sa11x0_irq.S revision 1.3 1 /* $NetBSD: sa11x0_irq.S,v 1.3 2002/07/19 18:36:26 ichiro Exp $ */
2
3 /*
4 * Copyright (c) 1998 Mark Brinicombe.
5 * Copyright (c) 1998 Causality Limited
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to the NetBSD Foundation
9 * by IWAMOTO Toshihiro.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by Mark Brinicombe
22 * for the NetBSD Project.
23 * 4. The name of the company nor the name of the author may be used to
24 * endorse or promote products derived from this software without specific
25 * prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
28 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
29 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
30 * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
31 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
32 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
33 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 */
39
40 #include "opt_irqstats.h"
41
42 #include "assym.h"
43 #include <machine/asm.h>
44 #include <machine/cpu.h>
45 #include <machine/frame.h>
46 #include <arm/sa11x0/sa11x0_reg.h>
47
48
49 .text
50 .align 0
51
52 Lcurrent_spl_level:
53 .word _C_LABEL(current_spl_level)
54
55 Lcurrent_intr_depth:
56 .word _C_LABEL(current_intr_depth)
57
58 Lspl_masks:
59 .word _C_LABEL(spl_masks)
60
61 .globl _C_LABEL(saipic_base)
62 _C_LABEL(saipic_base):
63 .word 0x00000000
64
65 #ifdef INTR_DEBUG
66 Ldbg_str:
67 .asciz "irq_entry %x %x\n"
68 #endif
69
70 /*
71 * Regsister usage
72 *
73 * r6 - Address of current handler
74 * r7 - Pointer to handler pointer list
75 * r8 - Current IRQ requests.
76 * r9 - Used to count through possible IRQ bits.
77 * r10 - Base address of SAIP
78 */
79
80 ASENTRY_NP(irq_entry)
81 sub lr, lr, #0x00000004 /* Adjust the lr */
82
83 PUSHFRAMEINSVC /* Push an interrupt frame */
84
85 /* Load r8 with the SAIPIC interrupt requests */
86
87 ldr r10, [pc, #_C_LABEL(saipic_base) - . - 8]
88 ldr r8, [r10, #(SAIPIC_IP)] /* Load IRQ pending register */
89
90 #ifdef INTR_DEBUG
91 ldr r2, [r10, #(SAIPIC_MR)]
92 add r0, pc, #Ldbg_str - . - 8
93 mov r1, r8
94 bl _C_LABEL(printf)
95 #endif
96 /*
97 * Note that we have entered the IRQ handler.
98 * We are in SVC mode so we cannot use the processor mode
99 * to determine if we are in an IRQ. Instead we will count the
100 * each time the interrupt handler is nested.
101 */
102
103 ldr r0, Lcurrent_intr_depth
104 ldr r1, [r0]
105 add r1, r1, #1
106 str r1, [r0]
107
108 /*
109 * Need to block all interrupts at the IPL or lower for
110 * all asserted interrupts.
111 * This basically emulates hardware interrupt priority levels.
112 * Means we need to go through the interrupt mask and for
113 * every asserted interrupt we need to mask out all other
114 * interrupts at the same or lower IPL.
115 * If only we could wait until the main loop but we need to sort
116 * this out first so interrupts can be re-enabled.
117 *
118 * This would benefit from a special ffs type routine
119 */
120
121 mov r9, #(_SPL_LEVELS - 1)
122 ldr r7, Lspl_masks
123
124 Lfind_highest_ipl:
125 ldr r2, [r7, r9, lsl #2]
126 tst r8, r2
127 subeq r9, r9, #1
128 beq Lfind_highest_ipl
129
130 /* r9 = SPL level of highest priority interrupt */
131 add r9, r9, #1
132 ldr r2, [r7, r9, lsl #2]
133 mvn r2, r2
134
135 ldr r0, Lcurrent_spl_level
136 ldr r1, [r0]
137 str r9, [r0]
138 stmfd sp!, {r1}
139
140 /* Update the SAIP irq masks */
141 bl _C_LABEL(irq_setmasks)
142
143 #ifdef INTR_DEBUG
144 stmfd sp!, {r0,r1,r2}
145 add r0, pc, #Ldbg_str - . - 8
146 mov r1, #1
147 mov r2, r9
148 bl _C_LABEL(printf)
149 ldmia sp!, {r0,r1,r2}
150 #endif
151 mrs r0, cpsr_all /* Enable IRQ's */
152 bic r0, r0, #I32_bit
153 msr cpsr_all, r0
154
155 ldr r7, [pc, #Lirqhandlers - . - 8]
156 mov r9, #0x00000001
157
158 irqloop:
159 /* This would benefit from a special ffs type routine */
160 tst r8, r9 /* Is a bit set ? */
161 beq nextirq /* No ? try next bit */
162
163 ldr r6, [r7] /* Get address of first handler structure */
164
165 teq r6, #0x00000000 /* Do we have a handler */
166 moveq r0, r8 /* IRQ requests as arg 0 */
167 beq _C_LABEL(stray_irqhandler) /* call special handler */
168
169 ldr r0, Lcnt /* Stat info */
170 ldr r1, [r0, #(V_INTR)]
171 add r1, r1, #0x00000001
172 str r1, [r0, #(V_INTR)]
173
174 /*
175 * XXX: Should stats be accumlated for every interrupt routine
176 * called or for every physical interrupt that is serviced.
