1#ifndef __HEAD_BOOKE_H__
2#define __HEAD_BOOKE_H__
3
4#include <asm/ptrace.h>	/* for STACK_FRAME_REGS_MARKER */
5#include <asm/kvm_asm.h>
6#include <asm/kvm_booke_hv_asm.h>
7
8/*
9 * Macros used for common Book-e exception handling
10 */
11
12#define SET_IVOR(vector_number, vector_label)		\
13		li	r26,vector_label@l; 		\
14		mtspr	SPRN_IVOR##vector_number,r26;	\
15		sync
16
17#if (THREAD_SHIFT < 15)
18#define ALLOC_STACK_FRAME(reg, val)			\
19	addi reg,reg,val
20#else
21#define ALLOC_STACK_FRAME(reg, val)			\
22	addis	reg,reg,val@ha;				\
23	addi	reg,reg,val@l
24#endif
25
26/*
27 * Macro used to get to thread save registers.
28 * Note that entries 0-3 are used for the prolog code, and the remaining
29 * entries are available for specific exception use in the event a handler
30 * requires more than 4 scratch registers.
31 */
32#define THREAD_NORMSAVE(offset)	(THREAD_NORMSAVES + (offset * 4))
33
34#define NORMAL_EXCEPTION_PROLOG(intno)						     \
35	mtspr	SPRN_SPRG_WSCRATCH0, r10;	/* save one register */	     \
36	mfspr	r10, SPRN_SPRG_THREAD;					     \
37	stw	r11, THREAD_NORMSAVE(0)(r10);				     \
38	stw	r13, THREAD_NORMSAVE(2)(r10);				     \
39	mfcr	r13;			/* save CR in r13 for now	   */\
40	mfspr	r11, SPRN_SRR1;		                                     \
41	DO_KVM	BOOKE_INTERRUPT_##intno SPRN_SRR1;			     \
42	andi.	r11, r11, MSR_PR;	/* check whether user or kernel    */\
43	mr	r11, r1;						     \
44	beq	1f;							     \
45	/* if from user, start at top of this thread's kernel stack */       \
46	lwz	r11, THREAD_INFO-THREAD(r10);				     \
47	ALLOC_STACK_FRAME(r11, THREAD_SIZE);				     \
481 :	subi	r11, r11, INT_FRAME_SIZE; /* Allocate exception frame */     \
49	stw	r13, _CCR(r11);		/* save various registers */	     \
50	stw	r12,GPR12(r11);						     \
51	stw	r9,GPR9(r11);						     \
52	mfspr	r13, SPRN_SPRG_RSCRATCH0;				     \
53	stw	r13, GPR10(r11);					     \
54	lwz	r12, THREAD_NORMSAVE(0)(r10);				     \
55	stw	r12,GPR11(r11);						     \
56	lwz	r13, THREAD_NORMSAVE(2)(r10); /* restore r13 */		     \
57	mflr	r10;							     \
58	stw	r10,_LINK(r11);						     \
59	mfspr	r12,SPRN_SRR0;						     \
60	stw	r1, GPR1(r11);						     \
61	mfspr	r9,SPRN_SRR1;						     \
62	stw	r1, 0(r11);						     \
63	mr	r1, r11;						     \
64	rlwinm	r9,r9,0,14,12;		/* clear MSR_WE (necessary?)	   */\
65	stw	r0,GPR0(r11);						     \
66	lis	r10, STACK_FRAME_REGS_MARKER@ha;/* exception frame marker */ \
67	addi	r10, r10, STACK_FRAME_REGS_MARKER@l;			     \
68	stw	r10, 8(r11);						     \
69	SAVE_4GPRS(3, r11);						     \
70	SAVE_2GPRS(7, r11)
71
72/* To handle the additional exception priority levels on 40x and Book-E
73 * processors we allocate a stack per additional priority level.
