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      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 <asm/cputable.h>
     53 
     54 #include "utils.h"
     55 
     56 int bufsize;
     57 int debug;
     58 int testing;
     59 volatile int gotsig;
     60 
     61 void sighandler(int sig, siginfo_t *info, void *ctx)
     62 {
     63 	ucontext_t *ucp = ctx;
     64 
     65 	if (!testing) {
     66 		signal(sig, SIG_DFL);
     67 		kill(0, sig);
     68 	}
     69 	gotsig = sig;
     70 #ifdef __powerpc64__
     71 	ucp->uc_mcontext.gp_regs[PT_NIP] += 4;
     72 #else
     73 	ucp->uc_mcontext.uc_regs->gregs[PT_NIP] += 4;
     74 #endif
     75 }
     76 
     77 #define XFORM(reg, n)  " " #reg " ,%"#n",%2 ;"
     78 #define DFORM(reg, n)  " " #reg " ,0(%"#n") ;"
     79 
     80 #define TEST(name, ld_op, st_op, form, ld_reg, st_reg)		\
     81 	void test_##name(char *s, char *d)			\
     82 	{							\
     83 		asm volatile(					\
     84 			#ld_op form(ld_reg, 0)			\
     85 			#st_op form(st_reg, 1)			\
     86 			:: "r"(s), "r"(d), "r"(0)		\
     87 			: "memory", "vs0", "vs32", "r31");	\
     88 	}							\
     89 	rc |= do_test(#name, test_##name)
     90 
     91 #define LOAD_VSX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 32, 32)
     92 #define STORE_VSX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 32)
     93 #define LOAD_VSX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 32, 32)
     94 #define STORE_VSX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 32)
     95 #define LOAD_VMX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 0, 32)
     96 #define STORE_VMX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 0)
     97 #define LOAD_VMX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 0, 32)
     98 #define STORE_VMX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 0)
     99 
    100 #define LOAD_XFORM_TEST(op) TEST(op, op, stdx, XFORM, 31, 31)
    101 #define STORE_XFORM_TEST(op) TEST(op, ldx, op, XFORM, 31, 31)
    102 #define LOAD_DFORM_TEST(op) TEST(op, op, std, DFORM, 31, 31)
    103 #define STORE_DFORM_TEST(op) TEST(op, ld, op, DFORM, 31, 31)
    104 
    105 #define LOAD_FLOAT_DFORM_TEST(op)  TEST(op, op, stfd, DFORM, 0, 0)
    106 #define STORE_FLOAT_DFORM_TEST(op) TEST(op, lfd, op, DFORM, 0, 0)
    107 #define LOAD_FLOAT_XFORM_TEST(op)  TEST(op, op, stfdx, XFORM, 0, 0)
    108 #define STORE_FLOAT_XFORM_TEST(op) TEST(op, lfdx, op, XFORM, 0, 0)
    109 
    110 
    111 /* FIXME: Unimplemented tests: */
    112 // STORE_DFORM_TEST(stq)   /* FIXME: need two registers for quad */
    113 // STORE_DFORM_TEST(stswi) /* FIXME: string instruction */
    114 
    115 // STORE_XFORM_TEST(stwat) /* AMO can't emulate or run on CI */
    116 // STORE_XFORM_TEST(stdat) /* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
    117 
    118 
    119 /* preload byte by byte */
    120 void preload_data(void *dst, int offset, int width)
    121 {
    122 	char *c = dst;
    123 	int i;
    124 
    125 	c += offset;
    126 
    127 	for (i = 0 ; i < width ; i++)
    128 		c[i] = i;
    129 }
    130 
    131 int test_memcpy(void *dst, void *src, int size, int offset,
    132 		void (*test_func)(char *, char *))
    133 {
    134 	char *s, *d;
    135 
    136 	s = src;
    137 	s += offset;
    138 	d = dst;
    139 	d += offset;
    140 
    141 	assert(size == 16);
    142 	gotsig = 0;
    143 	testing = 1;
    144 
    145 	test_func(s, d); /* run the actual test */
    146 
    147 	testing = 0;
    148 	if (gotsig) {
    149 		if (debug)
    150 			printf("  Got signal %i\n", gotsig);
    151 		return 1;
    152 	}
    153 	return 0;
    154 }
    155 
    156 void dumpdata(char *s1, char *s2, int n, char *test_name)
    157 {
    158 	int i;
    159 
    160 	printf("  %s: unexpected result:\n", test_name);
    161 	printf("    mem:");
    162 	for (i = 0; i < n; i++)
    163 		printf(" %02x", s1[i]);
    164 	printf("\n");
    165 	printf("    ci: ");
    166 	for (i = 0; i < n; i++)
    167 		printf(" %02x", s2[i]);
    168 	printf("\n");
    169 }
    170 
    171 int test_memcmp(void *s1, void *s2, int n, int offset, char *test_name)
    172 {
    173 	char *s1c, *s2c;
    174 
    175 	s1c = s1;
    176 	s1c += offset;
    177 	s2c = s2;
    178 	s2c += offset;
    179 
    180 	if (memcmp(s1c, s2c, n)) {
    181 		if (debug) {
    182 			printf("\n  Compare failed. Offset:%i length:%i\n",
    183 			       offset, n);
    184 			dumpdata(s1c, s2c, n, test_name);
    185 		}
    186 		return 1;
    187 	}
    188 	return 0;
    189 }
    190 
    191 /*
    192  * Do two memcpy tests using the same instructions. One cachable
    193  * memory and the other doesn't.
