xref: /openbmc/linux/arch/powerpc/kernel/head_booke.h (revision 002dff36)
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(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 	mr	r11, r1;						     \
57 	beq	1f;							     \
58 	BOOKE_CLEAR_BTB(r11)						\
59 	/* if from user, start at top of this thread's kernel stack */       \
60 	lwz	r11, TASK_STACK - THREAD(r10);				     \
61 	ALLOC_STACK_FRAME(r11, THREAD_SIZE);				     \
62 1 :	subi	r11, r11, INT_FRAME_SIZE; /* Allocate exception frame */     \
63 	stw	r13, _CCR(r11);		/* save various registers */	     \
64 	stw	r12,GPR12(r11);						     \
65 	stw	r9,GPR9(r11);						     \
66 	mfspr	r13, SPRN_SPRG_RSCRATCH0;				     \
67 	stw	r13, GPR10(r11);					     \
68 	lwz	r12, THREAD_NORMSAVE(0)(r10);				     \
69 	stw	r12,GPR11(r11);						     \
70 	lwz	r13, THREAD_NORMSAVE(2)(r10); /* restore r13 */		     \
71 	mflr	r10;							     \
72 	stw	r10,_LINK(r11);						     \
73 	mfspr	r12,SPRN_SRR0;						     \
74 	stw	r1, GPR1(r11);						     \
75 	mfspr	r9,SPRN_SRR1;						     \
76 	stw	r1, 0(r11);						     \
77 	mr	r1, r11;						     \
78 	rlwinm	r9,r9,0,14,12;		/* clear MSR_WE (necessary?)	   */\
79 	stw	r0,GPR0(r11);						     \
80 	lis	r10, STACK_FRAME_REGS_MARKER@ha;/* exception frame marker */ \
81 	addi	r10, r10, STACK_FRAME_REGS_MARKER@l;			     \
82 	stw	r10, 8(r11);						     \
83 	SAVE_4GPRS(3, r11);						     \
84 	SAVE_2GPRS(7, r11)
85 
86 .macro SYSCALL_ENTRY trapno intno srr1
87 	mfspr	r10, SPRN_SPRG_THREAD
88 #ifdef CONFIG_KVM_BOOKE_HV
89 BEGIN_FTR_SECTION
90 	mtspr	SPRN_SPRG_WSCRATCH0, r10
91 	stw	r11, THREAD_NORMSAVE(0)(r10)
92 	stw	r13, THREAD_NORMSAVE(2)(r10)
93 	mfcr	r13			/* save CR in r13 for now	   */
94 	mfspr	r11, SPRN_SRR1
95 	mtocrf	0x80, r11	/* check MSR[GS] without clobbering reg */
96 	bf	3, 1975f
97 	b	kvmppc_handler_\intno\()_\srr1
98 1975:
99 	mr	r12, r13
100 	lwz	r13, THREAD_NORMSAVE(2)(r10)
101 FTR_SECTION_ELSE
102 #endif
103 	mfcr	r12
104 #ifdef CONFIG_KVM_BOOKE_HV
105 ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
106 #endif
107 	mfspr	r9, SPRN_SRR1
108 	BOOKE_CLEAR_BTB(r11)
109 	andi.	r11, r9, MSR_PR
110 	lwz	r11, TASK_STACK - THREAD(r10)
111 	rlwinm	r12,r12,0,4,2	/* Clear SO bit in CR */
112 	beq-	99f
113 	ALLOC_STACK_FRAME(r11, THREAD_SIZE - INT_FRAME_SIZE)
114 	stw	r12, _CCR(r11)		/* save various registers */
115 	mflr	r12
116 	stw	r12,_LINK(r11)
117 	mfspr	r12,SPRN_SRR0
118 	stw	r1, GPR1(r11)
119 	stw	r1, 0(r11)
120 	mr	r1, r11
121 	stw	r12,_NIP(r11)
122 	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?)	   */
123 	lis	r12, STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