74 *
75 * On 40x critical is the only additional level
76 * On 44x/e500 we have critical and machine check
77 * On e200 we have critical and debug (machine check occurs via critical)
78 *
79 * Additionally we reserve a SPRG for each priority level so we can free up a
80 * GPR to use as the base for indirect access to the exception stacks.  This
81 * is necessary since the MMU is always on, for Book-E parts, and the stacks
82 * are offset from KERNELBASE.
83 *
84 * There is some space optimization to be had here if desired.  However
85 * to allow for a common kernel with support for debug exceptions either
86 * going to critical or their own debug level we aren't currently
87 * providing configurations that micro-optimize space usage.
88 */
89
90#define MC_STACK_BASE		mcheckirq_ctx
91#define CRIT_STACK_BASE		critirq_ctx
92
93/* only on e500mc/e200 */
94#define DBG_STACK_BASE		dbgirq_ctx
95
96#define EXC_LVL_FRAME_OVERHEAD	(THREAD_SIZE - INT_FRAME_SIZE - EXC_LVL_SIZE)
97
98#ifdef CONFIG_SMP
99#define BOOKE_LOAD_EXC_LEVEL_STACK(level)		\
100	mfspr	r8,SPRN_PIR;				\
101	slwi	r8,r8,2;				\
102	addis	r8,r8,level##_STACK_BASE@ha;		\
103	lwz	r8,level##_STACK_BASE@l(r8);		\
104	addi	r8,r8,EXC_LVL_FRAME_OVERHEAD;
105#else
106#define BOOKE_LOAD_EXC_LEVEL_STACK(level)		\
107	lis	r8,level##_STACK_BASE@ha;		\
108	lwz	r8,level##_STACK_BASE@l(r8);		\
109	addi	r8,r8,EXC_LVL_FRAME_OVERHEAD;
110#endif
111
112/*
113 * Exception prolog for critical/machine check exceptions.  This is a
114 * little different from the normal exception prolog above since a
115 * critical/machine check exception can potentially occur at any point
116 * during normal exception processing. Thus we cannot use the same SPRG
117 * registers as the normal prolog above. Instead we use a portion of the
118 * critical/machine check exception stack at low physical addresses.
119 */
120#define EXC_LEVEL_EXCEPTION_PROLOG(exc_level, intno, exc_level_srr0, exc_level_srr1) \
121	mtspr	SPRN_SPRG_WSCRATCH_##exc_level,r8;			     \
122	BOOKE_LOAD_EXC_LEVEL_STACK(exc_level);/* r8 points to the exc_level stack*/ \
123	stw	r9,GPR9(r8);		/* save various registers	   */\
124	mfcr	r9;			/* save CR in r9 for now	   */\
125	stw	r10,GPR10(r8);						     \
126	stw	r11,GPR11(r8);						     \
127	stw	r9,_CCR(r8);		/* save CR on stack		   */\
128	mfspr	r11,exc_level_srr1;	/* check whether user or kernel    */\
129	DO_KVM	BOOKE_INTERRUPT_##intno exc_level_srr1;		             \
130	andi.	r11,r11,MSR_PR;						     \
131	mfspr	r11,SPRN_SPRG_THREAD;	/* if from user, start at top of   */\
132	lwz	r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
133	addi	r11,r11,EXC_LVL_FRAME_OVERHEAD;	/* allocate stack frame    */\
134	beq	1f;							     \
135	/* COMING FROM USER MODE */					     \
