xref: /openbmc/linux/arch/powerpc/kernel/head_booke.h (revision 67559900)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __HEAD_BOOKE_H__
3 #define __HEAD_BOOKE_H__
4 
5 #include <asm/ptrace.h>	/* for STACK_FRAME_REGS_MARKER */
6 #include <asm/kvm_asm.h>
7 #include <asm/kvm_booke_hv_asm.h>
8 
9 #ifdef __ASSEMBLY__
10 
11 /*
12  * Macros used for common Book-e exception handling
13  */
14 
15 #define SET_IVOR(vector_number, vector_label)		\
16 		li	r26,vector_label@l; 		\
17 		mtspr	SPRN_IVOR##vector_number,r26;	\
18 		sync
19 
20 #if (THREAD_SHIFT < 15)
21 #define ALLOC_STACK_FRAME(reg, val)			\
22 	addi reg,reg,val
23 #else
24 #define ALLOC_STACK_FRAME(reg, val)			\
25 	addis	reg,reg,val@ha;				\
26 	addi	reg,reg,val@l
27 #endif
28 
29 /*
30  * Macro used to get to thread save registers.
31  * Note that entries 0-3 are used for the prolog code, and the remaining
32  * entries are available for specific exception use in the event a handler
33  * requires more than 4 scratch registers.
34  */
35 #define THREAD_NORMSAVE(offset)	(THREAD_NORMSAVES + (offset * 4))
36 
37 #ifdef CONFIG_PPC_FSL_BOOK3E
38 #define BOOKE_CLEAR_BTB(reg)									\
39 START_BTB_FLUSH_SECTION								\
40 	BTB_FLUSH(reg)									\
41 END_BTB_FLUSH_SECTION
42 #else
43 #define BOOKE_CLEAR_BTB(reg)
44 #endif
45 
46 
47 #define NORMAL_EXCEPTION_PROLOG(trapno, intno)						     \
48 	mtspr	SPRN_SPRG_WSCRATCH0, r10;	/* save one register */	     \
49 	mfspr	r10, SPRN_SPRG_THREAD;					     \
50 	stw	r11, THREAD_NORMSAVE(0)(r10);				     \
51 	stw	r13, THREAD_NORMSAVE(2)(r10);				     \
52 	mfcr	r13;			/* save CR in r13 for now	   */\
53 	mfspr	r11, SPRN_SRR1;		                                     \
54 	DO_KVM	BOOKE_INTERRUPT_##intno SPRN_SRR1;			     \
55 	andi.	r11, r11, MSR_PR;	/* check whether user or kernel    */\
56 	LOAD_REG_IMMEDIATE(r11, MSR_KERNEL);				\
57 	mtmsr	r11;							\
58 	mr	r11, r1;						     \
59 	beq	1f;							     \
60 	BOOKE_CLEAR_BTB(r11)						\
61 	/* if from user, start at top of this thread's kernel stack */       \
62 	lwz	r11, TASK_STACK - THREAD(r10);				     \
63 	ALLOC_STACK_FRAME(r11, THREAD_SIZE);				     \
64 1 :	subi	r11, r11, INT_FRAME_SIZE; /* Allocate exception frame */     \
65 	stw	r13, _CCR(r11);		/* save various registers */	     \
66 	stw	r12,GPR12(r11);						     \
67 	stw	r9,GPR9(r11);						     \
68 	mfspr	r13, SPRN_SPRG_RSCRATCH0;				     \
69 	stw	r13, GPR10(r11);					     \
70 	lwz	r12, THREAD_NORMSAVE(0)(r10);				     \
71 	stw	r12,GPR11(r11);						     \
72 	lwz	r13, THREAD_NORMSAVE(2)(r10); /* restore r13 */		     \
73 	mflr	r10;							     \
74 	stw	r10,_LINK(r11);						     \
75 	mfspr	r12,SPRN_SRR0;						     \
76 	stw	r1, GPR1(r11);						     \
77 	mfspr	r9,SPRN_SRR1;						     \
