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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 (we use /dev/fb0 for this).
13  *
14  * We initialise the source buffers, then use whichever set of load/store
15  * instructions is under test to copy bytes from the source buffers to the
16  * destination buffers. For the regular buffers, these instructions will
17  * execute normally. For the cache-inhibited buffers, these instructions
18  * will trap and cause an alignment fault, and the alignment fault handler
19  * will emulate the particular instruction under test. We then compare the
20  * destination buffers to ensure that the native and emulated cases give the
21  * same result.
22  *
23  * TODO:
24  *   - Any FIXMEs below
25  *   - Test VSX regs < 32 and > 32
26  *   - Test all loads and stores
27  *   - Check update forms do update register
28  *   - Test alignment faults over page boundary
29  *
30  * Some old binutils may not support all the instructions.
31  */
32 
33 
34 #include <sys/mman.h>
35 #include <sys/types.h>
36 #include <sys/stat.h>
37 #include <fcntl.h>
38 #include <unistd.h>
39 #include <stdbool.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <assert.h>
44 #include <getopt.h>
45 #include <setjmp.h>
46 #include <signal.h>
47 
48 #include <asm/cputable.h>
49 
50 #include "utils.h"
51 
52 int bufsize;
53 int debug;
54 int testing;
55 volatile int gotsig;
56 
sighandler(int sig,siginfo_t * info,void * ctx)57 void sighandler(int sig, siginfo_t *info, void *ctx)
58 {
59 	ucontext_t *ucp = ctx;
60 
61 	if (!testing) {
62 		signal(sig, SIG_DFL);
63 		kill(0, sig);
64 	}
65 	gotsig = sig;
66 #ifdef __powerpc64__
67 	ucp->uc_mcontext.gp_regs[PT_NIP] += 4;
68 #else
69 	ucp->uc_mcontext.uc_regs->gregs[PT_NIP] += 4;
70 #endif
71 }
72 
73 #define XFORM(reg, n)  " " #reg " ,%"#n",%2 ;"
74 #define DFORM(reg, n)  " " #reg " ,0(%"#n") ;"
75 
76 #define TEST(name, ld_op, st_op, form, ld_reg, st_reg)		\
77 	void test_##name(char *s, char *d)			\
78 	{							\
79 		asm volatile(					\
80 			#ld_op form(ld_reg, 0)			\
81 			#st_op form(st_reg, 1)			\
82 			:: "r"(s), "r"(d), "r"(0)		\
83 			: "memory", "vs0", "vs32", "r31");	\
84 	}							\
85 	rc |= do_test(#name, test_##name)
86 
87 #define LOAD_VSX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 32, 32)
88 #define STORE_VSX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 32)
89 #define LOAD_VSX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 32, 32)
90 #define STORE_VSX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 32)
91 #define LOAD_VMX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 0, 32)
92 #define STORE_VMX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 0)
93 #define LOAD_VMX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 0, 32)
94 #define STORE_VMX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 0)
95 
96 #define LOAD_XFORM_TEST(op) TEST(op, op, stdx, XFORM, 31, 31)
97 #define STORE_XFORM_TEST(op) TEST(op, ldx, op, XFORM, 31, 31)
98 #define LOAD_DFORM_TEST(op) TEST(op, op, std, DFORM, 31, 31)
99 #define STORE_DFORM_TEST(op) TEST(op, ld, op, DFORM, 31, 31)
100 
101 #define LOAD_FLOAT_DFORM_TEST(op)  TEST(op, op, stfd, DFORM, 0, 0)
102 #define STORE_FLOAT_DFORM_TEST(op) TEST(op, lfd, op, DFORM, 0, 0)
103 #define LOAD_FLOAT_XFORM_TEST(op)  TEST(op, op, stfdx, XFORM, 0, 0)
104 #define STORE_FLOAT_XFORM_TEST(op) TEST(op, lfdx, op, XFORM, 0, 0)
105 
106 