    194  */
    195 int do_test(char *test_name, void (*test_func)(char *, char *))
    196 {
    197 	int offset, width, fd, rc, r;
    198 	void *mem0, *mem1, *ci0, *ci1;
    199 
    200 	printf("\tDoing %s:\t", test_name);
    201 
    202 	fd = open("/dev/fb0", O_RDWR);
    203 	if (fd < 0) {
    204 		printf("\n");
    205 		perror("Can't open /dev/fb0 now?");
    206 		return 1;
    207 	}
    208 
    209 	ci0 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
    210 		   fd, 0x0);
    211 	ci1 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
    212 		   fd, bufsize);
    213 	if ((ci0 == MAP_FAILED) || (ci1 == MAP_FAILED)) {
    214 		printf("\n");
    215 		perror("mmap failed");
    216 		SKIP_IF(1);
    217 	}
    218 
    219 	rc = posix_memalign(&mem0, bufsize, bufsize);
    220 	if (rc) {
    221 		printf("\n");
    222 		return rc;
    223 	}
    224 
    225 	rc = posix_memalign(&mem1, bufsize, bufsize);
    226 	if (rc) {
    227 		printf("\n");
    228 		free(mem0);
    229 		return rc;
    230 	}
    231 
    232 	rc = 0;
    233 	/* offset = 0 no alignment fault, so skip */
    234 	for (offset = 1; offset < 16; offset++) {
    235 		width = 16; /* vsx == 16 bytes */
    236 		r = 0;
    237 
    238 		/* load pattern into memory byte by byte */
    239 		preload_data(ci0, offset, width);
    240 		preload_data(mem0, offset, width); // FIXME: remove??
    241 		memcpy(ci0, mem0, bufsize);
    242 		memcpy(ci1, mem1, bufsize); /* initialise output to the same */
    243 
    244 		/* sanity check */
    245 		test_memcmp(mem0, ci0, width, offset, test_name);
    246 
    247 		r |= test_memcpy(ci1,  ci0,  width, offset, test_func);
    248 		r |= test_memcpy(mem1, mem0, width, offset, test_func);
    249 		if (r && !debug) {
    250 			printf("FAILED: Got signal");
    251 			rc = 1;
    252 			break;
    253 		}
    254 
    255 		r |= test_memcmp(mem1, ci1, width, offset, test_name);
    256 		if (r && !debug) {
    257 			printf("FAILED: Wrong Data");
    258 			rc = 1;
    259 			break;
    260 		}
    261 	}
    262 
    263 	if (rc == 0)
    264 		printf("PASSED");
    265 
    266 	printf("\n");
    267 
    268 	munmap(ci0, bufsize);
    269 	munmap(ci1, bufsize);
    270 	free(mem0);
    271 	free(mem1);
    272 	close(fd);
    273 
    274 	return rc;
    275 }
    276 
    277 static bool can_open_fb0(void)
    278 {
    279 	int fd;
    280 
    281 	fd = open("/dev/fb0", O_RDWR);
    282 	if (fd < 0)
    283 		return false;
    284 
    285 	close(fd);
    286 	return true;
    287 }
    288 
    289 int test_alignment_handler_vsx_206(void)
    290 {
    291 	int rc = 0;
    292 
    293 	SKIP_IF(!can_open_fb0());
    294 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
    295 
    296 	printf("VSX: 2.06B\n");
    297 	LOAD_VSX_XFORM_TEST(lxvd2x);