124 	stw	r2,GPR2(r11)
125 	addi	r12, r12, STACK_FRAME_REGS_MARKER@l
126 	stw	r9,_MSR(r11)
127 	li	r2, \trapno + 1
128 	stw	r12, 8(r11)
129 	stw	r2,_TRAP(r11)
130 	SAVE_GPR(0, r11)
131 	SAVE_4GPRS(3, r11)
132 	SAVE_2GPRS(7, r11)
133 
134 	addi	r11,r1,STACK_FRAME_OVERHEAD
135 	addi	r2,r10,-THREAD
136 	stw	r11,PT_REGS(r10)
137 	/* Check to see if the dbcr0 register is set up to debug.  Use the
138 	   internal debug mode bit to do this. */
139 	lwz	r12,THREAD_DBCR0(r10)
140 	andis.	r12,r12,DBCR0_IDM@h
141 	ACCOUNT_CPU_USER_ENTRY(r2, r11, r12)
142 	beq+	3f
143 	/* From user and task is ptraced - load up global dbcr0 */
144 	li	r12,-1			/* clear all pending debug events */
145 	mtspr	SPRN_DBSR,r12
146 	lis	r11,global_dbcr0@ha
147 	tophys(r11,r11)
148 	addi	r11,r11,global_dbcr0@l
149 #ifdef CONFIG_SMP
150 	lwz	r10, TASK_CPU(r2)
151 	slwi	r10, r10, 3
152 	add	r11, r11, r10
153 #endif
154 	lwz	r12,0(r11)
155 	mtspr	SPRN_DBCR0,r12
156 	lwz	r12,4(r11)
157 	addi	r12,r12,-1
158 	stw	r12,4(r11)
159 
160 3:
161 	tovirt(r2, r2)			/* set r2 to current */
162 	lis	r11, transfer_to_syscall@h
163 	ori	r11, r11, transfer_to_syscall@l
164 #ifdef CONFIG_TRACE_IRQFLAGS
165 	/*
166 	 * If MSR is changing we need to keep interrupts disabled at this point
167 	 * otherwise we might risk taking an interrupt before we tell lockdep
168 	 * they are enabled.
169 	 */
170 	lis	r10, MSR_KERNEL@h
171 	ori	r10, r10, MSR_KERNEL@l
172 	rlwimi	r10, r9, 0, MSR_EE
173 #else
174 	lis	r10, (MSR_KERNEL | MSR_EE)@h
175 	ori	r10, r10, (MSR_KERNEL | MSR_EE)@l
176 #endif
177 	mtspr	SPRN_SRR1,r10
178 	mtspr	SPRN_SRR0,r11
179 	SYNC
180 	RFI				/* jump to handler, enable MMU */
181 99:	b	ret_from_kernel_syscall
182 .endm
183 
184 /* To handle the additional exception priority levels on 40x and Book-E
185  * processors we allocate a stack per additional priority level.
186  *
187  * On 40x critical is the only additional level
188  * On 44x/e500 we have critical and machine check
189  * On e200 we have critical and debug (machine check occurs via critical)
190  *
191  * Additionally we reserve a SPRG for each priority level so we can free up a
192  * GPR to use as the base for indirect access to the exception stacks.  This
193  * is necessary since the MMU is always on, for Book-E parts, and the stacks
194  * are offset from KERNELBASE.
195  *
196  * There is some space optimization to be had here if desired.  However
197  * to allow for a common kernel with support for debug exceptions either
198  * going to critical or their own debug level we aren't currently
199  * providing configurations that micro-optimize space usage.