107 /* FIXME: Unimplemented tests: */
108 // STORE_DFORM_TEST(stq)   /* FIXME: need two registers for quad */
109 // STORE_DFORM_TEST(stswi) /* FIXME: string instruction */
110 
111 // STORE_XFORM_TEST(stwat) /* AMO can't emulate or run on CI */
112 // STORE_XFORM_TEST(stdat) /* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
113 
114 
115 /* preload byte by byte */
preload_data(void * dst,int offset,int width)116 void preload_data(void *dst, int offset, int width)
117 {
118 	char *c = dst;
119 	int i;
120 
121 	c += offset;
122 
123 	for (i = 0 ; i < width ; i++)
124 		c[i] = i;
125 }
126 
test_memcpy(void * dst,void * src,int size,int offset,void (* test_func)(char *,char *))127 int test_memcpy(void *dst, void *src, int size, int offset,
128 		void (*test_func)(char *, char *))
129 {
130 	char *s, *d;
131 
132 	s = src;
133 	s += offset;
134 	d = dst;
135 	d += offset;
136 
137 	assert(size == 16);
138 	gotsig = 0;
139 	testing = 1;
140 
141 	test_func(s, d); /* run the actual test */
142 
143 	testing = 0;
144 	if (gotsig) {
145 		if (debug)
146 			printf("  Got signal %i\n", gotsig);
147 		return 1;
148 	}
149 	return 0;
150 }
151 
dumpdata(char * s1,char * s2,int n,char * test_name)152 void dumpdata(char *s1, char *s2, int n, char *test_name)
153 {
154 	int i;
155 
156 	printf("  %s: unexpected result:\n", test_name);
157 	printf("    mem:");
158 	for (i = 0; i < n; i++)
159 		printf(" %02x", s1[i]);
160 	printf("\n");
161 	printf("    ci: ");
162 	for (i = 0; i < n; i++)
163 		printf(" %02x", s2[i]);
164 	printf("\n");
165 }
166 
test_memcmp(void * s1,void * s2,int n,int offset,char * test_name)167 int test_memcmp(void *s1, void *s2, int n, int offset, char *test_name)
168 {
169 	char *s1c, *s2c;
170 
171 	s1c = s1;
172 	s1c += offset;
173 	s2c = s2;
174 	s2c += offset;
175 
176 	if (memcmp(s1c, s2c, n)) {
177 		if (debug) {
178 			printf("\n  Compare failed. Offset:%i length:%i\n",
179 			       offset, n);
180 			dumpdata(s1c, s2c, n, test_name);
181 		}
182 		return 1;
183 	}
184 	return 0;
185 }
186 
187 /*
188  * Do two memcpy tests using the same instructions. One cachable
189  * memory and the other doesn't.
190  */
do_test(char * test_name,void (* test_func)(char *,char *))191 int do_test(char *test_name, void (*test_func)(char *, char *))
192 {
193 	int offset, width, fd, rc, r;
194 	void *mem0, *mem1, *ci0, *ci1;
195 
196 	printf("\tDoing %s:\t", test_name);
197 
198 	fd = open("/dev/fb0", O_RDWR);
199 	if (fd < 0) {
200 		printf("\n");
201 		perror("Can't open /dev/fb0 now?");
202 		return 1;
203 	}
204 
205 	ci0 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
206 		   fd, 0x0);
207 	ci1 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
208 		   fd, bufsize);
209 	if ((ci0 == MAP_FAILED) || (ci1 == MAP_FAILED)) {
210 		printf("\n");
211 		perror("mmap failed");
212 		SKIP_IF(1);
213 	}
214 
215 	rc = posix_memalign(&mem0, bufsize, bufsize);
216 	if (rc) {
217 		printf("\n");
218 		return rc;
219 	}
220 
221 	rc = posix_memalign(&mem1, bufsize, bufsize);
222 	if (rc) {
223 		printf("\n");
224 		free(mem0);
225 		return rc;
226 	}
227 
228 	rc = 0;
229 	/* offset = 0 no alignment fault, so skip */
230 	for (offset = 1; offset < 16; offset++) {
231 		width = 16; /* vsx == 16 bytes */
232 		r = 0;
233 
234 		/* load pattern into memory byte by byte */
235 		preload_data(ci0, offset, width);
236 		preload_data(mem0, offset, width); // FIXME: remove??
