1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Test the powerpc alignment handler on POWER8/POWER9
4  *
5  * Copyright (C) 2017 IBM Corporation (Michael Neuling, Andrew Donnellan)
6  */
7 
8 /*
9  * This selftest exercises the powerpc alignment fault handler.
10  *
11  * We create two sets of source and destination buffers, one in regular memory,
12  * the other cache-inhibited (by default we use /dev/fb0 for this, but an
13  * alterative path for cache-inhibited memory may be provided).
14  *
15  * One way to get cache-inhibited memory is to use the "mem" kernel parameter
16  * to limit the kernel to less memory than actually exists.  Addresses above
17  * the limit may still be accessed but will be treated as cache-inhibited. For
18  * example, if there is actually 4GB of memory and the parameter "mem=3GB" is
19  * used, memory from address 0xC0000000 onwards is treated as cache-inhibited.
20  * To access this region /dev/mem is used. The kernel should be configured
21  * without CONFIG_STRICT_DEVMEM. In this case use:
22  *         ./alignment_handler /dev/mem 0xc0000000
23  *
24  * We initialise the source buffers, then use whichever set of load/store
25  * instructions is under test to copy bytes from the source buffers to the
26  * destination buffers. For the regular buffers, these instructions will
27  * execute normally. For the cache-inhibited buffers, these instructions
28  * will trap and cause an alignment fault, and the alignment fault handler
29  * will emulate the particular instruction under test. We then compare the
30  * destination buffers to ensure that the native and emulated cases give the
31  * same result.
32  *
33  * TODO:
34  *   - Any FIXMEs below
35  *   - Test VSX regs < 32 and > 32
36  *   - Test all loads and stores
37  *   - Check update forms do update register
38  *   - Test alignment faults over page boundary
39  *
40  * Some old binutils may not support all the instructions.
41  */
42 
43 
44 #include <sys/mman.h>
45 #include <sys/types.h>
46 #include <sys/stat.h>
47 #include <fcntl.h>
48 #include <unistd.h>
49 #include <stdbool.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <assert.h>
54 #include <getopt.h>
55 #include <setjmp.h>
56 #include <signal.h>
57 
58 #include <asm/cputable.h>
59 
60 #include "utils.h"
61 
62 int bufsize;
63 int debug;
64 int testing;
65 volatile int gotsig;
66 char *cipath = "/dev/fb0";
67 long cioffset;
68 
69 void sighandler(int sig, siginfo_t *info, void *ctx)
70 {
71 	ucontext_t *ucp = ctx;
72 
73 	if (!testing) {
74 		signal(sig, SIG_DFL);
75 		kill(0, sig);
76 	}
77 	gotsig = sig;
78 #ifdef __powerpc64__
79 	ucp->uc_mcontext.gp_regs[PT_NIP] += 4;
80 #else
81 	ucp->uc_mcontext.uc_regs->gregs[PT_NIP] += 4;
82 #endif
83 }
84 
85 #define XFORM(reg, n)  " " #reg " ,%"#n",%2 ;"
86 #define DFORM(reg, n)  " " #reg " ,0(%"#n") ;"
87 
88 #define TEST(name, ld_op, st_op, form, ld_reg, st_reg)		\
89 	void test_##name(char *s, char *d)			\
90 	{							\
91 		asm volatile(					\
92 			#ld_op form(ld_reg, 0)			\
93 			#st_op form(st_reg, 1)			\
94 			:: "r"(s), "r"(d), "r"(0)		\
95 			: "memory", "vs0", "vs32", "r31");	\
96 	}							\
97 	rc |= do_test(#name, test_##name)
98 
99 #define LOAD_VSX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 32, 32)
100 #define STORE_VSX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 32)
101 #define LOAD_VSX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 32, 32)
102 #define STORE_VSX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 32)
103 #define LOAD_VMX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 0, 32)
104 #define STORE_VMX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 0)
105 #define LOAD_VMX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 0, 32)