    298 	LOAD_VSX_XFORM_TEST(lxvw4x);
    299 	LOAD_VSX_XFORM_TEST(lxsdx);
    300 	LOAD_VSX_XFORM_TEST(lxvdsx);
    301 	STORE_VSX_XFORM_TEST(stxvd2x);
    302 	STORE_VSX_XFORM_TEST(stxvw4x);
    303 	STORE_VSX_XFORM_TEST(stxsdx);
    304 	return rc;
    305 }
    306 
    307 int test_alignment_handler_vsx_207(void)
    308 {
    309 	int rc = 0;
    310 
    311 	SKIP_IF(!can_open_fb0());
    312 	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_2_07));
    313 
    314 	printf("VSX: 2.07B\n");
    315 	LOAD_VSX_XFORM_TEST(lxsspx);
    316 	LOAD_VSX_XFORM_TEST(lxsiwax);
    317 	LOAD_VSX_XFORM_TEST(lxsiwzx);
    318 	STORE_VSX_XFORM_TEST(stxsspx);
    319 	STORE_VSX_XFORM_TEST(stxsiwx);
    320 	return rc;
    321 }
    322 
    323 int test_alignment_handler_vsx_300(void)
    324 {
    325 	int rc = 0;
    326 
    327 	SKIP_IF(!can_open_fb0());
    328 
    329 	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_3_00));
    330 	printf("VSX: 3.00B\n");
    331 	LOAD_VMX_DFORM_TEST(lxsd);
    332 	LOAD_VSX_XFORM_TEST(lxsibzx);
    333 	LOAD_VSX_XFORM_TEST(lxsihzx);
    334 	LOAD_VMX_DFORM_TEST(lxssp);
    335 	LOAD_VSX_DFORM_TEST(lxv);
    336 	LOAD_VSX_XFORM_TEST(lxvb16x);
    337 	LOAD_VSX_XFORM_TEST(lxvh8x);
    338 	LOAD_VSX_XFORM_TEST(lxvx);
    339 	LOAD_VSX_XFORM_TEST(lxvwsx);
    340 	LOAD_VSX_XFORM_TEST(lxvl);
    341 	LOAD_VSX_XFORM_TEST(lxvll);
    342 	STORE_VMX_DFORM_TEST(stxsd);
    343 	STORE_VSX_XFORM_TEST(stxsibx);
    344 	STORE_VSX_XFORM_TEST(stxsihx);
    345 	STORE_VMX_DFORM_TEST(stxssp);
    346 	STORE_VSX_DFORM_TEST(stxv);
    347 	STORE_VSX_XFORM_TEST(stxvb16x);
    348 	STORE_VSX_XFORM_TEST(stxvh8x);
    349 	STORE_VSX_XFORM_TEST(stxvx);
    350 	STORE_VSX_XFORM_TEST(stxvl);
    351 	STORE_VSX_XFORM_TEST(stxvll);
    352 	return rc;
    353 }
    354 
    355 int test_alignment_handler_integer(void)
    356 {
    357 	int rc = 0;
    358 
    359 	SKIP_IF(!can_open_fb0());
    360 
    361 	printf("Integer\n");
    362 	LOAD_DFORM_TEST(lbz);
    363 	LOAD_DFORM_TEST(lbzu);
    364 	LOAD_XFORM_TEST(lbzx);
    365 	LOAD_XFORM_TEST(lbzux);
    366 	LOAD_DFORM_TEST(lhz);
    367 	LOAD_DFORM_TEST(lhzu);
    368 	LOAD_XFORM_TEST(lhzx);
    369 	LOAD_XFORM_TEST(lhzux);
    370 	LOAD_DFORM_TEST(lha);
    371 	LOAD_DFORM_TEST(lhau);
    372 	LOAD_XFORM_TEST(lhax);
    373 	LOAD_XFORM_TEST(lhaux);
    374 	LOAD_XFORM_TEST(lhbrx);
    375 	LOAD_DFORM_TEST(lwz);
    376 	LOAD_DFORM_TEST(lwzu);
    377 	LOAD_XFORM_TEST(lwzx);
    378 	LOAD_XFORM_TEST(lwzux);
    379 	LOAD_DFORM_TEST(lwa);
    380 	LOAD_XFORM_TEST(lwax);
    381 	LOAD_XFORM_TEST(lwaux);
    382 	LOAD_XFORM_TEST(lwbrx);
    383 	LOAD_DFORM_TEST(ld);
    384 	LOAD_DFORM_TEST(ldu);
    385 	LOAD_XFORM_TEST(ldx);
    386 	LOAD_XFORM_TEST(ldux);
    387 	LOAD_DFORM_TEST(lmw);