237 		memcpy(ci0, mem0, bufsize);
238 		memcpy(ci1, mem1, bufsize); /* initialise output to the same */
239 
240 		/* sanity check */
241 		test_memcmp(mem0, ci0, width, offset, test_name);
242 
243 		r |= test_memcpy(ci1,  ci0,  width, offset, test_func);
244 		r |= test_memcpy(mem1, mem0, width, offset, test_func);
245 		if (r && !debug) {
246 			printf("FAILED: Got signal");
247 			rc = 1;
248 			break;
249 		}
250 
251 		r |= test_memcmp(mem1, ci1, width, offset, test_name);
252 		if (r && !debug) {
253 			printf("FAILED: Wrong Data");
254 			rc = 1;
255 			break;
256 		}
257 	}
258 
259 	if (rc == 0)
260 		printf("PASSED");
261 
262 	printf("\n");
263 
264 	munmap(ci0, bufsize);
265 	munmap(ci1, bufsize);
266 	free(mem0);
267 	free(mem1);
268 	close(fd);
269 
270 	return rc;
271 }
272 
can_open_fb0(void)273 static bool can_open_fb0(void)
274 {
275 	int fd;
276 
277 	fd = open("/dev/fb0", O_RDWR);
278 	if (fd < 0)
279 		return false;
280 
281 	close(fd);
282 	return true;
283 }
284 
test_alignment_handler_vsx_206(void)285 int test_alignment_handler_vsx_206(void)
286 {
287 	int rc = 0;
288 
289 	SKIP_IF(!can_open_fb0());
290 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
291 
292 	printf("VSX: 2.06B\n");
293 	LOAD_VSX_XFORM_TEST(lxvd2x);
294 	LOAD_VSX_XFORM_TEST(lxvw4x);
295 	LOAD_VSX_XFORM_TEST(lxsdx);
296 	LOAD_VSX_XFORM_TEST(lxvdsx);
297 	STORE_VSX_XFORM_TEST(stxvd2x);
298 	STORE_VSX_XFORM_TEST(stxvw4x);
299 	STORE_VSX_XFORM_TEST(stxsdx);
300 	return rc;
301 }
302 
test_alignment_handler_vsx_207(void)303 int test_alignment_handler_vsx_207(void)
304 {
305 	int rc = 0;
306 
307 	SKIP_IF(!can_open_fb0());
308 	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_2_07));
309 
310 	printf("VSX: 2.07B\n");
311 	LOAD_VSX_XFORM_TEST(lxsspx);
312 	LOAD_VSX_XFORM_TEST(lxsiwax);
313 	LOAD_VSX_XFORM_TEST(lxsiwzx);
314 	STORE_VSX_XFORM_TEST(stxsspx);
315 	STORE_VSX_XFORM_TEST(stxsiwx);
316 	return rc;
317 }
318 
test_alignment_handler_vsx_300(void)319 int test_alignment_handler_vsx_300(void)
320 {
321 	int rc = 0;
322 
323 	SKIP_IF(!can_open_fb0());
324 
325 	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_3_00));
326 	printf("VSX: 3.00B\n");
327 	LOAD_VMX_DFORM_TEST(lxsd);
328 	LOAD_VSX_XFORM_TEST(lxsibzx);
329 	LOAD_VSX_XFORM_TEST(lxsihzx);
330 	LOAD_VMX_DFORM_TEST(lxssp);
331 	LOAD_VSX_DFORM_TEST(lxv);
332 	LOAD_VSX_XFORM_TEST(lxvb16x);
333 	LOAD_VSX_XFORM_TEST(lxvh8x);
334 	LOAD_VSX_XFORM_TEST(lxvx);
335 	LOAD_VSX_XFORM_TEST(lxvwsx);
336 	LOAD_VSX_XFORM_TEST(lxvl);
337 	LOAD_VSX_XFORM_TEST(lxvll);
338 	STORE_VMX_DFORM_TEST(stxsd);
339 	STORE_VSX_XFORM_TEST(stxsibx);
340 	STORE_VSX_XFORM_TEST(stxsihx);
341 	STORE_VMX_DFORM_TEST(stxssp);
342 	STORE_VSX_DFORM_TEST(stxv);
343 	STORE_VSX_XFORM_TEST(stxvb16x);
344 	STORE_VSX_XFORM_TEST(stxvh8x);
345 	STORE_VSX_XFORM_TEST(stxvx);
346 	STORE_VSX_XFORM_TEST(stxvl);
347 	STORE_VSX_XFORM_TEST(stxvll);
348 	return rc;
349 }
350 
test_alignment_handler_integer(void)351 int test_alignment_handler_integer(void)