106 #define STORE_VMX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 0)
107 
108 #define LOAD_XFORM_TEST(op) TEST(op, op, stdx, XFORM, 31, 31)
109 #define STORE_XFORM_TEST(op) TEST(op, ldx, op, XFORM, 31, 31)
110 #define LOAD_DFORM_TEST(op) TEST(op, op, std, DFORM, 31, 31)
111 #define STORE_DFORM_TEST(op) TEST(op, ld, op, DFORM, 31, 31)
112 
113 #define LOAD_FLOAT_DFORM_TEST(op)  TEST(op, op, stfd, DFORM, 0, 0)
114 #define STORE_FLOAT_DFORM_TEST(op) TEST(op, lfd, op, DFORM, 0, 0)
115 #define LOAD_FLOAT_XFORM_TEST(op)  TEST(op, op, stfdx, XFORM, 0, 0)
116 #define STORE_FLOAT_XFORM_TEST(op) TEST(op, lfdx, op, XFORM, 0, 0)
117 
118 
119 /* FIXME: Unimplemented tests: */
120 // STORE_DFORM_TEST(stq)   /* FIXME: need two registers for quad */
121 // STORE_DFORM_TEST(stswi) /* FIXME: string instruction */
122 
123 // STORE_XFORM_TEST(stwat) /* AMO can't emulate or run on CI */
124 // STORE_XFORM_TEST(stdat) /* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
125 
126 
127 /* preload byte by byte */
128 void preload_data(void *dst, int offset, int width)
129 {
130 	char *c = dst;
131 	int i;
132 
133 	c += offset;
134 
135 	for (i = 0 ; i < width ; i++)
136 		c[i] = i;
137 }
138 
139 int test_memcpy(void *dst, void *src, int size, int offset,
140 		void (*test_func)(char *, char *))
141 {
142 	char *s, *d;
143 
144 	s = src;
145 	s += offset;
146 	d = dst;
147 	d += offset;
148 
149 	assert(size == 16);
150 	gotsig = 0;
151 	testing = 1;
152 
153 	test_func(s, d); /* run the actual test */
154 
155 	testing = 0;
156 	if (gotsig) {
157 		if (debug)
158 			printf("  Got signal %i\n", gotsig);
159 		return 1;
160 	}
161 	return 0;
162 }
163 
164 void dumpdata(char *s1, char *s2, int n, char *test_name)
165 {
166 	int i;
167 
168 	printf("  %s: unexpected result:\n", test_name);
169 	printf("    mem:");
170 	for (i = 0; i < n; i++)
171 		printf(" %02x", s1[i]);
172 	printf("\n");
173 	printf("    ci: ");
174 	for (i = 0; i < n; i++)
175 		printf(" %02x", s2[i]);
176 	printf("\n");
177 }
178 
179 int test_memcmp(void *s1, void *s2, int n, int offset, char *test_name)
180 {
181 	char *s1c, *s2c;
182 
183 	s1c = s1;
184 	s1c += offset;
185 	s2c = s2;
186 	s2c += offset;
187 
188 	if (memcmp(s1c, s2c, n)) {
189 		if (debug) {
190 			printf("\n  Compare failed. Offset:%i length:%i\n",
191 			       offset, n);
192 			dumpdata(s1c, s2c, n, test_name);
193 		}
194 		return 1;
195 	}
196 	return 0;
197 }
198 
199 /*
200  * Do two memcpy tests using the same instructions. One cachable
201  * memory and the other doesn't.
202  */
203 int do_test(char *test_name, void (*test_func)(char *, char *))
204 {
205 	int offset, width, fd, rc, r;
206 	void *mem0, *mem1, *ci0, *ci1;
207 
208 	printf("\tDoing %s:\t", test_name);
209 
210 	fd = open(cipath, O_RDWR);
211 	if (fd < 0) {
212 		printf("\n");
213 		perror("Can't open ci file now?");
214 		return 1;
215 	}
216 
217 	ci0 = mmap(NULL, bufsize, PROT_WRITE | PROT_READ, MAP_SHARED,
218 		   fd, cioffset);
219 	ci1 = mmap(NULL, bufsize, PROT_WRITE | PROT_READ, MAP_SHARED,
220 		   fd, cioffset + bufsize);
221 
222 	if ((ci0 == MAP_FAILED) || (ci1 == MAP_FAILED)) {
223 		printf("\n");
224 		perror("mmap failed");
225 		SKIP_IF(1);
226 	}
227 
228 	rc = posix_memalign(&mem0, bufsize, bufsize);
229 	if (rc) {
230 		printf("\n");
231 		return rc;
232 	}
233 
234 	rc = posix_memalign(&mem1, bufsize, bufsize);
235 	if (rc) {
236 		printf("\n");
237 		free(mem0);
238 		return rc;
239 	}
240 
241 	rc = 0;
242 	/* offset = 0 no alignment fault, so skip */
243 	for (offset = 1; offset < 16; offset++) {
244 		width = 16; /* vsx == 16 bytes */
245 		r = 0;
246 
247 		/* load pattern into memory byte by byte */
248 		preload_data(ci0, offset, width);
249 		preload_data(mem0, offset, width); // FIXME: remove??
