1 /*
2  * Test the powerpc alignment handler on POWER8/POWER9
3  *
4  * Copyright (C) 2017 IBM Corporation (Michael Neuling, Andrew Donnellan)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 /*
13  * This selftest exercises the powerpc alignment fault handler.
14  *
15  * We create two sets of source and destination buffers, one in regular memory,
16  * the other cache-inhibited (we use /dev/fb0 for this).
17  *
18  * We initialise the source buffers, then use whichever set of load/store
19  * instructions is under test to copy bytes from the source buffers to the
20  * destination buffers. For the regular buffers, these instructions will
21  * execute normally. For the cache-inhibited buffers, these instructions
22  * will trap and cause an alignment fault, and the alignment fault handler
23  * will emulate the particular instruction under test. We then compare the
24  * destination buffers to ensure that the native and emulated cases give the
25  * same result.
26  *
27  * TODO:
28  *   - Any FIXMEs below
29  *   - Test VSX regs < 32 and > 32
30  *   - Test all loads and stores
31  *   - Check update forms do update register
32  *   - Test alignment faults over page boundary
33  *
34  * Some old binutils may not support all the instructions.
35  */
36 
37 
38 #include <sys/mman.h>
39 #include <sys/types.h>
40 #include <sys/stat.h>
41 #include <fcntl.h>
42 #include <unistd.h>
43 #include <stdbool.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <assert.h>
48 #include <getopt.h>
49 #include <setjmp.h>
50 #include <signal.h>
51 
52 #include "utils.h"
53 
54 int bufsize;
55 int debug;
56 int testing;
57 volatile int gotsig;
58 
59 void sighandler(int sig, siginfo_t *info, void *ctx)
60 {
61 	ucontext_t *ucp = ctx;
62 
63 	if (!testing) {
64 		signal(sig, SIG_DFL);
65 		kill(0, sig);
66 	}
67 	gotsig = sig;
68 #ifdef __powerpc64__
69 	ucp->uc_mcontext.gp_regs[PT_NIP] += 4;
70 #else
71 	ucp->uc_mcontext.uc_regs->gregs[PT_NIP] += 4;
72 #endif
73 }
74 
75 #define XFORM(reg, n)  " " #reg " ,%"#n",%2 ;"
76 #define DFORM(reg, n)  " " #reg " ,0(%"#n") ;"
77 
78 #define TEST(name, ld_op, st_op, form, ld_reg, st_reg)		\
79 	void test_##name(char *s, char *d)			\
80 	{							\
81 		asm volatile(					\
82 			#ld_op form(ld_reg, 0)			\
83 			#st_op form(st_reg, 1)			\
84 			:: "r"(s), "r"(d), "r"(0)		\
85 			: "memory", "vs0", "vs32", "r31");	\
86 	}							\
87 	rc |= do_test(#name, test_##name)
88 
89 #define LOAD_VSX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 32, 32)
90 #define STORE_VSX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 32)
91 #define LOAD_VSX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 32, 32)
92 #define STORE_VSX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 32)
93 #define LOAD_VMX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 0, 32)
94 #define STORE_VMX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 0)
95 #define LOAD_VMX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 0, 32)
96 #define STORE_VMX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 0)
97 
98 #define LOAD_XFORM_TEST(op) TEST(op, op, stdx, XFORM, 31, 31)
99 #define STORE_XFORM_TEST(op) TEST(op, ldx, op, XFORM, 31, 31)
100 #define LOAD_DFORM_TEST(op) TEST(op, op, std, DFORM, 31, 31)
101 #define STORE_DFORM_TEST(op) TEST(op, ld, op, DFORM, 31, 31)
102 
103 #define LOAD_FLOAT_DFORM_TEST(op)  TEST(op, op, stfd, DFORM, 0, 0)
