xref: /openbmc/linux/arch/mips/kernel/genex.S (revision 87c2ce3b)
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle
7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8 * Copyright (C) 2001 MIPS Technologies, Inc.
9 * Copyright (C) 2002 Maciej W. Rozycki
10 */
11#include <linux/config.h>
12#include <linux/init.h>
13
14#include <asm/asm.h>
15#include <asm/cacheops.h>
16#include <asm/regdef.h>
17#include <asm/fpregdef.h>
18#include <asm/mipsregs.h>
19#include <asm/stackframe.h>
20#include <asm/war.h>
21
22#define PANIC_PIC(msg)					\
23		.set push;				\
24		.set	reorder;			\
25		PTR_LA	a0,8f;				\
26		.set	noat;				\
27		PTR_LA	AT, panic;			\
28		jr	AT;				\
299:		b	9b;				\
30		.set	pop;				\
31		TEXT(msg)
32
33	__INIT
34
35NESTED(except_vec0_generic, 0, sp)
36	PANIC_PIC("Exception vector 0 called")
37	END(except_vec0_generic)
38
39NESTED(except_vec1_generic, 0, sp)
40	PANIC_PIC("Exception vector 1 called")
41	END(except_vec1_generic)
42
43/*
44 * General exception vector for all other CPUs.
45 *
46 * Be careful when changing this, it has to be at most 128 bytes
47 * to fit into space reserved for the exception handler.
48 */
49NESTED(except_vec3_generic, 0, sp)
50	.set	push
51	.set	noat
52#if R5432_CP0_INTERRUPT_WAR
53	mfc0	k0, CP0_INDEX
54#endif
55	mfc0	k1, CP0_CAUSE
56	andi	k1, k1, 0x7c
57#ifdef CONFIG_64BIT
58	dsll	k1, k1, 1
59#endif
60	PTR_L	k0, exception_handlers(k1)
61	jr	k0
62	.set	pop
63	END(except_vec3_generic)
64
65/*
66 * General exception handler for CPUs with virtual coherency exception.
67 *
68 * Be careful when changing this, it has to be at most 256 (as a special
69 * exception) bytes to fit into space reserved for the exception handler.
70 */
71NESTED(except_vec3_r4000, 0, sp)
72	.set	push
73	.set	mips3
74	.set	noat
75	mfc0	k1, CP0_CAUSE
76	li	k0, 31<<2
77	andi	k1, k1, 0x7c
78	.set	push
79	.set	noreorder
80	.set	nomacro
81	beq	k1, k0, handle_vced
82	 li	k0, 14<<2
83	beq	k1, k0, handle_vcei
84#ifdef CONFIG_64BIT
85	 dsll	k1, k1, 1
86#endif
87	.set	pop
88	PTR_L	k0, exception_handlers(k1)
89	jr	k0
90
91	/*
92	 * Big shit, we now may have two dirty primary cache lines for the same
93	 * physical address.  We can safely invalidate the line pointed to by
94	 * c0_badvaddr because after return from this exception handler the
95	 * load / store will be re-executed.
96	 */
97handle_vced:
98	MFC0	k0, CP0_BADVADDR
99	li	k1, -4					# Is this ...
100	and	k0, k1					# ... really needed?
101	mtc0	zero, CP0_TAGLO
102	cache	Index_Store_Tag_D, (k0)
103	cache	Hit_Writeback_Inv_SD, (k0)
104#ifdef CONFIG_PROC_FS
105	PTR_LA	k0, vced_count
106	lw	k1, (k0)
107	addiu	k1, 1
108	sw	k1, (k0)
109#endif
110	eret
111
112handle_vcei:
113	MFC0	k0, CP0_BADVADDR
114	cache	Hit_Writeback_Inv_SD, (k0)		# also cleans pi
115#ifdef CONFIG_PROC_FS
116	PTR_LA	k0, vcei_count
117	lw	k1, (k0)
118	addiu	k1, 1
119	sw	k1, (k0)
120#endif
121	eret
122	.set	pop
123	END(except_vec3_r4000)
124
125/*
126 * Special interrupt vector for MIPS64 ISA & embedded MIPS processors.
127 * This is a dedicated interrupt exception vector which reduces the
128 * interrupt processing overhead.  The jump instruction will be replaced
129 * at the initialization time.
130 *
131 * Be careful when changing this, it has to be at most 128 bytes
132 * to fit into space reserved for the exception handler.
133 */
134NESTED(except_vec4, 0, sp)
1351:	j	1b			/* Dummy, will be replaced */
136	END(except_vec4)
137
138/*
139 * EJTAG debug exception handler.
140 * The EJTAG debug exception entry point is 0xbfc00480, which
141 * normally is in the boot PROM, so the boot PROM must do a
142 * unconditional jump to this vector.
143 */
144NESTED(except_vec_ejtag_debug, 0, sp)
145	j	ejtag_debug_handler
146	END(except_vec_ejtag_debug)
147
148	__FINIT
149
150/*
151 * Vectored interrupt handler.
152 * This prototype is copied to ebase + n*IntCtl.VS and patched
153 * to invoke the handler
154 */
155NESTED(except_vec_vi, 0, sp)
156	SAVE_SOME
157	SAVE_AT
158	.set	push
159	.set	noreorder
160EXPORT(except_vec_vi_lui)
161	lui	v0, 0		/* Patched */
162	j	except_vec_vi_handler
163EXPORT(except_vec_vi_ori)
164	 ori	v0, 0		/* Patched */
165	.set	pop
166	END(except_vec_vi)
167EXPORT(except_vec_vi_end)
168
169/*
170 * Common Vectored Interrupt code
171 * Complete the register saves and invoke the handler which is passed in $v0
172 */
173NESTED(except_vec_vi_handler, 0, sp)
174	SAVE_TEMP
175	SAVE_STATIC
176	CLI
177	move	a0, sp
178	jalr	v0
179	j	ret_from_irq
180	END(except_vec_vi_handler)
181
182/*
183 * EJTAG debug exception handler.
