1 #ifndef _ASM_POWERPC_EXCEPTION_H
2 #define _ASM_POWERPC_EXCEPTION_H
3 /*
4  * Extracted from head_64.S
5  *
6  *  PowerPC version
7  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
8  *
9  *  Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
10  *    Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
11  *  Adapted for Power Macintosh by Paul Mackerras.
12  *  Low-level exception handlers and MMU support
13  *  rewritten by Paul Mackerras.
14  *    Copyright (C) 1996 Paul Mackerras.
15  *
16  *  Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and
17  *    Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com
18  *
19  *  This file contains the low-level support and setup for the
20  *  PowerPC-64 platform, including trap and interrupt dispatch.
21  *
22  *  This program is free software; you can redistribute it and/or
23  *  modify it under the terms of the GNU General Public License
24  *  as published by the Free Software Foundation; either version
25  *  2 of the License, or (at your option) any later version.
26  */
27 /*
28  * The following macros define the code that appears as
29  * the prologue to each of the exception handlers.  They
30  * are split into two parts to allow a single kernel binary
31  * to be used for pSeries and iSeries.
32  *
33  * We make as much of the exception code common between native
34  * exception handlers (including pSeries LPAR) and iSeries LPAR
35  * implementations as possible.
36  */
37 
38 #define EX_R9		0
39 #define EX_R10		8
40 #define EX_R11		16
41 #define EX_R12		24
42 #define EX_R13		32
43 #define EX_SRR0		40
44 #define EX_DAR		48
45 #define EX_DSISR	56
46 #define EX_CCR		60
47 #define EX_R3		64
48 #define EX_LR		72
49 #define EX_CFAR		80
50 
51 /*
52  * We're short on space and time in the exception prolog, so we can't
53  * use the normal SET_REG_IMMEDIATE macro. Normally we just need the
54  * low halfword of the address, but for Kdump we need the whole low
55  * word.
56  */
57 #define LOAD_HANDLER(reg, label)					\
58 	addi	reg,reg,(label)-_stext;	/* virt addr of handler ... */
59 
60 /* Exception register prefixes */
61 #define EXC_HV	H
62 #define EXC_STD
63 
64 #define __EXCEPTION_PROLOG_1(area, extra, vec)				\
65 	GET_PACA(r13);							\
66 	std	r9,area+EX_R9(r13);	/* save r9 - r12 */		\
67 	std	r10,area+EX_R10(r13);					\
68 	BEGIN_FTR_SECTION_NESTED(66);					\
69 	mfspr	r10,SPRN_CFAR;						\
70 	std	r10,area+EX_CFAR(r13);					\
71 	END_FTR_SECTION_NESTED(CPU_FTR_CFAR, CPU_FTR_CFAR, 66);		\
72 	mfcr	r9;							\
73 	extra(vec);							\
74 	std	r11,area+EX_R11(r13);					\
75 	std	r12,area+EX_R12(r13);					\
76 	GET_SCRATCH0(r10);						\
77 	std	r10,area+EX_R13(r13)
78 #define EXCEPTION_PROLOG_1(area, extra, vec)				\
79 	__EXCEPTION_PROLOG_1(area, extra, vec)
80 
81 #define __EXCEPTION_PROLOG_PSERIES_1(label, h)				\
82 	ld	r12,PACAKBASE(r13);	/* get high part of &label */	\
83 	ld	r10,PACAKMSR(r13);	/* get MSR value for kernel */	\
84 	mfspr	r11,SPRN_##h##SRR0;	/* save SRR0 */			\
85 	LOAD_HANDLER(r12,label)						\
86 	mtspr	SPRN_##h##SRR0,r12;					\
87 	mfspr	r12,SPRN_##h##SRR1;	/* and SRR1 */			\
88 	mtspr	SPRN_##h##SRR1,r10;					\
