selftests/powerpc: Add alignment handler selftest

Add a selftest to exercise the powerpc alignment fault handler.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
[mpe: Add 32-bit support to the signal handler]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

tools/testing/selftests/powerpc/alignment/Makefile

-TEST_GEN_PROGS := copy_unaligned copy_first_unaligned paste_unaligned paste_last_unaligned
+TEST_GEN_PROGS := copy_unaligned copy_first_unaligned paste_unaligned \
+	paste_last_unaligned alignment_handler
 
 include ../../lib.mk
 

tools/testing/selftests/powerpc/alignment/alignment_handler.c

+/*
+ * Test the powerpc alignment handler on POWER8/POWER9
+ *
+ * Copyright (C) 2017 IBM Corporation (Michael Neuling, Andrew Donnellan)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+/*
+ * This selftest exercises the powerpc alignment fault handler.
+ *
+ * We create two sets of source and destination buffers, one in regular memory,
+ * the other cache-inhibited (we use /dev/fb0 for this).
+ *
+ * We initialise the source buffers, then use whichever set of load/store
+ * instructions is under test to copy bytes from the source buffers to the
+ * destination buffers. For the regular buffers, these instructions will
+ * execute normally. For the cache-inhibited buffers, these instructions
+ * will trap and cause an alignment fault, and the alignment fault handler
+ * will emulate the particular instruction under test. We then compare the
+ * destination buffers to ensure that the native and emulated cases give the
+ * same result.
+ *
+ * TODO:
+ *   - Any FIXMEs below
+ *   - Test VSX regs < 32 and > 32
+ *   - Test all loads and stores
+ *   - Check update forms do update register
+ *   - Test alignment faults over page boundary
+ *
+ * Some old binutils may not support all the instructions.
+ */
+
+
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <getopt.h>
+#include <setjmp.h>
+#include <signal.h>
+
+#include "utils.h"
+
+int bufsize;
+int debug;
+int testing;
+volatile int gotsig;
+
+void sighandler(int sig, siginfo_t *info, void *ctx)
+{
+	struct ucontext *ucp = ctx;
+
+	if (!testing) {
+		signal(sig, SIG_DFL);
+		kill(0, sig);
+	}
+	gotsig = sig;
+#ifdef __powerpc64__
+	ucp->uc_mcontext.gp_regs[PT_NIP] += 4;
+#else
+	ucp->uc_mcontext.uc_regs->gregs[PT_NIP] += 4;
+#endif
+}
+
+#define XFORM(reg, n)  " " #reg " ,%"#n",%2 ;"
+#define DFORM(reg, n)  " " #reg " ,0(%"#n") ;"
+
+#define TEST(name, ld_op, st_op, form, ld_reg, st_reg)		\
+	void test_##name(char *s, char *d)			\
+	{							\
+		asm volatile(					\
+			#ld_op form(ld_reg, 0)			\
+			#st_op form(st_reg, 1)			\
+			:: "r"(s), "r"(d), "r"(0)		\
+			: "memory", "vs0", "vs32", "r31");	\
+	}							\
+	rc |= do_test(#name, test_##name)
+
+#define LOAD_VSX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 32, 32)
+#define STORE_VSX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 32)
+#define LOAD_VSX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 32, 32)
+#define STORE_VSX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 32)
+#define LOAD_VMX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 0, 32)
+#define STORE_VMX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 0)
+#define LOAD_VMX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 0, 32)