    388 	STORE_DFORM_TEST(stb);
    389 	STORE_XFORM_TEST(stbx);
    390 	STORE_DFORM_TEST(stbu);
    391 	STORE_XFORM_TEST(stbux);
    392 	STORE_DFORM_TEST(sth);
    393 	STORE_XFORM_TEST(sthx);
    394 	STORE_DFORM_TEST(sthu);
    395 	STORE_XFORM_TEST(sthux);
    396 	STORE_XFORM_TEST(sthbrx);
    397 	STORE_DFORM_TEST(stw);
    398 	STORE_XFORM_TEST(stwx);
    399 	STORE_DFORM_TEST(stwu);
    400 	STORE_XFORM_TEST(stwux);
    401 	STORE_XFORM_TEST(stwbrx);
    402 	STORE_DFORM_TEST(std);
    403 	STORE_XFORM_TEST(stdx);
    404 	STORE_DFORM_TEST(stdu);
    405 	STORE_XFORM_TEST(stdux);
    406 	STORE_DFORM_TEST(stmw);
    407 
    408 	return rc;
    409 }
    410 
    411 int test_alignment_handler_integer_206(void)
    412 {
    413 	int rc = 0;
    414 
    415 	SKIP_IF(!can_open_fb0());
    416 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
    417 
    418 	printf("Integer: 2.06\n");
    419 
    420 	LOAD_XFORM_TEST(ldbrx);
    421 	STORE_XFORM_TEST(stdbrx);
    422 
    423 	return rc;
    424 }
    425 
    426 int test_alignment_handler_vmx(void)
    427 {
    428 	int rc = 0;
    429 
    430 	SKIP_IF(!can_open_fb0());
    431 	SKIP_IF(!have_hwcap(PPC_FEATURE_HAS_ALTIVEC));
    432 
    433 	printf("VMX\n");
    434 	LOAD_VMX_XFORM_TEST(lvx);
    435 
    436 	/*
    437 	 * FIXME: These loads only load part of the register, so our
    438 	 * testing method doesn't work. Also they don't take alignment
    439 	 * faults, so it's kinda pointless anyway
    440 	 *
    441 	 LOAD_VMX_XFORM_TEST(lvebx)
    442 	 LOAD_VMX_XFORM_TEST(lvehx)
    443 	 LOAD_VMX_XFORM_TEST(lvewx)
    444 	 LOAD_VMX_XFORM_TEST(lvxl)
    445 	*/
    446 	STORE_VMX_XFORM_TEST(stvx);
    447 	STORE_VMX_XFORM_TEST(stvebx);
    448 	STORE_VMX_XFORM_TEST(stvehx);
    449 	STORE_VMX_XFORM_TEST(stvewx);
    450 	STORE_VMX_XFORM_TEST(stvxl);
    451 	return rc;
    452 }
    453 
    454 int test_alignment_handler_fp(void)
    455 {
    456 	int rc = 0;
    457 
    458 	SKIP_IF(!can_open_fb0());
    459 
    460 	printf("Floating point\n");
    461 	LOAD_FLOAT_DFORM_TEST(lfd);
    462 	LOAD_FLOAT_XFORM_TEST(lfdx);
    463 	LOAD_FLOAT_DFORM_TEST(lfdu);
    464 	LOAD_FLOAT_XFORM_TEST(lfdux);
    465 	LOAD_FLOAT_DFORM_TEST(lfs);
    466 	LOAD_FLOAT_XFORM_TEST(lfsx);
    467 	LOAD_FLOAT_DFORM_TEST(lfsu);
    468 	LOAD_FLOAT_XFORM_TEST(lfsux);
    469 	STORE_FLOAT_DFORM_TEST(stfd);
    470 	STORE_FLOAT_XFORM_TEST(stfdx);
    471 	STORE_FLOAT_DFORM_TEST(stfdu);
    472 	STORE_FLOAT_XFORM_TEST(stfdux);
    473 	STORE_FLOAT_DFORM_TEST(stfs);
    474 	STORE_FLOAT_XFORM_TEST(stfsx);
    475 	STORE_FLOAT_DFORM_TEST(stfsu);
    476 	STORE_FLOAT_XFORM_TEST(stfsux);
    477 	STORE_FLOAT_XFORM_TEST(stfiwx);
    478 
    479 	return rc;
    480 }
    481 
    482 int test_alignment_handler_fp_205(void)
    483 {
    484 	int rc = 0;
