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 <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <assert.h>
47 #include <getopt.h>
48 #include <setjmp.h>
49 #include <signal.h>
50 
51 #include "utils.h"
52 
53 int bufsize;
54 int debug;
55 int testing;
56 volatile int gotsig;
57 
58 void sighandler(int sig, siginfo_t *info, void *ctx)
59 {
60 	ucontext_t *ucp = ctx;
61 
62 	if (!testing) {
63 		signal(sig, SIG_DFL);
64 		kill(0, sig);
65 	}
66 	gotsig = sig;
67 #ifdef __powerpc64__
68 	ucp->uc_mcontext.gp_regs[PT_NIP] += 4;
69 #else
70 	ucp->uc_mcontext.uc_regs->gregs[PT_NIP] += 4;
71 #endif
72 }
73 
74 #define XFORM(reg, n)  " " #reg " ,%"#n",%2 ;"
75 #define DFORM(reg, n)  " " #reg " ,0(%"#n") ;"
76 
77 #define TEST(name, ld_op, st_op, form, ld_reg, st_reg)		\
78 	void test_##name(char *s, char *d)			\
79 	{							\
80 		asm volatile(					\
81 			#ld_op form(ld_reg, 0)			\
82 			#st_op form(st_reg, 1)			\
83 			:: "r"(s), "r"(d), "r"(0)		\
84 			: "memory", "vs0", "vs32", "r31");	\
85 	}							\
86 	rc |= do_test(#name, test_##name)
87 
88 #define LOAD_VSX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 32, 32)
89 #define STORE_VSX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 32)
90 #define LOAD_VSX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 32, 32)
91 #define STORE_VSX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 32)
92 #define LOAD_VMX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 0, 32)
93 #define STORE_VMX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 0)
94 #define LOAD_VMX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 0, 32)
95 #define STORE_VMX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 0)
96 
97 #define LOAD_XFORM_TEST(op) TEST(op, op, stdx, XFORM, 31, 31)
98 #define STORE_XFORM_TEST(op) TEST(op, ldx, op, XFORM, 31, 31)
99 #define LOAD_DFORM_TEST(op) TEST(op, op, std, DFORM, 31, 31)
100 #define STORE_DFORM_TEST(op) TEST(op, ld, op, DFORM, 31, 31)
101 
102 #define LOAD_FLOAT_DFORM_TEST(op)  TEST(op, op, stfd, DFORM, 0, 0)
103 #define STORE_FLOAT_DFORM_TEST(op) TEST(op, lfd, op, DFORM, 0, 0)
104 #define LOAD_FLOAT_XFORM_TEST(op)  TEST(op, op, stfdx, XFORM, 0, 0)
105 #define STORE_FLOAT_XFORM_TEST(op) TEST(op, lfdx, op, XFORM, 0, 0)
106 
107 
108 /* FIXME: Unimplemented tests: */
109 // STORE_DFORM_TEST(stq)   /* FIXME: need two registers for quad */
110 // STORE_DFORM_TEST(stswi) /* FIXME: string instruction */
111 
112 // STORE_XFORM_TEST(stwat) /* AMO can't emulate or run on CI */
113 // STORE_XFORM_TEST(stdat) /* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
114 
115 
116 /* preload byte by byte */
117 void preload_data(void *dst, int offset, int width)
118 {
119 	char *c = dst;
120 	int i;
121 
122 	c += offset;
123 
124 	for (i = 0 ; i < width ; i++)
125 		c[i] = i;
126 }
127 
128 int test_memcpy(void *dst, void *src, int size, int offset,
129 		void (*test_func)(char *, char *))
130 {
131 	char *s, *d;
132 
133 	s = src;
134 	s += offset;
135 	d = dst;
136 	d += offset;
137 
138 	assert(size == 16);
139 	gotsig = 0;
140 	testing = 1;
141 
142 	test_func(s, d); /* run the actual test */
143 
144 	testing = 0;
145 	if (gotsig) {
146 		if (debug)
147 			printf("  Got signal %i\n", gotsig);
148 		return 1;
149 	}
150 	return 0;
151 }
152 
153 void dumpdata(char *s1, char *s2, int n, char *test_name)
154 {
155 	int i;
156 
157 	printf("  %s: unexpected result:\n", test_name);
158 	printf("    mem:");
159 	for (i = 0; i < n; i++)
160 		printf(" %02x", s1[i]);
161 	printf("\n");
162 	printf("    ci: ");
163 	for (i = 0; i < n; i++)
164 		printf(" %02x", s2[i]);
165 	printf("\n");
166 }
167 
168 int test_memcmp(void *s1, void *s2, int n, int offset, char *test_name)
169 {
170 	char *s1c, *s2c;
171 
172 	s1c = s1;
173 	s1c += offset;
174 	s2c = s2;
175 	s2c += offset;
176 
177 	if (memcmp(s1c, s2c, n)) {
178 		if (debug) {
179 			printf("\n  Compare failed. Offset:%i length:%i\n",
180 			       offset, n);
181 			dumpdata(s1c, s2c, n, test_name);
182 		}
183 		return 1;
184 	}
185 	return 0;
186 }
187 
188 /*
189  * Do two memcpy tests using the same instructions. One cachable
190  * memory and the other doesn't.