89 	h##rfid;							\
90 	b	.	/* prevent speculative execution */
91 #define EXCEPTION_PROLOG_PSERIES_1(label, h)				\
92 	__EXCEPTION_PROLOG_PSERIES_1(label, h)
93 
94 #define EXCEPTION_PROLOG_PSERIES(area, label, h, extra, vec)		\
95 	EXCEPTION_PROLOG_1(area, extra, vec);				\
96 	EXCEPTION_PROLOG_PSERIES_1(label, h);
97 
98 #define __KVMTEST(n)							\
99 	lbz	r10,HSTATE_IN_GUEST(r13);			\
100 	cmpwi	r10,0;							\
101 	bne	do_kvm_##n
102 
103 #define __KVM_HANDLER(area, h, n)					\
104 do_kvm_##n:								\
105 	ld	r10,area+EX_R10(r13);					\
106 	stw	r9,HSTATE_SCRATCH1(r13);			\
107 	ld	r9,area+EX_R9(r13);					\
108 	std	r12,HSTATE_SCRATCH0(r13);			\
109 	li	r12,n;							\
110 	b	kvmppc_interrupt
111 
112 #define __KVM_HANDLER_SKIP(area, h, n)					\
113 do_kvm_##n:								\
114 	cmpwi	r10,KVM_GUEST_MODE_SKIP;				\
115 	ld	r10,area+EX_R10(r13);					\
116 	beq	89f;							\
117 	stw	r9,HSTATE_SCRATCH1(r13);			\
118 	ld	r9,area+EX_R9(r13);					\
119 	std	r12,HSTATE_SCRATCH0(r13);			\
120 	li	r12,n;							\
121 	b	kvmppc_interrupt;					\
122 89:	mtocrf	0x80,r9;						\
123 	ld	r9,area+EX_R9(r13);					\
124 	b	kvmppc_skip_##h##interrupt
125 
126 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
127 #define KVMTEST(n)			__KVMTEST(n)
128 #define KVM_HANDLER(area, h, n)		__KVM_HANDLER(area, h, n)
129 #define KVM_HANDLER_SKIP(area, h, n)	__KVM_HANDLER_SKIP(area, h, n)
130 
131 #else
132 #define KVMTEST(n)
133 #define KVM_HANDLER(area, h, n)
134 #define KVM_HANDLER_SKIP(area, h, n)
135 #endif
136 
137 #ifdef CONFIG_KVM_BOOK3S_PR
138 #define KVMTEST_PR(n)			__KVMTEST(n)
139 #define KVM_HANDLER_PR(area, h, n)	__KVM_HANDLER(area, h, n)
140 #define KVM_HANDLER_PR_SKIP(area, h, n)	__KVM_HANDLER_SKIP(area, h, n)
141 
142 #else
143 #define KVMTEST_PR(n)
144 #define KVM_HANDLER_PR(area, h, n)
145 #define KVM_HANDLER_PR_SKIP(area, h, n)
146 #endif
147 
148 #define NOTEST(n)
149 
150 /*
151  * The common exception prolog is used for all except a few exceptions
152  * such as a segment miss on a kernel address.  We have to be prepared
153  * to take another exception from the point where we first touch the
154  * kernel stack onwards.
155  *
156  * On entry r13 points to the paca, r9-r13 are saved in the paca,
157  * r9 contains the saved CR, r11 and r12 contain the saved SRR0 and
158  * SRR1, and relocation is on.
159  */
160 #define EXCEPTION_PROLOG_COMMON(n, area)				   \
161 	andi.	r10,r12,MSR_PR;		/* See if coming from user	*/ \
162 	mr	r10,r1;			/* Save r1			*/ \
163 	subi	r1,r1,INT_FRAME_SIZE;	/* alloc frame on kernel stack	*/ \
164 	beq-	1f;							   \
165 	ld	r1,PACAKSAVE(r13);	/* kernel stack to use		*/ \
166 1:	cmpdi	cr1,r1,0;		/* check if r1 is in userspace	*/ \
167 	blt+	cr1,3f;			/* abort if it is		*/ \
168 	li	r1,(n);			/* will be reloaded later	*/ \
169 	sth	r1,PACA_TRAP_SAVE(r13);					   \
170 	std	r3,area+EX_R3(r13);					   \
171 	addi	r3,r13,area;		/* r3 -> where regs are saved*/	   \
172 	b	bad_stack;						   \
173 3:	std	r9,_CCR(r1);		/* save CR in stackframe	*/ \
174 	std	r11,_NIP(r1);		/* save SRR0 in stackframe	*/ \
175 	std	r12,_MSR(r1);		/* save SRR1 in stackframe	*/ \
