xen: Add support for preemption
[linux-2.6] / arch / mips / tx4938 / common / irq.c
1 /*
2  * linux/arch/mips/tx4938/common/irq.c
3  *
4  * Common tx4938 irq handler
5  * Copyright (C) 2000-2001 Toshiba Corporation
6  *
7  * 2003-2005 (c) MontaVista Software, Inc. This file is licensed under the
8  * terms of the GNU General Public License version 2. This program is
9  * licensed "as is" without any warranty of any kind, whether express
10  * or implied.
11  *
12  * Support for TX4938 in 2.6 - Manish Lachwani (mlachwani@mvista.com)
13  */
14 #include <linux/errno.h>
15 #include <linux/init.h>
16 #include <linux/kernel_stat.h>
17 #include <linux/module.h>
18 #include <linux/signal.h>
19 #include <linux/sched.h>
20 #include <linux/types.h>
21 #include <linux/interrupt.h>
22 #include <linux/ioport.h>
23 #include <linux/timex.h>
24 #include <linux/slab.h>
25 #include <linux/random.h>
26 #include <linux/irq.h>
27 #include <asm/bitops.h>
28 #include <asm/bootinfo.h>
29 #include <asm/io.h>
30 #include <asm/irq.h>
31 #include <asm/mipsregs.h>
32 #include <asm/system.h>
33 #include <asm/wbflush.h>
34 #include <asm/tx4938/rbtx4938.h>
35
36 /**********************************************************************************/
37 /* Forwad definitions for all pic's                                               */
38 /**********************************************************************************/
39
40 static void tx4938_irq_cp0_enable(unsigned int irq);
41 static void tx4938_irq_cp0_disable(unsigned int irq);
42
43 static void tx4938_irq_pic_enable(unsigned int irq);
44 static void tx4938_irq_pic_disable(unsigned int irq);
45
46 /**********************************************************************************/
47 /* Kernel structs for all pic's                                                   */
48 /**********************************************************************************/
49
50 #define TX4938_CP0_NAME "TX4938-CP0"
51 static struct irq_chip tx4938_irq_cp0_type = {
52         .name = TX4938_CP0_NAME,
53         .ack = tx4938_irq_cp0_disable,
54         .mask = tx4938_irq_cp0_disable,
55         .mask_ack = tx4938_irq_cp0_disable,
56         .unmask = tx4938_irq_cp0_enable,
57 };
58
59 #define TX4938_PIC_NAME "TX4938-PIC"
60 static struct irq_chip tx4938_irq_pic_type = {
61         .name = TX4938_PIC_NAME,
62         .ack = tx4938_irq_pic_disable,
63         .mask = tx4938_irq_pic_disable,
64         .mask_ack = tx4938_irq_pic_disable,
65         .unmask = tx4938_irq_pic_enable,
66 };
67
68 static struct irqaction tx4938_irq_pic_action = {
69         .handler = no_action,
70         .flags = 0,
71         .mask = CPU_MASK_NONE,
72         .name = TX4938_PIC_NAME
73 };
74
75 /**********************************************************************************/
76 /* Functions for cp0                                                              */
77 /**********************************************************************************/
78
79 #define tx4938_irq_cp0_mask(irq) ( 1 << ( irq-TX4938_IRQ_CP0_BEG+8 ) )
80
81 static void __init
82 tx4938_irq_cp0_init(void)
83 {
84         int i;
85
86         for (i = TX4938_IRQ_CP0_BEG; i <= TX4938_IRQ_CP0_END; i++)
87                 set_irq_chip_and_handler(i, &tx4938_irq_cp0_type,
88                                          handle_level_irq);
89 }
90
91 static void
92 tx4938_irq_cp0_enable(unsigned int irq)
93 {
94         set_c0_status(tx4938_irq_cp0_mask(irq));
95 }
96
97 static void
98 tx4938_irq_cp0_disable(unsigned int irq)
99 {
100         clear_c0_status(tx4938_irq_cp0_mask(irq));
101 }
102
103 /**********************************************************************************/
104 /* Functions for pic                                                              */
105 /**********************************************************************************/
106
107 u32
108 tx4938_irq_pic_addr(int irq)
109 {
110         /* MVMCP -- need to formulize this */
111         irq -= TX4938_IRQ_PIC_BEG;
112
113         switch (irq) {
114         case 17:
115         case 16:
116         case 1:
117         case 0:{
118                         return (TX4938_MKA(TX4938_IRC_IRLVL0));
119                 }
120         case 19:
121         case 18:
122         case 3:
123         case 2:{
124                         return (TX4938_MKA(TX4938_IRC_IRLVL1));
125                 }
126         case 21:
127         case 20:
128         case 5:
129         case 4:{
130                         return (TX4938_MKA(TX4938_IRC_IRLVL2));
131                 }
132         case 23:
133         case 22:
134         case 7:
135         case 6:{
136                         return (TX4938_MKA(TX4938_IRC_IRLVL3));
137                 }
138         case 25:
139         case 24:
140         case 9:
141         case 8:{