191  */
192 int do_test(char *test_name, void (*test_func)(char *, char *))
193 {
194 	int offset, width, fd, rc = 0, r;
195 	void *mem0, *mem1, *ci0, *ci1;
196 
197 	printf("\tDoing %s:\t", test_name);
198 
199 	fd = open("/dev/fb0", O_RDWR);
200 	if (fd < 0) {
201 		printf("\n");
202 		perror("Can't open /dev/fb0");
203 		SKIP_IF(1);
204 	}
205 
206 	ci0 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
207 		   fd, 0x0);
208 	ci1 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
209 		   fd, bufsize);
210 	if ((ci0 == MAP_FAILED) || (ci1 == MAP_FAILED)) {
211 		printf("\n");
212 		perror("mmap failed");
213 		SKIP_IF(1);
214 	}
215 
216 	rc = posix_memalign(&mem0, bufsize, bufsize);
217 	if (rc) {
218 		printf("\n");
219 		return rc;
220 	}
221 
222 	rc = posix_memalign(&mem1, bufsize, bufsize);
223 	if (rc) {
224 		printf("\n");
225 		free(mem0);
226 		return rc;
227 	}
228 
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 			break;
248 		}
249 
250 		r |= test_memcmp(mem1, ci1, width, offset, test_name);
251 		rc |= r;
252 		if (r && !debug) {
253 			printf("FAILED: Wrong Data");
254 			break;
255 		}
256 	}
257 	if (!r)
258 		printf("PASSED");
259 	printf("\n");
260 
261 	munmap(ci0, bufsize);
262 	munmap(ci1, bufsize);
263 	free(mem0);
264 	free(mem1);
265 
266 	return rc;
267 }
268 
269 int test_alignment_handler_vsx_206(void)
270 {
271 	int rc = 0;
272 
273 	printf("VSX: 2.06B\n");
274 	LOAD_VSX_XFORM_TEST(lxvd2x);
275 	LOAD_VSX_XFORM_TEST(lxvw4x);
276 	LOAD_VSX_XFORM_TEST(lxsdx);
277 	LOAD_VSX_XFORM_TEST(lxvdsx);
278 	STORE_VSX_XFORM_TEST(stxvd2x);
279 	STORE_VSX_XFORM_TEST(stxvw4x);
280 	STORE_VSX_XFORM_TEST(stxsdx);
281 	return rc;
282 }
283 
284 int test_alignment_handler_vsx_207(void)
285 {
286 	int rc = 0;
287 
288 	printf("VSX: 2.07B\n");
289 	LOAD_VSX_XFORM_TEST(lxsspx);
290 	LOAD_VSX_XFORM_TEST(lxsiwax);
291 	LOAD_VSX_XFORM_TEST(lxsiwzx);
292 	STORE_VSX_XFORM_TEST(stxsspx);
293 	STORE_VSX_XFORM_TEST(stxsiwx);
294 	return rc;
295 }
296 
297 int test_alignment_handler_vsx_300(void)
298 {
299 	int rc = 0;
300 
301 	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_3_00));
302 	printf("VSX: 3.00B\n");
303 	LOAD_VMX_DFORM_TEST(lxsd);
304 	LOAD_VSX_XFORM_TEST(lxsibzx);
305 	LOAD_VSX_XFORM_TEST(lxsihzx);
306 	LOAD_VMX_DFORM_TEST(lxssp);
307 	LOAD_VSX_DFORM_TEST(lxv);
308 	LOAD_VSX_XFORM_TEST(lxvb16x);
309 	LOAD_VSX_XFORM_TEST(lxvh8x);
310 	LOAD_VSX_XFORM_TEST(lxvx);
311 	LOAD_VSX_XFORM_TEST(lxvwsx);
312 	LOAD_VSX_XFORM_TEST(lxvl);
