[ACPI] Merge acpi-2.6.12 branch into 2.6.13-rc3
[linux-2.6] / arch / ia64 / kernel / irq_ia64.c
1 /*
2  * linux/arch/ia64/kernel/irq.c
3  *
4  * Copyright (C) 1998-2001 Hewlett-Packard Co
5  *      Stephane Eranian <eranian@hpl.hp.com>
6  *      David Mosberger-Tang <davidm@hpl.hp.com>
7  *
8  *  6/10/99: Updated to bring in sync with x86 version to facilitate
9  *           support for SMP and different interrupt controllers.
10  *
11  * 09/15/00 Goutham Rao <goutham.rao@intel.com> Implemented pci_irq_to_vector
12  *                      PCI to vector allocation routine.
13  * 04/14/2004 Ashok Raj <ashok.raj@intel.com>
14  *                                              Added CPU Hotplug handling for IPF.
15  */
16
17 #include <linux/config.h>
18 #include <linux/module.h>
19
20 #include <linux/jiffies.h>
21 #include <linux/errno.h>
22 #include <linux/init.h>
23 #include <linux/interrupt.h>
24 #include <linux/ioport.h>
25 #include <linux/kernel_stat.h>
26 #include <linux/slab.h>
27 #include <linux/ptrace.h>
28 #include <linux/random.h>       /* for rand_initialize_irq() */
29 #include <linux/signal.h>
30 #include <linux/smp.h>
31 #include <linux/smp_lock.h>
32 #include <linux/threads.h>
33 #include <linux/bitops.h>
34
35 #include <asm/delay.h>
36 #include <asm/intrinsics.h>
37 #include <asm/io.h>
38 #include <asm/hw_irq.h>
39 #include <asm/machvec.h>
40 #include <asm/pgtable.h>
41 #include <asm/system.h>
42
43 #ifdef CONFIG_PERFMON
44 # include <asm/perfmon.h>
45 #endif
46
47 #define IRQ_DEBUG       0
48
49 /* default base addr of IPI table */
50 void __iomem *ipi_base_addr = ((void __iomem *)
51                                (__IA64_UNCACHED_OFFSET | IA64_IPI_DEFAULT_BASE_ADDR));
52
53 /*
54  * Legacy IRQ to IA-64 vector translation table.
55  */
56 __u8 isa_irq_to_vector_map[16] = {
57         /* 8259 IRQ translation, first 16 entries */
58         0x2f, 0x20, 0x2e, 0x2d, 0x2c, 0x2b, 0x2a, 0x29,
59         0x28, 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21
60 };
61 EXPORT_SYMBOL(isa_irq_to_vector_map);
62
63 static unsigned long ia64_vector_mask[BITS_TO_LONGS(IA64_NUM_DEVICE_VECTORS)];
64
65 int
66 assign_irq_vector (int irq)
67 {
68         int pos, vector;
69  again:
70         pos = find_first_zero_bit(ia64_vector_mask, IA64_NUM_DEVICE_VECTORS);
71         vector = IA64_FIRST_DEVICE_VECTOR + pos;
72         if (vector > IA64_LAST_DEVICE_VECTOR)
73                 return -ENOSPC;
74         if (test_and_set_bit(pos, ia64_vector_mask))
75                 goto again;
76         return vector;
77 }
78
79 void
80 free_irq_vector (int vector)
81 {
82         int pos;
83
84         if (vector < IA64_FIRST_DEVICE_VECTOR || vector > IA64_LAST_DEVICE_VECTOR)
85                 return;
86
87         pos = vector - IA64_FIRST_DEVICE_VECTOR;
88         if (!test_and_clear_bit(pos, ia64_vector_mask))
89                 printk(KERN_WARNING "%s: double free!\n", __FUNCTION__);
90 }
91
92 #ifdef CONFIG_SMP
93 #       define IS_RESCHEDULE(vec)       (vec == IA64_IPI_RESCHEDULE)
94 #else
95 #       define IS_RESCHEDULE(vec)       (0)
96 #endif
97 /*
98  * That's where the IVT branches when we get an external
99  * interrupt. This branches to the correct hardware IRQ handler via
100  * function ptr.
101  */
102 void
103 ia64_handle_irq (ia64_vector vector, struct pt_regs *regs)
104 {
105         unsigned long saved_tpr;
106
107 #if IRQ_DEBUG
108         {
109                 unsigned long bsp, sp;
110
111                 /*
112                  * Note: if the interrupt happened while executing in
113                  * the context switch routine (ia64_switch_to), we may
114                  * get a spurious stack overflow here.  This is
115                  * because the register and the memory stack are not
116                  * switched atomically.