250 		memcpy(ci0, mem0, bufsize);
251 		memcpy(ci1, mem1, bufsize); /* initialise output to the same */
252 
253 		/* sanity check */
254 		test_memcmp(mem0, ci0, width, offset, test_name);
255 
256 		r |= test_memcpy(ci1,  ci0,  width, offset, test_func);
257 		r |= test_memcpy(mem1, mem0, width, offset, test_func);
258 		if (r && !debug) {
259 			printf("FAILED: Got signal");
260 			rc = 1;
261 			break;
262 		}
263 
264 		r |= test_memcmp(mem1, ci1, width, offset, test_name);
265 		if (r && !debug) {
266 			printf("FAILED: Wrong Data");
267 			rc = 1;
268 			break;
269 		}
270 	}
271 
272 	if (rc == 0)
273 		printf("PASSED");
274 
275 	printf("\n");
276 
277 	munmap(ci0, bufsize);
278 	munmap(ci1, bufsize);
279 	free(mem0);
280 	free(mem1);
281 	close(fd);
282 
283 	return rc;
284 }
285 
286 static bool can_open_cifile(void)
287 {
288 	int fd;
289 
290 	fd = open(cipath, O_RDWR);
291 	if (fd < 0)
292 		return false;
293 
294 	close(fd);
295 	return true;
296 }
297 
298 int test_alignment_handler_vsx_206(void)
299 {
300 	int rc = 0;
301 
302 	SKIP_IF(!can_open_cifile());
303 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
304 
305 	printf("VSX: 2.06B\n");
306 	LOAD_VSX_XFORM_TEST(lxvd2x);
307 	LOAD_VSX_XFORM_TEST(lxvw4x);
308 	LOAD_VSX_XFORM_TEST(lxsdx);
309 	LOAD_VSX_XFORM_TEST(lxvdsx);
310 	STORE_VSX_XFORM_TEST(stxvd2x);
311 	STORE_VSX_XFORM_TEST(stxvw4x);
312 	STORE_VSX_XFORM_TEST(stxsdx);
313 	return rc;
314 }
315 
316 int test_alignment_handler_vsx_207(void)
317 {
318 	int rc = 0;
319 
320 	SKIP_IF(!can_open_cifile());
321 	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_2_07));
322 
323 	printf("VSX: 2.07B\n");
324 	LOAD_VSX_XFORM_TEST(lxsspx);
325 	LOAD_VSX_XFORM_TEST(lxsiwax);
326 	LOAD_VSX_XFORM_TEST(lxsiwzx);
327 	STORE_VSX_XFORM_TEST(stxsspx);
328 	STORE_VSX_XFORM_TEST(stxsiwx);
329 	return rc;
330 }
331 
332 int test_alignment_handler_vsx_300(void)
333 {
334 	int rc = 0;
335 
336 	SKIP_IF(!can_open_cifile());
337 
338 	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_3_00));
339 	printf("VSX: 3.00B\n");
340 	LOAD_VMX_DFORM_TEST(lxsd);
341 	LOAD_VSX_XFORM_TEST(lxsibzx);
342 	LOAD_VSX_XFORM_TEST(lxsihzx);
343 	LOAD_VMX_DFORM_TEST(lxssp);
344 	LOAD_VSX_DFORM_TEST(lxv);
345 	LOAD_VSX_XFORM_TEST(lxvb16x);
346 	LOAD_VSX_XFORM_TEST(lxvh8x);
347 	LOAD_VSX_XFORM_TEST(lxvx);
348 	LOAD_VSX_XFORM_TEST(lxvwsx);
349 	LOAD_VSX_XFORM_TEST(lxvl);
350 	LOAD_VSX_XFORM_TEST(lxvll);
351 	STORE_VMX_DFORM_TEST(stxsd);
352 	STORE_VSX_XFORM_TEST(stxsibx);
353 	STORE_VSX_XFORM_TEST(stxsihx);
354 	STORE_VMX_DFORM_TEST(stxssp);
355 	STORE_VSX_DFORM_TEST(stxv);
356 	STORE_VSX_XFORM_TEST(stxvb16x);
357 	STORE_VSX_XFORM_TEST(stxvh8x);
358 	STORE_VSX_XFORM_TEST(stxvx);
359 	STORE_VSX_XFORM_TEST(stxvl);
360 	STORE_VSX_XFORM_TEST(stxvll);
361 	return rc;
362 }
363 
364 int test_alignment_handler_integer(void)
365 {
366 	int rc = 0;
367 
368 	SKIP_IF(!can_open_cifile());
369 
370 	printf("Integer\n");
371 	LOAD_DFORM_TEST(lbz);
