1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __HEAD_BOOKE_H__
3 #define __HEAD_BOOKE_H__
5 #include <asm/ptrace.h> /* for STACK_FRAME_REGS_MARKER */
6 #include <asm/kvm_asm.h>
7 #include <asm/kvm_booke_hv_asm.h>
10 * Macros used for common Book-e exception handling
13 #define SET_IVOR(vector_number, vector_label) \
14 li r26,vector_label@l; \
15 mtspr SPRN_IVOR##vector_number,r26; \
18 #if (THREAD_SHIFT < 15)
19 #define ALLOC_STACK_FRAME(reg, val) \
22 #define ALLOC_STACK_FRAME(reg, val) \
23 addis reg,reg,val@ha; \
28 * Macro used to get to thread save registers.
29 * Note that entries 0-3 are used for the prolog code, and the remaining
30 * entries are available for specific exception use in the event a handler
31 * requires more than 4 scratch registers.
33 #define THREAD_NORMSAVE(offset) (THREAD_NORMSAVES + (offset * 4))
35 #define NORMAL_EXCEPTION_PROLOG(intno) \
36 mtspr SPRN_SPRG_WSCRATCH0, r10; /* save one register */ \
37 mfspr r10, SPRN_SPRG_THREAD; \
38 stw r11, THREAD_NORMSAVE(0)(r10); \
39 stw r13, THREAD_NORMSAVE(2)(r10); \
40 mfcr r13; /* save CR in r13 for now */\
41 mfspr r11, SPRN_SRR1; \
42 DO_KVM BOOKE_INTERRUPT_##intno SPRN_SRR1; \
43 andi. r11, r11, MSR_PR; /* check whether user or kernel */\
46 /* if from user, start at top of this thread's kernel stack */ \
47 lwz r11, THREAD_INFO-THREAD(r10); \
48 ALLOC_STACK_FRAME(r11, THREAD_SIZE); \
49 1 : subi r11, r11, INT_FRAME_SIZE; /* Allocate exception frame */ \
50 stw r13, _CCR(r11); /* save various registers */ \
53 mfspr r13, SPRN_SPRG_RSCRATCH0; \
54 stw r13, GPR10(r11); \
55 lwz r12, THREAD_NORMSAVE(0)(r10); \
57 lwz r13, THREAD_NORMSAVE(2)(r10); /* restore r13 */ \
60 mfspr r12,SPRN_SRR0; \
65 rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\
67 lis r10, STACK_FRAME_REGS_MARKER@ha;/* exception frame marker */ \
68 addi r10, r10, STACK_FRAME_REGS_MARKER@l; \
73 /* To handle the additional exception priority levels on 40x and Book-E
74 * processors we allocate a stack per additional priority level.
76 * On 40x critical is the only additional level
77 * On 44x/e500 we have critical and machine check
78 * On e200 we have critical and debug (machine check occurs via critical)
80 * Additionally we reserve a SPRG for each priority level so we can free up a
81 * GPR to use as the base for indirect access to the exception stacks. This
82 * is necessary since the MMU is always on, for Book-E parts, and the stacks
83 * are offset from KERNELBASE.
85 * There is some space optimization to be had here if desired. However
86 * to allow for a common kernel with support for debug exceptions either
87 * going to critical or their own debug level we aren't currently
88 * providing configurations that micro-optimize space usage.
91 #define MC_STACK_BASE mcheckirq_ctx
92 #define CRIT_STACK_BASE critirq_ctx
94 /* only on e500mc/e200 */
95 #define DBG_STACK_BASE dbgirq_ctx
97 #define EXC_LVL_FRAME_OVERHEAD (THREAD_SIZE - INT_FRAME_SIZE - EXC_LVL_SIZE)
100 #define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
103 addis r8,r8,level##_STACK_BASE@ha; \
104 lwz r8,level##_STACK_BASE@l(r8); \
105 addi r8,r8,EXC_LVL_FRAME_OVERHEAD;
107 #define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
108 lis r8,level##_STACK_BASE@ha; \
109 lwz r8,level##_STACK_BASE@l(r8); \
110 addi r8,r8,EXC_LVL_FRAME_OVERHEAD;
114 * Exception prolog for critical/machine check exceptions. This is a
115 * little different from the normal exception prolog above since a
116 * critical/machine check exception can potentially occur at any point
117 * during normal exception processing. Thus we cannot use the same SPRG
118 * registers as the normal prolog above. Instead we use a portion of the
119 * critical/machine check exception stack at low physical addresses.