117                  */
118                 bsp = ia64_getreg(_IA64_REG_AR_BSP);
119                 sp = ia64_getreg(_IA64_REG_SP);
120
121                 if ((sp - bsp) < 1024) {
122                         static unsigned char count;
123                         static long last_time;
124
125                         if (jiffies - last_time > 5*HZ)
126                                 count = 0;
127                         if (++count < 5) {
128                                 last_time = jiffies;
129                                 printk("ia64_handle_irq: DANGER: less than "
130                                        "1KB of free stack space!!\n"
131                                        "(bsp=0x%lx, sp=%lx)\n", bsp, sp);
132                         }
133                 }
134         }
135 #endif /* IRQ_DEBUG */
136
137         /*
138          * Always set TPR to limit maximum interrupt nesting depth to
139          * 16 (without this, it would be ~240, which could easily lead
140          * to kernel stack overflows).
141          */
142         irq_enter();
143         saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
144         ia64_srlz_d();
145         while (vector != IA64_SPURIOUS_INT_VECTOR) {
146                 if (!IS_RESCHEDULE(vector)) {
147                         ia64_setreg(_IA64_REG_CR_TPR, vector);
148                         ia64_srlz_d();
149
150                         __do_IRQ(local_vector_to_irq(vector), regs);
151
152                         /*
153                          * Disable interrupts and send EOI:
154                          */
155                         local_irq_disable();
156                         ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
157                 }
158                 ia64_eoi();
159                 vector = ia64_get_ivr();
160         }
161         /*
162          * This must be done *after* the ia64_eoi().  For example, the keyboard softirq
163          * handler needs to be able to wait for further keyboard interrupts, which can't
164          * come through until ia64_eoi() has been done.
165          */
166         irq_exit();
167 }
168
169 #ifdef CONFIG_HOTPLUG_CPU
170 /*
171  * This function emulates a interrupt processing when a cpu is about to be
172  * brought down.
173  */
174 void ia64_process_pending_intr(void)
175 {
176         ia64_vector vector;
177         unsigned long saved_tpr;
178         extern unsigned int vectors_in_migration[NR_IRQS];
179
180         vector = ia64_get_ivr();
181
182          irq_enter();
183          saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
184          ia64_srlz_d();
185
186          /*
187           * Perform normal interrupt style processing
188           */
189         while (vector != IA64_SPURIOUS_INT_VECTOR) {
190                 if (!IS_RESCHEDULE(vector)) {
191                         ia64_setreg(_IA64_REG_CR_TPR, vector);
192                         ia64_srlz_d();
193
194                         /*
195                          * Now try calling normal ia64_handle_irq as it would have got called
196                          * from a real intr handler. Try passing null for pt_regs, hopefully
197                          * it will work. I hope it works!.
198                          * Probably could shared code.
199                          */
200                         vectors_in_migration[local_vector_to_irq(vector)]=0;
201                         __do_IRQ(local_vector_to_irq(vector), NULL);
202
203                         /*
204                          * Disable interrupts and send EOI
205                          */
206                         local_irq_disable();
207                         ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
208                 }
209                 ia64_eoi();
210                 vector = ia64_get_ivr();
211         }
212         irq_exit();
213 }
214 #endif
215
216
217 #ifdef CONFIG_SMP
218 extern irqreturn_t handle_IPI (int irq, void *dev_id, struct pt_regs *regs);
219
220 static struct irqaction ipi_irqaction = {
221         .handler =      handle_IPI,
222         .flags =        SA_INTERRUPT,
223         .name =         "IPI"
224 };
225 #endif
226
227 void
228 register_percpu_irq (ia64_vector vec, struct irqaction *action)
229 {
230         irq_desc_t *desc;
231         unsigned int irq;
232
233         for (irq = 0; irq < NR_IRQS; ++irq)
234                 if (irq_to_vector(irq) == vec) {
235                         desc = irq_descp(irq);
236                         desc->status |= IRQ_PER_CPU;
237                         desc->handler = &irq_type_ia64_lsapic;
238                         if (action)
239                                 setup_irq(irq, action);
240                 }
241 }
242
243 void __init
244 init_IRQ (void)
245 {
246         register_percpu_irq(IA64_SPURIOUS_INT_VECTOR, NULL);
247 #ifdef CONFIG_SMP
248         register_percpu_irq(IA64_IPI_VECTOR, &ipi_irqaction);
249 #endif
250 #ifdef CONFIG_PERFMON
251         pfm_init_percpu();
252 #endif
253         platform_irq_init();
254 }
255
256 void
257 ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect)
258 {
259         void __iomem *ipi_addr;
260         unsigned long ipi_data;
261         unsigned long phys_cpu_id;
262
263 #ifdef CONFIG_SMP
264         phys_cpu_id = cpu_physical_id(cpu);
265 #else
266         phys_cpu_id = (ia64_getreg(_IA64_REG_CR_LID) >> 16) & 0xffff;
267 #endif
268
269         /*
270          * cpu number is in 8bit ID and 8bit EID
271          */
272
273         ipi_data = (delivery_mode << 8) | (vector & 0xff);
274         ipi_addr = ipi_base_addr + ((phys_cpu_id << 4) | ((redirect & 1) << 3));
275
276         writeq(ipi_data, ipi_addr);
277 }