184 */
185NESTED(ejtag_debug_handler, PT_SIZE, sp)
186	.set	push
187	.set	noat
188	MTC0	k0, CP0_DESAVE
189	mfc0	k0, CP0_DEBUG
190
191	sll	k0, k0, 30	# Check for SDBBP.
192	bgez	k0, ejtag_return
193
194	PTR_LA	k0, ejtag_debug_buffer
195	LONG_S	k1, 0(k0)
196	SAVE_ALL
197	move	a0, sp
198	jal	ejtag_exception_handler
199	RESTORE_ALL
200	PTR_LA	k0, ejtag_debug_buffer
201	LONG_L	k1, 0(k0)
202
203ejtag_return:
204	MFC0	k0, CP0_DESAVE
205	.set	mips32
206	deret
207	.set pop
208	END(ejtag_debug_handler)
209
210/*
211 * This buffer is reserved for the use of the EJTAG debug
212 * handler.
213 */
214	.data
215EXPORT(ejtag_debug_buffer)
216	.fill	LONGSIZE
217	.previous
218
219	__INIT
220
221/*
222 * NMI debug exception handler for MIPS reference boards.
223 * The NMI debug exception entry point is 0xbfc00000, which
224 * normally is in the boot PROM, so the boot PROM must do a
225 * unconditional jump to this vector.
226 */
227NESTED(except_vec_nmi, 0, sp)
228	j	nmi_handler
229	END(except_vec_nmi)
230
231	__FINIT
232
233NESTED(nmi_handler, PT_SIZE, sp)
234	.set	push
235	.set	noat
236	.set	mips3
237	SAVE_ALL
238 	move	a0, sp
239	jal	nmi_exception_handler
240	RESTORE_ALL
241	eret
242	.set	pop
243	END(nmi_handler)
244
245	.macro	__build_clear_none
246	.endm
247
248	.macro	__build_clear_sti
249	STI
250	.endm
251
252	.macro	__build_clear_cli
253	CLI
254	.endm
255
256	.macro	__build_clear_fpe
257	cfc1	a1, fcr31
258	li	a2, ~(0x3f << 12)
259	and	a2, a1
260	ctc1	a2, fcr31
261	STI
262	.endm
263
264	.macro	__build_clear_ade
265	MFC0	t0, CP0_BADVADDR
266	PTR_S	t0, PT_BVADDR(sp)
267	KMODE
268	.endm
269
270	.macro	__BUILD_silent exception
271	.endm
272
273	/* Gas tries to parse the PRINT argument as a string containing
274	   string escapes and emits bogus warnings if it believes to
275	   recognize an unknown escape code.  So make the arguments
276	   start with an n and gas will believe \n is ok ...  */
277	.macro	__BUILD_verbose	nexception
278	LONG_L	a1, PT_EPC(sp)
279#ifdef CONFIG_32BIT
280	PRINT("Got \nexception at %08lx\012")
281#endif
282#ifdef CONFIG_64BIT
283	PRINT("Got \nexception at %016lx\012")
284#endif
285	.endm
286
287	.macro	__BUILD_count exception
288	LONG_L	t0,exception_count_\exception
289	LONG_ADDIU t0, 1
290	LONG_S	t0,exception_count_\exception
291	.comm	exception_count\exception, 8, 8
292	.endm
293
294	.macro	__BUILD_HANDLER exception handler clear verbose ext
295	.align	5
296	NESTED(handle_\exception, PT_SIZE, sp)
297	.set	noat
298	SAVE_ALL
299	FEXPORT(handle_\exception\ext)
300	__BUILD_clear_\clear
301	.set	at
302	__BUILD_\verbose \exception
303	move	a0, sp
304	jal	do_\handler
305	j	ret_from_exception
306	END(handle_\exception)
307	.endm
308
309	.macro	BUILD_HANDLER exception handler clear verbose
310	__BUILD_HANDLER	\exception \handler \clear \verbose _int
311	.endm
312
313	BUILD_HANDLER adel ade ade silent		/* #4  */
314	BUILD_HANDLER ades ade ade silent		/* #5  */
315	BUILD_HANDLER ibe be cli silent			/* #6  */
316	BUILD_HANDLER dbe be cli silent			/* #7  */
317	BUILD_HANDLER bp bp sti silent			/* #9  */
318	BUILD_HANDLER ri ri sti silent			/* #10 */
319	BUILD_HANDLER cpu cpu sti silent		/* #11 */
320	BUILD_HANDLER ov ov sti silent			/* #12 */
321	BUILD_HANDLER tr tr sti silent			/* #13 */
322	BUILD_HANDLER fpe fpe fpe silent		/* #15 */
323	BUILD_HANDLER mdmx mdmx sti silent		/* #22 */
324	BUILD_HANDLER watch watch sti verbose		/* #23 */
325	BUILD_HANDLER mcheck mcheck cli verbose		/* #24 */
326	BUILD_HANDLER mt mt sti verbose			/* #25 */
327	BUILD_HANDLER dsp dsp sti silent		/* #26 */
328	BUILD_HANDLER reserved reserved sti verbose	/* others */
329
330#ifdef CONFIG_64BIT
331/* A temporary overflow handler used by check_daddi(). */
332
333	__INIT
334
335	BUILD_HANDLER  daddi_ov daddi_ov none silent	/* #12 */
336#endif
337