Adding upstream version 6.8.9.upstream/6.8.9

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

12 files changed, 661 insertions, 33 deletions

diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile
index 7ea42fa02e..c376151982 100644
--- a/tools/testing/selftests/powerpc/Makefile
+++ b/tools/testing/selftests/powerpc/Makefile
@@ -32,6 +32,8 @@ SUB_DIRS = alignment		\
 	   vphn         \
 	   math		\
 	   papr_attributes	\
+	   papr_vpd		\
+	   papr_sysparm		\
 	   ptrace	\
 	   security	\
 	   mce
diff --git a/tools/testing/selftests/powerpc/math/fpu.h b/tools/testing/selftests/powerpc/math/fpu.h
new file mode 100644
index 0000000000..a8ad0d4260
--- /dev/null
+++ b/tools/testing/selftests/powerpc/math/fpu.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright 2023, Michael Ellerman, IBM Corporation.
+ */
+
+#ifndef _SELFTESTS_POWERPC_FPU_H
+#define _SELFTESTS_POWERPC_FPU_H
+
+static inline void randomise_darray(double *darray, int num)
+{
+	long val;
+
+	for (int i = 0; i < num; i++) {
+		val = random();
+		if (val & 1)
+			val *= -1;
+
+		if (val & 2)
+			darray[i] = 1.0 / val;
+		else
+			darray[i] = val * val;
+	}
+}
+
+#endif /* _SELFTESTS_POWERPC_FPU_H */
diff --git a/tools/testing/selftests/powerpc/math/fpu_asm.S b/tools/testing/selftests/powerpc/math/fpu_asm.S
index 9dc0c158f8..efe1e1be46 100644
--- a/tools/testing/selftests/powerpc/math/fpu_asm.S
+++ b/tools/testing/selftests/powerpc/math/fpu_asm.S
@@ -66,6 +66,40 @@ FUNC_START(check_fpu)
 	li	r3,0 # Success!!!
 1:	blr
 
+
+// int check_all_fprs(double darray[32])
+FUNC_START(check_all_fprs)
+	PUSH_BASIC_STACK(8)
+	mr	r4, r3	// r4 = darray
+	li	r3, 1	// prepare for failure
+
+	stfd	f31, STACK_FRAME_LOCAL(0, 0)(sp) // backup f31
+
+	// Check regs f0-f30, using f31 as scratch
+	.set i, 0
+	.rept 31
+	lfd	f31, (8 * i)(r4)	// load expected value
+	fcmpu	cr0, i, f31		// compare
+	bne	cr0, 1f			// bail if mismatch
+	.set i, i + 1
+	.endr
+
+	lfd	f31, STACK_FRAME_LOCAL(0, 0)(sp) // reload f31
+	stfd	f30, STACK_FRAME_LOCAL(0, 0)(sp) // backup f30
+
+	lfd	f30, (8 * 31)(r4)	// load expected value of f31
+	fcmpu	cr0, f30, f31		// compare
+	bne	cr0, 1f			// bail if mismatch
+
+	lfd	f30, STACK_FRAME_LOCAL(0, 0)(sp) // reload f30
+
+	// Success
+	li	r3, 0
+
+1:	POP_BASIC_STACK(8)
+	blr
+FUNC_END(check_all_fprs)
+
 FUNC_START(test_fpu)
 	# r3 holds pointer to where to put the result of fork
 	# r4 holds pointer to the pid
@@ -75,8 +109,9 @@ FUNC_START(test_fpu)
 	std	r3,STACK_FRAME_PARAM(0)(sp) # Address of darray
 	std r4,STACK_FRAME_PARAM(1)(sp) # Address of pid
 
-	bl load_fpu
-	nop
+	// Load FPRs with expected values
+	OP_REGS lfd, 8, 0, 31, r3
+
 	li	r0,__NR_fork
 	sc
 
@@ -85,7 +120,7 @@ FUNC_START(test_fpu)
 	std	r3,0(r9)
 
 	ld r3,STACK_FRAME_PARAM(0)(sp)
-	bl check_fpu
+	bl check_all_fprs
 	nop
 
 	POP_FPU(256)
@@ -104,8 +139,8 @@ FUNC_START(preempt_fpu)
 	std r4,STACK_FRAME_PARAM(1)(sp) # int *threads_starting
 	std r5,STACK_FRAME_PARAM(2)(sp) # int *running
 