136	stw	r9,_CCR(r11);		/* save CR			   */\
137	lwz	r10,GPR10(r8);		/* copy regs from exception stack  */\
138	lwz	r9,GPR9(r8);						     \
139	stw	r10,GPR10(r11);						     \
140	lwz	r10,GPR11(r8);						     \
141	stw	r9,GPR9(r11);						     \
142	stw	r10,GPR11(r11);						     \
143	b	2f;							     \
144	/* COMING FROM PRIV MODE */					     \
1451:	lwz	r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r11);		     \
146	lwz	r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r11);		     \
147	stw	r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r8);			     \
148	stw	r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r8);		     \
149	lwz	r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r11);			     \
150	stw	r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r8);			     \
151	mr	r11,r8;							     \
1522:	mfspr	r8,SPRN_SPRG_RSCRATCH_##exc_level;			     \
153	stw	r12,GPR12(r11);		/* save various registers	   */\
154	mflr	r10;							     \
155	stw	r10,_LINK(r11);						     \
156	mfspr	r12,SPRN_DEAR;		/* save DEAR and ESR in the frame  */\
157	stw	r12,_DEAR(r11);		/* since they may have had stuff   */\
158	mfspr	r9,SPRN_ESR;		/* in them at the point where the  */\
159	stw	r9,_ESR(r11);		/* exception was taken		   */\
160	mfspr	r12,exc_level_srr0;					     \
161	stw	r1,GPR1(r11);						     \
162	mfspr	r9,exc_level_srr1;					     \
163	stw	r1,0(r11);						     \
164	mr	r1,r11;							     \
165	rlwinm	r9,r9,0,14,12;		/* clear MSR_WE (necessary?)	   */\
166	stw	r0,GPR0(r11);						     \
167	SAVE_4GPRS(3, r11);						     \
168	SAVE_2GPRS(7, r11)
169
170#define CRITICAL_EXCEPTION_PROLOG(intno) \
171		EXC_LEVEL_EXCEPTION_PROLOG(CRIT, intno, SPRN_CSRR0, SPRN_CSRR1)
172#define DEBUG_EXCEPTION_PROLOG \
173		EXC_LEVEL_EXCEPTION_PROLOG(DBG, DEBUG, SPRN_DSRR0, SPRN_DSRR1)
174#define MCHECK_EXCEPTION_PROLOG \
175		EXC_LEVEL_EXCEPTION_PROLOG(MC, MACHINE_CHECK, \
176			SPRN_MCSRR0, SPRN_MCSRR1)
177
178/*
179 * Guest Doorbell -- this is a bit odd in that uses GSRR0/1 despite
180 * being delivered to the host.  This exception can only happen
181 * inside a KVM guest -- so we just handle up to the DO_KVM rather
182 * than try to fit this into one of the existing prolog macros.
183 */
184#define GUEST_DOORBELL_EXCEPTION \
185	START_EXCEPTION(GuestDoorbell);					     \
186	mtspr	SPRN_SPRG_WSCRATCH0, r10;	/* save one register */	     \
187	mfspr	r10, SPRN_SPRG_THREAD;					     \
188	stw	r11, THREAD_NORMSAVE(0)(r10);				     \
189	mfspr	r11, SPRN_SRR1;		                                     \
190	stw	r13, THREAD_NORMSAVE(2)(r10);				     \
191	mfcr	r13;			/* save CR in r13 for now	   */\
192	DO_KVM	BOOKE_INTERRUPT_GUEST_DBELL SPRN_GSRR1;			     \
193	trap
194
195/*
196 * Exception vectors.