78 	stw	r1, 0(r11);						     \
79 	mr	r1, r11;						     \
80 	rlwinm	r9,r9,0,14,12;		/* clear MSR_WE (necessary?)	   */\
81 	COMMON_EXCEPTION_PROLOG_END trapno
82 
83 .macro COMMON_EXCEPTION_PROLOG_END trapno
84 	stw	r0,GPR0(r1)
85 	lis	r10, STACK_FRAME_REGS_MARKER@ha	/* exception frame marker */
86 	addi	r10, r10, STACK_FRAME_REGS_MARKER@l
87 	stw	r10, 8(r1)
88 	li	r10, \trapno
89 	stw	r10,_TRAP(r1)
90 	SAVE_4GPRS(3, r1)
91 	SAVE_2GPRS(7, r1)
92 	SAVE_NVGPRS(r1)
93 	stw	r2,GPR2(r1)
94 	stw	r12,_NIP(r1)
95 	stw	r9,_MSR(r1)
96 	mfctr	r10
97 	mfspr	r2,SPRN_SPRG_THREAD
98 	stw	r10,_CTR(r1)
99 	tovirt(r2, r2)
100 	mfspr	r10,SPRN_XER
101 	addi	r2, r2, -THREAD
102 	stw	r10,_XER(r1)
103 	addi	r3,r1,STACK_FRAME_OVERHEAD
104 .endm
105 
106 .macro prepare_transfer_to_handler
107 #ifdef CONFIG_E500
108 	andi.	r12,r9,MSR_PR
109 	bne	777f
110 	bl	prepare_transfer_to_handler
111 777:
112 #endif
113 .endm
114 
115 .macro SYSCALL_ENTRY trapno intno srr1
116 	mfspr	r10, SPRN_SPRG_THREAD
117 #ifdef CONFIG_KVM_BOOKE_HV
118 BEGIN_FTR_SECTION
119 	mtspr	SPRN_SPRG_WSCRATCH0, r10
120 	stw	r11, THREAD_NORMSAVE(0)(r10)
121 	stw	r13, THREAD_NORMSAVE(2)(r10)
122 	mfcr	r13			/* save CR in r13 for now	   */
123 	mfspr	r11, SPRN_SRR1
124 	mtocrf	0x80, r11	/* check MSR[GS] without clobbering reg */
125 	bf	3, 1975f
126 	b	kvmppc_handler_\intno\()_\srr1
127 1975:
128 	mr	r12, r13
129 	lwz	r13, THREAD_NORMSAVE(2)(r10)
130 FTR_SECTION_ELSE
131 	mfcr	r12
132 ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
133 #else
134 	mfcr	r12
135 #endif
136 	mfspr	r9, SPRN_SRR1
137 	BOOKE_CLEAR_BTB(r11)
138 	mr	r11, r1
139 	lwz	r1, TASK_STACK - THREAD(r10)
140 	rlwinm	r12,r12,0,4,2	/* Clear SO bit in CR */
141 	ALLOC_STACK_FRAME(r1, THREAD_SIZE - INT_FRAME_SIZE)
142 	stw	r12, _CCR(r1)
143 	mfspr	r12,SPRN_SRR0
144 	stw	r12,_NIP(r1)
145 	b	transfer_to_syscall	/* jump to handler */
146 .endm
147 
148 /* To handle the additional exception priority levels on 40x and Book-E
149  * processors we allocate a stack per additional priority level.
150  *
151  * On 40x critical is the only additional level
152  * On 44x/e500 we have critical and machine check
153  *
154  * Additionally we reserve a SPRG for each priority level so we can free up a
155  * GPR to use as the base for indirect access to the exception stacks.  This
156  * is necessary since the MMU is always on, for Book-E parts, and the stacks
157  * are offset from KERNELBASE.
158  *
159  * There is some space optimization to be had here if desired.  However
160  * to allow for a common kernel with support for debug exceptions either
161  * going to critical or their own debug level we aren't currently
162  * providing configurations that micro-optimize space usage.