-	bl load_fpu
-	nop
+	// Load FPRs with expected values
+	OP_REGS lfd, 8, 0, 31, r3
 
 	sync
 	# Atomic DEC
@@ -116,8 +151,7 @@ FUNC_START(preempt_fpu)
 	bne- 1b
 
 2:	ld r3,STACK_FRAME_PARAM(0)(sp)
-	bl check_fpu
-	nop
+	bl check_all_fprs
 	cmpdi r3,0
 	bne 3f
 	ld r4,STACK_FRAME_PARAM(2)(sp)
diff --git a/tools/testing/selftests/powerpc/math/fpu_preempt.c b/tools/testing/selftests/powerpc/math/fpu_preempt.c
index 3e5b5663d2..9ddede0770 100644
--- a/tools/testing/selftests/powerpc/math/fpu_preempt.c
+++ b/tools/testing/selftests/powerpc/math/fpu_preempt.c
@@ -1,13 +1,12 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright 2015, Cyril Bur, IBM Corp.
+ * Copyright 2023, Michael Ellerman, IBM Corp.
  *
  * This test attempts to see if the FPU registers change across preemption.
- * Two things should be noted here a) The check_fpu function in asm only checks
- * the non volatile registers as it is reused from the syscall test b) There is
- * no way to be sure preemption happened so this test just uses many threads
- * and a long wait. As such, a successful test doesn't mean much but a failure
- * is bad.
+ * There is no way to be sure preemption happened so this test just uses many
+ * threads and a long wait. As such, a successful test doesn't mean much but
+ * a failure is bad.
  */
 
 #include <stdio.h>
@@ -20,9 +19,10 @@
 #include <pthread.h>
 
 #include "utils.h"
+#include "fpu.h"
 
 /* Time to wait for workers to get preempted (seconds) */
-#define PREEMPT_TIME 20
+#define PREEMPT_TIME 60
 /*
  * Factor by which to multiply number of online CPUs for total number of
  * worker threads
@@ -30,9 +30,7 @@
 #define THREAD_FACTOR 8
 
 
-__thread double darray[] = {0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0,
-		     1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0,
-		     2.1};
+__thread double darray[32];
 
 int threads_starting;
 int running;
@@ -42,12 +40,9 @@ extern int preempt_fpu(double *darray, int *threads_starting, int *running);
 void *preempt_fpu_c(void *p)
 {
 	long rc;
-	int i;
 
 	srand(pthread_self());
-	for (i = 0; i < 21; i++)
-		darray[i] = rand();
-
+	randomise_darray(darray, ARRAY_SIZE(darray));
 	rc = preempt_fpu(darray, &threads_starting, &running);
 
 	return (void *)rc;
diff --git a/tools/testing/selftests/powerpc/math/fpu_signal.c b/tools/testing/selftests/powerpc/math/fpu_signal.c
index 7b1addd504..8a64f63e37 100644
--- a/tools/testing/selftests/powerpc/math/fpu_signal.c
+++ b/tools/testing/selftests/powerpc/math/fpu_signal.c
@@ -18,6 +18,7 @@
 #include <pthread.h>
 
 #include "utils.h"
+#include "fpu.h"
 
 /* Number of times each thread should receive the signal */
 #define ITERATIONS 10
@@ -27,9 +28,7 @@
  */
 #define THREAD_FACTOR 8
 
-__thread double darray[] = {0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0,
-		     1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0,
-		     2.1};
+__thread double darray[32];
 
 bool bad_context;
 int threads_starting;
@@ -43,9 +42,9 @@ void signal_fpu_sig(int sig, siginfo_t *info, void *context)
 	ucontext_t *uc = context;
 	mcontext_t *mc = &uc->uc_mcontext;
 
-	/* Only the non volatiles were loaded up */
-	for (i = 14; i < 32; i++) {
-		if (mc->fp_regs[i] != darray[i - 14]) {
+	// Don't check f30/f31, they're used as scratches in check_all_fprs()
+	for (i = 0; i < 30; i++) {
+		if (mc->fp_regs[i] != darray[i]) {
 			bad_context = true;
 			break;
 		}
@@ -54,7 +53,6 @@ void signal_fpu_sig(int sig, siginfo_t *info, void *context)
 
 void *signal_fpu_c(void *p)
 {
-	int i;
 	long rc;
 	struct sigaction act;
 	act.sa_sigaction = signal_fpu_sig;
@@ -64,9 +62,7 @@ void *signal_fpu_c(void *p)
 		return p;
 
 	srand(pthread_self());
-	for (i = 0; i < 21; i++)
-		darray[i] = rand();
-
+	randomise_darray(darray, ARRAY_SIZE(darray));
 	rc = preempt_fpu(darray, &threads_starting, &running);
 
 	return (void *) rc;
diff --git a/tools/testing/selftests/powerpc/math/fpu_syscall.c b/tools/testing/selftests/powerpc/math/fpu_syscall.c
index 694f225c7e..751d46b133 100644
--- a/tools/testing/selftests/powerpc/math/fpu_syscall.c
+++ b/tools/testing/selftests/powerpc/math/fpu_syscall.c
@@ -14,12 +14,11 @@
 #include <stdlib.h>
 