372 	LOAD_DFORM_TEST(lbzu);
373 	LOAD_XFORM_TEST(lbzx);
374 	LOAD_XFORM_TEST(lbzux);
375 	LOAD_DFORM_TEST(lhz);
376 	LOAD_DFORM_TEST(lhzu);
377 	LOAD_XFORM_TEST(lhzx);
378 	LOAD_XFORM_TEST(lhzux);
379 	LOAD_DFORM_TEST(lha);
380 	LOAD_DFORM_TEST(lhau);
381 	LOAD_XFORM_TEST(lhax);
382 	LOAD_XFORM_TEST(lhaux);
383 	LOAD_XFORM_TEST(lhbrx);
384 	LOAD_DFORM_TEST(lwz);
385 	LOAD_DFORM_TEST(lwzu);
386 	LOAD_XFORM_TEST(lwzx);
387 	LOAD_XFORM_TEST(lwzux);
388 	LOAD_DFORM_TEST(lwa);
389 	LOAD_XFORM_TEST(lwax);
390 	LOAD_XFORM_TEST(lwaux);
391 	LOAD_XFORM_TEST(lwbrx);
392 	LOAD_DFORM_TEST(ld);
393 	LOAD_DFORM_TEST(ldu);
394 	LOAD_XFORM_TEST(ldx);
395 	LOAD_XFORM_TEST(ldux);
396 	LOAD_DFORM_TEST(lmw);
397 	STORE_DFORM_TEST(stb);
398 	STORE_XFORM_TEST(stbx);
399 	STORE_DFORM_TEST(stbu);
400 	STORE_XFORM_TEST(stbux);
401 	STORE_DFORM_TEST(sth);
402 	STORE_XFORM_TEST(sthx);
403 	STORE_DFORM_TEST(sthu);
404 	STORE_XFORM_TEST(sthux);
405 	STORE_XFORM_TEST(sthbrx);
406 	STORE_DFORM_TEST(stw);
407 	STORE_XFORM_TEST(stwx);
408 	STORE_DFORM_TEST(stwu);
409 	STORE_XFORM_TEST(stwux);
410 	STORE_XFORM_TEST(stwbrx);
411 	STORE_DFORM_TEST(std);
412 	STORE_XFORM_TEST(stdx);
413 	STORE_DFORM_TEST(stdu);
414 	STORE_XFORM_TEST(stdux);
415 	STORE_DFORM_TEST(stmw);
416 
417 	return rc;
418 }
419 
420 int test_alignment_handler_integer_206(void)
421 {
422 	int rc = 0;
423 
424 	SKIP_IF(!can_open_cifile());
425 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
426 
427 	printf("Integer: 2.06\n");
428 
429 	LOAD_XFORM_TEST(ldbrx);
430 	STORE_XFORM_TEST(stdbrx);
431 
432 	return rc;
433 }
434 
435 int test_alignment_handler_vmx(void)
436 {
437 	int rc = 0;
438 
439 	SKIP_IF(!can_open_cifile());
440 	SKIP_IF(!have_hwcap(PPC_FEATURE_HAS_ALTIVEC));
441 
442 	printf("VMX\n");
443 	LOAD_VMX_XFORM_TEST(lvx);
444 
445 	/*
446 	 * FIXME: These loads only load part of the register, so our
447 	 * testing method doesn't work. Also they don't take alignment
448 	 * faults, so it's kinda pointless anyway
449 	 *
450 	 LOAD_VMX_XFORM_TEST(lvebx)
451 	 LOAD_VMX_XFORM_TEST(lvehx)
452 	 LOAD_VMX_XFORM_TEST(lvewx)
453 	 LOAD_VMX_XFORM_TEST(lvxl)
454 	*/
455 	STORE_VMX_XFORM_TEST(stvx);
456 	STORE_VMX_XFORM_TEST(stvebx);
457 	STORE_VMX_XFORM_TEST(stvehx);
458 	STORE_VMX_XFORM_TEST(stvewx);
459 	STORE_VMX_XFORM_TEST(stvxl);
460 	return rc;
461 }
462 
463 int test_alignment_handler_fp(void)
464 {
465 	int rc = 0;
466 
467 	SKIP_IF(!can_open_cifile());
468 
469 	printf("Floating point\n");
470 	LOAD_FLOAT_DFORM_TEST(lfd);
471 	LOAD_FLOAT_XFORM_TEST(lfdx);
472 	LOAD_FLOAT_DFORM_TEST(lfdu);
473 	LOAD_FLOAT_XFORM_TEST(lfdux);
474 	LOAD_FLOAT_DFORM_TEST(lfs);
475 	LOAD_FLOAT_XFORM_TEST(lfsx);
476 	LOAD_FLOAT_DFORM_TEST(lfsu);
477 	LOAD_FLOAT_XFORM_TEST(lfsux);
478 	STORE_FLOAT_DFORM_TEST(stfd);
479 	STORE_FLOAT_XFORM_TEST(stfdx);
480 	STORE_FLOAT_DFORM_TEST(stfdu);
481 	STORE_FLOAT_XFORM_TEST(stfdux);
482 	STORE_FLOAT_DFORM_TEST(stfs);
483 	STORE_FLOAT_XFORM_TEST(stfsx);