163  */
164 
165 #define MC_STACK_BASE		mcheckirq_ctx
166 #define CRIT_STACK_BASE		critirq_ctx
167 
168 /* only on e500mc */
169 #define DBG_STACK_BASE		dbgirq_ctx
170 
171 #ifdef CONFIG_SMP
172 #define BOOKE_LOAD_EXC_LEVEL_STACK(level)		\
173 	mfspr	r8,SPRN_PIR;				\
174 	slwi	r8,r8,2;				\
175 	addis	r8,r8,level##_STACK_BASE@ha;		\
176 	lwz	r8,level##_STACK_BASE@l(r8);		\
177 	addi	r8,r8,THREAD_SIZE - INT_FRAME_SIZE;
178 #else
179 #define BOOKE_LOAD_EXC_LEVEL_STACK(level)		\
180 	lis	r8,level##_STACK_BASE@ha;		\
181 	lwz	r8,level##_STACK_BASE@l(r8);		\
182 	addi	r8,r8,THREAD_SIZE - INT_FRAME_SIZE;
183 #endif
184 
185 /*
186  * Exception prolog for critical/machine check exceptions.  This is a
187  * little different from the normal exception prolog above since a
188  * critical/machine check exception can potentially occur at any point
189  * during normal exception processing. Thus we cannot use the same SPRG
190  * registers as the normal prolog above. Instead we use a portion of the
191  * critical/machine check exception stack at low physical addresses.
192  */
193 #define EXC_LEVEL_EXCEPTION_PROLOG(exc_level, trapno, intno, exc_level_srr0, exc_level_srr1) \
194 	mtspr	SPRN_SPRG_WSCRATCH_##exc_level,r8;			     \
195 	BOOKE_LOAD_EXC_LEVEL_STACK(exc_level);/* r8 points to the exc_level stack*/ \
196 	stw	r9,GPR9(r8);		/* save various registers	   */\
197 	mfcr	r9;			/* save CR in r9 for now	   */\
198 	stw	r10,GPR10(r8);						     \
199 	stw	r11,GPR11(r8);						     \
200 	stw	r9,_CCR(r8);		/* save CR on stack		   */\
201 	mfspr	r11,exc_level_srr1;	/* check whether user or kernel    */\
202 	DO_KVM	BOOKE_INTERRUPT_##intno exc_level_srr1;		             \
203 	BOOKE_CLEAR_BTB(r10)						\
204 	andi.	r11,r11,MSR_PR;						     \
205 	LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE));	\
206 	mtmsr	r11;							\
207 	mfspr	r11,SPRN_SPRG_THREAD;	/* if from user, start at top of   */\
208 	lwz	r11, TASK_STACK - THREAD(r11); /* this thread's kernel stack */\
209 	addi	r11,r11,THREAD_SIZE - INT_FRAME_SIZE;	/* allocate stack frame    */\
210 	beq	1f;							     \
211 	/* COMING FROM USER MODE */					     \
212 	stw	r9,_CCR(r11);		/* save CR			   */\
213 	lwz	r10,GPR10(r8);		/* copy regs from exception stack  */\
214 	lwz	r9,GPR9(r8);						     \
215 	stw	r10,GPR10(r11);						     \
216 	lwz	r10,GPR11(r8);						     \
217 	stw	r9,GPR9(r11);						     \
218 	stw	r10,GPR11(r11);						     \
219 	b	2f;							     \
220 	/* COMING FROM PRIV MODE */					     \
221 1:	mr	r11, r8;							     \
222 2:	mfspr	r8,SPRN_SPRG_RSCRATCH_##exc_level;			     \