+#define STORE_VMX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 0)
+
+#define LOAD_XFORM_TEST(op) TEST(op, op, stdx, XFORM, 31, 31)
+#define STORE_XFORM_TEST(op) TEST(op, ldx, op, XFORM, 31, 31)
+#define LOAD_DFORM_TEST(op) TEST(op, op, std, DFORM, 31, 31)
+#define STORE_DFORM_TEST(op) TEST(op, ld, op, DFORM, 31, 31)
+
+#define LOAD_FLOAT_DFORM_TEST(op)  TEST(op, op, stfd, DFORM, 0, 0)
+#define STORE_FLOAT_DFORM_TEST(op) TEST(op, lfd, op, DFORM, 0, 0)
+#define LOAD_FLOAT_XFORM_TEST(op)  TEST(op, op, stfdx, XFORM, 0, 0)
+#define STORE_FLOAT_XFORM_TEST(op) TEST(op, lfdx, op, XFORM, 0, 0)
+
+
+/* FIXME: Unimplemented tests: */
+// STORE_DFORM_TEST(stq)   /* FIXME: need two registers for quad */
+// STORE_DFORM_TEST(stswi) /* FIXME: string instruction */
+
+// STORE_XFORM_TEST(stwat) /* AMO can't emulate or run on CI */
+// STORE_XFORM_TEST(stdat) /* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
+
+
+/* preload byte by byte */
+void preload_data(void *dst, int offset, int width)
+{
+	char *c = dst;
+	int i;
+
+	c += offset;
+
+	for (i = 0 ; i < width ; i++)
+		c[i] = i;
+}
+
+int test_memcpy(void *dst, void *src, int size, int offset,
+		void (*test_func)(char *, char *))
+{
+	char *s, *d;
+
+	s = src;
+	s += offset;
+	d = dst;
+	d += offset;
+
+	assert(size == 16);
+	gotsig = 0;
+	testing = 1;
+
+	test_func(s, d); /* run the actual test */
+
+	testing = 0;
+	if (gotsig) {
+		if (debug)
+			printf("  Got signal %i\n", gotsig);
+		return 1;
+	}
+	return 0;
+}
+
+void dumpdata(char *s1, char *s2, int n, char *test_name)
+{
+	int i;
+
+	printf("  %s: unexpected result:\n", test_name);
+	printf("    mem:");
+	for (i = 0; i < n; i++)
+		printf(" %02x", s1[i]);
+	printf("\n");
+	printf("    ci: ");
+	for (i = 0; i < n; i++)
+		printf(" %02x", s2[i]);
+	printf("\n");
+}
+
+int test_memcmp(void *s1, void *s2, int n, int offset, char *test_name)
+{
+	char *s1c, *s2c;
+
+	s1c = s1;
+	s1c += offset;
+	s2c = s2;
+	s2c += offset;
+
+	if (memcmp(s1c, s2c, n)) {
+		if (debug) {
+			printf("\n  Compare failed. Offset:%i length:%i\n",
+			       offset, n);
+			dumpdata(s1c, s2c, n, test_name);
+		}
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * Do two memcpy tests using the same instructions. One cachable
+ * memory and the other doesn't.
+ */
+int do_test(char *test_name, void (*test_func)(char *, char *))
+{
+	int offset, width, fd, rc = 0, r;
+	void *mem0, *mem1, *ci0, *ci1;
+
+	printf("\tDoing %s:\t", test_name);
+
+	fd = open("/dev/fb0", O_RDWR);
+	if (fd < 0) {
+		printf("\n");
+		perror("Can't open /dev/fb0");
+		SKIP_IF(1);
+	}
+
+	ci0 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
+		   fd, 0x0);
+	ci1 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
+		   fd, bufsize);
+	if ((ci0 == MAP_FAILED) || (ci1 == MAP_FAILED)) {
+		printf("\n");
+		perror("mmap failed");
+		SKIP_IF(1);
+	}
+
+	rc = posix_memalign(&mem0, bufsize, bufsize);
+	if (rc) {
+		printf("\n");
+		return rc;
+	}
+
+	rc = posix_memalign(&mem1, bufsize, bufsize);
+	if (rc) {
+		printf("\n");
+		free(mem0);
+		return rc;
+	}
+
+	/* offset = 0 no alignment fault, so skip */
+	for (offset = 1; offset < 16; offset++) {
+		width = 16; /* vsx == 16 bytes */
+		r = 0;
+
+		/* load pattern into memory byte by byte */
+		preload_data(ci0, offset, width);
+		preload_data(mem0, offset, width); // FIXME: remove??