200  */
201 
202 #define MC_STACK_BASE		mcheckirq_ctx
203 #define CRIT_STACK_BASE		critirq_ctx
204 
205 /* only on e500mc/e200 */
206 #define DBG_STACK_BASE		dbgirq_ctx
207 
208 #define EXC_LVL_FRAME_OVERHEAD	(THREAD_SIZE - INT_FRAME_SIZE - EXC_LVL_SIZE)
209 
210 #ifdef CONFIG_SMP
211 #define BOOKE_LOAD_EXC_LEVEL_STACK(level)		\
212 	mfspr	r8,SPRN_PIR;				\
213 	slwi	r8,r8,2;				\
214 	addis	r8,r8,level##_STACK_BASE@ha;		\
215 	lwz	r8,level##_STACK_BASE@l(r8);		\
216 	addi	r8,r8,EXC_LVL_FRAME_OVERHEAD;
217 #else
218 #define BOOKE_LOAD_EXC_LEVEL_STACK(level)		\
219 	lis	r8,level##_STACK_BASE@ha;		\
220 	lwz	r8,level##_STACK_BASE@l(r8);		\
221 	addi	r8,r8,EXC_LVL_FRAME_OVERHEAD;
222 #endif
223 
224 /*
225  * Exception prolog for critical/machine check exceptions.  This is a
226  * little different from the normal exception prolog above since a
227  * critical/machine check exception can potentially occur at any point
228  * during normal exception processing. Thus we cannot use the same SPRG
229  * registers as the normal prolog above. Instead we use a portion of the
230  * critical/machine check exception stack at low physical addresses.
231  */
232 #define EXC_LEVEL_EXCEPTION_PROLOG(exc_level, intno, exc_level_srr0, exc_level_srr1) \
233 	mtspr	SPRN_SPRG_WSCRATCH_##exc_level,r8;			     \
234 	BOOKE_LOAD_EXC_LEVEL_STACK(exc_level);/* r8 points to the exc_level stack*/ \
235 	stw	r9,GPR9(r8);		/* save various registers	   */\
236 	mfcr	r9;			/* save CR in r9 for now	   */\
237 	stw	r10,GPR10(r8);						     \
238 	stw	r11,GPR11(r8);						     \
239 	stw	r9,_CCR(r8);		/* save CR on stack		   */\
240 	mfspr	r11,exc_level_srr1;	/* check whether user or kernel    */\
241 	DO_KVM	BOOKE_INTERRUPT_##intno exc_level_srr1;		             \
242 	BOOKE_CLEAR_BTB(r10)						\
243 	andi.	r11,r11,MSR_PR;						     \
244 	mfspr	r11,SPRN_SPRG_THREAD;	/* if from user, start at top of   */\
245 	lwz	r11, TASK_STACK - THREAD(r11); /* this thread's kernel stack */\
246 	addi	r11,r11,EXC_LVL_FRAME_OVERHEAD;	/* allocate stack frame    */\
247 	beq	1f;							     \
248 	/* COMING FROM USER MODE */					     \
249 	stw	r9,_CCR(r11);		/* save CR			   */\
250 	lwz	r10,GPR10(r8);		/* copy regs from exception stack  */\
251 	lwz	r9,GPR9(r8);						     \
252 	stw	r10,GPR10(r11);						     \
253 	lwz	r10,GPR11(r8);						     \
254 	stw	r9,GPR9(r11);						     \
255 	stw	r10,GPR11(r11);						     \
256 	b	2f;							     \
257 	/* COMING FROM PRIV MODE */					     \
258 1:	mr	r11, r8;							     \
259 2:	mfspr	r8,SPRN_SPRG_RSCRATCH_##exc_level;			     \
260 	stw	r12,GPR12(r11);		/* save various registers	   */\
261 	mflr	r10;							     \
262 	stw	r10,_LINK(r11);						     \
263 	mfspr	r12,SPRN_DEAR;		/* save DEAR and ESR in the frame  */\
264 	stw	r12,_DEAR(r11);		/* since they may have had stuff   */\
265 	mfspr	r9,SPRN_ESR;		/* in them at the point where the  */\
266 	stw	r9,_ESR(r11);		/* exception was taken		   */\
267 	mfspr	r12,exc_level_srr0;					     \
268 	stw	r1,GPR1(r11);						     \
269 	mfspr	r9,exc_level_srr1;					     \
270 	stw	r1,0(r11);						     \
271 	mr	r1,r11;							     \
272 	rlwinm	r9,r9,0,14,12;		/* clear MSR_WE (necessary?)	   */\