121 #define EXC_LEVEL_EXCEPTION_PROLOG(exc_level, intno, exc_level_srr0, exc_level_srr1) \
122 mtspr SPRN_SPRG_WSCRATCH_##exc_level,r8; \
123 BOOKE_LOAD_EXC_LEVEL_STACK(exc_level);/* r8 points to the exc_level stack*/ \
124 stw r9,GPR9(r8); /* save various registers */\
125 mfcr r9; /* save CR in r9 for now */\
128 stw r9,_CCR(r8); /* save CR on stack */\
129 mfspr r11,exc_level_srr1; /* check whether user or kernel */\
130 DO_KVM BOOKE_INTERRUPT_##intno exc_level_srr1; \
131 andi. r11,r11,MSR_PR; \
132 mfspr r11,SPRN_SPRG_THREAD; /* if from user, start at top of */\
133 lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
134 addi r11,r11,EXC_LVL_FRAME_OVERHEAD; /* allocate stack frame */\
136 /* COMING FROM USER MODE */ \
137 stw r9,_CCR(r11); /* save CR */\
138 lwz r10,GPR10(r8); /* copy regs from exception stack */\
140 stw r10,GPR10(r11); \
143 stw r10,GPR11(r11); \
145 /* COMING FROM PRIV MODE */ \
146 1: lwz r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r11); \
147 lwz r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r11); \
148 stw r9,TI_FLAGS-EXC_LVL_FRAME_OVERHEAD(r8); \
149 stw r10,TI_PREEMPT-EXC_LVL_FRAME_OVERHEAD(r8); \
150 lwz r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r11); \
151 stw r9,TI_TASK-EXC_LVL_FRAME_OVERHEAD(r8); \
153 2: mfspr r8,SPRN_SPRG_RSCRATCH_##exc_level; \
154 stw r12,GPR12(r11); /* save various registers */\
156 stw r10,_LINK(r11); \
157 mfspr r12,SPRN_DEAR; /* save DEAR and ESR in the frame */\
158 stw r12,_DEAR(r11); /* since they may have had stuff */\
159 mfspr r9,SPRN_ESR; /* in them at the point where the */\
160 stw r9,_ESR(r11); /* exception was taken */\
161 mfspr r12,exc_level_srr0; \
163 mfspr r9,exc_level_srr1; \
166 rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\
168 SAVE_4GPRS(3, r11); \
171 #define CRITICAL_EXCEPTION_PROLOG(intno) \
172 EXC_LEVEL_EXCEPTION_PROLOG(CRIT, intno, SPRN_CSRR0, SPRN_CSRR1)
173 #define DEBUG_EXCEPTION_PROLOG \
174 EXC_LEVEL_EXCEPTION_PROLOG(DBG, DEBUG, SPRN_DSRR0, SPRN_DSRR1)
175 #define MCHECK_EXCEPTION_PROLOG \
176 EXC_LEVEL_EXCEPTION_PROLOG(MC, MACHINE_CHECK, \
177 SPRN_MCSRR0, SPRN_MCSRR1)
180 * Guest Doorbell -- this is a bit odd in that uses GSRR0/1 despite
181 * being delivered to the host. This exception can only happen
182 * inside a KVM guest -- so we just handle up to the DO_KVM rather
183 * than try to fit this into one of the existing prolog macros.
185 #define GUEST_DOORBELL_EXCEPTION \
186 START_EXCEPTION(GuestDoorbell); \
187 mtspr SPRN_SPRG_WSCRATCH0, r10; /* save one register */ \
188 mfspr r10, SPRN_SPRG_THREAD; \
189 stw r11, THREAD_NORMSAVE(0)(r10); \
190 mfspr r11, SPRN_SRR1; \
191 stw r13, THREAD_NORMSAVE(2)(r10); \
192 mfcr r13; /* save CR in r13 for now */\
193 DO_KVM BOOKE_INTERRUPT_GUEST_DBELL SPRN_GSRR1; \
199 #define START_EXCEPTION(label) \
203 #define EXCEPTION(n, intno, label, hdlr, xfer) \
204 START_EXCEPTION(label); \
205 NORMAL_EXCEPTION_PROLOG(intno); \
206 addi r3,r1,STACK_FRAME_OVERHEAD; \
209 #define CRITICAL_EXCEPTION(n, intno, label, hdlr) \
210 START_EXCEPTION(label); \
211 CRITICAL_EXCEPTION_PROLOG(intno); \
212 addi r3,r1,STACK_FRAME_OVERHEAD; \
213 EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
214 NOCOPY, crit_transfer_to_handler, \
217 #define MCHECK_EXCEPTION(n, label, hdlr) \
218 START_EXCEPTION(label); \
219 MCHECK_EXCEPTION_PROLOG; \
222 addi r3,r1,STACK_FRAME_OVERHEAD; \
223 EXC_XFER_TEMPLATE(hdlr, n+4, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
224 NOCOPY, mcheck_transfer_to_handler, \
227 #define EXC_XFER_TEMPLATE(hdlr, trap, msr, copyee, tfer, ret) \
229 stw r10,_TRAP(r11); \
237 #define COPY_EE(d, s) rlwimi d,s,0,16,16
240 #define EXC_XFER_STD(n, hdlr) \
241 EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, NOCOPY, transfer_to_handler_full, \
242 ret_from_except_full)
244 #define EXC_XFER_LITE(n, hdlr) \
245 EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \
248 #define EXC_XFER_EE(n, hdlr) \
249 EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, COPY_EE, transfer_to_handler_full, \
250 ret_from_except_full)
252 #define EXC_XFER_EE_LITE(n, hdlr) \
253 EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, COPY_EE, transfer_to_handler, \
256 /* Check for a single step debug exception while in an exception
257 * handler before state has been saved. This is to catch the case
258 * where an instruction that we are trying to single step causes
259 * an exception (eg ITLB/DTLB miss) and thus the first instruction of
260 * the exception handler generates a single step debug exception.
