloc(sun4d_handler_data) failed.\n");
309  		prom_halt();
310  	}
311  	handler_data->cpuid    = board_to_cpu[board];
312  	handler_data->real_irq = real_irq;
313  	irq_set_chip_and_handler_name(irq, &sun4d_irq,
314  	                              handle_level_irq, "level");
315  	irq_set_handler_data(irq, handler_data);
316  
317  err_out:
318  	return irq;
319  }
320  
321  
322  
sun4d_build_device_irq(struct platform_device * op,unsigned int real_irq)323  static unsigned int sun4d_build_device_irq(struct platform_device *op,
324                                             unsigned int real_irq)
325  {
326  	struct device_node *dp = op->dev.of_node;
327  	struct device_node *board_parent, *bus = dp->parent;
328  	char *bus_connection;
329  	const struct linux_prom_registers *regs;
330  	unsigned int pil;
331  	unsigned int irq;
332  	int board, slot;
333  	int sbusl;
334  
335  	irq = real_irq;
336  	while (bus) {
337  		if (!strcmp(bus->name, "sbi")) {
338  			bus_connection = "io-unit";
339  			break;
340  		}
341  
342  		if (!strcmp(bus->name, "bootbus")) {
343  			bus_connection = "cpu-unit";
344  			break;
345  		}
346  
347  		bus = bus->parent;
348  	}
349  	if (!bus)
350  		goto err_out;
351  
352  	regs = of_get_property(dp, "reg", NULL);
353  	if (!regs)
354  		goto err_out;
355  
356  	slot = regs->which_io;
357  
358  	/*
359  	 * If Bus nodes parent is not io-unit/cpu-unit or the io-unit/cpu-unit
360  	 * lacks a "board#" property, something is very wrong.
361  	 */
362  	if (!bus->parent || strcmp(bus->parent->name, bus_connection)) {
363  		printk(KERN_ERR "%s: Error, parent is not %s.\n",
364  			bus->full_name, bus_connection);
365  		goto err_out;
366  	}
367  	board_parent = bus->parent;
368  	board = of_getintprop_default(board_parent, "board#", -1);
369  	if (board == -1) {
370  		printk(KERN_ERR "%s: Error, lacks board# property.\n",
371  			board_parent->full_name);
372  		goto err_out;
373  	}
374  
375  	sbusl = pil_to_sbus[real_irq];
376  	if (sbusl)
377  		pil = sun4d_encode_irq(board, sbusl, slot);
378  	else
379  		pil = real_irq;
380  
381  	irq = _sun4d_build_device_irq(real_irq, pil, board);
382  err_out:
383  	return irq;
384  }
385  
sun4d_build_timer_irq(unsigned int board,unsigned int real_irq)386  static unsigned int sun4d_build_timer_irq(unsigned int board,
387                                            unsigned int real_irq)
388  {
389  	return _sun4d_build_device_irq(real_irq, real_irq, board);
390  }
391  
392  
sun4d_fixup_trap_table(void)393  static void __init sun4d_fixup_trap_table(void)
394  {
395  #ifdef CONFIG_SMP
396  	unsigned long flags;
397  	struct tt_entry *trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (14 - 1)];
398  
399  	/* Adjust so that we jump directly to smp4d_ticker */
400  	lvl14_save[2] += smp4d_ticker - real_irq_entry;
401  
402  	/* For SMP we use the level 14 ticker, however the bootup code
403  	 * has copied the firmware's level 14 vector into the boot cpu's
404  	 * trap table, we must fix this now or we get squashed.