    485 
    486 	SKIP_IF(!can_open_fb0());
    487 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_05));
    488 
    489 	printf("Floating point: 2.05\n");
    490 
    491 	LOAD_FLOAT_DFORM_TEST(lfdp);
    492 	LOAD_FLOAT_XFORM_TEST(lfdpx);
    493 	LOAD_FLOAT_XFORM_TEST(lfiwax);
    494 	STORE_FLOAT_DFORM_TEST(stfdp);
    495 	STORE_FLOAT_XFORM_TEST(stfdpx);
    496 
    497 	return rc;
    498 }
    499 
    500 int test_alignment_handler_fp_206(void)
    501 {
    502 	int rc = 0;
    503 
    504 	SKIP_IF(!can_open_fb0());
    505 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));
    506 
    507 	printf("Floating point: 2.06\n");
    508 
    509 	LOAD_FLOAT_XFORM_TEST(lfiwzx);
    510 
    511 	return rc;
    512 }
    513 
    514 void usage(char *prog)
    515 {
    516 	printf("Usage: %s [options]\n", prog);
    517 	printf("  -d	Enable debug error output\n");
    518 	printf("\n");
    519 	printf("This test requires a POWER8 or POWER9 CPU and a usable ");
    520 	printf("framebuffer at /dev/fb0.\n");
    521 }
    522 
    523 int main(int argc, char *argv[])
    524 {
    525 
    526 	struct sigaction sa;
    527 	int rc = 0;
    528 	int option = 0;
    529 
    530 	while ((option = getopt(argc, argv, "d")) != -1) {
    531 		switch (option) {
    532 		case 'd':
    533 			debug++;
    534 			break;
    535 		default:
    536 			usage(argv[0]);
    537 			exit(1);
    538 		}
    539 	}
    540 
    541 	bufsize = getpagesize();
    542 
    543 	sa.sa_sigaction = sighandler;
    544 	sigemptyset(&sa.sa_mask);
    545 	sa.sa_flags = SA_SIGINFO;
    546 	if (sigaction(SIGSEGV, &sa, NULL) == -1
    547 	    || sigaction(SIGBUS, &sa, NULL) == -1
    548 	    || sigaction(SIGILL, &sa, NULL) == -1) {
    549 		perror("sigaction");
    550 		exit(1);
    551 	}
    552 
    553 	rc |= test_harness(test_alignment_handler_vsx_206,
    554 			   "test_alignment_handler_vsx_206");
    555 	rc |= test_harness(test_alignment_handler_vsx_207,
    556 			   "test_alignment_handler_vsx_207");
    557 	rc |= test_harness(test_alignment_handler_vsx_300,
    558 			   "test_alignment_handler_vsx_300");
    559 	rc |= test_harness(test_alignment_handler_integer,
    560 			   "test_alignment_handler_integer");
    561 	rc |= test_harness(test_alignment_handler_integer_206,
    562 			   "test_alignment_handler_integer_206");
    563 	rc |= test_harness(test_alignment_handler_vmx,
    564 			   "test_alignment_handler_vmx");
    565 	rc |= test_harness(test_alignment_handler_fp,
    566 			   "test_alignment_handler_fp");
    567 	rc |= test_harness(test_alignment_handler_fp_205,
    568 			   "test_alignment_handler_fp_205");
    569 	rc |= test_harness(test_alignment_handler_fp_206,
    570 			   "test_alignment_handler_fp_206");
    571 	return rc;
    572 }
    573