+		memcpy(ci0, mem0, bufsize);
+		memcpy(ci1, mem1, bufsize); /* initialise output to the same */
+
+		/* sanity check */
+		test_memcmp(mem0, ci0, width, offset, test_name);
+
+		r |= test_memcpy(ci1,  ci0,  width, offset, test_func);
+		r |= test_memcpy(mem1, mem0, width, offset, test_func);
+		if (r && !debug) {
+			printf("FAILED: Got signal");
+			break;
+		}
+
+		r |= test_memcmp(mem1, ci1, width, offset, test_name);
+		rc |= r;
+		if (r && !debug) {
+			printf("FAILED: Wrong Data");
+			break;
+		}
+	}
+	if (!r)
+		printf("PASSED");
+	printf("\n");
+
+	munmap(ci0, bufsize);
+	munmap(ci1, bufsize);
+	free(mem0);
+	free(mem1);
+
+	return rc;
+}
+
+int test_alignment_handler_vsx_206(void)
+{
+	int rc = 0;
+
+	printf("VSX: 2.06B\n");
+	LOAD_VSX_XFORM_TEST(lxvd2x);
+	LOAD_VSX_XFORM_TEST(lxvw4x);
+	LOAD_VSX_XFORM_TEST(lxsdx);
+	LOAD_VSX_XFORM_TEST(lxvdsx);
+	STORE_VSX_XFORM_TEST(stxvd2x);
+	STORE_VSX_XFORM_TEST(stxvw4x);
+	STORE_VSX_XFORM_TEST(stxsdx);
+	return rc;
+}
+
+int test_alignment_handler_vsx_207(void)
+{
+	int rc = 0;
+
+	printf("VSX: 2.07B\n");
+	LOAD_VSX_XFORM_TEST(lxsspx);
+	LOAD_VSX_XFORM_TEST(lxsiwax);
+	LOAD_VSX_XFORM_TEST(lxsiwzx);
+	STORE_VSX_XFORM_TEST(stxsspx);
+	STORE_VSX_XFORM_TEST(stxsiwx);
+	return rc;
+}
+
+int test_alignment_handler_vsx_300(void)
+{
+	int rc = 0;
+
+	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_3_00));
+	printf("VSX: 3.00B\n");
+	LOAD_VMX_DFORM_TEST(lxsd);
+	LOAD_VSX_XFORM_TEST(lxsibzx);
+	LOAD_VSX_XFORM_TEST(lxsihzx);
+	LOAD_VMX_DFORM_TEST(lxssp);
+	LOAD_VSX_DFORM_TEST(lxv);
+	LOAD_VSX_XFORM_TEST(lxvb16x);
+	LOAD_VSX_XFORM_TEST(lxvh8x);
+	LOAD_VSX_XFORM_TEST(lxvx);
+	LOAD_VSX_XFORM_TEST(lxvwsx);
+	LOAD_VSX_XFORM_TEST(lxvl);
+	LOAD_VSX_XFORM_TEST(lxvll);
+	STORE_VMX_DFORM_TEST(stxsd);
+	STORE_VSX_XFORM_TEST(stxsibx);
+	STORE_VSX_XFORM_TEST(stxsihx);
+	STORE_VMX_DFORM_TEST(stxssp);
+	STORE_VSX_DFORM_TEST(stxv);
+	STORE_VSX_XFORM_TEST(stxvb16x);
+	STORE_VSX_XFORM_TEST(stxvh8x);
+	STORE_VSX_XFORM_TEST(stxvx);
+	STORE_VSX_XFORM_TEST(stxvl);
+	STORE_VSX_XFORM_TEST(stxvll);
+	return rc;
+}
+
+int test_alignment_handler_integer(void)
+{
+	int rc = 0;
+
+	printf("Integer\n");
+	LOAD_DFORM_TEST(lbz);
+	LOAD_DFORM_TEST(lbzu);
+	LOAD_XFORM_TEST(lbzx);
+	LOAD_XFORM_TEST(lbzux);
+	LOAD_DFORM_TEST(lhz);
+	LOAD_DFORM_TEST(lhzu);
+	LOAD_XFORM_TEST(lhzx);
+	LOAD_XFORM_TEST(lhzux);
+	LOAD_DFORM_TEST(lha);
+	LOAD_DFORM_TEST(lhau);
+	LOAD_XFORM_TEST(lhax);
+	LOAD_XFORM_TEST(lhaux);
+	LOAD_XFORM_TEST(lhbrx);
+	LOAD_DFORM_TEST(lwz);
+	LOAD_DFORM_TEST(lwzu);
+	LOAD_XFORM_TEST(lwzx);
+	LOAD_XFORM_TEST(lwzux);
+	LOAD_DFORM_TEST(lwa);
+	LOAD_XFORM_TEST(lwax);
+	LOAD_XFORM_TEST(lwaux);
+	LOAD_XFORM_TEST(lwbrx);
+	LOAD_DFORM_TEST(ld);
+	LOAD_DFORM_TEST(ldu);
+	LOAD_XFORM_TEST(ldx);
+	LOAD_XFORM_TEST(ldux);
+	LOAD_XFORM_TEST(ldbrx);
+	LOAD_DFORM_TEST(lmw);
+	STORE_DFORM_TEST(stb);
+	STORE_XFORM_TEST(stbx);
+	STORE_DFORM_TEST(stbu);
+	STORE_XFORM_TEST(stbux);
+	STORE_DFORM_TEST(sth);
+	STORE_XFORM_TEST(sthx);
+	STORE_DFORM_TEST(sthu);
+	STORE_XFORM_TEST(sthux);
+	STORE_XFORM_TEST(sthbrx);
+	STORE_DFORM_TEST(stw);