405  	 */
406  	local_irq_save(flags);
407  	patchme_maybe_smp_msg[0] = 0x01000000; /* NOP out the branch */
408  	trap_table->inst_one = lvl14_save[0];
409  	trap_table->inst_two = lvl14_save[1];
410  	trap_table->inst_three = lvl14_save[2];
411  	trap_table->inst_four = lvl14_save[3];
412  	local_ops->cache_all();
413  	local_irq_restore(flags);
414  #endif
415  }
416  
sun4d_init_timers(void)417  static void __init sun4d_init_timers(void)
418  {
419  	struct device_node *dp;
420  	struct resource res;
421  	unsigned int irq;
422  	const u32 *reg;
423  	int err;
424  	int board;
425  
426  	dp = of_find_node_by_name(NULL, "cpu-unit");
427  	if (!dp) {
428  		prom_printf("sun4d_init_timers: Unable to find cpu-unit\n");
429  		prom_halt();
430  	}
431  
432  	/* Which cpu-unit we use is arbitrary, we can view the bootbus timer
433  	 * registers via any cpu's mapping.  The first 'reg' property is the
434  	 * bootbus.
435  	 */
436  	reg = of_get_property(dp, "reg", NULL);
437  	if (!reg) {
438  		prom_printf("sun4d_init_timers: No reg property\n");
439  		prom_halt();
440  	}
441  
442  	board = of_getintprop_default(dp, "board#", -1);
443  	if (board == -1) {
444  		prom_printf("sun4d_init_timers: No board# property on cpu-unit\n");
445  		prom_halt();
446  	}
447  
448  	of_node_put(dp);
449  
450  	res.start = reg[1];
451  	res.end = reg[2] - 1;
452  	res.flags = reg[0] & 0xff;
453  	sun4d_timers = of_ioremap(&res, BW_TIMER_LIMIT,
454  				  sizeof(struct sun4d_timer_regs), "user timer");
455  	if (!sun4d_timers) {
456  		prom_printf("sun4d_init_timers: Can't map timer regs\n");
457  		prom_halt();
458  	}
459  
460  #ifdef CONFIG_SMP
461  	sparc_config.cs_period = SBUS_CLOCK_RATE * 2;  /* 2 seconds */
462  #else
463  	sparc_config.cs_period = SBUS_CLOCK_RATE / HZ; /* 1/HZ sec  */
464  	sparc_config.features |= FEAT_L10_CLOCKEVENT;
465  #endif
466  	sparc_config.features |= FEAT_L10_CLOCKSOURCE;
467  	sbus_writel(timer_value(sparc_config.cs_period),
468  		    &sun4d_timers->l10_timer_limit);
469  
470  	master_l10_counter = &sun4d_timers->l10_cur_count;
471  
472  	irq = sun4d_build_timer_irq(board, SUN4D_TIMER_IRQ);
473  	err = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL);
474  	if (err) {
475  		prom_printf("sun4d_init_timers: request_irq() failed with %d\n",
476  		             err);
477  		prom_halt();
478  	}
479  	sun4d_load_profile_irqs();
480  	sun4d_fixup_trap_table();
481  }
482  
sun4d_init_sbi_irq(void)483  void __init sun4d_init_sbi_irq(void)
484  {
485  	struct device_node *dp;
486  	int target_cpu;
487  
488  	target_cpu = boot_cpu_id;
489  	for_each_node_by_name(dp, "sbi") {
490  		int devid = of_getintprop_default(dp, "device-id", 0);
491  		int board = of_getintprop_default(dp, "board#", 0);
492  		unsigned int mask;
493  
494  		set_sbi_tid(devid, target_cpu << 3);
495  		board_to_cpu[board] = target_cpu;
496  
497  		/* Get rid of pending irqs from PROM */
498  		mask = acquire_sbi(devid, 0xffffffff);
499  		if (mask) {
500  			printk(KERN_ERR "Clearing pending IRQs %08x on SBI %d\n",
501  			       mask, board);
502  			release_sbi(devid, mask);
503  		}
504  	}
505  }
506  
sun4d_init_IRQ(void)507  void __init sun4d_init_IRQ(void)
508  {
509  	local_irq_disable();
510  
511  	sparc_config.init_timers      = sun4d_init_timers;
512  	sparc_config.build_device_irq = sun4d_build_device_irq;
513  	sparc_config.clock_rate       = SBUS_CLOCK_RATE;
514  	sparc_config.clear_clock_irq  = sun4d_clear_clock_irq;
515  	sparc_config.load_profile_irq = sun4d_load_profile_irq;
516  
517  	/* Cannot enable interrupts until OBP ticker is disabled. */
518  }
519