223 	stw	r12,GPR12(r11);		/* save various registers	   */\
224 	mflr	r10;							     \
225 	stw	r10,_LINK(r11);						     \
226 	mfspr	r12,SPRN_DEAR;		/* save DEAR and ESR in the frame  */\
227 	stw	r12,_DEAR(r11);		/* since they may have had stuff   */\
228 	mfspr	r9,SPRN_ESR;		/* in them at the point where the  */\
229 	stw	r9,_ESR(r11);		/* exception was taken		   */\
230 	mfspr	r12,exc_level_srr0;					     \
231 	stw	r1,GPR1(r11);						     \
232 	mfspr	r9,exc_level_srr1;					     \
233 	stw	r1,0(r11);						     \
234 	mr	r1,r11;							     \
235 	rlwinm	r9,r9,0,14,12;		/* clear MSR_WE (necessary?)	   */\
236 	COMMON_EXCEPTION_PROLOG_END trapno
237 
238 #define SAVE_xSRR(xSRR)			\
239 	mfspr	r0,SPRN_##xSRR##0;	\
240 	stw	r0,_##xSRR##0(r1);	\
241 	mfspr	r0,SPRN_##xSRR##1;	\
242 	stw	r0,_##xSRR##1(r1)
243 
244 
245 .macro SAVE_MMU_REGS
246 #ifdef CONFIG_PPC_BOOK3E_MMU
247 	mfspr	r0,SPRN_MAS0
248 	stw	r0,MAS0(r1)
249 	mfspr	r0,SPRN_MAS1
250 	stw	r0,MAS1(r1)
251 	mfspr	r0,SPRN_MAS2
252 	stw	r0,MAS2(r1)
253 	mfspr	r0,SPRN_MAS3
254 	stw	r0,MAS3(r1)
255 	mfspr	r0,SPRN_MAS6
256 	stw	r0,MAS6(r1)
257 #ifdef CONFIG_PHYS_64BIT
258 	mfspr	r0,SPRN_MAS7
259 	stw	r0,MAS7(r1)
260 #endif /* CONFIG_PHYS_64BIT */
261 #endif /* CONFIG_PPC_BOOK3E_MMU */
262 #ifdef CONFIG_44x
263 	mfspr	r0,SPRN_MMUCR
264 	stw	r0,MMUCR(r1)
265 #endif
266 .endm
267 
268 #define CRITICAL_EXCEPTION_PROLOG(trapno, intno) \
269 		EXC_LEVEL_EXCEPTION_PROLOG(CRIT, trapno+2, intno, SPRN_CSRR0, SPRN_CSRR1)
270 #define DEBUG_EXCEPTION_PROLOG(trapno) \
271 		EXC_LEVEL_EXCEPTION_PROLOG(DBG, trapno+8, DEBUG, SPRN_DSRR0, SPRN_DSRR1)
272 #define MCHECK_EXCEPTION_PROLOG(trapno) \
273 		EXC_LEVEL_EXCEPTION_PROLOG(MC, trapno+4, MACHINE_CHECK, \
274 			SPRN_MCSRR0, SPRN_MCSRR1)
275 
276 /*
277  * Guest Doorbell -- this is a bit odd in that uses GSRR0/1 despite
278  * being delivered to the host.  This exception can only happen
279  * inside a KVM guest -- so we just handle up to the DO_KVM rather
280  * than try to fit this into one of the existing prolog macros.
281  */
282 #define GUEST_DOORBELL_EXCEPTION \
283 	START_EXCEPTION(GuestDoorbell);					     \
284 	mtspr	SPRN_SPRG_WSCRATCH0, r10;	/* save one register */	     \
285 	mfspr	r10, SPRN_SPRG_THREAD;					     \
286 	stw	r11, THREAD_NORMSAVE(0)(r10);				     \
287 	mfspr	r11, SPRN_SRR1;		                                     \
288 	stw	r13, THREAD_NORMSAVE(2)(r10);				     \
289 	mfcr	r13;			/* save CR in r13 for now	   */\
290 	DO_KVM	BOOKE_INTERRUPT_GUEST_DBELL SPRN_GSRR1;			     \
291 	trap
292 
293 /*
294  * Exception vectors.