177 */
178
179 #ifdef IRQSTATS
180 ldr r0, Lintrcnt
181 ldr r1, [r6, #(IH_COUNT)]
182
183 add r0, r0, r1, lsl #2
184 ldr r1, [r0]
185 add r1, r1, #0x00000001
186 str r1, [r0]
187 #endif /* IRQSTATS */
188
189 irqchainloop:
190 #ifdef INTR_DEBUG
191 stmfd sp!, {r0,r1,r2}
192 add r0, pc, #Ldbg_str - . - 8
193 mov r1, #2
194 bl _C_LABEL(printf)
195 ldmia sp!, {r0,r1,r2}
196 #endif
197 add lr, pc, #nextinchain - . - 8 /* return address */
198 ldr r0, [r6, #(IH_ARG)] /* Get argument pointer */
199 teq r0, #0x00000000 /* If arg is zero pass stack frame */
200 addeq r0, sp, #4 /* ... stack frame [XXX needs care] */
201 ldr pc, [r6, #(IH_FUNC)] /* Call handler */
202
203 nextinchain:
204 teq r0, #0x00000001 /* Was the irq serviced ? */
205 beq irqdone
206
207 ldr r6, [r6, #(IH_NEXT)]
208 teq r6, #0x00000000
209 bne irqchainloop
210
211 irqdone:
212 nextirq:
213 add r7, r7, #0x00000004 /* update pointer to handlers */
214 mov r9, r9, lsl #1 /* move on to next bit */
215 teq r9, #(1 << 31) /* done the last bit ? */
216 bne irqloop /* no - loop back. */
217
218 ldmfd sp!, {r2}
219 ldr r1, Lcurrent_spl_level
220 str r2, [r1]
221
222 /* Restore previous disabled mask */
223 bl _C_LABEL(irq_setmasks)
224
225 bl _C_LABEL(dosoftints) /* Handle the soft interrupts */
226
227 /* Manage AST's. Maybe this should be done as a soft interrupt ? */
228 ldr r0, [sp] /* Get the SPSR from stack */
229
230 and r0, r0, #(PSR_MODE) /* Test for USR32 mode before the IRQ */
231 teq r0, #(PSR_USR32_MODE)
232 ldreq r0, Lastpending /* Do we have an AST pending ? */
233 ldreq r1, [r0]
234 teqeq r1, #0x00000001
235
236 beq irqast /* call the AST handler */
237
238 /* Kill IRQ's in preparation for exit */
239 mrs r0, cpsr_all
240 orr r0, r0, #(I32_bit)
241 msr cpsr_all, r0
242
243 #ifdef INTR_DEBUG
244 add r0, pc, #Ldbg_str - . - 8
245 mov r1, #3
246 ldr r2, [r10, #(SAIPIC_MR)]
247 bl _C_LABEL(printf)
248 #endif
249
250 /* Decrement the nest count */
251 ldr r0, Lcurrent_intr_depth
252 ldr r1, [r0]
253 sub r1, r1, #1
254 str r1, [r0]
255
256 PULLFRAMEFROMSVCANDEXIT
257
258 /* NOT REACHED */
259 b . - 8
260
261 /*
262 * Ok, snag with current intr depth ...
263 * If ast() calls mi_sleep() the current_intr_depth will not be
264 * decremented until the process is woken up. This can result
265 * in the system believing it is still in the interrupt handler.
266 * If we are calling ast() then correct the current_intr_depth
267 * before the call.
268 */
269 irqast:
270 mov r1, #0x00000000 /* Clear ast_pending */
271 str r1, [r0]
272
273 /* Kill IRQ's so we atomically decrement current_intr_depth */
274 mrs r2, cpsr_all
275 orr r3, r2, #(I32_bit)
276 msr cpsr_all, r3
277
278 /* Decrement the interrupt nesting count */
279 ldr r0, Lcurrent_intr_depth
280 ldr r1, [r0]
281 sub r1, r1, #1
282 str r1, [r0]
283
284 /* Restore IRQ's */
285 msr cpsr_all, r2
286
287 mov r0, sp
288 bl _C_LABEL(ast)
289
290 /* Kill IRQ's in preparation for exit */
291 mrs r0, cpsr_all
292 orr r0, r0, #(I32_bit)
293 msr cpsr_all, r0
294
295 PULLFRAMEFROMSVCANDEXIT
296
297 /* NOT REACHED */
298 b . - 8
299
300
301 ENTRY(irq_setmasks)
302 /* Disable interrupts */
303 mrs r3, cpsr_all
304 orr r1, r3, #(I32_bit)
305 msr cpsr_all, r1
306
307 /* Calculate interrupt mask */
308 ldr r0, Lspl_masks
309 ldr r2, Lcurrent_spl_level
310 ldr r2, [r2]
311 ldr r2, [r0, r2, lsl #2]
312
313 ldr r0, [pc, #_C_LABEL(saipic_base) - . - 8]
314 str r2, [r0, #(SAIPIC_MR)] /* Set mask register */
315
316 /* Restore old cpsr and exit */
317 msr cpsr_all, r3
318 mov pc, lr
319
320 Lcnt:
321 .word _C_LABEL(uvmexp)
322
323 #ifdef IRQSTATS
324 Lintrcnt:
325 .word _C_LABEL(intrcnt)
326 #endif
327
328 Lirqhandlers:
329 .word _C_LABEL(irqhandlers) /* Pointer to array of irqhandlers */
330
331 Lastpending:
332 .word _C_LABEL(astpending)
333
334
335
336 #ifdef IRQSTATS
337 .globl _C_LABEL(intrcnt), _C_LABEL(sintrcnt)
338
339 _C_LABEL(intrcnt):
340 .space ICU_LEN*4 /* XXX Should be linked to number of interrupts */
341
342 _C_LABEL(sintrcnt):
343 .space 32*4
344 #endif
345