273 	stw	r0,GPR0(r11);						     \
274 	SAVE_4GPRS(3, r11);						     \
275 	SAVE_2GPRS(7, r11)
276 
277 #define CRITICAL_EXCEPTION_PROLOG(intno) \
278 		EXC_LEVEL_EXCEPTION_PROLOG(CRIT, intno, SPRN_CSRR0, SPRN_CSRR1)
279 #define DEBUG_EXCEPTION_PROLOG \
280 		EXC_LEVEL_EXCEPTION_PROLOG(DBG, DEBUG, SPRN_DSRR0, SPRN_DSRR1)
281 #define MCHECK_EXCEPTION_PROLOG \
282 		EXC_LEVEL_EXCEPTION_PROLOG(MC, MACHINE_CHECK, \
283 			SPRN_MCSRR0, SPRN_MCSRR1)
284 
285 /*
286  * Guest Doorbell -- this is a bit odd in that uses GSRR0/1 despite
287  * being delivered to the host.  This exception can only happen
288  * inside a KVM guest -- so we just handle up to the DO_KVM rather
289  * than try to fit this into one of the existing prolog macros.
290  */
291 #define GUEST_DOORBELL_EXCEPTION \
292 	START_EXCEPTION(GuestDoorbell);					     \
293 	mtspr	SPRN_SPRG_WSCRATCH0, r10;	/* save one register */	     \
294 	mfspr	r10, SPRN_SPRG_THREAD;					     \
295 	stw	r11, THREAD_NORMSAVE(0)(r10);				     \
296 	mfspr	r11, SPRN_SRR1;		                                     \
297 	stw	r13, THREAD_NORMSAVE(2)(r10);				     \
298 	mfcr	r13;			/* save CR in r13 for now	   */\
299 	DO_KVM	BOOKE_INTERRUPT_GUEST_DBELL SPRN_GSRR1;			     \
300 	trap
301 
302 /*
303  * Exception vectors.
304  */
305 #define	START_EXCEPTION(label)						     \
306         .align 5;              						     \
307 label:
308 
309 #define EXCEPTION(n, intno, label, hdlr, xfer)			\
310 	START_EXCEPTION(label);					\
311 	NORMAL_EXCEPTION_PROLOG(intno);				\
312 	addi	r3,r1,STACK_FRAME_OVERHEAD;			\
313 	xfer(n, hdlr)
314 
315 #define CRITICAL_EXCEPTION(n, intno, label, hdlr)			\
316 	START_EXCEPTION(label);						\
317 	CRITICAL_EXCEPTION_PROLOG(intno);				\
318 	addi	r3,r1,STACK_FRAME_OVERHEAD;				\
319 	EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
320 			  crit_transfer_to_handler, ret_from_crit_exc)
321 
322 #define MCHECK_EXCEPTION(n, label, hdlr)			\
323 	START_EXCEPTION(label);					\
324 	MCHECK_EXCEPTION_PROLOG;				\
325 	mfspr	r5,SPRN_ESR;					\
326 	stw	r5,_ESR(r11);					\
327 	addi	r3,r1,STACK_FRAME_OVERHEAD;			\
328 	EXC_XFER_TEMPLATE(hdlr, n+4, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
329 			  mcheck_transfer_to_handler, ret_from_mcheck_exc)
330 
331 #define EXC_XFER_TEMPLATE(hdlr, trap, msr, tfer, ret)	\
332 	li	r10,trap;					\
333 	stw	r10,_TRAP(r11);					\
334 	lis	r10,msr@h;					\
335 	ori	r10,r10,msr@l;					\
336 	bl	tfer;		 				\
337 	.long	hdlr;						\
338 	.long	ret
339 
340 #define EXC_XFER_STD(n, hdlr)		\
341 	EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, transfer_to_handler_full, \
342 			  ret_from_except_full)
343 
344 #define EXC_XFER_LITE(n, hdlr)		\
345 	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, transfer_to_handler, \
346 			  ret_from_except)
347 
348 /* Check for a single step debug exception while in an exception
349  * handler before state has been saved.  This is to catch the case
350  * where an instruction that we are trying to single step causes
351  * an exception (eg ITLB/DTLB miss) and thus the first instruction of
352  * the exception handler generates a single step debug exception.