295  */
296 #define	START_EXCEPTION(label)						     \
297         .align 5;              						     \
298 label:
299 
300 #define EXCEPTION(n, intno, label, hdlr)			\
301 	START_EXCEPTION(label);					\
302 	NORMAL_EXCEPTION_PROLOG(n, intno);			\
303 	prepare_transfer_to_handler;				\
304 	bl	hdlr;						\
305 	b	interrupt_return
306 
307 #define CRITICAL_EXCEPTION(n, intno, label, hdlr)			\
308 	START_EXCEPTION(label);						\
309 	CRITICAL_EXCEPTION_PROLOG(n, intno);				\
310 	SAVE_MMU_REGS;							\
311 	SAVE_xSRR(SRR);							\
312 	prepare_transfer_to_handler;					\
313 	bl	hdlr;							\
314 	b	ret_from_crit_exc
315 
316 #define MCHECK_EXCEPTION(n, label, hdlr)			\
317 	START_EXCEPTION(label);					\
318 	MCHECK_EXCEPTION_PROLOG(n);				\
319 	mfspr	r5,SPRN_ESR;					\
320 	stw	r5,_ESR(r11);					\
321 	SAVE_xSRR(DSRR);					\
322 	SAVE_xSRR(CSRR);					\
323 	SAVE_MMU_REGS;						\
324 	SAVE_xSRR(SRR);						\
325 	prepare_transfer_to_handler;				\
326 	bl	hdlr;						\
327 	b	ret_from_mcheck_exc
328 
329 /* Check for a single step debug exception while in an exception
330  * handler before state has been saved.  This is to catch the case
331  * where an instruction that we are trying to single step causes
332  * an exception (eg ITLB/DTLB miss) and thus the first instruction of
333  * the exception handler generates a single step debug exception.
334  *
335  * If we get a debug trap on the first instruction of an exception handler,
336  * we reset the MSR_DE in the _exception handler's_ MSR (the debug trap is
337  * a critical exception, so we are using SPRN_CSRR1 to manipulate the MSR).
338  * The exception handler was handling a non-critical interrupt, so it will
339  * save (and later restore) the MSR via SPRN_CSRR1, which will still have
340  * the MSR_DE bit set.
341  */
342 #define DEBUG_DEBUG_EXCEPTION						      \
343 	START_EXCEPTION(DebugDebug);					      \
344 	DEBUG_EXCEPTION_PROLOG(2000);						      \
345 									      \
346 	/*								      \
347 	 * If there is a single step or branch-taken exception in an	      \
348 	 * exception entry sequence, it was probably meant to apply to	      \
349 	 * the code where the exception occurred (since exception entry	      \
350 	 * doesn't turn off DE automatically).  We simulate the effect	      \
351 	 * of turning off DE on entry to an exception handler by turning      \
352 	 * off DE in the DSRR1 value and clearing the debug status.	      \
353 	 */								      \
354 	mfspr	r10,SPRN_DBSR;		/* check single-step/branch taken */  \
355 	andis.	r10,r10,(DBSR_IC|DBSR_BT)@h;				      \
356 	beq+	2f;							      \
357 									      \
358 	lis	r10,interrupt_base@h;	/* check if exception in vectors */   \
359 	ori	r10,r10,interrupt_base@l;				      \
360 	cmplw	r12,r10;						      \
361 	blt+	2f;			/* addr below exception vectors */    \
362 									      \
363 	lis	r10,interrupt_end@h;					      \
364 	ori	r10,r10,interrupt_end@l;				      \
365 	cmplw	r12,r10;						      \
366 	bgt+	2f;			/* addr above exception vectors */    \
367 									      \
368 	/* here it looks like we got an inappropriate debug exception. */     \
369 1:	rlwinm	r9,r9,0,~MSR_DE;	/* clear DE in the CDRR1 value */     \
370 	lis	r10,(DBSR_IC|DBSR_BT)@h;	/* clear the IC event */      \
371 	mtspr	SPRN_DBSR,r10;						      \
372 	/* restore state and get out */					      \
373 	lwz	r10,_CCR(r11);						      \
374 	lwz	r0,GPR0(r11);						      \
375 	lwz	r1,GPR1(r11);						      \
376 	mtcrf	0x80,r10;						      \
377 	mtspr	SPRN_DSRR0,r12;						      \
378 	mtspr	SPRN_DSRR1,r9;						      \
379 	lwz	r9,GPR9(r11);						      \
380 	lwz	r12,GPR12(r11);						      \
381 	mtspr	SPRN_SPRG_WSCRATCH_DBG,r8;				      \
382 	BOOKE_LOAD_EXC_LEVEL_STACK(DBG); /* r8 points to the debug stack */ \
383 	lwz	r10,GPR10(r8);						      \