176 	std	r10,0(r1);		/* make stack chain pointer	*/ \
177 	std	r0,GPR0(r1);		/* save r0 in stackframe	*/ \
178 	std	r10,GPR1(r1);		/* save r1 in stackframe	*/ \
179 	ACCOUNT_CPU_USER_ENTRY(r9, r10);				   \
180 	std	r2,GPR2(r1);		/* save r2 in stackframe	*/ \
181 	SAVE_4GPRS(3, r1);		/* save r3 - r6 in stackframe	*/ \
182 	SAVE_2GPRS(7, r1);		/* save r7, r8 in stackframe	*/ \
183 	ld	r9,area+EX_R9(r13);	/* move r9, r10 to stackframe	*/ \
184 	ld	r10,area+EX_R10(r13);					   \
185 	std	r9,GPR9(r1);						   \
186 	std	r10,GPR10(r1);						   \
187 	ld	r9,area+EX_R11(r13);	/* move r11 - r13 to stackframe	*/ \
188 	ld	r10,area+EX_R12(r13);					   \
189 	ld	r11,area+EX_R13(r13);					   \
190 	std	r9,GPR11(r1);						   \
191 	std	r10,GPR12(r1);						   \
192 	std	r11,GPR13(r1);						   \
193 	BEGIN_FTR_SECTION_NESTED(66);					   \
194 	ld	r10,area+EX_CFAR(r13);					   \
195 	std	r10,ORIG_GPR3(r1);					   \
196 	END_FTR_SECTION_NESTED(CPU_FTR_CFAR, CPU_FTR_CFAR, 66);		   \
197 	ld	r2,PACATOC(r13);	/* get kernel TOC into r2	*/ \
198 	mflr	r9;			/* save LR in stackframe	*/ \
199 	std	r9,_LINK(r1);						   \
200 	mfctr	r10;			/* save CTR in stackframe	*/ \
201 	std	r10,_CTR(r1);						   \
202 	lbz	r10,PACASOFTIRQEN(r13);				   \
203 	mfspr	r11,SPRN_XER;		/* save XER in stackframe	*/ \
204 	std	r10,SOFTE(r1);						   \
205 	std	r11,_XER(r1);						   \
206 	li	r9,(n)+1;						   \
207 	std	r9,_TRAP(r1);		/* set trap number		*/ \
208 	li	r10,0;							   \
209 	ld	r11,exception_marker@toc(r2);				   \
210 	std	r10,RESULT(r1);		/* clear regs->result		*/ \
211 	std	r11,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame	*/ \
212 	ACCOUNT_STOLEN_TIME
213 
214 /*
215  * Exception vectors.
216  */
217 #define STD_EXCEPTION_PSERIES(loc, vec, label)		\
218 	. = loc;					\
219 	.globl label##_pSeries;				\
220 label##_pSeries:					\
221 	HMT_MEDIUM;					\
222 	SET_SCRATCH0(r13);		/* save r13 */		\
223 	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common,	\
224 				 EXC_STD, KVMTEST_PR, vec)
225 
226 #define STD_EXCEPTION_HV(loc, vec, label)		\
227 	. = loc;					\
228 	.globl label##_hv;				\
229 label##_hv:						\
230 	HMT_MEDIUM;					\
231 	SET_SCRATCH0(r13);	/* save r13 */			\
232 	EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common,	\
233 				 EXC_HV, KVMTEST, vec)
234 
235 /* This associate vector numbers with bits in paca->irq_happened */
236 #define SOFTEN_VALUE_0x500	PACA_IRQ_EE
237 #define SOFTEN_VALUE_0x502	PACA_IRQ_EE
238 #define SOFTEN_VALUE_0x900	PACA_IRQ_DEC
239 #define SOFTEN_VALUE_0x982	PACA_IRQ_DEC
240 
241 #define __SOFTEN_TEST(h, vec)						\
242 	lbz	r10,PACASOFTIRQEN(r13);					\
243 	cmpwi	r10,0;							\
244 	li	r10,SOFTEN_VALUE_##vec;					\
245 	beq	masked_##h##interrupt
246 #define _SOFTEN_TEST(h, vec)	__SOFTEN_TEST(h, vec)
247 
248 #define SOFTEN_TEST_PR(vec)						\
249 	KVMTEST_PR(vec);						\
250 	_SOFTEN_TEST(EXC_STD, vec)
251 
252 #define SOFTEN_TEST_HV(vec)						\
253 	KVMTEST(vec);							\
254 	_SOFTEN_TEST(EXC_HV, vec)
255 
256 #define SOFTEN_TEST_HV_201(vec)						\
257 	KVMTEST(vec);							\
258 	_SOFTEN_TEST(EXC_STD, vec)
259 
260 #define __MASKABLE_EXCEPTION_PSERIES(vec, label, h, extra)		\