484 	STORE_FLOAT_DFORM_TEST(stfsu);
485 	STORE_FLOAT_XFORM_TEST(stfsux);
486 	STORE_FLOAT_XFORM_TEST(stfiwx);
487 
488 	return rc;
489 }
490 
491 int test_alignment_handler_fp_205(void)
492 {
493 	int rc = 0;
494 
495 	SKIP_IF(!can_open_cifile());
496 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_05));
497 
498 	printf("Floating point: 2.05\n");
499 
500 	LOAD_FLOAT_DFORM_TEST(lfdp);
501 	LOAD_FLOAT_XFORM_TEST(lfdpx);
502 	LOAD_FLOAT_XFORM_TEST(lfiwax);
503 	STORE_FLOAT_DFORM_TEST(stfdp);
504 	STORE_FLOAT_XFORM_TEST(stfdpx);
505 
506 	return rc;
507 }
508 
509 int test_alignment_handler_fp_206(void)
510 {
511 	int rc = 0;
512 
513 	SKIP_IF(!can_open_cifile());
514 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
515 
516 	printf("Floating point: 2.06\n");
517 
518 	LOAD_FLOAT_XFORM_TEST(lfiwzx);
519 
520 	return rc;
521 }
522 
523 void usage(char *prog)
524 {
525 	printf("Usage: %s [options] [path [offset]]\n", prog);
526 	printf("  -d	Enable debug error output\n");
527 	printf("\n");
528 	printf("This test requires a POWER8 or POWER9 CPU and either a ");
529 	printf("usable framebuffer at /dev/fb0 or the path to usable ");
530 	printf("cache-inhibited memory and optional offset to be provided\n");
531 }
532 
533 int main(int argc, char *argv[])
534 {
535 
536 	struct sigaction sa;
537 	int rc = 0;
538 	int option = 0;
539 
540 	while ((option = getopt(argc, argv, "d")) != -1) {
541 		switch (option) {
542 		case 'd':
543 			debug++;
544 			break;
545 		default:
546 			usage(argv[0]);
547 			exit(1);
548 		}
549 	}
550 	argc -= optind;
551 	argv += optind;
552 
553 	if (argc > 0)
554 		cipath = argv[0];
555 	if (argc > 1)
556 		cioffset = strtol(argv[1], 0, 0x10);
557 
558 	bufsize = getpagesize();
559 
560 	sa.sa_sigaction = sighandler;
561 	sigemptyset(&sa.sa_mask);
562 	sa.sa_flags = SA_SIGINFO;
563 	if (sigaction(SIGSEGV, &sa, NULL) == -1
564 	    || sigaction(SIGBUS, &sa, NULL) == -1
565 	    || sigaction(SIGILL, &sa, NULL) == -1) {
566 		perror("sigaction");
567 		exit(1);
568 	}
569 
570 	rc |= test_harness(test_alignment_handler_vsx_206,
571 			   "test_alignment_handler_vsx_206");
572 	rc |= test_harness(test_alignment_handler_vsx_207,
573 			   "test_alignment_handler_vsx_207");
574 	rc |= test_harness(test_alignment_handler_vsx_300,
575 			   "test_alignment_handler_vsx_300");
576 	rc |= test_harness(test_alignment_handler_integer,
577 			   "test_alignment_handler_integer");
578 	rc |= test_harness(test_alignment_handler_integer_206,
579 			   "test_alignment_handler_integer_206");
580 	rc |= test_harness(test_alignment_handler_vmx,
581 			   "test_alignment_handler_vmx");
582 	rc |= test_harness(test_alignment_handler_fp,
583 			   "test_alignment_handler_fp");
584 	rc |= test_harness(test_alignment_handler_fp_205,
585 			   "test_alignment_handler_fp_205");
586 	rc |= test_harness(test_alignment_handler_fp_206,
587 			   "test_alignment_handler_fp_206");
588 	return rc;
589 }
590