384 	lwz	r11,GPR11(r8);						      \
385 	mfspr	r8,SPRN_SPRG_RSCRATCH_DBG;				      \
386 									      \
387 	PPC_RFDI;							      \
388 	b	.;							      \
389 									      \
390 	/* continue normal handling for a debug exception... */		      \
391 2:	mfspr	r4,SPRN_DBSR;						      \
392 	stw	r4,_ESR(r11);		/* DebugException takes DBSR in _ESR */\
393 	SAVE_xSRR(CSRR);						      \
394 	SAVE_MMU_REGS;							      \
395 	SAVE_xSRR(SRR);							      \
396 	prepare_transfer_to_handler;				      \
397 	bl	DebugException;						      \
398 	b	ret_from_debug_exc
399 
400 #define DEBUG_CRIT_EXCEPTION						      \
401 	START_EXCEPTION(DebugCrit);					      \
402 	CRITICAL_EXCEPTION_PROLOG(2000,DEBUG);				      \
403 									      \
404 	/*								      \
405 	 * If there is a single step or branch-taken exception in an	      \
406 	 * exception entry sequence, it was probably meant to apply to	      \
407 	 * the code where the exception occurred (since exception entry	      \
408 	 * doesn't turn off DE automatically).  We simulate the effect	      \
409 	 * of turning off DE on entry to an exception handler by turning      \
410 	 * off DE in the CSRR1 value and clearing the debug status.	      \
411 	 */								      \
412 	mfspr	r10,SPRN_DBSR;		/* check single-step/branch taken */  \
413 	andis.	r10,r10,(DBSR_IC|DBSR_BT)@h;				      \
414 	beq+	2f;							      \
415 									      \
416 	lis	r10,interrupt_base@h;	/* check if exception in vectors */   \
417 	ori	r10,r10,interrupt_base@l;				      \
418 	cmplw	r12,r10;						      \
419 	blt+	2f;			/* addr below exception vectors */    \
420 									      \
421 	lis	r10,interrupt_end@h;					      \
422 	ori	r10,r10,interrupt_end@l;				      \
423 	cmplw	r12,r10;						      \
424 	bgt+	2f;			/* addr above exception vectors */    \
425 									      \
426 	/* here it looks like we got an inappropriate debug exception. */     \
427 1:	rlwinm	r9,r9,0,~MSR_DE;	/* clear DE in the CSRR1 value */     \
428 	lis	r10,(DBSR_IC|DBSR_BT)@h;	/* clear the IC event */      \
429 	mtspr	SPRN_DBSR,r10;						      \
430 	/* restore state and get out */					      \
431 	lwz	r10,_CCR(r11);						      \
432 	lwz	r0,GPR0(r11);						      \
433 	lwz	r1,GPR1(r11);						      \
434 	mtcrf	0x80,r10;						      \
435 	mtspr	SPRN_CSRR0,r12;						      \
436 	mtspr	SPRN_CSRR1,r9;						      \
437 	lwz	r9,GPR9(r11);						      \
438 	lwz	r12,GPR12(r11);						      \
439 	mtspr	SPRN_SPRG_WSCRATCH_CRIT,r8;				      \
440 	BOOKE_LOAD_EXC_LEVEL_STACK(CRIT); /* r8 points to the debug stack */  \
441 	lwz	r10,GPR10(r8);						      \
442 	lwz	r11,GPR11(r8);						      \
443 	mfspr	r8,SPRN_SPRG_RSCRATCH_CRIT;				      \
444 									      \
445 	rfci;								      \
446 	b	.;							      \
447 									      \
448 	/* continue normal handling for a critical exception... */	      \
449 2:	mfspr	r4,SPRN_DBSR;						      \
450 	stw	r4,_ESR(r11);		/* DebugException takes DBSR in _ESR */\
451 	SAVE_MMU_REGS;							      \
452 	SAVE_xSRR(SRR);							      \
453 	prepare_transfer_to_handler;					      \
454 	bl	DebugException;						      \
455 	b	ret_from_crit_exc
456 
457 #define DATA_STORAGE_EXCEPTION						      \
458 	START_EXCEPTION(DataStorage)					      \
459 	NORMAL_EXCEPTION_PROLOG(0x300, DATA_STORAGE);		      \
460 	mfspr	r5,SPRN_ESR;		/* Grab the ESR and save it */	      \
461 	stw	r5,_ESR(r11);						      \
462 	mfspr	r4,SPRN_DEAR;		/* Grab the DEAR */		      \
463 	stw	r4, _DEAR(r11);						      \
464 	prepare_transfer_to_handler;					      \
465 	bl	do_page_fault;						      \
466 	b	interrupt_return
467 
468 /*
469  * Instruction TLB Error interrupt handlers may call InstructionStorage
470  * directly without clearing ESR, so the ESR at this point may be left over
471  * from a prior interrupt.