197 */
198#define	START_EXCEPTION(label)						     \
199        .align 5;              						     \
200label:
201
202#define EXCEPTION(n, intno, label, hdlr, xfer)			\
203	START_EXCEPTION(label);					\
204	NORMAL_EXCEPTION_PROLOG(intno);				\
205	addi	r3,r1,STACK_FRAME_OVERHEAD;			\
206	xfer(n, hdlr)
207
208#define CRITICAL_EXCEPTION(n, intno, label, hdlr)			\
209	START_EXCEPTION(label);						\
210	CRITICAL_EXCEPTION_PROLOG(intno);				\
211	addi	r3,r1,STACK_FRAME_OVERHEAD;				\
212	EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
213			  NOCOPY, crit_transfer_to_handler, \
214			  ret_from_crit_exc)
215
216#define MCHECK_EXCEPTION(n, label, hdlr)			\
217	START_EXCEPTION(label);					\
218	MCHECK_EXCEPTION_PROLOG;				\
219	mfspr	r5,SPRN_ESR;					\
220	stw	r5,_ESR(r11);					\
221	addi	r3,r1,STACK_FRAME_OVERHEAD;			\
222	EXC_XFER_TEMPLATE(hdlr, n+4, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
223			  NOCOPY, mcheck_transfer_to_handler,   \
224			  ret_from_mcheck_exc)
225
226#define EXC_XFER_TEMPLATE(hdlr, trap, msr, copyee, tfer, ret)	\
227	li	r10,trap;					\
228	stw	r10,_TRAP(r11);					\
229	lis	r10,msr@h;					\
230	ori	r10,r10,msr@l;					\
231	copyee(r10, r9);					\
232	bl	tfer;		 				\
233	.long	hdlr;						\
234	.long	ret
235
236#define COPY_EE(d, s)		rlwimi d,s,0,16,16
237#define NOCOPY(d, s)
238
239#define EXC_XFER_STD(n, hdlr)		\
240	EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, NOCOPY, transfer_to_handler_full, \
241			  ret_from_except_full)
242
243#define EXC_XFER_LITE(n, hdlr)		\
244	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \
245			  ret_from_except)
246
247#define EXC_XFER_EE(n, hdlr)		\
248	EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, COPY_EE, transfer_to_handler_full, \
249			  ret_from_except_full)
250
251#define EXC_XFER_EE_LITE(n, hdlr)	\
252	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, COPY_EE, transfer_to_handler, \
253			  ret_from_except)
254
255/* Check for a single step debug exception while in an exception
256 * handler before state has been saved.  This is to catch the case
257 * where an instruction that we are trying to single step causes
258 * an exception (eg ITLB/DTLB miss) and thus the first instruction of
259 * the exception handler generates a single step debug exception.
260 *
261 * If we get a debug trap on the first instruction of an exception handler,
262 * we reset the MSR_DE in the _exception handler's_ MSR (the debug trap is
263 * a critical exception, so we are using SPRN_CSRR1 to manipulate the MSR).
264 * The exception handler was handling a non-critical interrupt, so it will
265 * save (and later restore) the MSR via SPRN_CSRR1, which will still have
266 * the MSR_DE bit set.
267 */
268#define DEBUG_DEBUG_EXCEPTION						      \
269	START_EXCEPTION(DebugDebug);					      \
270	DEBUG_EXCEPTION_PROLOG;						      \
271									      \
272	/*								      \
273	 * If there is a single step or branch-taken exception in an	      \
274	 * exception entry sequence, it was probably meant to apply to	      \
275	 * the code where the exception occurred (since exception entry	      \
276	 * doesn't turn off DE automatically).  We simulate the effect	      \
277	 * of turning off DE on entry to an exception handler by turning      \
278	 * off DE in the DSRR1 value and clearing the debug status.	      \
279	 */								      \
280	mfspr	r10,SPRN_DBSR;		/* check single-step/branch taken */  \
281	andis.	r10,r10,(DBSR_IC|DBSR_BT)@h;				      \
282	beq+	2f;							      \