262 * If we get a debug trap on the first instruction of an exception handler,
263 * we reset the MSR_DE in the _exception handler's_ MSR (the debug trap is
264 * a critical exception, so we are using SPRN_CSRR1 to manipulate the MSR).
265 * The exception handler was handling a non-critical interrupt, so it will
266 * save (and later restore) the MSR via SPRN_CSRR1, which will still have
267 * the MSR_DE bit set.
269 #define DEBUG_DEBUG_EXCEPTION \
270 START_EXCEPTION(DebugDebug); \
271 DEBUG_EXCEPTION_PROLOG; \
274 * If there is a single step or branch-taken exception in an \
275 * exception entry sequence, it was probably meant to apply to \
276 * the code where the exception occurred (since exception entry \
277 * doesn't turn off DE automatically). We simulate the effect \
278 * of turning off DE on entry to an exception handler by turning \
279 * off DE in the DSRR1 value and clearing the debug status. \
281 mfspr r10,SPRN_DBSR; /* check single-step/branch taken */ \
282 andis. r10,r10,(DBSR_IC|DBSR_BT)@h; \
285 lis r10,interrupt_base@h; /* check if exception in vectors */ \
286 ori r10,r10,interrupt_base@l; \
288 blt+ 2f; /* addr below exception vectors */ \
290 lis r10,interrupt_end@h; \
291 ori r10,r10,interrupt_end@l; \
293 bgt+ 2f; /* addr above exception vectors */ \
295 /* here it looks like we got an inappropriate debug exception. */ \
296 1: rlwinm r9,r9,0,~MSR_DE; /* clear DE in the CDRR1 value */ \
297 lis r10,(DBSR_IC|DBSR_BT)@h; /* clear the IC event */ \
298 mtspr SPRN_DBSR,r10; \
299 /* restore state and get out */ \
304 mtspr SPRN_DSRR0,r12; \
305 mtspr SPRN_DSRR1,r9; \
307 lwz r12,GPR12(r11); \
308 mtspr SPRN_SPRG_WSCRATCH_DBG,r8; \
309 BOOKE_LOAD_EXC_LEVEL_STACK(DBG); /* r8 points to the debug stack */ \
312 mfspr r8,SPRN_SPRG_RSCRATCH_DBG; \
317 /* continue normal handling for a debug exception... */ \
318 2: mfspr r4,SPRN_DBSR; \
319 addi r3,r1,STACK_FRAME_OVERHEAD; \
320 EXC_XFER_TEMPLATE(DebugException, 0x2008, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), NOCOPY, debug_transfer_to_handler, ret_from_debug_exc)
322 #define DEBUG_CRIT_EXCEPTION \
323 START_EXCEPTION(DebugCrit); \
324 CRITICAL_EXCEPTION_PROLOG(DEBUG); \
327 * If there is a single step or branch-taken exception in an \
328 * exception entry sequence, it was probably meant to apply to \
329 * the code where the exception occurred (since exception entry \
330 * doesn't turn off DE automatically). We simulate the effect \
331 * of turning off DE on entry to an exception handler by turning \
332 * off DE in the CSRR1 value and clearing the debug status. \
334 mfspr r10,SPRN_DBSR; /* check single-step/branch taken */ \
335 andis. r10,r10,(DBSR_IC|DBSR_BT)@h; \
338 lis r10,interrupt_base@h; /* check if exception in vectors */ \
339 ori r10,r10,interrupt_base@l; \
341 blt+ 2f; /* addr below exception vectors */ \
343 lis r10,interrupt_end@h; \