472  *
473  * In any case, do_page_fault for BOOK3E does not use ESR and always expects
474  * dsisr to be 0. ESR_DST from a prior store in particular would confuse fault
475  * handling.
476  */
477 #define INSTRUCTION_STORAGE_EXCEPTION					      \
478 	START_EXCEPTION(InstructionStorage)				      \
479 	NORMAL_EXCEPTION_PROLOG(0x400, INST_STORAGE);			      \
480 	li	r5,0;			/* Store 0 in regs->esr (dsisr) */    \
481 	stw	r5,_ESR(r11);						      \
482 	stw	r12, _DEAR(r11);	/* Set regs->dear (dar) to SRR0 */    \
483 	prepare_transfer_to_handler;					      \
484 	bl	do_page_fault;						      \
485 	b	interrupt_return
486 
487 #define ALIGNMENT_EXCEPTION						      \
488 	START_EXCEPTION(Alignment)					      \
489 	NORMAL_EXCEPTION_PROLOG(0x600, ALIGNMENT);		      \
490 	mfspr   r4,SPRN_DEAR;           /* Grab the DEAR and save it */	      \
491 	stw     r4,_DEAR(r11);						      \
492 	prepare_transfer_to_handler;					      \
493 	bl	alignment_exception;					      \
494 	REST_NVGPRS(r1);						      \
495 	b	interrupt_return
496 
497 #define PROGRAM_EXCEPTION						      \
498 	START_EXCEPTION(Program)					      \
499 	NORMAL_EXCEPTION_PROLOG(0x700, PROGRAM);		      \
500 	mfspr	r4,SPRN_ESR;		/* Grab the ESR and save it */	      \
501 	stw	r4,_ESR(r11);						      \
502 	prepare_transfer_to_handler;					      \
503 	bl	program_check_exception;				      \
504 	REST_NVGPRS(r1);						      \
505 	b	interrupt_return
506 
507 #define DECREMENTER_EXCEPTION						      \
508 	START_EXCEPTION(Decrementer)					      \
509 	NORMAL_EXCEPTION_PROLOG(0x900, DECREMENTER);		      \
510 	lis     r0,TSR_DIS@h;           /* Setup the DEC interrupt mask */    \
511 	mtspr   SPRN_TSR,r0;		/* Clear the DEC interrupt */	      \
512 	prepare_transfer_to_handler;					      \
513 	bl	timer_interrupt;					      \
514 	b	interrupt_return
515 
516 #define FP_UNAVAILABLE_EXCEPTION					      \
517 	START_EXCEPTION(FloatingPointUnavailable)			      \
518 	NORMAL_EXCEPTION_PROLOG(0x800, FP_UNAVAIL);		      \
519 	beq	1f;							      \
520 	bl	load_up_fpu;		/* if from user, just load it up */   \
521 	b	fast_exception_return;					      \
522 1:	prepare_transfer_to_handler;					      \
523 	bl	kernel_fp_unavailable_exception;			      \
524 	b	interrupt_return
525 
526 #endif /* __ASSEMBLY__ */
527 #endif /* __HEAD_BOOKE_H__ */
528