353  *
354  * If we get a debug trap on the first instruction of an exception handler,
355  * we reset the MSR_DE in the _exception handler's_ MSR (the debug trap is
356  * a critical exception, so we are using SPRN_CSRR1 to manipulate the MSR).
357  * The exception handler was handling a non-critical interrupt, so it will
358  * save (and later restore) the MSR via SPRN_CSRR1, which will still have
359  * the MSR_DE bit set.
360  */
361 #define DEBUG_DEBUG_EXCEPTION						      \
362 	START_EXCEPTION(DebugDebug);					      \
363 	DEBUG_EXCEPTION_PROLOG;						      \
364 									      \
365 	/*								      \
366 	 * If there is a single step or branch-taken exception in an	      \
367 	 * exception entry sequence, it was probably meant to apply to	      \
368 	 * the code where the exception occurred (since exception entry	      \
369 	 * doesn't turn off DE automatically).  We simulate the effect	      \
370 	 * of turning off DE on entry to an exception handler by turning      \
371 	 * off DE in the DSRR1 value and clearing the debug status.	      \
372 	 */								      \
373 	mfspr	r10,SPRN_DBSR;		/* check single-step/branch taken */  \
374 	andis.	r10,r10,(DBSR_IC|DBSR_BT)@h;				      \
375 	beq+	2f;							      \
376 									      \
377 	lis	r10,interrupt_base@h;	/* check if exception in vectors */   \
378 	ori	r10,r10,interrupt_base@l;				      \
379 	cmplw	r12,r10;						      \
380 	blt+	2f;			/* addr below exception vectors */    \
381 									      \
382 	lis	r10,interrupt_end@h;					      \
383 	ori	r10,r10,interrupt_end@l;				      \
384 	cmplw	r12,r10;						      \
385 	bgt+	2f;			/* addr above exception vectors */    \
386 									      \
387 	/* here it looks like we got an inappropriate debug exception. */     \
388 1:	rlwinm	r9,r9,0,~MSR_DE;	/* clear DE in the CDRR1 value */     \
389 	lis	r10,(DBSR_IC|DBSR_BT)@h;	/* clear the IC event */      \
390 	mtspr	SPRN_DBSR,r10;						      \
391 	/* restore state and get out */					      \
392 	lwz	r10,_CCR(r11);						      \
393 	lwz	r0,GPR0(r11);						      \
394 	lwz	r1,GPR1(r11);						      \
395 	mtcrf	0x80,r10;						      \
396 	mtspr	SPRN_DSRR0,r12;						      \
397 	mtspr	SPRN_DSRR1,r9;						      \
398 	lwz	r9,GPR9(r11);						      \
399 	lwz	r12,GPR12(r11);						      \
400 	mtspr	SPRN_SPRG_WSCRATCH_DBG,r8;				      \
401 	BOOKE_LOAD_EXC_LEVEL_STACK(DBG); /* r8 points to the debug stack */ \
402 	lwz	r10,GPR10(r8);						      \
403 	lwz	r11,GPR11(r8);						      \
404 	mfspr	r8,SPRN_SPRG_RSCRATCH_DBG;				      \
405 									      \
406 	PPC_RFDI;							      \
407 	b	.;							      \
408 									      \
409 	/* continue normal handling for a debug exception... */		      \
410 2:	mfspr	r4,SPRN_DBSR;						      \
411 	addi	r3,r1,STACK_FRAME_OVERHEAD;				      \