283									      \
284	lis	r10,interrupt_base@h;	/* check if exception in vectors */   \
285	ori	r10,r10,interrupt_base@l;				      \
286	cmplw	r12,r10;						      \
287	blt+	2f;			/* addr below exception vectors */    \
288									      \
289	lis	r10,interrupt_end@h;					      \
290	ori	r10,r10,interrupt_end@l;				      \
291	cmplw	r12,r10;						      \
292	bgt+	2f;			/* addr above exception vectors */    \
293									      \
294	/* here it looks like we got an inappropriate debug exception. */     \
2951:	rlwinm	r9,r9,0,~MSR_DE;	/* clear DE in the CDRR1 value */     \
296	lis	r10,(DBSR_IC|DBSR_BT)@h;	/* clear the IC event */      \
297	mtspr	SPRN_DBSR,r10;						      \
298	/* restore state and get out */					      \
299	lwz	r10,_CCR(r11);						      \
300	lwz	r0,GPR0(r11);						      \
301	lwz	r1,GPR1(r11);						      \
302	mtcrf	0x80,r10;						      \
303	mtspr	SPRN_DSRR0,r12;						      \
304	mtspr	SPRN_DSRR1,r9;						      \
305	lwz	r9,GPR9(r11);						      \
306	lwz	r12,GPR12(r11);						      \
307	mtspr	SPRN_SPRG_WSCRATCH_DBG,r8;				      \
308	BOOKE_LOAD_EXC_LEVEL_STACK(DBG); /* r8 points to the debug stack */ \
309	lwz	r10,GPR10(r8);						      \
310	lwz	r11,GPR11(r8);						      \
311	mfspr	r8,SPRN_SPRG_RSCRATCH_DBG;				      \
312									      \
313	PPC_RFDI;							      \
314	b	.;							      \
315									      \
316	/* continue normal handling for a debug exception... */		      \
3172:	mfspr	r4,SPRN_DBSR;						      \
318	addi	r3,r1,STACK_FRAME_OVERHEAD;				      \
319	EXC_XFER_TEMPLATE(DebugException, 0x2008, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), NOCOPY, debug_transfer_to_handler, ret_from_debug_exc)
320
321#define DEBUG_CRIT_EXCEPTION						      \
322	START_EXCEPTION(DebugCrit);					      \
323	CRITICAL_EXCEPTION_PROLOG(DEBUG);				      \
324									      \
325	/*								      \
326	 * If there is a single step or branch-taken exception in an	      \
327	 * exception entry sequence, it was probably meant to apply to	      \
328	 * the code where the exception occurred (since exception entry	      \
329	 * doesn't turn off DE automatically).  We simulate the effect	      \
330	 * of turning off DE on entry to an exception handler by turning      \
331	 * off DE in the CSRR1 value and clearing the debug status.	      \
332	 */								      \
333	mfspr	r10,SPRN_DBSR;		/* check single-step/branch taken */  \
334	andis.	r10,r10,(DBSR_IC|DBSR_BT)@h;				      \
335	beq+	2f;							      \
336									      \
337	lis	r10,interrupt_base@h;	/* check if exception in vectors */   \
338	ori	r10,r10,interrupt_base@l;				      \
339	cmplw	r12,r10;						      \
340	blt+	2f;			/* addr below exception vectors */    \
341									      \
342	lis	r10,interrupt_end@h;					      \
343	ori	r10,r10,interrupt_end@l;				      \
344	cmplw	r12,r10;						      \
345	bgt+	2f;			/* addr above exception vectors */    \
346									      \
347	/* here it looks like we got an inappropriate debug exception. */     \
3481:	rlwinm	r9,r9,0,~MSR_DE;	/* clear DE in the CSRR1 value */     \
349	lis	r10,(DBSR_IC|DBSR_BT)@h;	/* clear the IC event */      \
350	mtspr	SPRN_DBSR,r10;						      \
351	/* restore state and get out */					      \
352	lwz	r10,_CCR(r11);						      \
353	lwz	r0,GPR0(r11);						      \
354	lwz	r1,GPR1(r11);						      \
355	mtcrf	0x80,r10;						      \
356	mtspr	SPRN_CSRR0,r12;						      \
357	mtspr	SPRN_CSRR1,r9;						      \
358	lwz	r9,GPR9(r11);						      \
359	lwz	r12,GPR12(r11);						      \