104 #define STORE_FLOAT_DFORM_TEST(op) TEST(op, lfd, op, DFORM, 0, 0)
105 #define LOAD_FLOAT_XFORM_TEST(op)  TEST(op, op, stfdx, XFORM, 0, 0)
106 #define STORE_FLOAT_XFORM_TEST(op) TEST(op, lfdx, op, XFORM, 0, 0)
107 
108 
109 /* FIXME: Unimplemented tests: */
110 // STORE_DFORM_TEST(stq)   /* FIXME: need two registers for quad */
111 // STORE_DFORM_TEST(stswi) /* FIXME: string instruction */
112 
113 // STORE_XFORM_TEST(stwat) /* AMO can't emulate or run on CI */
114 // STORE_XFORM_TEST(stdat) /* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
115 
116 
117 /* preload byte by byte */
118 void preload_data(void *dst, int offset, int width)
119 {
120 	char *c = dst;
121 	int i;
122 
123 	c += offset;
124 
125 	for (i = 0 ; i < width ; i++)
126 		c[i] = i;
127 }
128 
129 int test_memcpy(void *dst, void *src, int size, int offset,
130 		void (*test_func)(char *, char *))
131 {
132 	char *s, *d;
133 
134 	s = src;
135 	s += offset;
136 	d = dst;
137 	d += offset;
138 
139 	assert(size == 16);
140 	gotsig = 0;
141 	testing = 1;
142 
143 	test_func(s, d); /* run the actual test */
144 
145 	testing = 0;
146 	if (gotsig) {
147 		if (debug)
148 			printf("  Got signal %i\n", gotsig);
149 		return 1;
150 	}
151 	return 0;
152 }
153 
154 void dumpdata(char *s1, char *s2, int n, char *test_name)
155 {
156 	int i;
157 
158 	printf("  %s: unexpected result:\n", test_name);
159 	printf("    mem:");
160 	for (i = 0; i < n; i++)
161 		printf(" %02x", s1[i]);
162 	printf("\n");
163 	printf("    ci: ");
164 	for (i = 0; i < n; i++)
165 		printf(" %02x", s2[i]);
166 	printf("\n");
167 }
168 
169 int test_memcmp(void *s1, void *s2, int n, int offset, char *test_name)
170 {
171 	char *s1c, *s2c;
172 
173 	s1c = s1;
174 	s1c += offset;
175 	s2c = s2;
176 	s2c += offset;
177 
178 	if (memcmp(s1c, s2c, n)) {
179 		if (debug) {
180 			printf("\n  Compare failed. Offset:%i length:%i\n",
181 			       offset, n);
182 			dumpdata(s1c, s2c, n, test_name);
183 		}
184 		return 1;
185 	}
186 	return 0;
187 }
188 
189 /*
190  * Do two memcpy tests using the same instructions. One cachable
191  * memory and the other doesn't.
192  */
193 int do_test(char *test_name, void (*test_func)(char *, char *))
194 {
195 	int offset, width, fd, rc, r;
196 	void *mem0, *mem1, *ci0, *ci1;
197 
198 	printf("\tDoing %s:\t", test_name);
199 
200 	fd = open("/dev/fb0", O_RDWR);
201 	if (fd < 0) {
202 		printf("\n");
203 		perror("Can't open /dev/fb0 now?");
204 		return 1;
205 	}
206 
207 	ci0 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
208 		   fd, 0x0);
209 	ci1 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
210 		   fd, bufsize);
211 	if ((ci0 == MAP_FAILED) || (ci1 == MAP_FAILED)) {
212 		printf("\n");
213 		perror("mmap failed");
214 		SKIP_IF(1);
215 	}
216 
217 	rc = posix_memalign(&mem0, bufsize, bufsize);
218 	if (rc) {
219 		printf("\n");
220 		return rc;
221 	}
222 
223 	rc = posix_memalign(&mem1, bufsize, bufsize);
224 	if (rc) {
225 		printf("\n");
226 		free(mem0);
227 		return rc;
228 	}
229 
230 	rc = 0;
231 	/* offset = 0 no alignment fault, so skip */
232 	for (offset = 1; offset < 16; offset++) {
233 		width = 16; /* vsx == 16 bytes */
234 		r = 0;
235 
236 		/* load pattern into memory byte by byte */
237 		preload_data(ci0, offset, width);
238 		preload_data(mem0, offset, width); // FIXME: remove??