412 	EXC_XFER_TEMPLATE(DebugException, 0x2008, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), debug_transfer_to_handler, ret_from_debug_exc)
413 
414 #define DEBUG_CRIT_EXCEPTION						      \
415 	START_EXCEPTION(DebugCrit);					      \
416 	CRITICAL_EXCEPTION_PROLOG(DEBUG);				      \
417 									      \
418 	/*								      \
419 	 * If there is a single step or branch-taken exception in an	      \
420 	 * exception entry sequence, it was probably meant to apply to	      \
421 	 * the code where the exception occurred (since exception entry	      \
422 	 * doesn't turn off DE automatically).  We simulate the effect	      \
423 	 * of turning off DE on entry to an exception handler by turning      \
424 	 * off DE in the CSRR1 value and clearing the debug status.	      \
425 	 */								      \
426 	mfspr	r10,SPRN_DBSR;		/* check single-step/branch taken */  \
427 	andis.	r10,r10,(DBSR_IC|DBSR_BT)@h;				      \
428 	beq+	2f;							      \
429 									      \
430 	lis	r10,interrupt_base@h;	/* check if exception in vectors */   \
431 	ori	r10,r10,interrupt_base@l;				      \
432 	cmplw	r12,r10;						      \
433 	blt+	2f;			/* addr below exception vectors */    \
434 									      \
435 	lis	r10,interrupt_end@h;					      \
436 	ori	r10,r10,interrupt_end@l;				      \
437 	cmplw	r12,r10;						      \
438 	bgt+	2f;			/* addr above exception vectors */    \
439 									      \
440 	/* here it looks like we got an inappropriate debug exception. */     \
441 1:	rlwinm	r9,r9,0,~MSR_DE;	/* clear DE in the CSRR1 value */     \
442 	lis	r10,(DBSR_IC|DBSR_BT)@h;	/* clear the IC event */      \
443 	mtspr	SPRN_DBSR,r10;						      \
444 	/* restore state and get out */					      \
445 	lwz	r10,_CCR(r11);						      \
446 	lwz	r0,GPR0(r11);						      \
447 	lwz	r1,GPR1(r11);						      \
448 	mtcrf	0x80,r10;						      \
449 	mtspr	SPRN_CSRR0,r12;						      \
450 	mtspr	SPRN_CSRR1,r9;						      \
451 	lwz	r9,GPR9(r11);						      \
452 	lwz	r12,GPR12(r11);						      \
453 	mtspr	SPRN_SPRG_WSCRATCH_CRIT,r8;				      \
454 	BOOKE_LOAD_EXC_LEVEL_STACK(CRIT); /* r8 points to the debug stack */  \
455 	lwz	r10,GPR10(r8);						      \
456 	lwz	r11,GPR11(r8);						      \
457 	mfspr	r8,SPRN_SPRG_RSCRATCH_CRIT;				      \
458 									      \
459 	rfci;								      \
460 	b	.;							      \
461 									      \
462 	/* continue normal handling for a critical exception... */	      \
463 2:	mfspr	r4,SPRN_DBSR;						      \
464 	addi	r3,r1,STACK_FRAME_OVERHEAD;				      \
465 	EXC_XFER_TEMPLATE(DebugException, 0x2002, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), crit_transfer_to_handler, ret_from_crit_exc)
466 
467 #define DATA_STORAGE_EXCEPTION						      \
468 	START_EXCEPTION(DataStorage)					      \
469 	NORMAL_EXCEPTION_PROLOG(DATA_STORAGE);		      \
470 	mfspr	r5,SPRN_ESR;		/* Grab the ESR and save it */	      \