+	STORE_XFORM_TEST(stwx);
+	STORE_DFORM_TEST(stwu);
+	STORE_XFORM_TEST(stwux);
+	STORE_XFORM_TEST(stwbrx);
+	STORE_DFORM_TEST(std);
+	STORE_XFORM_TEST(stdx);
+	STORE_DFORM_TEST(stdu);
+	STORE_XFORM_TEST(stdux);
+	STORE_XFORM_TEST(stdbrx);
+	STORE_DFORM_TEST(stmw);
+	return rc;
+}
+
+int test_alignment_handler_vmx(void)
+{
+	int rc = 0;
+
+	printf("VMX\n");
+	LOAD_VMX_XFORM_TEST(lvx);
+
+	/*
+	 * FIXME: These loads only load part of the register, so our
+	 * testing method doesn't work. Also they don't take alignment
+	 * faults, so it's kinda pointless anyway
+	 *
+	 LOAD_VMX_XFORM_TEST(lvebx)
+	 LOAD_VMX_XFORM_TEST(lvehx)
+	 LOAD_VMX_XFORM_TEST(lvewx)
+	 LOAD_VMX_XFORM_TEST(lvxl)
+	*/
+	STORE_VMX_XFORM_TEST(stvx);
+	STORE_VMX_XFORM_TEST(stvebx);
+	STORE_VMX_XFORM_TEST(stvehx);
+	STORE_VMX_XFORM_TEST(stvewx);
+	STORE_VMX_XFORM_TEST(stvxl);
+	return rc;
+}
+
+int test_alignment_handler_fp(void)
+{
+	int rc = 0;
+
+	printf("Floating point\n");
+	LOAD_FLOAT_DFORM_TEST(lfd);
+	LOAD_FLOAT_XFORM_TEST(lfdx);
+	LOAD_FLOAT_DFORM_TEST(lfdp);
+	LOAD_FLOAT_XFORM_TEST(lfdpx);
+	LOAD_FLOAT_DFORM_TEST(lfdu);
+	LOAD_FLOAT_XFORM_TEST(lfdux);
+	LOAD_FLOAT_DFORM_TEST(lfs);
+	LOAD_FLOAT_XFORM_TEST(lfsx);
+	LOAD_FLOAT_DFORM_TEST(lfsu);
+	LOAD_FLOAT_XFORM_TEST(lfsux);
+	LOAD_FLOAT_XFORM_TEST(lfiwzx);
+	LOAD_FLOAT_XFORM_TEST(lfiwax);
+	STORE_FLOAT_DFORM_TEST(stfd);
+	STORE_FLOAT_XFORM_TEST(stfdx);
+	STORE_FLOAT_DFORM_TEST(stfdp);
+	STORE_FLOAT_XFORM_TEST(stfdpx);
+	STORE_FLOAT_DFORM_TEST(stfdu);
+	STORE_FLOAT_XFORM_TEST(stfdux);
+	STORE_FLOAT_DFORM_TEST(stfs);
+	STORE_FLOAT_XFORM_TEST(stfsx);
+	STORE_FLOAT_DFORM_TEST(stfsu);
+	STORE_FLOAT_XFORM_TEST(stfsux);
+	STORE_FLOAT_XFORM_TEST(stfiwx);
+
+	return rc;
+}
+
+void usage(char *prog)
+{
+	printf("Usage: %s [options]\n", prog);
+	printf("  -d	Enable debug error output\n");
+	printf("\n");
+	printf("This test requires a POWER8 or POWER9 CPU and a usable ");
+	printf("framebuffer at /dev/fb0.\n");
+}
+
+int main(int argc, char *argv[])
+{
+
+	struct sigaction sa;
+	int rc = 0;
+	int option = 0;
+
+	while ((option = getopt(argc, argv, "d")) != -1) {
+		switch (option) {
+		case 'd':
+			debug++;
+			break;
+		default:
+			usage(argv[0]);
+			exit(1);
+		}
+	}
+
+	bufsize = getpagesize();
+
+	sa.sa_sigaction = sighandler;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_SIGINFO;
+	if (sigaction(SIGSEGV, &sa, NULL) == -1
+	    || sigaction(SIGBUS, &sa, NULL) == -1
+	    || sigaction(SIGILL, &sa, NULL) == -1) {
+		perror("sigaction");
+		exit(1);
+	}
+
+	rc |= test_harness(test_alignment_handler_vsx_206,
+			   "test_alignment_handler_vsx_206");
+	rc |= test_harness(test_alignment_handler_vsx_207,
+			   "test_alignment_handler_vsx_207");
+	rc |= test_harness(test_alignment_handler_vsx_300,
+			   "test_alignment_handler_vsx_300");
+	rc |= test_harness(test_alignment_handler_integer,
+			   "test_alignment_handler_integer");
+	rc |= test_harness(test_alignment_handler_vmx,
+			   "test_alignment_handler_vmx");
+	rc |= test_harness(test_alignment_handler_fp,
+			   "test_alignment_handler_fp");
+	return rc;
+}