239 		memcpy(ci0, mem0, bufsize);
240 		memcpy(ci1, mem1, bufsize); /* initialise output to the same */
241 
242 		/* sanity check */
243 		test_memcmp(mem0, ci0, width, offset, test_name);
244 
245 		r |= test_memcpy(ci1,  ci0,  width, offset, test_func);
246 		r |= test_memcpy(mem1, mem0, width, offset, test_func);
247 		if (r && !debug) {
248 			printf("FAILED: Got signal");
249 			rc = 1;
250 			break;
251 		}
252 
253 		r |= test_memcmp(mem1, ci1, width, offset, test_name);
254 		if (r && !debug) {
255 			printf("FAILED: Wrong Data");
256 			rc = 1;
257 			break;
258 		}
259 	}
260 
261 	if (rc == 0)
262 		printf("PASSED");
263 
264 	printf("\n");
265 
266 	munmap(ci0, bufsize);
267 	munmap(ci1, bufsize);
268 	free(mem0);
269 	free(mem1);
270 	close(fd);
271 
272 	return rc;
273 }
274 
275 static bool can_open_fb0(void)
276 {
277 	int fd;
278 
279 	fd = open("/dev/fb0", O_RDWR);
280 	if (fd < 0)
281 		return false;
282 
283 	close(fd);
284 	return true;
285 }
286 
287 int test_alignment_handler_vsx_206(void)
288 {
289 	int rc = 0;
290 
291 	SKIP_IF(!can_open_fb0());
292 
293 	printf("VSX: 2.06B\n");
294 	LOAD_VSX_XFORM_TEST(lxvd2x);
295 	LOAD_VSX_XFORM_TEST(lxvw4x);
296 	LOAD_VSX_XFORM_TEST(lxsdx);
297 	LOAD_VSX_XFORM_TEST(lxvdsx);
298 	STORE_VSX_XFORM_TEST(stxvd2x);
299 	STORE_VSX_XFORM_TEST(stxvw4x);
300 	STORE_VSX_XFORM_TEST(stxsdx);
301 	return rc;
302 }
303 
304 int test_alignment_handler_vsx_207(void)
305 {
306 	int rc = 0;
307 
308 	SKIP_IF(!can_open_fb0());
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 
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 
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 	LOAD_XFORM_TEST(ldbrx);
384 	LOAD_DFORM_TEST(lmw);
385 	STORE_DFORM_TEST(stb);
386 	STORE_XFORM_TEST(stbx);
387 	STORE_DFORM_TEST(stbu);
388 	STORE_XFORM_TEST(stbux);
389 	STORE_DFORM_TEST(sth);
390 	STORE_XFORM_TEST(sthx);
391 	STORE_DFORM_TEST(sthu);
392 	STORE_XFORM_TEST(sthux);
393 	STORE_XFORM_TEST(sthbrx);
394 	STORE_DFORM_TEST(stw);
395 	STORE_XFORM_TEST(stwx);
396 	STORE_DFORM_TEST(stwu);
397 	STORE_XFORM_TEST(stwux);
398 	STORE_XFORM_TEST(stwbrx);
399 	STORE_DFORM_TEST(std);
400 	STORE_XFORM_TEST(stdx);
401 	STORE_DFORM_TEST(stdu);
402 	STORE_XFORM_TEST(stdux);
403 	STORE_XFORM_TEST(stdbrx);
404 	STORE_DFORM_TEST(stmw);
405 	return rc;
406 }
407 
408 int test_alignment_handler_vmx(void)
409 {
410 	int rc = 0;
411 
412 	SKIP_IF(!can_open_fb0());
413 
414 	printf("VMX\n");
415 	LOAD_VMX_XFORM_TEST(lvx);
416 
417 	/*
418 	 * FIXME: These loads only load part of the register, so our
419 	 * testing method doesn't work. Also they don't take alignment
420 	 * faults, so it's kinda pointless anyway
421 	 *
422 	 LOAD_VMX_XFORM_TEST(lvebx)
423 	 LOAD_VMX_XFORM_TEST(lvehx)