471 	stw	r5,_ESR(r11);						      \
472 	mfspr	r4,SPRN_DEAR;		/* Grab the DEAR */		      \
473 	stw	r4, _DEAR(r11);						      \
474 	EXC_XFER_LITE(0x0300, handle_page_fault)
475 
476 #define INSTRUCTION_STORAGE_EXCEPTION					      \
477 	START_EXCEPTION(InstructionStorage)				      \
478 	NORMAL_EXCEPTION_PROLOG(INST_STORAGE);		      \
479 	mfspr	r5,SPRN_ESR;		/* Grab the ESR and save it */	      \
480 	stw	r5,_ESR(r11);						      \
481 	mr      r4,r12;                 /* Pass SRR0 as arg2 */		      \
482 	stw	r4, _DEAR(r11);						      \
483 	li      r5,0;                   /* Pass zero as arg3 */		      \
484 	EXC_XFER_LITE(0x0400, handle_page_fault)
485 
486 #define ALIGNMENT_EXCEPTION						      \
487 	START_EXCEPTION(Alignment)					      \
488 	NORMAL_EXCEPTION_PROLOG(ALIGNMENT);		      \
489 	mfspr   r4,SPRN_DEAR;           /* Grab the DEAR and save it */	      \
490 	stw     r4,_DEAR(r11);						      \
491 	addi    r3,r1,STACK_FRAME_OVERHEAD;				      \
492 	EXC_XFER_STD(0x0600, alignment_exception)
493 
494 #define PROGRAM_EXCEPTION						      \
495 	START_EXCEPTION(Program)					      \
496 	NORMAL_EXCEPTION_PROLOG(PROGRAM);		      \
497 	mfspr	r4,SPRN_ESR;		/* Grab the ESR and save it */	      \
498 	stw	r4,_ESR(r11);						      \
499 	addi	r3,r1,STACK_FRAME_OVERHEAD;				      \
500 	EXC_XFER_STD(0x0700, program_check_exception)
501 
502 #define DECREMENTER_EXCEPTION						      \
503 	START_EXCEPTION(Decrementer)					      \
504 	NORMAL_EXCEPTION_PROLOG(DECREMENTER);		      \
505 	lis     r0,TSR_DIS@h;           /* Setup the DEC interrupt mask */    \
506 	mtspr   SPRN_TSR,r0;		/* Clear the DEC interrupt */	      \
507 	addi    r3,r1,STACK_FRAME_OVERHEAD;				      \
508 	EXC_XFER_LITE(0x0900, timer_interrupt)
509 
510 #define FP_UNAVAILABLE_EXCEPTION					      \
511 	START_EXCEPTION(FloatingPointUnavailable)			      \
512 	NORMAL_EXCEPTION_PROLOG(FP_UNAVAIL);		      \
513 	beq	1f;							      \
514 	bl	load_up_fpu;		/* if from user, just load it up */   \
515 	b	fast_exception_return;					      \
516 1:	addi	r3,r1,STACK_FRAME_OVERHEAD;				      \
517 	EXC_XFER_STD(0x800, kernel_fp_unavailable_exception)
518 
519 #else /* __ASSEMBLY__ */
520 struct exception_regs {
521 	unsigned long mas0;
522 	unsigned long mas1;
523 	unsigned long mas2;
524 	unsigned long mas3;
525 	unsigned long mas6;
526 	unsigned long mas7;
527 	unsigned long srr0;
528 	unsigned long srr1;
529 	unsigned long csrr0;
530 	unsigned long csrr1;
531 	unsigned long dsrr0;
532 	unsigned long dsrr1;
533 	unsigned long saved_ksp_limit;
534 };
535 
536 /* ensure this structure is always sized to a multiple of the stack alignment */
537 #define STACK_EXC_LVL_FRAME_SIZE	ALIGN(sizeof (struct exception_regs), 16)
538 
539 #endif /* __ASSEMBLY__ */
540 #endif /* __HEAD_BOOKE_H__ */
541