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Diffstat (limited to 'arch/tile/kernel/intvec_32.S')
-rw-r--r-- | arch/tile/kernel/intvec_32.S | 2018 |
1 files changed, 2018 insertions, 0 deletions
diff --git a/arch/tile/kernel/intvec_32.S b/arch/tile/kernel/intvec_32.S new file mode 100644 index 000000000000..84f296ca9e63 --- /dev/null +++ b/arch/tile/kernel/intvec_32.S | |||
@@ -0,0 +1,2018 @@ | |||
1 | /* | ||
2 | * Copyright 2010 Tilera Corporation. All Rights Reserved. | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or | ||
5 | * modify it under the terms of the GNU General Public License | ||
6 | * as published by the Free Software Foundation, version 2. | ||
7 | * | ||
8 | * This program is distributed in the hope that it will be useful, but | ||
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | ||
10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | ||
11 | * NON INFRINGEMENT. See the GNU General Public License for | ||
12 | * more details. | ||
13 | * | ||
14 | * Linux interrupt vectors. | ||
15 | */ | ||
16 | |||
17 | #include <linux/linkage.h> | ||
18 | #include <linux/errno.h> | ||
19 | #include <linux/init.h> | ||
20 | #include <linux/unistd.h> | ||
21 | #include <asm/ptrace.h> | ||
22 | #include <asm/thread_info.h> | ||
23 | #include <asm/irqflags.h> | ||
24 | #include <asm/atomic.h> | ||
25 | #include <asm/asm-offsets.h> | ||
26 | #include <hv/hypervisor.h> | ||
27 | #include <arch/abi.h> | ||
28 | #include <arch/interrupts.h> | ||
29 | #include <arch/spr_def.h> | ||
30 | |||
31 | #ifdef CONFIG_PREEMPT | ||
32 | # error "No support for kernel preemption currently" | ||
33 | #endif | ||
34 | |||
35 | #if INT_INTCTRL_1 < 32 || INT_INTCTRL_1 >= 48 | ||
36 | # error INT_INTCTRL_1 coded to set high interrupt mask | ||
37 | #endif | ||
38 | |||
39 | #define PTREGS_PTR(reg, ptreg) addli reg, sp, C_ABI_SAVE_AREA_SIZE + (ptreg) | ||
40 | |||
41 | #define PTREGS_OFFSET_SYSCALL PTREGS_OFFSET_REG(TREG_SYSCALL_NR) | ||
42 | |||
43 | #if !CHIP_HAS_WH64() | ||
44 | /* By making this an empty macro, we can use wh64 in the code. */ | ||
45 | .macro wh64 reg | ||
46 | .endm | ||
47 | #endif | ||
48 | |||
49 | .macro push_reg reg, ptr=sp, delta=-4 | ||
50 | { | ||
51 | sw \ptr, \reg | ||
52 | addli \ptr, \ptr, \delta | ||
53 | } | ||
54 | .endm | ||
55 | |||
56 | .macro pop_reg reg, ptr=sp, delta=4 | ||
57 | { | ||
58 | lw \reg, \ptr | ||
59 | addli \ptr, \ptr, \delta | ||
60 | } | ||
61 | .endm | ||
62 | |||
63 | .macro pop_reg_zero reg, zreg, ptr=sp, delta=4 | ||
64 | { | ||
65 | move \zreg, zero | ||
66 | lw \reg, \ptr | ||
67 | addi \ptr, \ptr, \delta | ||
68 | } | ||
69 | .endm | ||
70 | |||
71 | .macro push_extra_callee_saves reg | ||
72 | PTREGS_PTR(\reg, PTREGS_OFFSET_REG(51)) | ||
73 | push_reg r51, \reg | ||
74 | push_reg r50, \reg | ||
75 | push_reg r49, \reg | ||
76 | push_reg r48, \reg | ||
77 | push_reg r47, \reg | ||
78 | push_reg r46, \reg | ||
79 | push_reg r45, \reg | ||
80 | push_reg r44, \reg | ||
81 | push_reg r43, \reg | ||
82 | push_reg r42, \reg | ||
83 | push_reg r41, \reg | ||
84 | push_reg r40, \reg | ||
85 | push_reg r39, \reg | ||
86 | push_reg r38, \reg | ||
87 | push_reg r37, \reg | ||
88 | push_reg r36, \reg | ||
89 | push_reg r35, \reg | ||
90 | push_reg r34, \reg, PTREGS_OFFSET_BASE - PTREGS_OFFSET_REG(34) | ||
91 | .endm | ||
92 | |||
93 | .macro panic str | ||
94 | .pushsection .rodata, "a" | ||
95 | 1: | ||
96 | .asciz "\str" | ||
97 | .popsection | ||
98 | { | ||
99 | moveli r0, lo16(1b) | ||
100 | } | ||
101 | { | ||
102 | auli r0, r0, ha16(1b) | ||
103 | jal panic | ||
104 | } | ||
105 | .endm | ||
106 | |||
107 | #ifdef __COLLECT_LINKER_FEEDBACK__ | ||
108 | .pushsection .text.intvec_feedback,"ax" | ||
109 | intvec_feedback: | ||
110 | .popsection | ||
111 | #endif | ||
112 | |||
113 | /* | ||
114 | * Default interrupt handler. | ||
115 | * | ||
116 | * vecnum is where we'll put this code. | ||
117 | * c_routine is the C routine we'll call. | ||
118 | * | ||
119 | * The C routine is passed two arguments: | ||
120 | * - A pointer to the pt_regs state. | ||
121 | * - The interrupt vector number. | ||
122 | * | ||
123 | * The "processing" argument specifies the code for processing | ||
124 | * the interrupt. Defaults to "handle_interrupt". | ||
125 | */ | ||
126 | .macro int_hand vecnum, vecname, c_routine, processing=handle_interrupt | ||
127 | .org (\vecnum << 8) | ||
128 | intvec_\vecname: | ||
129 | .ifc \vecnum, INT_SWINT_1 | ||
130 | blz TREG_SYSCALL_NR_NAME, sys_cmpxchg | ||
131 | .endif | ||
132 | |||
133 | /* Temporarily save a register so we have somewhere to work. */ | ||
134 | |||
135 | mtspr SYSTEM_SAVE_1_1, r0 | ||
136 | mfspr r0, EX_CONTEXT_1_1 | ||
137 | |||
138 | /* The cmpxchg code clears sp to force us to reset it here on fault. */ | ||
139 | { | ||
140 | bz sp, 2f | ||
141 | andi r0, r0, SPR_EX_CONTEXT_1_1__PL_MASK /* mask off ICS */ | ||
142 | } | ||
143 | |||
144 | .ifc \vecnum, INT_DOUBLE_FAULT | ||
145 | /* | ||
146 | * For double-faults from user-space, fall through to the normal | ||
147 | * register save and stack setup path. Otherwise, it's the | ||
148 | * hypervisor giving us one last chance to dump diagnostics, and we | ||
149 | * branch to the kernel_double_fault routine to do so. | ||
150 | */ | ||
151 | bz r0, 1f | ||
152 | j _kernel_double_fault | ||
153 | 1: | ||
154 | .else | ||
155 | /* | ||
156 | * If we're coming from user-space, then set sp to the top of | ||
157 | * the kernel stack. Otherwise, assume sp is already valid. | ||
158 | */ | ||
159 | { | ||
160 | bnz r0, 0f | ||
161 | move r0, sp | ||
162 | } | ||
163 | .endif | ||
164 | |||
165 | .ifc \c_routine, do_page_fault | ||
166 | /* | ||
167 | * The page_fault handler may be downcalled directly by the | ||
168 | * hypervisor even when Linux is running and has ICS set. | ||
169 | * | ||
170 | * In this case the contents of EX_CONTEXT_1_1 reflect the | ||
171 | * previous fault and can't be relied on to choose whether or | ||
172 | * not to reinitialize the stack pointer. So we add a test | ||
173 | * to see whether SYSTEM_SAVE_1_2 has the high bit set, | ||
174 | * and if so we don't reinitialize sp, since we must be coming | ||
175 | * from Linux. (In fact the precise case is !(val & ~1), | ||
176 | * but any Linux PC has to have the high bit set.) | ||
177 | * | ||
178 | * Note that the hypervisor *always* sets SYSTEM_SAVE_1_2 for | ||
179 | * any path that turns into a downcall to one of our TLB handlers. | ||
180 | */ | ||
181 | mfspr r0, SYSTEM_SAVE_1_2 | ||
182 | { | ||
183 | blz r0, 0f /* high bit in S_S_1_2 is for a PC to use */ | ||
184 | move r0, sp | ||
185 | } | ||
186 | .endif | ||
187 | |||
188 | 2: | ||
189 | /* | ||
190 | * SYSTEM_SAVE_1_0 holds the cpu number in the low bits, and | ||
191 | * the current stack top in the higher bits. So we recover | ||
192 | * our stack top by just masking off the low bits, then | ||
193 | * point sp at the top aligned address on the actual stack page. | ||
194 | */ | ||
195 | mfspr r0, SYSTEM_SAVE_1_0 | ||
196 | mm r0, r0, zero, LOG2_THREAD_SIZE, 31 | ||
197 | |||
198 | 0: | ||
199 | /* | ||
200 | * Align the stack mod 64 so we can properly predict what | ||
201 | * cache lines we need to write-hint to reduce memory fetch | ||
202 | * latency as we enter the kernel. The layout of memory is | ||
203 | * as follows, with cache line 0 at the lowest VA, and cache | ||
204 | * line 4 just below the r0 value this "andi" computes. | ||
205 | * Note that we never write to cache line 4, and we skip | ||
206 | * cache line 1 for syscalls. | ||
207 | * | ||
208 | * cache line 4: ptregs padding (two words) | ||
209 | * cache line 3: r46...lr, pc, ex1, faultnum, orig_r0, flags, pad | ||
210 | * cache line 2: r30...r45 | ||
211 | * cache line 1: r14...r29 | ||
212 | * cache line 0: 2 x frame, r0..r13 | ||
213 | */ | ||
214 | andi r0, r0, -64 | ||
215 | |||
216 | /* | ||
217 | * Push the first four registers on the stack, so that we can set | ||
218 | * them to vector-unique values before we jump to the common code. | ||
219 | * | ||
220 | * Registers are pushed on the stack as a struct pt_regs, | ||
221 | * with the sp initially just above the struct, and when we're | ||
222 | * done, sp points to the base of the struct, minus | ||
223 | * C_ABI_SAVE_AREA_SIZE, so we can directly jal to C code. | ||
224 | * | ||
225 | * This routine saves just the first four registers, plus the | ||
226 | * stack context so we can do proper backtracing right away, | ||
227 | * and defers to handle_interrupt to save the rest. | ||
228 | * The backtracer needs pc, ex1, lr, sp, r52, and faultnum. | ||
229 | */ | ||
230 | addli r0, r0, PTREGS_OFFSET_LR - (PTREGS_SIZE + KSTK_PTREGS_GAP) | ||
231 | wh64 r0 /* cache line 3 */ | ||
232 | { | ||
233 | sw r0, lr | ||
234 | addli r0, r0, PTREGS_OFFSET_SP - PTREGS_OFFSET_LR | ||
235 | } | ||
236 | { | ||
237 | sw r0, sp | ||
238 | addli sp, r0, PTREGS_OFFSET_REG(52) - PTREGS_OFFSET_SP | ||
239 | } | ||
240 | { | ||
241 | sw sp, r52 | ||
242 | addli sp, sp, PTREGS_OFFSET_REG(1) - PTREGS_OFFSET_REG(52) | ||
243 | } | ||
244 | wh64 sp /* cache line 0 */ | ||
245 | { | ||
246 | sw sp, r1 | ||
247 | addli sp, sp, PTREGS_OFFSET_REG(2) - PTREGS_OFFSET_REG(1) | ||