142                         return (TX4938_MKA(TX4938_IRC_IRLVL4));
143                 }
144         case 27:
145         case 26:
146         case 11:
147         case 10:{
148                         return (TX4938_MKA(TX4938_IRC_IRLVL5));
149                 }
150         case 29:
151         case 28:
152         case 13:
153         case 12:{
154                         return (TX4938_MKA(TX4938_IRC_IRLVL6));
155                 }
156         case 31:
157         case 30:
158         case 15:
159         case 14:{
160                         return (TX4938_MKA(TX4938_IRC_IRLVL7));
161                 }
162         }
163
164         return 0;
165 }
166
167 u32
168 tx4938_irq_pic_mask(int irq)
169 {
170         /* MVMCP -- need to formulize this */
171         irq -= TX4938_IRQ_PIC_BEG;
172
173         switch (irq) {
174         case 31:
175         case 29:
176         case 27:
177         case 25:
178         case 23:
179         case 21:
180         case 19:
181         case 17:{
182                         return (0x07000000);
183                 }
184         case 30:
185         case 28:
186         case 26:
187         case 24:
188         case 22:
189         case 20:
190         case 18:
191         case 16:{
192                         return (0x00070000);
193                 }
194         case 15:
195         case 13:
196         case 11:
197         case 9:
198         case 7:
199         case 5:
200         case 3:
201         case 1:{
202                         return (0x00000700);
203                 }
204         case 14:
205         case 12:
206         case 10:
207         case 8:
208         case 6:
209         case 4:
210         case 2:
211         case 0:{
212                         return (0x00000007);
213                 }
214         }
215         return 0x00000000;
216 }
217
218 static void
219 tx4938_irq_pic_modify(unsigned pic_reg, unsigned clr_bits, unsigned set_bits)
220 {
221         unsigned long val = 0;
222
223         val = TX4938_RD(pic_reg);
224         val &= (~clr_bits);
225         val |= (set_bits);
226         TX4938_WR(pic_reg, val);
227         mmiowb();
228         TX4938_RD(pic_reg);
229 }
230
231 static void __init
232 tx4938_irq_pic_init(void)
233 {
234         int i;
235
236         for (i = TX4938_IRQ_PIC_BEG; i <= TX4938_IRQ_PIC_END; i++)
237                 set_irq_chip_and_handler(i, &tx4938_irq_pic_type,
238                                          handle_level_irq);
239
240         setup_irq(TX4938_IRQ_NEST_PIC_ON_CP0, &tx4938_irq_pic_action);
241
242         TX4938_WR(0xff1ff640, 0x6);     /* irq level mask -- only accept hightest */
243         TX4938_WR(0xff1ff600, TX4938_RD(0xff1ff600) | 0x1);     /* irq enable */
244 }
245
246 static void
247 tx4938_irq_pic_enable(unsigned int irq)
248 {
249         tx4938_irq_pic_modify(tx4938_irq_pic_addr(irq), 0,
250                               tx4938_irq_pic_mask(irq));
251 }
252
253 static void
254 tx4938_irq_pic_disable(unsigned int irq)
255 {
256         tx4938_irq_pic_modify(tx4938_irq_pic_addr(irq),
257                               tx4938_irq_pic_mask(irq), 0);
258 }
259
260 /**********************************************************************************/
261 /* Main init functions                                                            */
262 /**********************************************************************************/
263
264 void __init
265 tx4938_irq_init(void)
266 {
267         tx4938_irq_cp0_init();
268         tx4938_irq_pic_init();
269 }
270
271 int
272 tx4938_irq_nested(void)
273 {
274         int sw_irq = 0;
275         u32 level2;
276
277         level2 = TX4938_RD(0xff1ff6a0);
278         if ((level2 & 0x10000) == 0) {
279                 level2 &= 0x1f;
280                 sw_irq = TX4938_IRQ_PIC_BEG + level2;
281                 if (sw_irq == 26) {
282                         {
283                                 extern int toshiba_rbtx4938_irq_nested(int sw_irq);
284                                 sw_irq = toshiba_rbtx4938_irq_nested(sw_irq);
285                         }
286                 }
287         }
288
289         wbflush();
290         return sw_irq;
291 }
292
293 asmlinkage void plat_irq_dispatch(void)
294 {
295         unsigned int pending = read_c0_cause() & read_c0_status();
296
297         if (pending & STATUSF_IP7)
298                 do_IRQ(TX4938_IRQ_CPU_TIMER);
299         else if (pending & STATUSF_IP2) {
300                 int irq = tx4938_irq_nested();
301                 if (irq)
302                         do_IRQ(irq);
303                 else
304                         spurious_interrupt();
305         } else if (pending & STATUSF_IP1)
306                 do_IRQ(TX4938_IRQ_USER1);
307         else if (pending & STATUSF_IP0)
308                 do_IRQ(TX4938_IRQ_USER0);
309 }