352 {
353 	int rc = 0;
354 
355 	SKIP_IF(!can_open_fb0());
356 
357 	printf("Integer\n");
358 	LOAD_DFORM_TEST(lbz);
359 	LOAD_DFORM_TEST(lbzu);
360 	LOAD_XFORM_TEST(lbzx);
361 	LOAD_XFORM_TEST(lbzux);
362 	LOAD_DFORM_TEST(lhz);
363 	LOAD_DFORM_TEST(lhzu);
364 	LOAD_XFORM_TEST(lhzx);
365 	LOAD_XFORM_TEST(lhzux);
366 	LOAD_DFORM_TEST(lha);
367 	LOAD_DFORM_TEST(lhau);
368 	LOAD_XFORM_TEST(lhax);
369 	LOAD_XFORM_TEST(lhaux);
370 	LOAD_XFORM_TEST(lhbrx);
371 	LOAD_DFORM_TEST(lwz);
372 	LOAD_DFORM_TEST(lwzu);
373 	LOAD_XFORM_TEST(lwzx);
374 	LOAD_XFORM_TEST(lwzux);
375 	LOAD_DFORM_TEST(lwa);
376 	LOAD_XFORM_TEST(lwax);
377 	LOAD_XFORM_TEST(lwaux);
378 	LOAD_XFORM_TEST(lwbrx);
379 	LOAD_DFORM_TEST(ld);
380 	LOAD_DFORM_TEST(ldu);
381 	LOAD_XFORM_TEST(ldx);
382 	LOAD_XFORM_TEST(ldux);
383 	STORE_DFORM_TEST(stb);
384 	STORE_XFORM_TEST(stbx);
385 	STORE_DFORM_TEST(stbu);
386 	STORE_XFORM_TEST(stbux);
387 	STORE_DFORM_TEST(sth);
388 	STORE_XFORM_TEST(sthx);
389 	STORE_DFORM_TEST(sthu);
390 	STORE_XFORM_TEST(sthux);
391 	STORE_XFORM_TEST(sthbrx);
392 	STORE_DFORM_TEST(stw);
393 	STORE_XFORM_TEST(stwx);
394 	STORE_DFORM_TEST(stwu);
395 	STORE_XFORM_TEST(stwux);
396 	STORE_XFORM_TEST(stwbrx);
397 	STORE_DFORM_TEST(std);
398 	STORE_XFORM_TEST(stdx);
399 	STORE_DFORM_TEST(stdu);
400 	STORE_XFORM_TEST(stdux);
401 
402 #ifdef __BIG_ENDIAN__
403 	LOAD_DFORM_TEST(lmw);
404 	STORE_DFORM_TEST(stmw);
405 #endif
406 
407 	return rc;
408 }
409 
test_alignment_handler_integer_206(void)410 int test_alignment_handler_integer_206(void)
411 {
412 	int rc = 0;
413 
414 	SKIP_IF(!can_open_fb0());
415 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
416 
417 	printf("Integer: 2.06\n");
418 
419 	LOAD_XFORM_TEST(ldbrx);
420 	STORE_XFORM_TEST(stdbrx);
421 
422 	return rc;
423 }
424 
test_alignment_handler_vmx(void)425 int test_alignment_handler_vmx(void)
426 {
427 	int rc = 0;
428 
429 	SKIP_IF(!can_open_fb0());
430 	SKIP_IF(!have_hwcap(PPC_FEATURE_HAS_ALTIVEC));
431 
432 	printf("VMX\n");
433 	LOAD_VMX_XFORM_TEST(lvx);
434 
435 	/*
436 	 * FIXME: These loads only load part of the register, so our
437 	 * testing method doesn't work. Also they don't take alignment
438 	 * faults, so it's kinda pointless anyway
439 	 *
440 	 LOAD_VMX_XFORM_TEST(lvebx)
441 	 LOAD_VMX_XFORM_TEST(lvehx)
442 	 LOAD_VMX_XFORM_TEST(lvewx)
443 	 LOAD_VMX_XFORM_TEST(lvxl)
444 	*/
445 	STORE_VMX_XFORM_TEST(stvx);
446 	STORE_VMX_XFORM_TEST(stvebx);
447 	STORE_VMX_XFORM_TEST(stvehx);
448 	STORE_VMX_XFORM_TEST(stvewx);
449 	STORE_VMX_XFORM_TEST(stvxl);
450 	return rc;
451 }
452 
test_alignment_handler_fp(void)453 int test_alignment_handler_fp(void)
454 {
455 	int rc = 0;
456 
457 	SKIP_IF(!can_open_fb0());
458 
459 	printf("Floating point\n");
460 	LOAD_FLOAT_DFORM_TEST(lfd);
461 	LOAD_FLOAT_XFORM_TEST(lfdx);
462 	LOAD_FLOAT_DFORM_TEST(lfdu);
463 	LOAD_FLOAT_XFORM_TEST(lfdux);
464 	LOAD_FLOAT_DFORM_TEST(lfs);
465 	LOAD_FLOAT_XFORM_TEST(lfsx);
466 	LOAD_FLOAT_DFORM_TEST(lfsu);
467 	LOAD_FLOAT_XFORM_TEST(lfsux);