248 | } | ||
249 | { | ||
250 | sw sp, r2 | ||
251 | addli sp, sp, PTREGS_OFFSET_REG(3) - PTREGS_OFFSET_REG(2) | ||
252 | } | ||
253 | { | ||
254 | sw sp, r3 | ||
255 | addli sp, sp, PTREGS_OFFSET_PC - PTREGS_OFFSET_REG(3) | ||
256 | } | ||
257 | mfspr r0, EX_CONTEXT_1_0 | ||
258 | .ifc \processing,handle_syscall | ||
259 | /* | ||
260 | * Bump the saved PC by one bundle so that when we return, we won't | ||
261 | * execute the same swint instruction again. We need to do this while | ||
262 | * we're in the critical section. | ||
263 | */ | ||
264 | addi r0, r0, 8 | ||
265 | .endif | ||
266 | { | ||
267 | sw sp, r0 | ||
268 | addli sp, sp, PTREGS_OFFSET_EX1 - PTREGS_OFFSET_PC | ||
269 | } | ||
270 | mfspr r0, EX_CONTEXT_1_1 | ||
271 | { | ||
272 | sw sp, r0 | ||
273 | addi sp, sp, PTREGS_OFFSET_FAULTNUM - PTREGS_OFFSET_EX1 | ||
274 | /* | ||
275 | * Use r0 for syscalls so it's a temporary; use r1 for interrupts | ||
276 | * so that it gets passed through unchanged to the handler routine. | ||
277 | * Note that the .if conditional confusingly spans bundles. | ||
278 | */ | ||
279 | .ifc \processing,handle_syscall | ||
280 | movei r0, \vecnum | ||
281 | } | ||
282 | { | ||
283 | sw sp, r0 | ||
284 | .else | ||
285 | movei r1, \vecnum | ||
286 | } | ||
287 | { | ||
288 | sw sp, r1 | ||
289 | .endif | ||
290 | addli sp, sp, PTREGS_OFFSET_REG(0) - PTREGS_OFFSET_FAULTNUM | ||
291 | } | ||
292 | mfspr r0, SYSTEM_SAVE_1_1 /* Original r0 */ | ||
293 | { | ||
294 | sw sp, r0 | ||
295 | addi sp, sp, -PTREGS_OFFSET_REG(0) - 4 | ||
296 | } | ||
297 | { | ||
298 | sw sp, zero /* write zero into "Next SP" frame pointer */ | ||
299 | addi sp, sp, -4 /* leave SP pointing at bottom of frame */ | ||
300 | } | ||
301 | .ifc \processing,handle_syscall | ||
302 | j handle_syscall | ||
303 | .else | ||
304 | /* | ||
305 | * Capture per-interrupt SPR context to registers. | ||
306 | * We overload the meaning of r3 on this path such that if its bit 31 | ||
307 | * is set, we have to mask all interrupts including NMIs before | ||
308 | * clearing the interrupt critical section bit. | ||
309 | * See discussion below at "finish_interrupt_save". | ||
310 | */ | ||
311 | .ifc \c_routine, do_page_fault | ||
312 | mfspr r2, SYSTEM_SAVE_1_3 /* address of page fault */ | ||
313 | mfspr r3, SYSTEM_SAVE_1_2 /* info about page fault */ | ||
314 | .else | ||
315 | .ifc \vecnum, INT_DOUBLE_FAULT | ||
316 | { | ||
317 | mfspr r2, SYSTEM_SAVE_1_2 /* double fault info from HV */ | ||
318 | movei r3, 0 | ||
319 | } | ||
320 | .else | ||
321 | .ifc \c_routine, do_trap | ||
322 | { | ||
323 | mfspr r2, GPV_REASON | ||
324 | movei r3, 0 | ||
325 | } | ||
326 | .else | ||
327 | .ifc \c_routine, op_handle_perf_interrupt | ||
328 | { | ||
329 | mfspr r2, PERF_COUNT_STS | ||
330 | movei r3, -1 /* not used, but set for consistency */ | ||
331 | } | ||
332 | .else | ||
333 | #if CHIP_HAS_AUX_PERF_COUNTERS() | ||
334 | .ifc \c_routine, op_handle_aux_perf_interrupt | ||
335 | { | ||
336 | mfspr r2, AUX_PERF_COUNT_STS | ||
337 | movei r3, -1 /* not used, but set for consistency */ | ||
338 | } | ||
339 | .else | ||
340 | #endif | ||
341 | movei r3, 0 | ||
342 | #if CHIP_HAS_AUX_PERF_COUNTERS() | ||
343 | .endif | ||
344 | #endif | ||
345 | .endif | ||
346 | .endif | ||
347 | .endif | ||
348 | .endif | ||
349 | /* Put function pointer in r0 */ | ||
350 | moveli r0, lo16(\c_routine) | ||
351 | { | ||
352 | auli r0, r0, ha16(\c_routine) | ||
353 | j \processing | ||
354 | } | ||
355 | .endif | ||
356 | ENDPROC(intvec_\vecname) | ||
357 | |||
358 | #ifdef __COLLECT_LINKER_FEEDBACK__ | ||
359 | .pushsection .text.intvec_feedback,"ax" | ||
360 | .org (\vecnum << 5) | ||
361 | FEEDBACK_ENTER_EXPLICIT(intvec_\vecname, .intrpt1, 1 << 8) | ||
362 | jrp lr | ||
363 | .popsection | ||
364 | #endif | ||
365 | |||
366 | .endm | ||
367 | |||
368 | |||
369 | /* | ||
370 | * Save the rest of the registers that we didn't save in the actual | ||
371 | * vector itself. We can't use r0-r10 inclusive here. | ||
372 | */ | ||
373 | .macro finish_interrupt_save, function | ||
374 | |||
375 | /* If it's a syscall, save a proper orig_r0, otherwise just zero. */ | ||
376 | PTREGS_PTR(r52, PTREGS_OFFSET_ORIG_R0) | ||
377 | { | ||
378 | .ifc \function,handle_syscall | ||
379 | sw r52, r0 | ||
380 | .else | ||
381 | sw r52, zero | ||
382 | .endif | ||
383 | PTREGS_PTR(r52, PTREGS_OFFSET_TP) | ||
384 | } | ||
385 | |||
386 | /* | ||
387 | * For ordinary syscalls, we save neither caller- nor callee- | ||
388 | * save registers, since the syscall invoker doesn't expect the | ||
389 | * caller-saves to be saved, and the called kernel functions will | ||
390 | * take care of saving the callee-saves for us. | ||
391 | * | ||
392 | * For interrupts we save just the caller-save registers. Saving | ||
393 | * them is required (since the "caller" can't save them). Again, | ||
394 | * the called kernel functions will restore the callee-save | ||
395 | * registers for us appropriately. | ||
396 | * | ||
397 | * On return, we normally restore nothing special for syscalls, | ||
398 | * and just the caller-save registers for interrupts. | ||
399 | * | ||
400 | * However, there are some important caveats to all this: | ||
401 | * | ||
402 | * - We always save a few callee-save registers to give us | ||
403 | * some scratchpad registers to carry across function calls. | ||
404 | * | ||
405 | * - fork/vfork/etc require us to save all the callee-save | ||
406 | * registers, which we do in PTREGS_SYSCALL_ALL_REGS, below. | ||
407 | * | ||
408 | * - We always save r0..r5 and r10 for syscalls, since we need | ||
409 | * to reload them a bit later for the actual kernel call, and | ||
410 | * since we might need them for -ERESTARTNOINTR, etc. | ||
411 | * | ||
412 | * - Before invoking a signal handler, we save the unsaved | ||
413 | * callee-save registers so they are visible to the | ||
414 | * signal handler or any ptracer. | ||
415 | * | ||
416 | * - If the unsaved callee-save registers are modified, we set | ||
417 | * a bit in pt_regs so we know to reload them from pt_regs | ||
418 | * and not just rely on the kernel function unwinding. | ||
419 | * (Done for ptrace register writes and SA_SIGINFO handler.) | ||
420 | */ | ||
421 | { | ||
422 | sw r52, tp | ||
423 | PTREGS_PTR(r52, PTREGS_OFFSET_REG(33)) | ||
424 | } | ||
425 | wh64 r52 /* cache line 2 */ | ||
426 | push_reg r33, r52 | ||
427 | push_reg r32, r52 | ||
428 | push_reg r31, r52 | ||
429 | .ifc \function,handle_syscall | ||
430 | push_reg r30, r52, PTREGS_OFFSET_SYSCALL - PTREGS_OFFSET_REG(30) | ||
431 | push_reg TREG_SYSCALL_NR_NAME, r52, \ | ||
432 | PTREGS_OFFSET_REG(5) - PTREGS_OFFSET_SYSCALL | ||
433 | .else | ||
434 | |||
435 | push_reg r30, r52, PTREGS_OFFSET_REG(29) - PTREGS_OFFSET_REG(30) | ||
436 | wh64 r52 /* cache line 1 */ | ||
437 | push_reg r29, r52 | ||
438 | push_reg r28, r52 | ||
439 | push_reg r27, r52 | ||
440 | push_reg r26, r52 | ||
441 | push_reg r25, r52 | ||
442 | push_reg r24, r52 | ||
443 | push_reg r23, r52 | ||
444 | push_reg r22, r52 | ||
445 | push_reg r21, r52 | ||
446 | push_reg r20, r52 | ||
447 | push_reg r19, r52 | ||
448 | push_reg r18, r52 | ||
449 | push_reg r17, r52 | ||
450 | push_reg r16, r52 | ||
451 | push_reg r15, r52 | ||
452 | push_reg r14, r52 | ||
453 | push_reg r13, r52 | ||
454 | push_reg r12, r52 | ||
455 | push_reg r11, r52 | ||
456 | push_reg r10, r52 | ||
457 | push_reg r9, r52 | ||
458 | push_reg r8, r52 | ||
459 | push_reg r7, r52 | ||
460 | push_reg r6, r52 | ||
461 | |||
462 | .endif | ||
463 | |||
464 | push_reg r5, r52 | ||
465 | sw r52, r4 | ||
466 | |||
467 | /* Load tp with our per-cpu offset. */ | ||
468 | #ifdef CONFIG_SMP | ||
469 | { | ||
470 | mfspr r20, SYSTEM_SAVE_1_0 | ||
471 | moveli r21, lo16(__per_cpu_offset) | ||
472 | } | ||
473 | { | ||
474 | auli r21, r21, ha16(__per_cpu_offset) | ||
475 | mm r20, r20, zero, 0, LOG2_THREAD_SIZE-1 | ||
476 | } | ||
477 | s2a r20, r20, r21 | ||
478 | lw tp, r20 | ||
479 | #else | ||
480 | move tp, zero | ||
481 | #endif | ||
482 | |||
483 | /* | ||
484 | * If we will be returning to the kernel, we will need to | ||
485 | * reset the interrupt masks to the state they had before. | ||
486 | * Set DISABLE_IRQ in flags iff we came from PL1 with irqs disabled. | ||
487 | * We load flags in r32 here so we can jump to .Lrestore_regs | ||
488 | * directly after do_page_fault_ics() if necessary. | ||
489 | */ | ||
490 | mfspr r32, EX_CONTEXT_1_1 | ||
491 | { | ||
492 | andi r32, r32, SPR_EX_CONTEXT_1_1__PL_MASK /* mask off ICS */ | ||
493 | PTREGS_PTR(r21, PTREGS_OFFSET_FLAGS) | ||
494 | } | ||
495 | bzt r32, 1f /* zero if from user space */ | ||
496 | IRQS_DISABLED(r32) /* zero if irqs enabled */ | ||
497 | #if PT_FLAGS_DISABLE_IRQ != 1 | ||
498 | # error Value of IRQS_DISABLED used to set PT_FLAGS_DISABLE_IRQ; fix | ||
499 | #endif | ||
500 | 1: | ||
501 | .ifnc \function,handle_syscall | ||
502 | /* Record the fact that we saved the caller-save registers above. */ | ||
503 | ori r32, r32, PT_FLAGS_CALLER_SAVES | ||
504 | .endif | ||
505 | sw r21, r32 | ||
506 | |||
507 | #ifdef __COLLECT_LINKER_FEEDBACK__ | ||
508 | /* | ||
509 | * Notify the feedback routines that we were in the | ||