424 	 LOAD_VMX_XFORM_TEST(lvewx)
425 	 LOAD_VMX_XFORM_TEST(lvxl)
426 	*/
427 	STORE_VMX_XFORM_TEST(stvx);
428 	STORE_VMX_XFORM_TEST(stvebx);
429 	STORE_VMX_XFORM_TEST(stvehx);
430 	STORE_VMX_XFORM_TEST(stvewx);
431 	STORE_VMX_XFORM_TEST(stvxl);
432 	return rc;
433 }
434 
435 int test_alignment_handler_fp(void)
436 {
437 	int rc = 0;
438 
439 	SKIP_IF(!can_open_fb0());
440 
441 	printf("Floating point\n");
442 	LOAD_FLOAT_DFORM_TEST(lfd);
443 	LOAD_FLOAT_XFORM_TEST(lfdx);
444 	LOAD_FLOAT_DFORM_TEST(lfdp);
445 	LOAD_FLOAT_XFORM_TEST(lfdpx);
446 	LOAD_FLOAT_DFORM_TEST(lfdu);
447 	LOAD_FLOAT_XFORM_TEST(lfdux);
448 	LOAD_FLOAT_DFORM_TEST(lfs);
449 	LOAD_FLOAT_XFORM_TEST(lfsx);
450 	LOAD_FLOAT_DFORM_TEST(lfsu);
451 	LOAD_FLOAT_XFORM_TEST(lfsux);
452 	LOAD_FLOAT_XFORM_TEST(lfiwzx);
453 	LOAD_FLOAT_XFORM_TEST(lfiwax);
454 	STORE_FLOAT_DFORM_TEST(stfd);
455 	STORE_FLOAT_XFORM_TEST(stfdx);
456 	STORE_FLOAT_DFORM_TEST(stfdp);
457 	STORE_FLOAT_XFORM_TEST(stfdpx);
458 	STORE_FLOAT_DFORM_TEST(stfdu);
459 	STORE_FLOAT_XFORM_TEST(stfdux);
460 	STORE_FLOAT_DFORM_TEST(stfs);
461 	STORE_FLOAT_XFORM_TEST(stfsx);
462 	STORE_FLOAT_DFORM_TEST(stfsu);
463 	STORE_FLOAT_XFORM_TEST(stfsux);
464 	STORE_FLOAT_XFORM_TEST(stfiwx);
465 
466 	return rc;
467 }
468 
469 void usage(char *prog)
470 {
471 	printf("Usage: %s [options]\n", prog);
472 	printf("  -d	Enable debug error output\n");
473 	printf("\n");
474 	printf("This test requires a POWER8 or POWER9 CPU and a usable ");
475 	printf("framebuffer at /dev/fb0.\n");
476 }
477 
478 int main(int argc, char *argv[])
479 {
480 
481 	struct sigaction sa;
482 	int rc = 0;
483 	int option = 0;
484 
485 	while ((option = getopt(argc, argv, "d")) != -1) {
486 		switch (option) {
487 		case 'd':
488 			debug++;
489 			break;
490 		default:
491 			usage(argv[0]);
492 			exit(1);
493 		}
494 	}
495 
496 	bufsize = getpagesize();
497 
498 	sa.sa_sigaction = sighandler;
499 	sigemptyset(&sa.sa_mask);
500 	sa.sa_flags = SA_SIGINFO;
501 	if (sigaction(SIGSEGV, &sa, NULL) == -1
502 	    || sigaction(SIGBUS, &sa, NULL) == -1
503 	    || sigaction(SIGILL, &sa, NULL) == -1) {
504 		perror("sigaction");
505 		exit(1);
506 	}
507 
508 	rc |= test_harness(test_alignment_handler_vsx_206,
509 			   "test_alignment_handler_vsx_206");
510 	rc |= test_harness(test_alignment_handler_vsx_207,
511 			   "test_alignment_handler_vsx_207");
512 	rc |= test_harness(test_alignment_handler_vsx_300,
513 			   "test_alignment_handler_vsx_300");
514 	rc |= test_harness(test_alignment_handler_integer,
515 			   "test_alignment_handler_integer");
516 	rc |= test_harness(test_alignment_handler_vmx,
517 			   "test_alignment_handler_vmx");
518 	rc |= test_harness(test_alignment_handler_fp,
519 			   "test_alignment_handler_fp");
520 	return rc;
521 }
522