468 	STORE_FLOAT_DFORM_TEST(stfd);
469 	STORE_FLOAT_XFORM_TEST(stfdx);
470 	STORE_FLOAT_DFORM_TEST(stfdu);
471 	STORE_FLOAT_XFORM_TEST(stfdux);
472 	STORE_FLOAT_DFORM_TEST(stfs);
473 	STORE_FLOAT_XFORM_TEST(stfsx);
474 	STORE_FLOAT_DFORM_TEST(stfsu);
475 	STORE_FLOAT_XFORM_TEST(stfsux);
476 	STORE_FLOAT_XFORM_TEST(stfiwx);
477 
478 	return rc;
479 }
480 
test_alignment_handler_fp_205(void)481 int test_alignment_handler_fp_205(void)
482 {
483 	int rc = 0;
484 
485 	SKIP_IF(!can_open_fb0());
486 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_05));
487 
488 	printf("Floating point: 2.05\n");
489 
490 	LOAD_FLOAT_DFORM_TEST(lfdp);
491 	LOAD_FLOAT_XFORM_TEST(lfdpx);
492 	LOAD_FLOAT_XFORM_TEST(lfiwax);
493 	STORE_FLOAT_DFORM_TEST(stfdp);
494 	STORE_FLOAT_XFORM_TEST(stfdpx);
495 
496 	return rc;
497 }
498 
test_alignment_handler_fp_206(void)499 int test_alignment_handler_fp_206(void)
500 {
501 	int rc = 0;
502 
503 	SKIP_IF(!can_open_fb0());
504 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
505 
506 	printf("Floating point: 2.06\n");
507 
508 	LOAD_FLOAT_XFORM_TEST(lfiwzx);
509 
510 	return rc;
511 }
512 
usage(char * prog)513 void usage(char *prog)
514 {
515 	printf("Usage: %s [options]\n", prog);
516 	printf("  -d	Enable debug error output\n");
517 	printf("\n");
518 	printf("This test requires a POWER8 or POWER9 CPU and a usable ");
519 	printf("framebuffer at /dev/fb0.\n");
520 }
521 
main(int argc,char * argv[])522 int main(int argc, char *argv[])
523 {
524 
525 	struct sigaction sa;
526 	int rc = 0;
527 	int option = 0;
528 
529 	while ((option = getopt(argc, argv, "d")) != -1) {
530 		switch (option) {
531 		case 'd':
532 			debug++;
533 			break;
534 		default:
535 			usage(argv[0]);
536 			exit(1);
537 		}
538 	}
539 
540 	bufsize = getpagesize();
541 
542 	sa.sa_sigaction = sighandler;
543 	sigemptyset(&sa.sa_mask);
544 	sa.sa_flags = SA_SIGINFO;
545 	if (sigaction(SIGSEGV, &sa, NULL) == -1
546 	    || sigaction(SIGBUS, &sa, NULL) == -1
547 	    || sigaction(SIGILL, &sa, NULL) == -1) {
548 		perror("sigaction");
549 		exit(1);
550 	}
551 
552 	rc |= test_harness(test_alignment_handler_vsx_206,
553 			   "test_alignment_handler_vsx_206");
554 	rc |= test_harness(test_alignment_handler_vsx_207,
555 			   "test_alignment_handler_vsx_207");
556 	rc |= test_harness(test_alignment_handler_vsx_300,
557 			   "test_alignment_handler_vsx_300");
558 	rc |= test_harness(test_alignment_handler_integer,
559 			   "test_alignment_handler_integer");
560 	rc |= test_harness(test_alignment_handler_integer_206,
561 			   "test_alignment_handler_integer_206");
562 	rc |= test_harness(test_alignment_handler_vmx,
563 			   "test_alignment_handler_vmx");
564 	rc |= test_harness(test_alignment_handler_fp,
565 			   "test_alignment_handler_fp");
566 	rc |= test_harness(test_alignment_handler_fp_205,
567 			   "test_alignment_handler_fp_205");
568 	rc |= test_harness(test_alignment_handler_fp_206,
569 			   "test_alignment_handler_fp_206");
570 	return rc;
571 }
572