510 | * appropriate fixed interrupt vector area. Note that we | ||
511 | * still have ICS set at this point, so we can't invoke any | ||
512 | * atomic operations or we will panic. The feedback | ||
513 | * routines internally preserve r0..r10 and r30 up. | ||
514 | */ | ||
515 | .ifnc \function,handle_syscall | ||
516 | shli r20, r1, 5 | ||
517 | .else | ||
518 | moveli r20, INT_SWINT_1 << 5 | ||
519 | .endif | ||
520 | addli r20, r20, lo16(intvec_feedback) | ||
521 | auli r20, r20, ha16(intvec_feedback) | ||
522 | jalr r20 | ||
523 | |||
524 | /* And now notify the feedback routines that we are here. */ | ||
525 | FEEDBACK_ENTER(\function) | ||
526 | #endif | ||
527 | |||
528 | /* | ||
529 | * we've captured enough state to the stack (including in | ||
530 | * particular our EX_CONTEXT state) that we can now release | ||
531 | * the interrupt critical section and replace it with our | ||
532 | * standard "interrupts disabled" mask value. This allows | ||
533 | * synchronous interrupts (and profile interrupts) to punch | ||
534 | * through from this point onwards. | ||
535 | * | ||
536 | * If bit 31 of r3 is set during a non-NMI interrupt, we know we | ||
537 | * are on the path where the hypervisor has punched through our | ||
538 | * ICS with a page fault, so we call out to do_page_fault_ics() | ||
539 | * to figure out what to do with it. If the fault was in | ||
540 | * an atomic op, we unlock the atomic lock, adjust the | ||
541 | * saved register state a little, and return "zero" in r4, | ||
542 | * falling through into the normal page-fault interrupt code. | ||
543 | * If the fault was in a kernel-space atomic operation, then | ||
544 | * do_page_fault_ics() resolves it itself, returns "one" in r4, | ||
545 | * and as a result goes directly to restoring registers and iret, | ||
546 | * without trying to adjust the interrupt masks at all. | ||
547 | * The do_page_fault_ics() API involves passing and returning | ||
548 | * a five-word struct (in registers) to avoid writing the | ||
549 | * save and restore code here. | ||
550 | */ | ||
551 | .ifc \function,handle_nmi | ||
552 | IRQ_DISABLE_ALL(r20) | ||
553 | .else | ||
554 | .ifnc \function,handle_syscall | ||
555 | bgezt r3, 1f | ||
556 | { | ||
557 | PTREGS_PTR(r0, PTREGS_OFFSET_BASE) | ||
558 | jal do_page_fault_ics | ||
559 | } | ||
560 | FEEDBACK_REENTER(\function) | ||
561 | bzt r4, 1f | ||
562 | j .Lrestore_regs | ||
563 | 1: | ||
564 | .endif | ||
565 | IRQ_DISABLE(r20, r21) | ||
566 | .endif | ||
567 | mtspr INTERRUPT_CRITICAL_SECTION, zero | ||
568 | |||
569 | #if CHIP_HAS_WH64() | ||
570 | /* | ||
571 | * Prepare the first 256 stack bytes to be rapidly accessible | ||
572 | * without having to fetch the background data. We don't really | ||
573 | * know how far to write-hint, but kernel stacks generally | ||
574 | * aren't that big, and write-hinting here does take some time. | ||
575 | */ | ||
576 | addi r52, sp, -64 | ||
577 | { | ||
578 | wh64 r52 | ||
579 | addi r52, r52, -64 | ||
580 | } | ||
581 | { | ||
582 | wh64 r52 | ||
583 | addi r52, r52, -64 | ||
584 | } | ||
585 | { | ||
586 | wh64 r52 | ||
587 | addi r52, r52, -64 | ||
588 | } | ||
589 | wh64 r52 | ||
590 | #endif | ||
591 | |||
592 | #ifdef CONFIG_TRACE_IRQFLAGS | ||
593 | .ifnc \function,handle_nmi | ||
594 | /* | ||
595 | * We finally have enough state set up to notify the irq | ||
596 | * tracing code that irqs were disabled on entry to the handler. | ||
597 | * The TRACE_IRQS_OFF call clobbers registers r0-r29. | ||
598 | * For syscalls, we already have the register state saved away | ||
599 | * on the stack, so we don't bother to do any register saves here, | ||
600 | * and later we pop the registers back off the kernel stack. | ||
601 | * For interrupt handlers, save r0-r3 in callee-saved registers. | ||
602 | */ | ||
603 | .ifnc \function,handle_syscall | ||
604 | { move r30, r0; move r31, r1 } | ||
605 | { move r32, r2; move r33, r3 } | ||
606 | .endif | ||
607 | TRACE_IRQS_OFF | ||
608 | .ifnc \function,handle_syscall | ||
609 | { move r0, r30; move r1, r31 } | ||
610 | { move r2, r32; move r3, r33 } | ||
611 | .endif | ||
612 | .endif | ||
613 | #endif | ||
614 | |||
615 | .endm | ||
616 | |||
617 | .macro check_single_stepping, kind, not_single_stepping | ||
618 | /* | ||
619 | * Check for single stepping in user-level priv | ||
620 | * kind can be "normal", "ill", or "syscall" | ||
621 | * At end, if fall-thru | ||
622 | * r29: thread_info->step_state | ||
623 | * r28: &pt_regs->pc | ||
624 | * r27: pt_regs->pc | ||
625 | * r26: thread_info->step_state->buffer | ||
626 | */ | ||
627 | |||
628 | /* Check for single stepping */ | ||
629 | GET_THREAD_INFO(r29) | ||
630 | { | ||
631 | /* Get pointer to field holding step state */ | ||
632 | addi r29, r29, THREAD_INFO_STEP_STATE_OFFSET | ||
633 | |||
634 | /* Get pointer to EX1 in register state */ | ||
635 | PTREGS_PTR(r27, PTREGS_OFFSET_EX1) | ||
636 | } | ||
637 | { | ||
638 | /* Get pointer to field holding PC */ | ||
639 | PTREGS_PTR(r28, PTREGS_OFFSET_PC) | ||
640 | |||
641 | /* Load the pointer to the step state */ | ||
642 | lw r29, r29 | ||
643 | } | ||
644 | /* Load EX1 */ | ||
645 | lw r27, r27 | ||
646 | { | ||
647 | /* Points to flags */ | ||
648 | addi r23, r29, SINGLESTEP_STATE_FLAGS_OFFSET | ||
649 | |||
650 | /* No single stepping if there is no step state structure */ | ||
651 | bzt r29, \not_single_stepping | ||
652 | } | ||
653 | { | ||
654 | /* mask off ICS and any other high bits */ | ||
655 | andi r27, r27, SPR_EX_CONTEXT_1_1__PL_MASK | ||
656 | |||
657 | /* Load pointer to single step instruction buffer */ | ||
658 | lw r26, r29 | ||
659 | } | ||
660 | /* Check priv state */ | ||
661 | bnz r27, \not_single_stepping | ||
662 | |||
663 | /* Get flags */ | ||
664 | lw r22, r23 | ||
665 | { | ||
666 | /* Branch if single-step mode not enabled */ | ||
667 | bbnst r22, \not_single_stepping | ||
668 | |||
669 | /* Clear enabled flag */ | ||
670 | andi r22, r22, ~SINGLESTEP_STATE_MASK_IS_ENABLED | ||
671 | } | ||
672 | .ifc \kind,normal | ||
673 | { | ||
674 | /* Load PC */ | ||
675 | lw r27, r28 | ||
676 | |||
677 | /* Point to the entry containing the original PC */ | ||
678 | addi r24, r29, SINGLESTEP_STATE_ORIG_PC_OFFSET | ||
679 | } | ||
680 | { | ||
681 | /* Disable single stepping flag */ | ||
682 | sw r23, r22 | ||
683 | } | ||
684 | { | ||
685 | /* Get the original pc */ | ||
686 | lw r24, r24 | ||
687 | |||
688 | /* See if the PC is at the start of the single step buffer */ | ||
689 | seq r25, r26, r27 | ||
690 | } | ||
691 | /* | ||
692 | * NOTE: it is really expected that the PC be in the single step buffer | ||
693 | * at this point | ||
694 | */ | ||
695 | bzt r25, \not_single_stepping | ||
696 | |||
697 | /* Restore the original PC */ | ||
698 | sw r28, r24 | ||
699 | .else | ||
700 | .ifc \kind,syscall | ||
701 | { | ||
702 | /* Load PC */ | ||
703 | lw r27, r28 | ||
704 | |||
705 | /* Point to the entry containing the next PC */ | ||
706 | addi r24, r29, SINGLESTEP_STATE_NEXT_PC_OFFSET | ||
707 | } | ||
708 | { | ||
709 | /* Increment the stopped PC by the bundle size */ | ||
710 | addi r26, r26, 8 | ||
711 | |||
712 | /* Disable single stepping flag */ | ||
713 | sw r23, r22 | ||
714 | } | ||
715 | { | ||
716 | /* Get the next pc */ | ||
717 | lw r24, r24 | ||
718 | |||
719 | /* | ||
720 | * See if the PC is one bundle past the start of the | ||
721 | * single step buffer | ||
722 | */ | ||
723 | seq r25, r26, r27 | ||
724 | } | ||
725 | { | ||
726 | /* | ||
727 | * NOTE: it is really expected that the PC be in the | ||
728 | * single step buffer at this point | ||
729 | */ | ||
730 | bzt r25, \not_single_stepping | ||
731 | } | ||
732 | /* Set to the next PC */ | ||
733 | sw r28, r24 | ||
734 | .else | ||
735 | { | ||
736 | /* Point to 3rd bundle in buffer */ | ||
737 | addi r25, r26, 16 | ||
738 | |||
739 | /* Load PC */ | ||
740 | lw r27, r28 | ||
741 | } | ||
742 | { | ||
743 | /* Disable single stepping flag */ | ||
744 | sw r23, r22 | ||
745 | |||
746 | /* See if the PC is in the single step buffer */ | ||
747 | slte_u r24, r26, r27 | ||
748 | } | ||
749 | { | ||
750 | slte_u r25, r27, r25 | ||
751 | |||
752 | /* | ||
753 | * NOTE: it is really expected that the PC be in the | ||
754 | * single step buffer at this point | ||
755 | */ | ||
756 | bzt r24, \not_single_stepping | ||
757 | } | ||
758 | bzt r25, \not_single_stepping | ||
759 | .endif | ||
760 | .endif | ||
761 | .endm | ||
762 | |||
763 | /* | ||
764 | * Redispatch a downcall. | ||
765 | */ | ||
766 | .macro dc_dispatch vecnum, vecname | ||
767 | .org (\vecnum << 8) | ||
768 | intvec_\vecname: | ||
769 | j hv_downcall_dispatch | ||
770 | ENDPROC(intvec_\vecname) | ||
771 | .endm | ||
772 | |||
773 | /* | ||
774 | * Common code for most interrupts. The C function we're eventually | ||
775 | * going to is in r0, and the faultnum is in r1; the original | ||
776 | * values for those registers are on the stack. | ||
777 | */ | ||
778 | .pushsection .text.handle_interrupt,"ax" | ||
779 | handle_interrupt: | ||
780 | finish_interrupt_save handle_interrupt | ||
781 | |||
782 | /* | ||
783 | * Check for if we are single stepping in user level. If so, then | ||
784 | * we need to restore the PC. | ||
785 | */ | ||