344 ori r10,r10,interrupt_end@l; \
346 bgt+ 2f; /* addr above exception vectors */ \
348 /* here it looks like we got an inappropriate debug exception. */ \
349 1: rlwinm r9,r9,0,~MSR_DE; /* clear DE in the CSRR1 value */ \
350 lis r10,(DBSR_IC|DBSR_BT)@h; /* clear the IC event */ \
351 mtspr SPRN_DBSR,r10; \
352 /* restore state and get out */ \
357 mtspr SPRN_CSRR0,r12; \
358 mtspr SPRN_CSRR1,r9; \
360 lwz r12,GPR12(r11); \
361 mtspr SPRN_SPRG_WSCRATCH_CRIT,r8; \
362 BOOKE_LOAD_EXC_LEVEL_STACK(CRIT); /* r8 points to the debug stack */ \
365 mfspr r8,SPRN_SPRG_RSCRATCH_CRIT; \
370 /* continue normal handling for a critical exception... */ \
371 2: mfspr r4,SPRN_DBSR; \
372 addi r3,r1,STACK_FRAME_OVERHEAD; \
373 EXC_XFER_TEMPLATE(DebugException, 0x2002, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), NOCOPY, crit_transfer_to_handler, ret_from_crit_exc)
375 #define DATA_STORAGE_EXCEPTION \
376 START_EXCEPTION(DataStorage) \
377 NORMAL_EXCEPTION_PROLOG(DATA_STORAGE); \
378 mfspr r5,SPRN_ESR; /* Grab the ESR and save it */ \
380 mfspr r4,SPRN_DEAR; /* Grab the DEAR */ \
381 EXC_XFER_LITE(0x0300, handle_page_fault)
383 #define INSTRUCTION_STORAGE_EXCEPTION \
384 START_EXCEPTION(InstructionStorage) \
385 NORMAL_EXCEPTION_PROLOG(INST_STORAGE); \
386 mfspr r5,SPRN_ESR; /* Grab the ESR and save it */ \
388 mr r4,r12; /* Pass SRR0 as arg2 */ \
389 li r5,0; /* Pass zero as arg3 */ \
390 EXC_XFER_LITE(0x0400, handle_page_fault)
392 #define ALIGNMENT_EXCEPTION \
393 START_EXCEPTION(Alignment) \
394 NORMAL_EXCEPTION_PROLOG(ALIGNMENT); \
395 mfspr r4,SPRN_DEAR; /* Grab the DEAR and save it */ \
397 addi r3,r1,STACK_FRAME_OVERHEAD; \
398 EXC_XFER_EE(0x0600, alignment_exception)
400 #define PROGRAM_EXCEPTION \
401 START_EXCEPTION(Program) \
402 NORMAL_EXCEPTION_PROLOG(PROGRAM); \
403 mfspr r4,SPRN_ESR; /* Grab the ESR and save it */ \
405 addi r3,r1,STACK_FRAME_OVERHEAD; \
406 EXC_XFER_STD(0x0700, program_check_exception)
408 #define DECREMENTER_EXCEPTION \
409 START_EXCEPTION(Decrementer) \
410 NORMAL_EXCEPTION_PROLOG(DECREMENTER); \
411 lis r0,TSR_DIS@h; /* Setup the DEC interrupt mask */ \
412 mtspr SPRN_TSR,r0; /* Clear the DEC interrupt */ \
413 addi r3,r1,STACK_FRAME_OVERHEAD; \
414 EXC_XFER_LITE(0x0900, timer_interrupt)
416 #define FP_UNAVAILABLE_EXCEPTION \
417 START_EXCEPTION(FloatingPointUnavailable) \
418 NORMAL_EXCEPTION_PROLOG(FP_UNAVAIL); \
420 bl load_up_fpu; /* if from user, just load it up */ \
421 b fast_exception_return; \
422 1: addi r3,r1,STACK_FRAME_OVERHEAD; \
423 EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
426 struct exception_regs
{
439 unsigned long saved_ksp_limit
;
442 /* ensure this structure is always sized to a multiple of the stack alignment */
443 #define STACK_EXC_LVL_FRAME_SIZE _ALIGN_UP(sizeof (struct exception_regs), 16)
445 #endif /* __ASSEMBLY__ */
446 #endif /* __HEAD_BOOKE_H__ */