261 	HMT_MEDIUM;							\
262 	SET_SCRATCH0(r13);    /* save r13 */				\
263 	__EXCEPTION_PROLOG_1(PACA_EXGEN, extra, vec);		\
264 	EXCEPTION_PROLOG_PSERIES_1(label##_common, h);
265 #define _MASKABLE_EXCEPTION_PSERIES(vec, label, h, extra)		\
266 	__MASKABLE_EXCEPTION_PSERIES(vec, label, h, extra)
267 
268 #define MASKABLE_EXCEPTION_PSERIES(loc, vec, label)			\
269 	. = loc;							\
270 	.globl label##_pSeries;						\
271 label##_pSeries:							\
272 	_MASKABLE_EXCEPTION_PSERIES(vec, label,				\
273 				    EXC_STD, SOFTEN_TEST_PR)
274 
275 #define MASKABLE_EXCEPTION_HV(loc, vec, label)				\
276 	. = loc;							\
277 	.globl label##_hv;						\
278 label##_hv:								\
279 	_MASKABLE_EXCEPTION_PSERIES(vec, label,				\
280 				    EXC_HV, SOFTEN_TEST_HV)
281 
282 /*
283  * Our exception common code can be passed various "additions"
284  * to specify the behaviour of interrupts, whether to kick the
285  * runlatch, etc...
286  */
287 
288 /* Exception addition: Hard disable interrupts */
289 #define DISABLE_INTS	SOFT_DISABLE_INTS(r10,r11)
290 
291 /* Exception addition: Keep interrupt state */
292 #define ENABLE_INTS				\
293 	ld	r11,PACAKMSR(r13);		\
294 	ld	r12,_MSR(r1);			\
295 	rlwimi	r11,r12,0,MSR_EE;		\
296 	mtmsrd	r11,1
297 
298 #define ADD_NVGPRS				\
299 	bl	.save_nvgprs
300 
301 #define RUNLATCH_ON				\
302 BEGIN_FTR_SECTION				\
303 	clrrdi	r3,r1,THREAD_SHIFT;		\
304 	ld	r4,TI_LOCAL_FLAGS(r3);		\
305 	andi.	r0,r4,_TLF_RUNLATCH;		\
306 	beql	ppc64_runlatch_on_trampoline;	\
307 END_FTR_SECTION_IFSET(CPU_FTR_CTRL)
308 
309 #define EXCEPTION_COMMON(trap, label, hdlr, ret, additions)	\
310 	.align	7;						\
311 	.globl label##_common;					\
312 label##_common:							\
313 	EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN);		\
314 	additions;						\
315 	addi	r3,r1,STACK_FRAME_OVERHEAD;			\
316 	bl	hdlr;						\
317 	b	ret
318 
319 #define STD_EXCEPTION_COMMON(trap, label, hdlr)			\
320 	EXCEPTION_COMMON(trap, label, hdlr, ret_from_except,	\
321 			 ADD_NVGPRS;DISABLE_INTS)
322 
323 /*
324  * Like STD_EXCEPTION_COMMON, but for exceptions that can occur
325  * in the idle task and therefore need the special idle handling
326  * (finish nap and runlatch)
327  */
328 #define STD_EXCEPTION_COMMON_ASYNC(trap, label, hdlr)		  \
329 	EXCEPTION_COMMON(trap, label, hdlr, ret_from_except_lite, \
330 			 FINISH_NAP;RUNLATCH_ON;DISABLE_INTS)
331 
332 /*
333  * When the idle code in power4_idle puts the CPU into NAP mode,
334  * it has to do so in a loop, and relies on the external interrupt
335  * and decrementer interrupt entry code to get it out of the loop.
336  * It sets the _TLF_NAPPING bit in current_thread_info()->local_flags
337  * to signal that it is in the loop and needs help to get out.
338  */
339 #ifdef CONFIG_PPC_970_NAP
340 #define FINISH_NAP				\
341 BEGIN_FTR_SECTION				\
342 	clrrdi	r11,r1,THREAD_SHIFT;		\
343 	ld	r9,TI_LOCAL_FLAGS(r11);		\
344 	andi.	r10,r9,_TLF_NAPPING;		\
345 	bnel	power4_fixup_nap;		\
346 END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
347 #else
348 #define FINISH_NAP
349 #endif
350 
351 #endif	/* _ASM_POWERPC_EXCEPTION_H */
352