786 | |||
787 | check_single_stepping normal, .Ldispatch_interrupt | ||
788 | .Ldispatch_interrupt: | ||
789 | |||
790 | /* Jump to the C routine; it should enable irqs as soon as possible. */ | ||
791 | { | ||
792 | jalr r0 | ||
793 | PTREGS_PTR(r0, PTREGS_OFFSET_BASE) | ||
794 | } | ||
795 | FEEDBACK_REENTER(handle_interrupt) | ||
796 | { | ||
797 | movei r30, 0 /* not an NMI */ | ||
798 | j interrupt_return | ||
799 | } | ||
800 | STD_ENDPROC(handle_interrupt) | ||
801 | |||
802 | /* | ||
803 | * This routine takes a boolean in r30 indicating if this is an NMI. | ||
804 | * If so, we also expect a boolean in r31 indicating whether to | ||
805 | * re-enable the oprofile interrupts. | ||
806 | */ | ||
807 | STD_ENTRY(interrupt_return) | ||
808 | /* If we're resuming to kernel space, don't check thread flags. */ | ||
809 | { | ||
810 | bnz r30, .Lrestore_all /* NMIs don't special-case user-space */ | ||
811 | PTREGS_PTR(r29, PTREGS_OFFSET_EX1) | ||
812 | } | ||
813 | lw r29, r29 | ||
814 | andi r29, r29, SPR_EX_CONTEXT_1_1__PL_MASK /* mask off ICS */ | ||
815 | { | ||
816 | bzt r29, .Lresume_userspace | ||
817 | PTREGS_PTR(r29, PTREGS_OFFSET_PC) | ||
818 | } | ||
819 | |||
820 | /* If we're resuming to _cpu_idle_nap, bump PC forward by 8. */ | ||
821 | { | ||
822 | lw r28, r29 | ||
823 | moveli r27, lo16(_cpu_idle_nap) | ||
824 | } | ||
825 | { | ||
826 | auli r27, r27, ha16(_cpu_idle_nap) | ||
827 | } | ||
828 | { | ||
829 | seq r27, r27, r28 | ||
830 | } | ||
831 | { | ||
832 | bbns r27, .Lrestore_all | ||
833 | addi r28, r28, 8 | ||
834 | } | ||
835 | sw r29, r28 | ||
836 | j .Lrestore_all | ||
837 | |||
838 | .Lresume_userspace: | ||
839 | FEEDBACK_REENTER(interrupt_return) | ||
840 | |||
841 | /* | ||
842 | * Disable interrupts so as to make sure we don't | ||
843 | * miss an interrupt that sets any of the thread flags (like | ||
844 | * need_resched or sigpending) between sampling and the iret. | ||
845 | * Routines like schedule() or do_signal() may re-enable | ||
846 | * interrupts before returning. | ||
847 | */ | ||
848 | IRQ_DISABLE(r20, r21) | ||
849 | TRACE_IRQS_OFF /* Note: clobbers registers r0-r29 */ | ||
850 | |||
851 | /* Get base of stack in r32; note r30/31 are used as arguments here. */ | ||
852 | GET_THREAD_INFO(r32) | ||
853 | |||
854 | |||
855 | /* Check to see if there is any work to do before returning to user. */ | ||
856 | { | ||
857 | addi r29, r32, THREAD_INFO_FLAGS_OFFSET | ||
858 | moveli r28, lo16(_TIF_ALLWORK_MASK) | ||
859 | } | ||
860 | { | ||
861 | lw r29, r29 | ||
862 | auli r28, r28, ha16(_TIF_ALLWORK_MASK) | ||
863 | } | ||
864 | and r28, r29, r28 | ||
865 | bnz r28, .Lwork_pending | ||
866 | |||
867 | /* | ||
868 | * In the NMI case we | ||
869 | * omit the call to single_process_check_nohz, which normally checks | ||
870 | * to see if we should start or stop the scheduler tick, because | ||
871 | * we can't call arbitrary Linux code from an NMI context. | ||
872 | * We always call the homecache TLB deferral code to re-trigger | ||
873 | * the deferral mechanism. | ||
874 | * | ||
875 | * The other chunk of responsibility this code has is to reset the | ||
876 | * interrupt masks appropriately to reset irqs and NMIs. We have | ||
877 | * to call TRACE_IRQS_OFF and TRACE_IRQS_ON to support all the | ||
878 | * lockdep-type stuff, but we can't set ICS until afterwards, since | ||
879 | * ICS can only be used in very tight chunks of code to avoid | ||
880 | * tripping over various assertions that it is off. | ||
881 | * | ||
882 | * (There is what looks like a window of vulnerability here since | ||
883 | * we might take a profile interrupt between the two SPR writes | ||
884 | * that set the mask, but since we write the low SPR word first, | ||
885 | * and our interrupt entry code checks the low SPR word, any | ||
886 | * profile interrupt will actually disable interrupts in both SPRs | ||
887 | * before returning, which is OK.) | ||
888 | */ | ||
889 | .Lrestore_all: | ||
890 | PTREGS_PTR(r0, PTREGS_OFFSET_EX1) | ||
891 | { | ||
892 | lw r0, r0 | ||
893 | PTREGS_PTR(r32, PTREGS_OFFSET_FLAGS) | ||
894 | } | ||
895 | { | ||
896 | andi r0, r0, SPR_EX_CONTEXT_1_1__PL_MASK | ||
897 | lw r32, r32 | ||
898 | } | ||
899 | bnz r0, 1f | ||
900 | j 2f | ||
901 | #if PT_FLAGS_DISABLE_IRQ != 1 | ||
902 | # error Assuming PT_FLAGS_DISABLE_IRQ == 1 so we can use bbnst below | ||
903 | #endif | ||
904 | 1: bbnst r32, 2f | ||
905 | IRQ_DISABLE(r20,r21) | ||
906 | TRACE_IRQS_OFF | ||
907 | movei r0, 1 | ||
908 | mtspr INTERRUPT_CRITICAL_SECTION, r0 | ||
909 | bzt r30, .Lrestore_regs | ||
910 | j 3f | ||
911 | 2: TRACE_IRQS_ON | ||
912 | movei r0, 1 | ||
913 | mtspr INTERRUPT_CRITICAL_SECTION, r0 | ||
914 | IRQ_ENABLE(r20, r21) | ||
915 | bzt r30, .Lrestore_regs | ||
916 | 3: | ||
917 | |||
918 | |||
919 | /* | ||
920 | * We now commit to returning from this interrupt, since we will be | ||
921 | * doing things like setting EX_CONTEXT SPRs and unwinding the stack | ||
922 | * frame. No calls should be made to any other code after this point. | ||
923 | * This code should only be entered with ICS set. | ||
924 | * r32 must still be set to ptregs.flags. | ||
925 | * We launch loads to each cache line separately first, so we can | ||
926 | * get some parallelism out of the memory subsystem. | ||
927 | * We start zeroing caller-saved registers throughout, since | ||
928 | * that will save some cycles if this turns out to be a syscall. | ||
929 | */ | ||
930 | .Lrestore_regs: | ||
931 | FEEDBACK_REENTER(interrupt_return) /* called from elsewhere */ | ||
932 | |||
933 | /* | ||
934 | * Rotate so we have one high bit and one low bit to test. | ||
935 | * - low bit says whether to restore all the callee-saved registers, | ||
936 | * or just r30-r33, and r52 up. | ||
937 | * - high bit (i.e. sign bit) says whether to restore all the | ||
938 | * caller-saved registers, or just r0. | ||
939 | */ | ||
940 | #if PT_FLAGS_CALLER_SAVES != 2 || PT_FLAGS_RESTORE_REGS != 4 | ||
941 | # error Rotate trick does not work :-) | ||
942 | #endif | ||
943 | { | ||
944 | rli r20, r32, 30 | ||
945 | PTREGS_PTR(sp, PTREGS_OFFSET_REG(0)) | ||
946 | } | ||
947 | |||
948 | /* | ||
949 | * Load cache lines 0, 2, and 3 in that order, then use | ||
950 | * the last loaded value, which makes it likely that the other | ||
951 | * cache lines have also loaded, at which point we should be | ||
952 | * able to safely read all the remaining words on those cache | ||
953 | * lines without waiting for the memory subsystem. | ||
954 | */ | ||
955 | pop_reg_zero r0, r28, sp, PTREGS_OFFSET_REG(30) - PTREGS_OFFSET_REG(0) | ||
956 | pop_reg_zero r30, r2, sp, PTREGS_OFFSET_PC - PTREGS_OFFSET_REG(30) | ||
957 | pop_reg_zero r21, r3, sp, PTREGS_OFFSET_EX1 - PTREGS_OFFSET_PC | ||
958 | pop_reg_zero lr, r4, sp, PTREGS_OFFSET_REG(52) - PTREGS_OFFSET_EX1 | ||
959 | { | ||
960 | mtspr EX_CONTEXT_1_0, r21 | ||
961 | move r5, zero | ||
962 | } | ||
963 | { | ||
964 | mtspr EX_CONTEXT_1_1, lr | ||
965 | andi lr, lr, SPR_EX_CONTEXT_1_1__PL_MASK /* mask off ICS */ | ||
966 | } | ||
967 | |||
968 | /* Restore callee-saveds that we actually use. */ | ||
969 | pop_reg_zero r52, r6, sp, PTREGS_OFFSET_REG(31) - PTREGS_OFFSET_REG(52) | ||
970 | pop_reg_zero r31, r7 | ||
971 | pop_reg_zero r32, r8 | ||
972 | pop_reg_zero r33, r9, sp, PTREGS_OFFSET_REG(29) - PTREGS_OFFSET_REG(33) | ||
973 | |||
974 | /* | ||
975 | * If we modified other callee-saveds, restore them now. | ||
976 | * This is rare, but could be via ptrace or signal handler. | ||
977 | */ | ||
978 | { | ||
979 | move r10, zero | ||
980 | bbs r20, .Lrestore_callees | ||
981 | } | ||
982 | .Lcontinue_restore_regs: | ||
983 | |||
984 | /* Check if we're returning from a syscall. */ | ||
985 | { | ||
986 | move r11, zero | ||
987 | blzt r20, 1f /* no, so go restore callee-save registers */ | ||
988 | } | ||
989 | |||
990 | /* | ||
991 | * Check if we're returning to userspace. | ||
992 | * Note that if we're not, we don't worry about zeroing everything. | ||
993 | */ | ||
994 | { | ||
995 | addli sp, sp, PTREGS_OFFSET_LR - PTREGS_OFFSET_REG(29) | ||
996 | bnz lr, .Lkernel_return | ||
997 | } | ||
998 | |||
999 | /* | ||
1000 | * On return from syscall, we've restored r0 from pt_regs, but we | ||
1001 | * clear the remainder of the caller-saved registers. We could | ||
1002 | * restore the syscall arguments, but there's not much point, | ||
1003 | * and it ensures user programs aren't trying to use the | ||
1004 | * caller-saves if we clear them, as well as avoiding leaking | ||
1005 | * kernel pointers into userspace. | ||
1006 | */ | ||
1007 | pop_reg_zero lr, r12, sp, PTREGS_OFFSET_TP - PTREGS_OFFSET_LR | ||
1008 | pop_reg_zero tp, r13, sp, PTREGS_OFFSET_SP - PTREGS_OFFSET_TP | ||
1009 | { | ||
1010 | lw sp, sp | ||
1011 | move r14, zero | ||
1012 | move r15, zero | ||
1013 | } | ||
1014 | { move r16, zero; move r17, zero } | ||
1015 | { move r18, zero; move r19, zero } | ||
1016 | { move r20, zero; move r21, zero } | ||
1017 | { move r22, zero; move r23, zero } | ||
1018 | { move r24, zero; move r25, zero } | ||
1019 | { move r26, zero; move r27, zero } | ||
1020 | |||
1021 | /* Set r1 to errno if we are returning an error, otherwise zero. */ | ||