313 	LOAD_VSX_XFORM_TEST(lxvll);
314 	STORE_VMX_DFORM_TEST(stxsd);
315 	STORE_VSX_XFORM_TEST(stxsibx);
316 	STORE_VSX_XFORM_TEST(stxsihx);
317 	STORE_VMX_DFORM_TEST(stxssp);
318 	STORE_VSX_DFORM_TEST(stxv);
319 	STORE_VSX_XFORM_TEST(stxvb16x);
320 	STORE_VSX_XFORM_TEST(stxvh8x);
321 	STORE_VSX_XFORM_TEST(stxvx);
322 	STORE_VSX_XFORM_TEST(stxvl);
323 	STORE_VSX_XFORM_TEST(stxvll);
324 	return rc;
325 }
326 
327 int test_alignment_handler_integer(void)
328 {
329 	int rc = 0;
330 
331 	printf("Integer\n");
332 	LOAD_DFORM_TEST(lbz);
333 	LOAD_DFORM_TEST(lbzu);
334 	LOAD_XFORM_TEST(lbzx);
335 	LOAD_XFORM_TEST(lbzux);
336 	LOAD_DFORM_TEST(lhz);
337 	LOAD_DFORM_TEST(lhzu);
338 	LOAD_XFORM_TEST(lhzx);
339 	LOAD_XFORM_TEST(lhzux);
340 	LOAD_DFORM_TEST(lha);
341 	LOAD_DFORM_TEST(lhau);
342 	LOAD_XFORM_TEST(lhax);
343 	LOAD_XFORM_TEST(lhaux);
344 	LOAD_XFORM_TEST(lhbrx);
345 	LOAD_DFORM_TEST(lwz);
346 	LOAD_DFORM_TEST(lwzu);
347 	LOAD_XFORM_TEST(lwzx);
348 	LOAD_XFORM_TEST(lwzux);
349 	LOAD_DFORM_TEST(lwa);
350 	LOAD_XFORM_TEST(lwax);
351 	LOAD_XFORM_TEST(lwaux);
352 	LOAD_XFORM_TEST(lwbrx);
353 	LOAD_DFORM_TEST(ld);
354 	LOAD_DFORM_TEST(ldu);
355 	LOAD_XFORM_TEST(ldx);
356 	LOAD_XFORM_TEST(ldux);
357 	LOAD_XFORM_TEST(ldbrx);
358 	LOAD_DFORM_TEST(lmw);
359 	STORE_DFORM_TEST(stb);
360 	STORE_XFORM_TEST(stbx);
361 	STORE_DFORM_TEST(stbu);
362 	STORE_XFORM_TEST(stbux);
363 	STORE_DFORM_TEST(sth);
364 	STORE_XFORM_TEST(sthx);
365 	STORE_DFORM_TEST(sthu);
366 	STORE_XFORM_TEST(sthux);
367 	STORE_XFORM_TEST(sthbrx);
368 	STORE_DFORM_TEST(stw);
369 	STORE_XFORM_TEST(stwx);
370 	STORE_DFORM_TEST(stwu);
371 	STORE_XFORM_TEST(stwux);
372 	STORE_XFORM_TEST(stwbrx);
373 	STORE_DFORM_TEST(std);
374 	STORE_XFORM_TEST(stdx);
375 	STORE_DFORM_TEST(stdu);
376 	STORE_XFORM_TEST(stdux);
377 	STORE_XFORM_TEST(stdbrx);
378 	STORE_DFORM_TEST(stmw);
379 	return rc;
380 }
381 
382 int test_alignment_handler_vmx(void)
383 {
384 	int rc = 0;
385 
386 	printf("VMX\n");
387 	LOAD_VMX_XFORM_TEST(lvx);
388 
389 	/*
390 	 * FIXME: These loads only load part of the register, so our
391 	 * testing method doesn't work. Also they don't take alignment
392 	 * faults, so it's kinda pointless anyway
393 	 *
394 	 LOAD_VMX_XFORM_TEST(lvebx)
395 	 LOAD_VMX_XFORM_TEST(lvehx)
396 	 LOAD_VMX_XFORM_TEST(lvewx)
397 	 LOAD_VMX_XFORM_TEST(lvxl)
398 	*/
399 	STORE_VMX_XFORM_TEST(stvx);
400 	STORE_VMX_XFORM_TEST(stvebx);
401 	STORE_VMX_XFORM_TEST(stvehx);
402 	STORE_VMX_XFORM_TEST(stvewx);
403 	STORE_VMX_XFORM_TEST(stvxl);