360	mtspr	SPRN_SPRG_WSCRATCH_CRIT,r8;				      \
361	BOOKE_LOAD_EXC_LEVEL_STACK(CRIT); /* r8 points to the debug stack */  \
362	lwz	r10,GPR10(r8);						      \
363	lwz	r11,GPR11(r8);						      \
364	mfspr	r8,SPRN_SPRG_RSCRATCH_CRIT;				      \
365									      \
366	rfci;								      \
367	b	.;							      \
368									      \
369	/* continue normal handling for a critical exception... */	      \
3702:	mfspr	r4,SPRN_DBSR;						      \
371	addi	r3,r1,STACK_FRAME_OVERHEAD;				      \
372	EXC_XFER_TEMPLATE(DebugException, 0x2002, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), NOCOPY, crit_transfer_to_handler, ret_from_crit_exc)
373
374#define DATA_STORAGE_EXCEPTION						      \
375	START_EXCEPTION(DataStorage)					      \
376	NORMAL_EXCEPTION_PROLOG(DATA_STORAGE);		      \
377	mfspr	r5,SPRN_ESR;		/* Grab the ESR and save it */	      \
378	stw	r5,_ESR(r11);						      \
379	mfspr	r4,SPRN_DEAR;		/* Grab the DEAR */		      \
380	EXC_XFER_LITE(0x0300, handle_page_fault)
381
382#define INSTRUCTION_STORAGE_EXCEPTION					      \
383	START_EXCEPTION(InstructionStorage)				      \
384	NORMAL_EXCEPTION_PROLOG(INST_STORAGE);		      \
385	mfspr	r5,SPRN_ESR;		/* Grab the ESR and save it */	      \
386	stw	r5,_ESR(r11);						      \
387	mr      r4,r12;                 /* Pass SRR0 as arg2 */		      \
388	li      r5,0;                   /* Pass zero as arg3 */		      \
389	EXC_XFER_LITE(0x0400, handle_page_fault)
390
391#define ALIGNMENT_EXCEPTION						      \
392	START_EXCEPTION(Alignment)					      \
393	NORMAL_EXCEPTION_PROLOG(ALIGNMENT);		      \
394	mfspr   r4,SPRN_DEAR;           /* Grab the DEAR and save it */	      \
395	stw     r4,_DEAR(r11);						      \
396	addi    r3,r1,STACK_FRAME_OVERHEAD;				      \
397	EXC_XFER_EE(0x0600, alignment_exception)
398
399#define PROGRAM_EXCEPTION						      \
400	START_EXCEPTION(Program)					      \
401	NORMAL_EXCEPTION_PROLOG(PROGRAM);		      \
402	mfspr	r4,SPRN_ESR;		/* Grab the ESR and save it */	      \
403	stw	r4,_ESR(r11);						      \
404	addi	r3,r1,STACK_FRAME_OVERHEAD;				      \
405	EXC_XFER_STD(0x0700, program_check_exception)
406
407#define DECREMENTER_EXCEPTION						      \
408	START_EXCEPTION(Decrementer)					      \
409	NORMAL_EXCEPTION_PROLOG(DECREMENTER);		      \
410	lis     r0,TSR_DIS@h;           /* Setup the DEC interrupt mask */    \
411	mtspr   SPRN_TSR,r0;		/* Clear the DEC interrupt */	      \
412	addi    r3,r1,STACK_FRAME_OVERHEAD;				      \
413	EXC_XFER_LITE(0x0900, timer_interrupt)
414
415#define FP_UNAVAILABLE_EXCEPTION					      \
416	START_EXCEPTION(FloatingPointUnavailable)			      \
417	NORMAL_EXCEPTION_PROLOG(FP_UNAVAIL);		      \
418	beq	1f;							      \
419	bl	load_up_fpu;		/* if from user, just load it up */   \
420	b	fast_exception_return;					      \
4211:	addi	r3,r1,STACK_FRAME_OVERHEAD;				      \
422	EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
423
424#ifndef __ASSEMBLY__
425struct exception_regs {
426	unsigned long mas0;
427	unsigned long mas1;
428	unsigned long mas2;
429	unsigned long mas3;
430	unsigned long mas6;
431	unsigned long mas7;
432	unsigned long srr0;
433	unsigned long srr1;
434	unsigned long csrr0;
435	unsigned long csrr1;
436	unsigned long dsrr0;
437	unsigned long dsrr1;
438	unsigned long saved_ksp_limit;
439};
440
441/* ensure this structure is always sized to a multiple of the stack alignment */
442#define STACK_EXC_LVL_FRAME_SIZE	_ALIGN_UP(sizeof (struct exception_regs), 16)
443
444#endif /* __ASSEMBLY__ */
445#endif /* __HEAD_BOOKE_H__ */
446