1022 | { | ||
1023 | moveli r29, 1024 | ||
1024 | sub r1, zero, r0 | ||
1025 | } | ||
1026 | slt_u r29, r1, r29 | ||
1027 | { | ||
1028 | mnz r1, r29, r1 | ||
1029 | move r29, zero | ||
1030 | } | ||
1031 | iret | ||
1032 | |||
1033 | /* | ||
1034 | * Not a syscall, so restore caller-saved registers. | ||
1035 | * First kick off a load for cache line 1, which we're touching | ||
1036 | * for the first time here. | ||
1037 | */ | ||
1038 | .align 64 | ||
1039 | 1: pop_reg r29, sp, PTREGS_OFFSET_REG(1) - PTREGS_OFFSET_REG(29) | ||
1040 | pop_reg r1 | ||
1041 | pop_reg r2 | ||
1042 | pop_reg r3 | ||
1043 | pop_reg r4 | ||
1044 | pop_reg r5 | ||
1045 | pop_reg r6 | ||
1046 | pop_reg r7 | ||
1047 | pop_reg r8 | ||
1048 | pop_reg r9 | ||
1049 | pop_reg r10 | ||
1050 | pop_reg r11 | ||
1051 | pop_reg r12 | ||
1052 | pop_reg r13 | ||
1053 | pop_reg r14 | ||
1054 | pop_reg r15 | ||
1055 | pop_reg r16 | ||
1056 | pop_reg r17 | ||
1057 | pop_reg r18 | ||
1058 | pop_reg r19 | ||
1059 | pop_reg r20 | ||
1060 | pop_reg r21 | ||
1061 | pop_reg r22 | ||
1062 | pop_reg r23 | ||
1063 | pop_reg r24 | ||
1064 | pop_reg r25 | ||
1065 | pop_reg r26 | ||
1066 | pop_reg r27 | ||
1067 | pop_reg r28, sp, PTREGS_OFFSET_LR - PTREGS_OFFSET_REG(28) | ||
1068 | /* r29 already restored above */ | ||
1069 | bnz lr, .Lkernel_return | ||
1070 | pop_reg lr, sp, PTREGS_OFFSET_TP - PTREGS_OFFSET_LR | ||
1071 | pop_reg tp, sp, PTREGS_OFFSET_SP - PTREGS_OFFSET_TP | ||
1072 | lw sp, sp | ||
1073 | iret | ||
1074 | |||
1075 | /* | ||
1076 | * We can't restore tp when in kernel mode, since a thread might | ||
1077 | * have migrated from another cpu and brought a stale tp value. | ||
1078 | */ | ||
1079 | .Lkernel_return: | ||
1080 | pop_reg lr, sp, PTREGS_OFFSET_SP - PTREGS_OFFSET_LR | ||
1081 | lw sp, sp | ||
1082 | iret | ||
1083 | |||
1084 | /* Restore callee-saved registers from r34 to r51. */ | ||
1085 | .Lrestore_callees: | ||
1086 | addli sp, sp, PTREGS_OFFSET_REG(34) - PTREGS_OFFSET_REG(29) | ||
1087 | pop_reg r34 | ||
1088 | pop_reg r35 | ||
1089 | pop_reg r36 | ||
1090 | pop_reg r37 | ||
1091 | pop_reg r38 | ||
1092 | pop_reg r39 | ||
1093 | pop_reg r40 | ||
1094 | pop_reg r41 | ||
1095 | pop_reg r42 | ||
1096 | pop_reg r43 | ||
1097 | pop_reg r44 | ||
1098 | pop_reg r45 | ||
1099 | pop_reg r46 | ||
1100 | pop_reg r47 | ||
1101 | pop_reg r48 | ||
1102 | pop_reg r49 | ||
1103 | pop_reg r50 | ||
1104 | pop_reg r51, sp, PTREGS_OFFSET_REG(29) - PTREGS_OFFSET_REG(51) | ||
1105 | j .Lcontinue_restore_regs | ||
1106 | |||
1107 | .Lwork_pending: | ||
1108 | /* Mask the reschedule flag */ | ||
1109 | andi r28, r29, _TIF_NEED_RESCHED | ||
1110 | |||
1111 | { | ||
1112 | /* | ||
1113 | * If the NEED_RESCHED flag is called, we call schedule(), which | ||
1114 | * may drop this context right here and go do something else. | ||
1115 | * On return, jump back to .Lresume_userspace and recheck. | ||
1116 | */ | ||
1117 | bz r28, .Lasync_tlb | ||
1118 | |||
1119 | /* Mask the async-tlb flag */ | ||
1120 | andi r28, r29, _TIF_ASYNC_TLB | ||
1121 | } | ||
1122 | |||
1123 | jal schedule | ||
1124 | FEEDBACK_REENTER(interrupt_return) | ||
1125 | |||
1126 | /* Reload the flags and check again */ | ||
1127 | j .Lresume_userspace | ||
1128 | |||
1129 | .Lasync_tlb: | ||
1130 | { | ||
1131 | bz r28, .Lneed_sigpending | ||
1132 | |||
1133 | /* Mask the sigpending flag */ | ||
1134 | andi r28, r29, _TIF_SIGPENDING | ||
1135 | } | ||
1136 | |||
1137 | PTREGS_PTR(r0, PTREGS_OFFSET_BASE) | ||
1138 | jal do_async_page_fault | ||
1139 | FEEDBACK_REENTER(interrupt_return) | ||
1140 | |||
1141 | /* | ||
1142 | * Go restart the "resume userspace" process. We may have | ||
1143 | * fired a signal, and we need to disable interrupts again. | ||
1144 | */ | ||
1145 | j .Lresume_userspace | ||
1146 | |||
1147 | .Lneed_sigpending: | ||
1148 | /* | ||
1149 | * At this point we are either doing signal handling or single-step, | ||
1150 | * so either way make sure we have all the registers saved. | ||
1151 | */ | ||
1152 | push_extra_callee_saves r0 | ||
1153 | |||
1154 | { | ||
1155 | /* If no signal pending, skip to singlestep check */ | ||
1156 | bz r28, .Lneed_singlestep | ||
1157 | |||
1158 | /* Mask the singlestep flag */ | ||
1159 | andi r28, r29, _TIF_SINGLESTEP | ||
1160 | } | ||
1161 | |||
1162 | jal do_signal | ||
1163 | FEEDBACK_REENTER(interrupt_return) | ||
1164 | |||
1165 | /* Reload the flags and check again */ | ||
1166 | j .Lresume_userspace | ||
1167 | |||
1168 | .Lneed_singlestep: | ||
1169 | { | ||
1170 | /* Get a pointer to the EX1 field */ | ||
1171 | PTREGS_PTR(r29, PTREGS_OFFSET_EX1) | ||
1172 | |||
1173 | /* If we get here, our bit must be set. */ | ||
1174 | bz r28, .Lwork_confusion | ||
1175 | } | ||
1176 | /* If we are in priv mode, don't single step */ | ||
1177 | lw r28, r29 | ||
1178 | andi r28, r28, SPR_EX_CONTEXT_1_1__PL_MASK /* mask off ICS */ | ||
1179 | bnz r28, .Lrestore_all | ||
1180 | |||
1181 | /* Allow interrupts within the single step code */ | ||
1182 | TRACE_IRQS_ON /* Note: clobbers registers r0-r29 */ | ||
1183 | IRQ_ENABLE(r20, r21) | ||
1184 | |||
1185 | /* try to single-step the current instruction */ | ||
1186 | PTREGS_PTR(r0, PTREGS_OFFSET_BASE) | ||
1187 | jal single_step_once | ||
1188 | FEEDBACK_REENTER(interrupt_return) | ||
1189 | |||
1190 | /* Re-disable interrupts. TRACE_IRQS_OFF in .Lrestore_all. */ | ||
1191 | IRQ_DISABLE(r20,r21) | ||
1192 | |||
1193 | j .Lrestore_all | ||
1194 | |||
1195 | .Lwork_confusion: | ||
1196 | move r0, r28 | ||
1197 | panic "thread_info allwork flags unhandled on userspace resume: %#x" | ||
1198 | |||
1199 | STD_ENDPROC(interrupt_return) | ||
1200 | |||
1201 | /* | ||
1202 | * This interrupt variant clears the INT_INTCTRL_1 interrupt mask bit | ||
1203 | * before returning, so we can properly get more downcalls. | ||
1204 | */ | ||
1205 | .pushsection .text.handle_interrupt_downcall,"ax" | ||
1206 | handle_interrupt_downcall: | ||
1207 | finish_interrupt_save handle_interrupt_downcall | ||
1208 | check_single_stepping normal, .Ldispatch_downcall | ||
1209 | .Ldispatch_downcall: | ||
1210 | |||
1211 | /* Clear INTCTRL_1 from the set of interrupts we ever enable. */ | ||
1212 | GET_INTERRUPTS_ENABLED_MASK_PTR(r30) | ||
1213 | { | ||
1214 | addi r30, r30, 4 | ||
1215 | movei r31, INT_MASK(INT_INTCTRL_1) | ||
1216 | } | ||
1217 | { | ||
1218 | lw r20, r30 | ||
1219 | nor r21, r31, zero | ||
1220 | } | ||
1221 | and r20, r20, r21 | ||
1222 | sw r30, r20 | ||
1223 | |||
1224 | { | ||
1225 | jalr r0 | ||
1226 | PTREGS_PTR(r0, PTREGS_OFFSET_BASE) | ||
1227 | } | ||
1228 | FEEDBACK_REENTER(handle_interrupt_downcall) | ||
1229 | |||
1230 | /* Allow INTCTRL_1 to be enabled next time we enable interrupts. */ | ||
1231 | lw r20, r30 | ||
1232 | or r20, r20, r31 | ||
1233 | sw r30, r20 | ||
1234 | |||
1235 | { | ||
1236 | movei r30, 0 /* not an NMI */ | ||
1237 | j interrupt_return | ||
1238 | } | ||
1239 | STD_ENDPROC(handle_interrupt_downcall) | ||
1240 | |||
1241 | /* | ||
1242 | * Some interrupts don't check for single stepping | ||
1243 | */ | ||
1244 | .pushsection .text.handle_interrupt_no_single_step,"ax" | ||
1245 | handle_interrupt_no_single_step: | ||
1246 | finish_interrupt_save handle_interrupt_no_single_step | ||
1247 | { | ||
1248 | jalr r0 | ||
1249 | PTREGS_PTR(r0, PTREGS_OFFSET_BASE) | ||
1250 | } | ||
1251 | FEEDBACK_REENTER(handle_interrupt_no_single_step) | ||
1252 | { | ||
1253 | movei r30, 0 /* not an NMI */ | ||
1254 | j interrupt_return | ||
1255 | } | ||
1256 | STD_ENDPROC(handle_interrupt_no_single_step) | ||
1257 | |||
1258 | /* | ||
1259 | * "NMI" interrupts mask ALL interrupts before calling the | ||
1260 | * handler, and don't check thread flags, etc., on the way | ||
1261 | * back out. In general, the only things we do here for NMIs | ||
1262 | * are the register save/restore, fixing the PC if we were | ||
1263 | * doing single step, and the dataplane kernel-TLB management. | ||
1264 | * We don't (for example) deal with start/stop of the sched tick. | ||
1265 | */ | ||
1266 | .pushsection .text.handle_nmi,"ax" | ||
1267 | handle_nmi: | ||
1268 | finish_interrupt_save handle_nmi | ||
1269 | check_single_stepping normal, .Ldispatch_nmi | ||
1270 | .Ldispatch_nmi: | ||
1271 | { | ||
1272 | jalr r0 | ||
1273 | PTREGS_PTR(r0, PTREGS_OFFSET_BASE) | ||
1274 | } | ||
1275 | FEEDBACK_REENTER(handle_nmi) | ||
1276 | j interrupt_return | ||
1277 | STD_ENDPROC(handle_nmi) | ||
1278 | |||
1279 | /* | ||
1280 | * Parallel code for syscalls to handle_interrupt. | ||
1281 | */ | ||
1282 | .pushsection .text.handle_syscall,"ax" | ||
1283 | handle_syscall: | ||
1284 | finish_interrupt_save handle_syscall | ||
1285 | |||
1286 | /* | ||
1287 | * Check for if we are single stepping in user level. If so, then | ||
1288 | * we need to restore the PC. | ||
1289 | */ | ||
1290 | check_single_stepping syscall, .Ldispatch_syscall | ||
1291 | .Ldispatch_syscall: | ||
1292 | |||
1293 | /* Enable irqs. */ | ||
1294 | TRACE_IRQS_ON | ||
1295 | IRQ_ENABLE(r20, r21) | ||
1296 | |||
1297 | /* Bump the counter for syscalls made on this tile. */ | ||
1298 | moveli r20, lo16(irq_stat + IRQ_CPUSTAT_SYSCALL_COUNT_OFFSET) | ||
1299 | auli r20, r20, ha16(irq_stat + IRQ_CPUSTAT_SYSCALL_COUNT_OFFSET) | ||