404 	return rc;
405 }
406 
407 int test_alignment_handler_fp(void)
408 {
409 	int rc = 0;
410 
411 	printf("Floating point\n");
412 	LOAD_FLOAT_DFORM_TEST(lfd);
413 	LOAD_FLOAT_XFORM_TEST(lfdx);
414 	LOAD_FLOAT_DFORM_TEST(lfdp);
415 	LOAD_FLOAT_XFORM_TEST(lfdpx);
416 	LOAD_FLOAT_DFORM_TEST(lfdu);
417 	LOAD_FLOAT_XFORM_TEST(lfdux);
418 	LOAD_FLOAT_DFORM_TEST(lfs);
419 	LOAD_FLOAT_XFORM_TEST(lfsx);
420 	LOAD_FLOAT_DFORM_TEST(lfsu);
421 	LOAD_FLOAT_XFORM_TEST(lfsux);
422 	LOAD_FLOAT_XFORM_TEST(lfiwzx);
423 	LOAD_FLOAT_XFORM_TEST(lfiwax);
424 	STORE_FLOAT_DFORM_TEST(stfd);
425 	STORE_FLOAT_XFORM_TEST(stfdx);
426 	STORE_FLOAT_DFORM_TEST(stfdp);
427 	STORE_FLOAT_XFORM_TEST(stfdpx);
428 	STORE_FLOAT_DFORM_TEST(stfdu);
429 	STORE_FLOAT_XFORM_TEST(stfdux);
430 	STORE_FLOAT_DFORM_TEST(stfs);
431 	STORE_FLOAT_XFORM_TEST(stfsx);
432 	STORE_FLOAT_DFORM_TEST(stfsu);
433 	STORE_FLOAT_XFORM_TEST(stfsux);
434 	STORE_FLOAT_XFORM_TEST(stfiwx);
435 
436 	return rc;
437 }
438 
439 void usage(char *prog)
440 {
441 	printf("Usage: %s [options]\n", prog);
442 	printf("  -d	Enable debug error output\n");
443 	printf("\n");
444 	printf("This test requires a POWER8 or POWER9 CPU and a usable ");
445 	printf("framebuffer at /dev/fb0.\n");
446 }
447 
448 int main(int argc, char *argv[])
449 {
450 
451 	struct sigaction sa;
452 	int rc = 0;
453 	int option = 0;
454 
455 	while ((option = getopt(argc, argv, "d")) != -1) {
456 		switch (option) {
457 		case 'd':
458 			debug++;
459 			break;
460 		default:
461 			usage(argv[0]);
462 			exit(1);
463 		}
464 	}
465 
466 	bufsize = getpagesize();
467 
468 	sa.sa_sigaction = sighandler;
469 	sigemptyset(&sa.sa_mask);
470 	sa.sa_flags = SA_SIGINFO;
471 	if (sigaction(SIGSEGV, &sa, NULL) == -1
472 	    || sigaction(SIGBUS, &sa, NULL) == -1
473 	    || sigaction(SIGILL, &sa, NULL) == -1) {
474 		perror("sigaction");
475 		exit(1);
476 	}
477 
478 	rc |= test_harness(test_alignment_handler_vsx_206,
479 			   "test_alignment_handler_vsx_206");
480 	rc |= test_harness(test_alignment_handler_vsx_207,
481 			   "test_alignment_handler_vsx_207");
482 	rc |= test_harness(test_alignment_handler_vsx_300,
483 			   "test_alignment_handler_vsx_300");
484 	rc |= test_harness(test_alignment_handler_integer,
485 			   "test_alignment_handler_integer");
486 	rc |= test_harness(test_alignment_handler_vmx,
487 			   "test_alignment_handler_vmx");
488 	rc |= test_harness(test_alignment_handler_fp,
489 			   "test_alignment_handler_fp");
490 	return rc;
491 }
492