1300 | add r20, r20, tp | ||
1301 | lw r21, r20 | ||
1302 | addi r21, r21, 1 | ||
1303 | sw r20, r21 | ||
1304 | |||
1305 | /* Trace syscalls, if requested. */ | ||
1306 | GET_THREAD_INFO(r31) | ||
1307 | addi r31, r31, THREAD_INFO_FLAGS_OFFSET | ||
1308 | lw r30, r31 | ||
1309 | andi r30, r30, _TIF_SYSCALL_TRACE | ||
1310 | bzt r30, .Lrestore_syscall_regs | ||
1311 | jal do_syscall_trace | ||
1312 | FEEDBACK_REENTER(handle_syscall) | ||
1313 | |||
1314 | /* | ||
1315 | * We always reload our registers from the stack at this | ||
1316 | * point. They might be valid, if we didn't build with | ||
1317 | * TRACE_IRQFLAGS, and this isn't a dataplane tile, and we're not | ||
1318 | * doing syscall tracing, but there are enough cases now that it | ||
1319 | * seems simplest just to do the reload unconditionally. | ||
1320 | */ | ||
1321 | .Lrestore_syscall_regs: | ||
1322 | PTREGS_PTR(r11, PTREGS_OFFSET_REG(0)) | ||
1323 | pop_reg r0, r11 | ||
1324 | pop_reg r1, r11 | ||
1325 | pop_reg r2, r11 | ||
1326 | pop_reg r3, r11 | ||
1327 | pop_reg r4, r11 | ||
1328 | pop_reg r5, r11, PTREGS_OFFSET_SYSCALL - PTREGS_OFFSET_REG(5) | ||
1329 | pop_reg TREG_SYSCALL_NR_NAME, r11 | ||
1330 | |||
1331 | /* Ensure that the syscall number is within the legal range. */ | ||
1332 | moveli r21, __NR_syscalls | ||
1333 | { | ||
1334 | slt_u r21, TREG_SYSCALL_NR_NAME, r21 | ||
1335 | moveli r20, lo16(sys_call_table) | ||
1336 | } | ||
1337 | { | ||
1338 | bbns r21, .Linvalid_syscall | ||
1339 | auli r20, r20, ha16(sys_call_table) | ||
1340 | } | ||
1341 | s2a r20, TREG_SYSCALL_NR_NAME, r20 | ||
1342 | lw r20, r20 | ||
1343 | |||
1344 | /* Jump to syscall handler. */ | ||
1345 | jalr r20; .Lhandle_syscall_link: | ||
1346 | FEEDBACK_REENTER(handle_syscall) | ||
1347 | |||
1348 | /* | ||
1349 | * Write our r0 onto the stack so it gets restored instead | ||
1350 | * of whatever the user had there before. | ||
1351 | */ | ||
1352 | PTREGS_PTR(r29, PTREGS_OFFSET_REG(0)) | ||
1353 | sw r29, r0 | ||
1354 | |||
1355 | /* Do syscall trace again, if requested. */ | ||
1356 | lw r30, r31 | ||
1357 | andi r30, r30, _TIF_SYSCALL_TRACE | ||
1358 | bzt r30, 1f | ||
1359 | jal do_syscall_trace | ||
1360 | FEEDBACK_REENTER(handle_syscall) | ||
1361 | 1: j .Lresume_userspace /* jump into middle of interrupt_return */ | ||
1362 | |||
1363 | .Linvalid_syscall: | ||
1364 | /* Report an invalid syscall back to the user program */ | ||
1365 | { | ||
1366 | PTREGS_PTR(r29, PTREGS_OFFSET_REG(0)) | ||
1367 | movei r28, -ENOSYS | ||
1368 | } | ||
1369 | sw r29, r28 | ||
1370 | j .Lresume_userspace /* jump into middle of interrupt_return */ | ||
1371 | STD_ENDPROC(handle_syscall) | ||
1372 | |||
1373 | /* Return the address for oprofile to suppress in backtraces. */ | ||
1374 | STD_ENTRY_SECTION(handle_syscall_link_address, .text.handle_syscall) | ||
1375 | lnk r0 | ||
1376 | { | ||
1377 | addli r0, r0, .Lhandle_syscall_link - . | ||
1378 | jrp lr | ||
1379 | } | ||
1380 | STD_ENDPROC(handle_syscall_link_address) | ||
1381 | |||
1382 | STD_ENTRY(ret_from_fork) | ||
1383 | jal sim_notify_fork | ||
1384 | jal schedule_tail | ||
1385 | FEEDBACK_REENTER(ret_from_fork) | ||
1386 | j .Lresume_userspace /* jump into middle of interrupt_return */ | ||
1387 | STD_ENDPROC(ret_from_fork) | ||
1388 | |||
1389 | /* | ||
1390 | * Code for ill interrupt. | ||
1391 | */ | ||
1392 | .pushsection .text.handle_ill,"ax" | ||
1393 | handle_ill: | ||
1394 | finish_interrupt_save handle_ill | ||
1395 | |||
1396 | /* | ||
1397 | * Check for if we are single stepping in user level. If so, then | ||
1398 | * we need to restore the PC. | ||
1399 | */ | ||
1400 | check_single_stepping ill, .Ldispatch_normal_ill | ||
1401 | |||
1402 | { | ||
1403 | /* See if the PC is the 1st bundle in the buffer */ | ||
1404 | seq r25, r27, r26 | ||
1405 | |||
1406 | /* Point to the 2nd bundle in the buffer */ | ||
1407 | addi r26, r26, 8 | ||
1408 | } | ||
1409 | { | ||
1410 | /* Point to the original pc */ | ||
1411 | addi r24, r29, SINGLESTEP_STATE_ORIG_PC_OFFSET | ||
1412 | |||
1413 | /* Branch if the PC is the 1st bundle in the buffer */ | ||
1414 | bnz r25, 3f | ||
1415 | } | ||
1416 | { | ||
1417 | /* See if the PC is the 2nd bundle of the buffer */ | ||
1418 | seq r25, r27, r26 | ||
1419 | |||
1420 | /* Set PC to next instruction */ | ||
1421 | addi r24, r29, SINGLESTEP_STATE_NEXT_PC_OFFSET | ||
1422 | } | ||
1423 | { | ||
1424 | /* Point to flags */ | ||
1425 | addi r25, r29, SINGLESTEP_STATE_FLAGS_OFFSET | ||
1426 | |||
1427 | /* Branch if PC is in the second bundle */ | ||
1428 | bz r25, 2f | ||
1429 | } | ||
1430 | /* Load flags */ | ||
1431 | lw r25, r25 | ||
1432 | { | ||
1433 | /* | ||
1434 | * Get the offset for the register to restore | ||
1435 | * Note: the lower bound is 2, so we have implicit scaling by 4. | ||
1436 | * No multiplication of the register number by the size of a register | ||
1437 | * is needed. | ||
1438 | */ | ||
1439 | mm r27, r25, zero, SINGLESTEP_STATE_TARGET_LB, \ | ||
1440 | SINGLESTEP_STATE_TARGET_UB | ||
1441 | |||
1442 | /* Mask Rewrite_LR */ | ||
1443 | andi r25, r25, SINGLESTEP_STATE_MASK_UPDATE | ||
1444 | } | ||
1445 | { | ||
1446 | addi r29, r29, SINGLESTEP_STATE_UPDATE_VALUE_OFFSET | ||
1447 | |||
1448 | /* Don't rewrite temp register */ | ||
1449 | bz r25, 3f | ||
1450 | } | ||
1451 | { | ||
1452 | /* Get the temp value */ | ||
1453 | lw r29, r29 | ||
1454 | |||
1455 | /* Point to where the register is stored */ | ||
1456 | add r27, r27, sp | ||
1457 | } | ||
1458 | |||
1459 | /* Add in the C ABI save area size to the register offset */ | ||
1460 | addi r27, r27, C_ABI_SAVE_AREA_SIZE | ||
1461 | |||
1462 | /* Restore the user's register with the temp value */ | ||
1463 | sw r27, r29 | ||
1464 | j 3f | ||
1465 | |||
1466 | 2: | ||
1467 | /* Must be in the third bundle */ | ||
1468 | addi r24, r29, SINGLESTEP_STATE_BRANCH_NEXT_PC_OFFSET | ||
1469 | |||
1470 | 3: | ||
1471 | /* set PC and continue */ | ||
1472 | lw r26, r24 | ||
1473 | sw r28, r26 | ||
1474 | |||
1475 | /* Clear TIF_SINGLESTEP */ | ||
1476 | GET_THREAD_INFO(r0) | ||
1477 | |||
1478 | addi r1, r0, THREAD_INFO_FLAGS_OFFSET | ||
1479 | { | ||
1480 | lw r2, r1 | ||
1481 | addi r0, r0, THREAD_INFO_TASK_OFFSET /* currently a no-op */ | ||
1482 | } | ||
1483 | andi r2, r2, ~_TIF_SINGLESTEP | ||
1484 | sw r1, r2 | ||
1485 | |||
1486 | /* Issue a sigtrap */ | ||
1487 | { | ||
1488 | lw r0, r0 /* indirect thru thread_info to get task_info*/ | ||
1489 | addi r1, sp, C_ABI_SAVE_AREA_SIZE /* put ptregs pointer into r1 */ | ||
1490 | move r2, zero /* load error code into r2 */ | ||
1491 | } | ||
1492 | |||
1493 | jal send_sigtrap /* issue a SIGTRAP */ | ||
1494 | FEEDBACK_REENTER(handle_ill) | ||
1495 | j .Lresume_userspace /* jump into middle of interrupt_return */ | ||
1496 | |||
1497 | .Ldispatch_normal_ill: | ||
1498 | { | ||
1499 | jalr r0 | ||
1500 | PTREGS_PTR(r0, PTREGS_OFFSET_BASE) | ||
1501 | } | ||
1502 | FEEDBACK_REENTER(handle_ill) | ||
1503 | { | ||
1504 | movei r30, 0 /* not an NMI */ | ||
1505 | j interrupt_return | ||
1506 | } | ||
1507 | STD_ENDPROC(handle_ill) | ||
1508 | |||
1509 | .pushsection .rodata, "a" | ||
1510 | .align 8 | ||
1511 | bpt_code: | ||
1512 | bpt | ||
1513 | ENDPROC(bpt_code) | ||
1514 | .popsection | ||
1515 | |||
1516 | /* Various stub interrupt handlers and syscall handlers */ | ||
1517 | |||
1518 | STD_ENTRY_LOCAL(_kernel_double_fault) | ||
1519 | mfspr r1, EX_CONTEXT_1_0 | ||
1520 | move r2, lr | ||
1521 | move r3, sp | ||
1522 | move r4, r52 | ||
1523 | addi sp, sp, -C_ABI_SAVE_AREA_SIZE | ||
1524 | j kernel_double_fault | ||
1525 | STD_ENDPROC(_kernel_double_fault) | ||
1526 | |||
1527 | STD_ENTRY_LOCAL(bad_intr) | ||
1528 | mfspr r2, EX_CONTEXT_1_0 | ||
1529 | panic "Unhandled interrupt %#x: PC %#lx" | ||
1530 | STD_ENDPROC(bad_intr) | ||
1531 | |||
1532 | /* Put address of pt_regs in reg and jump. */ | ||
1533 | #define PTREGS_SYSCALL(x, reg) \ | ||
1534 | STD_ENTRY(x); \ | ||
1535 | { \ | ||
1536 | PTREGS_PTR(reg, PTREGS_OFFSET_BASE); \ | ||
1537 | j _##x \ | ||
1538 | }; \ | ||
1539 | STD_ENDPROC(x) | ||
1540 | |||
1541 | PTREGS_SYSCALL(sys_execve, r3) | ||
1542 | PTREGS_SYSCALL(sys_sigaltstack, r2) | ||
1543 | PTREGS_SYSCALL(sys_rt_sigreturn, r0) | ||
1544 | |||
1545 | /* Save additional callee-saves to pt_regs, put address in reg and jump. */ | ||
1546 | #define PTREGS_SYSCALL_ALL_REGS(x, reg) \ | ||
1547 | STD_ENTRY(x); \ | ||
1548 | push_extra_callee_saves reg; \ | ||
1549 | j _##x; \ | ||
1550 | STD_ENDPROC(x) | ||
1551 | |||
1552 | PTREGS_SYSCALL_ALL_REGS(sys_fork, r0) | ||
1553 | PTREGS_SYSCALL_ALL_REGS(sys_vfork, r0) | ||
1554 | PTREGS_SYSCALL_ALL_REGS(sys_clone, r4) | ||
1555 | PTREGS_SYSCALL_ALL_REGS(sys_cmpxchg_badaddr, r1) | ||
1556 | |||
1557 | /* | ||
1558 | * This entrypoint is taken for the cmpxchg and atomic_update fast | ||
1559 | * swints. We may wish to generalize it to other fast swints at some | ||
1560 | * point, but for now there are just two very similar ones, which | ||
1561 | * makes it faster. | ||
1562 | * | ||
1563 | * The fast swint code is designed to have a small footprint. It does | ||
1564 | * not save or restore any GPRs, counting on the caller-save registers | ||
1565 | * to be available to it on entry. It does not modify any callee-save | ||
1566 | * registers (including "lr"). It does not check what PL it is being | ||
1567 | * called at, so you'd better not call it other than at PL0. | ||
1568 | * | ||
1569 | * It does not use the stack, but since it might be re-interrupted by | ||
1570 | * a page fault which would assume the stack was valid, it does | ||
1571 | * save/restore the stack pointer and zero it out to make sure it gets reset. | ||
1572 | * Since we always keep interrupts disabled, the hypervisor won't | ||
1573 | * clobber our EX_CONTEXT_1_x registers, so we don't save/restore them | ||
1574 | * (other than to advance the PC on return). | ||
1575 | * | ||
1576 | * We have to manually validate the user vs kernel address range | ||
1577 | * (since at PL1 we can read/write both), and for performance reasons | ||
1578 | * we don't allow cmpxchg on the fc000000 memory region, since we only | ||
1579 | * validate that the user address is below PAGE_OFFSET. | ||
1580 | * | ||
1581 | * We place it in the __HEAD section to ensure it is relatively | ||
1582 | * near to the intvec_SWINT_1 code (reachable by a conditional branch). | ||
1583 | * | ||
1584 | * Must match register usage in do_page_fault(). | ||
1585 | */ | ||
1586 | __HEAD | ||
1587 | .align 64 | ||
1588 | /* Align much later jump on the start of a cache line. */ | ||
1589 | #if !ATOMIC_LOCKS_FOUND_VIA_TABLE() | ||
1590 | nop; nop | ||
1591 | #endif | ||
1592 | ENTRY(sys_cmpxchg) | ||
1593 | |||
1594 | /* | ||
1595 | * Save "sp" and set it zero for any possible page fault. | ||
1596 | * | ||
1597 | * HACK: We want to both zero sp and check r0's alignment, | ||
1598 | * so we do both at once. If "sp" becomes nonzero we | ||
1599 | * know r0 is unaligned and branch to the error handler that | ||
1600 | * restores sp, so this is OK. | ||
1601 | * | ||
1602 | * ICS is disabled right now so having a garbage but nonzero | ||
1603 | * sp is OK, since we won't execute any faulting instructions | ||
1604 | * when it is nonzero. | ||
1605 | */ | ||
1606 | { | ||
1607 | move r27, sp | ||
1608 | andi sp, r0, 3 | ||
1609 | } | ||
1610 | |||
1611 | /* | ||
1612 | * Get the lock address in ATOMIC_LOCK_REG, and also validate that the | ||
1613 | * address is less than PAGE_OFFSET, since that won't trap at PL1. | ||
1614 | * We only use bits less than PAGE_SHIFT to avoid having to worry | ||
1615 | * about aliasing among multiple mappings of the same physical page, | ||
1616 | * and we ignore the low 3 bits so we have one lock that covers | ||
1617 | * both a cmpxchg64() and a cmpxchg() on either its low or high word. | ||
1618 | * NOTE: this code must match __atomic_hashed_lock() in lib/atomic.c. | ||
1619 | */ | ||
1620 | |||
1621 | #if ATOMIC_LOCKS_FOUND_VIA_TABLE() | ||
1622 | { | ||
1623 | /* Check for unaligned input. */ | ||
1624 | bnz sp, .Lcmpxchg_badaddr | ||
1625 | mm r25, r0, zero, 3, PAGE_SHIFT-1 | ||
1626 | } | ||
1627 | { | ||
1628 | crc32_32 r25, zero, r25 | ||
1629 | moveli r21, lo16(atomic_lock_ptr) | ||
1630 | } | ||
1631 | { | ||
1632 | auli r21, r21, ha16(atomic_lock_ptr) | ||
1633 | auli r23, zero, hi16(PAGE_OFFSET) /* hugepage-aligned */ | ||
1634 | } | ||
1635 | { | ||
1636 | shri r20, r25, 32 - ATOMIC_HASH_L1_SHIFT | ||
1637 | slt_u r23, r0, r23 | ||
1638 | |||
1639 | /* | ||
1640 | * Ensure that the TLB is loaded before we take out the lock. | ||
1641 | * On TILEPro, this will start fetching the value all the way | ||
1642 | * into our L1 as well (and if it gets modified before we | ||
1643 | * grab the lock, it will be invalidated from our cache | ||
1644 | * before we reload it). On tile64, we'll start fetching it | ||
1645 | * into our L1 if we're the home, and if we're not, we'll | ||
1646 | * still at least start fetching it into the home's L2. | ||
1647 | */ | ||
1648 | lw r26, r0 | ||
1649 | } | ||
1650 | { | ||
1651 | s2a r21, r20, r21 | ||
1652 | bbns r23, .Lcmpxchg_badaddr | ||
1653 | } | ||
1654 | { | ||
1655 | lw r21, r21 | ||
1656 | seqi r23, TREG_SYSCALL_NR_NAME, __NR_FAST_cmpxchg64 | ||
1657 | andi r25, r25, ATOMIC_HASH_L2_SIZE - 1 | ||
1658 | } | ||
1659 | { | ||
1660 | /* Branch away at this point if we're doing a 64-bit cmpxchg. */ | ||
1661 | bbs r23, .Lcmpxchg64 | ||
1662 | andi r23, r0, 7 /* Precompute alignment for cmpxchg64. */ | ||
1663 | } | ||
1664 | |||
1665 | { | ||
1666 | /* | ||
1667 | * We very carefully align the code that actually runs with | ||
1668 | * the lock held (nine bundles) so that we know it is all in | ||
1669 | * the icache when we start. This instruction (the jump) is | ||
1670 | * at the start of the first cache line, address zero mod 64; | ||
1671 | * we jump to somewhere in the second cache line to issue the | ||
1672 | * tns, then jump back to finish up. | ||
1673 | */ | ||
1674 | s2a ATOMIC_LOCK_REG_NAME, r25, r21 | ||
1675 | j .Lcmpxchg32_tns | ||
1676 | } | ||
1677 | |||
1678 | #else /* ATOMIC_LOCKS_FOUND_VIA_TABLE() */ | ||
1679 | { | ||
1680 | /* Check for unaligned input. */ | ||
1681 | bnz sp, .Lcmpxchg_badaddr | ||
1682 | auli r23, zero, hi16(PAGE_OFFSET) /* hugepage-aligned */ | ||
1683 | } | ||
1684 | { | ||
1685 | /* | ||
1686 | * Slide bits into position for 'mm'. We want to ignore | ||
1687 | * the low 3 bits of r0, and consider only the next | ||
1688 | * ATOMIC_HASH_SHIFT bits. | ||
1689 | * Because of C pointer arithmetic, we want to compute this: | ||
1690 | * | ||
1691 | * ((char*)atomic_locks + | ||
1692 | * (((r0 >> 3) & (1 << (ATOMIC_HASH_SIZE - 1))) << 2)) | ||
1693 | * | ||
1694 | * Instead of two shifts we just ">> 1", and use 'mm' | ||
1695 | * to ignore the low and high bits we don't want. | ||
1696 | */ | ||
1697 | shri r25, r0, 1 | ||
1698 | |||
1699 | slt_u r23, r0, r23 | ||
1700 | |||
1701 | /* | ||
1702 | * Ensure that the TLB is loaded before we take out the lock. | ||
1703 | * On tilepro, this will start fetching the value all the way | ||
1704 | * into our L1 as well (and if it gets modified before we | ||
1705 | * grab the lock, it will be invalidated from our cache | ||
1706 | * before we reload it). On tile64, we'll start fetching it | ||
1707 | * into our L1 if we're the home, and if we're not, we'll | ||
1708 | * still at least start fetching it into the home's L2. | ||
1709 | */ | ||
1710 | lw r26, r0 | ||
1711 | } | ||
1712 | { | ||
1713 | /* atomic_locks is page aligned so this suffices to get its addr. */ | ||
1714 | auli r21, zero, hi16(atomic_locks) | ||
1715 | |||
1716 | bbns r23, .Lcmpxchg_badaddr | ||
1717 | } | ||
1718 | { | ||
1719 | /* | ||
1720 | * Insert the hash bits into the page-aligned pointer. | ||
1721 | * ATOMIC_HASH_SHIFT is so big that we don't actually hash | ||
1722 | * the unmasked address bits, as that may cause unnecessary | ||
1723 | * collisions. | ||
1724 | */ | ||
1725 | mm ATOMIC_LOCK_REG_NAME, r25, r21, 2, (ATOMIC_HASH_SHIFT + 2) - 1 | ||
1726 | |||
1727 | seqi r23, TREG_SYSCALL_NR_NAME, __NR_FAST_cmpxchg64 | ||
1728 | } | ||
1729 | { | ||
1730 | /* Branch away at this point if we're doing a 64-bit cmpxchg. */ | ||
1731 | bbs r23, .Lcmpxchg64 | ||
1732 | andi r23, r0, 7 /* Precompute alignment for cmpxchg64. */ | ||
1733 | } | ||
1734 | { | ||
1735 | /* | ||
1736 | * We very carefully align the code that actually runs with | ||
1737 | * the lock held (nine bundles) so that we know it is all in | ||
1738 | * the icache when we start. This instruction (the jump) is | ||
1739 | * at the start of the first cache line, address zero mod 64; | ||
1740 | * we jump to somewhere in the second cache line to issue the | ||
1741 | * tns, then jump back to finish up. | ||
1742 | */ | ||
1743 | j .Lcmpxchg32_tns | ||
1744 | } | ||
1745 | |||
1746 | #endif /* ATOMIC_LOCKS_FOUND_VIA_TABLE() */ | ||
1747 | |||
1748 | ENTRY(__sys_cmpxchg_grab_lock) | ||
1749 | |||
1750 | /* | ||
1751 | * Perform the actual cmpxchg or atomic_update. | ||
1752 | * Note that __futex_mark_unlocked() in uClibc relies on | ||
1753 | * atomic_update() to always perform an "mf", so don't make | ||
1754 | * it optional or conditional without modifying that code. | ||
1755 | */ | ||
1756 | .Ldo_cmpxchg32: | ||
1757 | { | ||
1758 | lw r21, r0 | ||
1759 | seqi r23, TREG_SYSCALL_NR_NAME, __NR_FAST_atomic_update | ||
1760 | move r24, r2 | ||
1761 | } | ||
1762 | { | ||
1763 | seq r22, r21, r1 /* See if cmpxchg matches. */ | ||
1764 | and r25, r21, r1 /* If atomic_update, compute (*mem & mask) */ | ||
1765 | } | ||
1766 | { | ||
1767 | or r22, r22, r23 /* Skip compare branch for atomic_update. */ | ||
1768 | add r25, r25, r2 /* Compute (*mem & mask) + addend. */ | ||
1769 | } | ||
1770 | { | ||
1771 | mvnz r24, r23, r25 /* Use atomic_update value if appropriate. */ | ||
1772 | bbns r22, .Lcmpxchg32_mismatch | ||
1773 | } | ||
1774 | sw r0, r24 | ||
1775 | |||
1776 | /* Do slow mtspr here so the following "mf" waits less. */ | ||
1777 | { | ||
1778 | move sp, r27 | ||
1779 | mtspr EX_CONTEXT_1_0, r28 | ||
1780 | } | ||
1781 | mf | ||
1782 | |||
1783 | /* The following instruction is the start of the second cache line. */ | ||
1784 | { | ||
1785 | move r0, r21 | ||
1786 | sw ATOMIC_LOCK_REG_NAME, zero | ||
1787 | } | ||
1788 | iret | ||
1789 | |||
1790 | /* Duplicated code here in the case where we don't overlap "mf" */ | ||
1791 | .Lcmpxchg32_mismatch: | ||
1792 | { | ||
1793 | move r0, r21 | ||
1794 | sw ATOMIC_LOCK_REG_NAME, zero | ||
1795 | } | ||
1796 | { | ||
1797 | move sp, r27 | ||
1798 | mtspr EX_CONTEXT_1_0, r28 | ||
1799 | } | ||
1800 | iret | ||
1801 | |||
1802 | /* | ||
1803 | * The locking code is the same for 32-bit cmpxchg/atomic_update, | ||
1804 | * and for 64-bit cmpxchg. We provide it as a macro and put | ||
1805 | * it into both versions. We can't share the code literally | ||
1806 | * since it depends on having the right branch-back address. | ||
1807 | * Note that the first few instructions should share the cache | ||
1808 | * line with the second half of the actual locked code. | ||
1809 | */ | ||
1810 | .macro cmpxchg_lock, bitwidth | ||
1811 | |||
1812 | /* Lock; if we succeed, jump back up to the read-modify-write. */ | ||
1813 | #ifdef CONFIG_SMP | ||
1814 | tns r21, ATOMIC_LOCK_REG_NAME | ||
1815 | #else | ||
1816 | /* | ||
1817 | * Non-SMP preserves all the lock infrastructure, to keep the | ||
1818 | * code simpler for the interesting (SMP) case. However, we do | ||
1819 | * one small optimization here and in atomic_asm.S, which is | ||
1820 | * to fake out acquiring the actual lock in the atomic_lock table. | ||
1821 | */ | ||
1822 | movei r21, 0 | ||
1823 | #endif | ||
1824 | |||
1825 | /* Issue the slow SPR here while the tns result is in flight. */ | ||
1826 | mfspr r28, EX_CONTEXT_1_0 | ||
1827 | |||
1828 | { | ||
1829 | addi r28, r28, 8 /* return to the instruction after the swint1 */ | ||
1830 | bzt r21, .Ldo_cmpxchg\bitwidth | ||
1831 | } | ||
1832 | /* | ||
1833 | * The preceding instruction is the last thing that must be | ||
1834 | * on the second cache line. | ||
1835 | */ | ||
1836 | |||
1837 | #ifdef CONFIG_SMP | ||
1838 | /* | ||
1839 | * We failed to acquire the tns lock on our first try. Now use | ||
1840 | * bounded exponential backoff to retry, like __atomic_spinlock(). | ||
1841 | */ | ||
1842 | { | ||
1843 | moveli r23, 2048 /* maximum backoff time in cycles */ | ||
1844 | moveli r25, 32 /* starting backoff time in cycles */ | ||
1845 | } | ||
1846 | 1: mfspr r26, CYCLE_LOW /* get start point for this backoff */ | ||
1847 | 2: mfspr r22, CYCLE_LOW /* test to see if we've backed off enough */ | ||
1848 | sub r22, r22, r26 | ||
1849 | slt r22, r22, r25 | ||
1850 | bbst r22, 2b | ||
1851 | { | ||
1852 | shli r25, r25, 1 /* double the backoff; retry the tns */ | ||
1853 | tns r21, ATOMIC_LOCK_REG_NAME | ||
1854 | } | ||
1855 | slt r26, r23, r25 /* is the proposed backoff too big? */ | ||
1856 | { | ||
1857 | mvnz r25, r26, r23 | ||
1858 | bzt r21, .Ldo_cmpxchg\bitwidth | ||
1859 | } | ||
1860 | j 1b | ||
1861 | #endif /* CONFIG_SMP */ | ||
1862 | .endm | ||
1863 | |||
1864 | .Lcmpxchg32_tns: | ||
1865 | cmpxchg_lock 32 | ||
1866 | |||
1867 | /* | ||
1868 | * This code is invoked from sys_cmpxchg after most of the | ||
1869 | * preconditions have been checked. We still need to check | ||
1870 | * that r0 is 8-byte aligned, since if it's not we won't | ||
1871 | * actually be atomic. However, ATOMIC_LOCK_REG has the atomic | ||
1872 | * lock pointer and r27/r28 have the saved SP/PC. | ||
1873 | * r23 is holding "r0 & 7" so we can test for alignment. | ||
1874 | * The compare value is in r2/r3; the new value is in r4/r5. | ||
1875 | * On return, we must put the old value in r0/r1. | ||
1876 | */ | ||
1877 | .align 64 | ||
1878 | .Lcmpxchg64: | ||
1879 | { | ||
1880 | #if ATOMIC_LOCKS_FOUND_VIA_TABLE() | ||
1881 | s2a ATOMIC_LOCK_REG_NAME, r25, r21 | ||
1882 | #endif | ||
1883 | bzt r23, .Lcmpxchg64_tns | ||
1884 | } | ||
1885 | j .Lcmpxchg_badaddr | ||
1886 | |||
1887 | .Ldo_cmpxchg64: | ||
1888 | { | ||
1889 | lw r21, r0 | ||
1890 | addi r25, r0, 4 | ||
1891 | } | ||
1892 | { | ||
1893 | lw r1, r25 | ||
1894 | } | ||
1895 | seq r26, r21, r2 | ||
1896 | { | ||
1897 | bz r26, .Lcmpxchg64_mismatch | ||
1898 | seq r26, r1, r3 | ||
1899 | } | ||
1900 | { | ||
1901 | bz r26, .Lcmpxchg64_mismatch | ||
1902 | } | ||
1903 | sw r0, r4 | ||
1904 | sw r25, r5 | ||
1905 | |||
1906 | /* | ||
1907 | * The 32-bit path provides optimized "match" and "mismatch" | ||
1908 | * iret paths, but we don't have enough bundles in this cache line | ||
1909 | * to do that, so we just make even the "mismatch" path do an "mf". | ||
1910 | */ | ||
1911 | .Lcmpxchg64_mismatch: | ||
1912 | { | ||
1913 | move sp, r27 | ||
1914 | mtspr EX_CONTEXT_1_0, r28 | ||
1915 | } | ||
1916 | mf | ||
1917 | { | ||
1918 | move r0, r21 | ||
1919 | sw ATOMIC_LOCK_REG_NAME, zero | ||
1920 | } | ||
1921 | iret | ||
1922 | |||
1923 | .Lcmpxchg64_tns: | ||
1924 | cmpxchg_lock 64 | ||
1925 | |||
1926 | |||
1927 | /* | ||
1928 | * Reset sp and revector to sys_cmpxchg_badaddr(), which will | ||
1929 | * just raise the appropriate signal and exit. Doing it this | ||
1930 | * way means we don't have to duplicate the code in intvec.S's | ||
1931 | * int_hand macro that locates the top of the stack. | ||
1932 | */ | ||
1933 | .Lcmpxchg_badaddr: | ||
1934 | { | ||
1935 | moveli TREG_SYSCALL_NR_NAME, __NR_cmpxchg_badaddr | ||
1936 | move sp, r27 | ||
1937 | } | ||
1938 | j intvec_SWINT_1 | ||
1939 | ENDPROC(sys_cmpxchg) | ||
1940 | ENTRY(__sys_cmpxchg_end) | ||
1941 | |||
1942 | |||
1943 | /* The single-step support may need to read all the registers. */ | ||
1944 | int_unalign: | ||
1945 | push_extra_callee_saves r0 | ||
1946 | j do_trap | ||
1947 | |||
1948 | /* Include .intrpt1 array of interrupt vectors */ | ||
1949 | .section ".intrpt1", "ax" | ||
1950 | |||
1951 | #define op_handle_perf_interrupt bad_intr | ||
1952 | #define op_handle_aux_perf_interrupt bad_intr | ||
1953 | |||
1954 | #ifndef CONFIG_HARDWALL | ||
1955 | #define do_hardwall_trap bad_intr | ||
1956 | #endif | ||
1957 | |||
1958 | int_hand INT_ITLB_MISS, ITLB_MISS, \ | ||
1959 | do_page_fault, handle_interrupt_no_single_step | ||
1960 | int_hand INT_MEM_ERROR, MEM_ERROR, bad_intr | ||
1961 | int_hand INT_ILL, ILL, do_trap, handle_ill | ||
1962 | int_hand INT_GPV, GPV, do_trap | ||
1963 | int_hand INT_SN_ACCESS, SN_ACCESS, do_trap | ||
1964 | int_hand INT_IDN_ACCESS, IDN_ACCESS, do_trap | ||
1965 | int_hand INT_UDN_ACCESS, UDN_ACCESS, do_trap | ||
1966 | int_hand INT_IDN_REFILL, IDN_REFILL, bad_intr | ||
1967 | int_hand INT_UDN_REFILL, UDN_REFILL, bad_intr | ||
1968 | int_hand INT_IDN_COMPLETE, IDN_COMPLETE, bad_intr | ||
1969 | int_hand INT_UDN_COMPLETE, UDN_COMPLETE, bad_intr | ||
1970 | int_hand INT_SWINT_3, SWINT_3, do_trap | ||
1971 | int_hand INT_SWINT_2, SWINT_2, do_trap | ||
1972 | int_hand INT_SWINT_1, SWINT_1, SYSCALL, handle_syscall | ||
1973 | int_hand INT_SWINT_0, SWINT_0, do_trap | ||
1974 | int_hand INT_UNALIGN_DATA, UNALIGN_DATA, int_unalign | ||
1975 | int_hand INT_DTLB_MISS, DTLB_MISS, do_page_fault | ||
1976 | int_hand INT_DTLB_ACCESS, DTLB_ACCESS, do_page_fault | ||
1977 | int_hand INT_DMATLB_MISS, DMATLB_MISS, do_page_fault | ||
1978 | int_hand INT_DMATLB_ACCESS, DMATLB_ACCESS, do_page_fault | ||
1979 | int_hand INT_SNITLB_MISS, SNITLB_MISS, do_page_fault | ||
1980 | int_hand INT_SN_NOTIFY, SN_NOTIFY, bad_intr | ||
1981 | int_hand INT_SN_FIREWALL, SN_FIREWALL, do_hardwall_trap | ||
1982 | int_hand INT_IDN_FIREWALL, IDN_FIREWALL, bad_intr | ||
1983 | int_hand INT_UDN_FIREWALL, UDN_FIREWALL, do_hardwall_trap | ||
1984 | int_hand INT_TILE_TIMER, TILE_TIMER, do_timer_interrupt | ||
1985 | int_hand INT_IDN_TIMER, IDN_TIMER, bad_intr | ||
1986 | int_hand INT_UDN_TIMER, UDN_TIMER, bad_intr | ||
1987 | int_hand INT_DMA_NOTIFY, DMA_NOTIFY, bad_intr | ||
1988 | int_hand INT_IDN_CA, IDN_CA, bad_intr | ||
1989 | int_hand INT_UDN_CA, UDN_CA, bad_intr | ||
1990 | int_hand INT_IDN_AVAIL, IDN_AVAIL, bad_intr | ||
1991 | int_hand INT_UDN_AVAIL, UDN_AVAIL, bad_intr | ||
1992 | int_hand INT_PERF_COUNT, PERF_COUNT, \ | ||
1993 | op_handle_perf_interrupt, handle_nmi | ||
1994 | int_hand INT_INTCTRL_3, INTCTRL_3, bad_intr | ||
1995 | int_hand INT_INTCTRL_2, INTCTRL_2, bad_intr | ||
1996 | dc_dispatch INT_INTCTRL_1, INTCTRL_1 | ||
1997 | int_hand INT_INTCTRL_0, INTCTRL_0, bad_intr | ||
1998 | int_hand INT_MESSAGE_RCV_DWNCL, MESSAGE_RCV_DWNCL, \ | ||
1999 | hv_message_intr, handle_interrupt_downcall | ||
2000 | int_hand INT_DEV_INTR_DWNCL, DEV_INTR_DWNCL, \ | ||
2001 | tile_dev_intr, handle_interrupt_downcall | ||
2002 | int_hand INT_I_ASID, I_ASID, bad_intr | ||
2003 | int_hand INT_D_ASID, D_ASID, bad_intr | ||
2004 | int_hand INT_DMATLB_MISS_DWNCL, DMATLB_MISS_DWNCL, \ | ||
2005 | do_page_fault, handle_interrupt_downcall | ||
2006 | int_hand INT_SNITLB_MISS_DWNCL, SNITLB_MISS_DWNCL, \ | ||
2007 | do_page_fault, handle_interrupt_downcall | ||
2008 | int_hand INT_DMATLB_ACCESS_DWNCL, DMATLB_ACCESS_DWNCL, \ | ||
2009 | do_page_fault, handle_interrupt_downcall | ||
2010 | int_hand INT_SN_CPL, SN_CPL, bad_intr | ||
2011 | int_hand INT_DOUBLE_FAULT, DOUBLE_FAULT, do_trap | ||
2012 | #if CHIP_HAS_AUX_PERF_COUNTERS() | ||
2013 | int_hand INT_AUX_PERF_COUNT, AUX_PERF_COUNT, \ | ||
2014 | op_handle_aux_perf_interrupt, handle_nmi | ||
2015 | #endif | ||
2016 | |||
2017 | /* Synthetic interrupt delivered only by the simulator */ | ||
2018 | int_hand INT_BREAKPOINT, BREAKPOINT, do_breakpoint | ||