 #include "utils.h"
+#include "fpu.h"
 
 extern int test_fpu(double *darray, pid_t *pid);
 
-double darray[] = {0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0,
-		     1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0,
-		     2.1};
+double darray[32];
 
 int syscall_fpu(void)
 {
@@ -27,6 +26,9 @@ int syscall_fpu(void)
 	int i;
 	int ret;
 	int child_ret;
+
+	randomise_darray(darray, ARRAY_SIZE(darray));
+
 	for (i = 0; i < 1000; i++) {
 		/* test_fpu will fork() */
 		ret = test_fpu(darray, &fork_pid);
diff --git a/tools/testing/selftests/powerpc/papr_sysparm/.gitignore b/tools/testing/selftests/powerpc/papr_sysparm/.gitignore
new file mode 100644
index 0000000000..f2a69bf59d
--- /dev/null
+++ b/tools/testing/selftests/powerpc/papr_sysparm/.gitignore
@@ -0,0 +1 @@
+/papr_sysparm
diff --git a/tools/testing/selftests/powerpc/papr_sysparm/Makefile b/tools/testing/selftests/powerpc/papr_sysparm/Makefile
new file mode 100644
index 0000000000..7f79e43763
--- /dev/null
+++ b/tools/testing/selftests/powerpc/papr_sysparm/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+noarg:
+	$(MAKE) -C ../
+
+TEST_GEN_PROGS := papr_sysparm
+
+top_srcdir = ../../../../..
+include ../../lib.mk
+
+$(TEST_GEN_PROGS): ../harness.c ../utils.c
+
+$(OUTPUT)/papr_sysparm: CFLAGS += $(KHDR_INCLUDES)
diff --git a/tools/testing/selftests/powerpc/papr_sysparm/papr_sysparm.c b/tools/testing/selftests/powerpc/papr_sysparm/papr_sysparm.c
new file mode 100644
index 0000000000..f56c15a11e
--- /dev/null
+++ b/tools/testing/selftests/powerpc/papr_sysparm/papr_sysparm.c
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include <asm/papr-sysparm.h>
+
+#include "utils.h"
+
+#define DEVPATH "/dev/papr-sysparm"
+
+static int open_close(void)
+{
+	const int devfd = open(DEVPATH, O_RDONLY);
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+
+	FAIL_IF(devfd < 0);
+	FAIL_IF(close(devfd) != 0);
+
+	return 0;
+}
+
+static int get_splpar(void)
+{
+	struct papr_sysparm_io_block sp = {
+		.parameter = 20, // SPLPAR characteristics
+	};
+	const int devfd = open(DEVPATH, O_RDONLY);
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+
+	FAIL_IF(devfd < 0);
+	FAIL_IF(ioctl(devfd, PAPR_SYSPARM_IOC_GET, &sp) != 0);
+	FAIL_IF(sp.length == 0);
+	FAIL_IF(sp.length > sizeof(sp.data));
+	FAIL_IF(close(devfd) != 0);
+
+	return 0;
+}
+
+static int get_bad_parameter(void)
+{
+	struct papr_sysparm_io_block sp = {
+		.parameter = UINT32_MAX, // there are only ~60 specified parameters
+	};
+	const int devfd = open(DEVPATH, O_RDONLY);
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+
+	FAIL_IF(devfd < 0);
+
+	// Ensure expected error
+	FAIL_IF(ioctl(devfd, PAPR_SYSPARM_IOC_GET, &sp) != -1);
+	FAIL_IF(errno != EOPNOTSUPP);
+
+	// Ensure the buffer is unchanged
+	FAIL_IF(sp.length != 0);
+	for (size_t i = 0; i < ARRAY_SIZE(sp.data); ++i)
+		FAIL_IF(sp.data[i] != 0);
+
+	FAIL_IF(close(devfd) != 0);
+
+	return 0;
+}
+
+static int check_efault_common(unsigned long cmd)
+{
+	const int devfd = open(DEVPATH, O_RDWR);
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+
+	FAIL_IF(devfd < 0);
+
+	// Ensure expected error
+	FAIL_IF(ioctl(devfd, cmd, NULL) != -1);
+	FAIL_IF(errno != EFAULT);
+
+	FAIL_IF(close(devfd) != 0);
+
+	return 0;
+}
+
+static int check_efault_get(void)
+{
+	return check_efault_common(PAPR_SYSPARM_IOC_GET);
+}
+
+static int check_efault_set(void)
+{
+	return check_efault_common(PAPR_SYSPARM_IOC_SET);
+}
+
+static int set_hmc0(void)
+{
+	struct papr_sysparm_io_block sp = {
+		.parameter = 0, // HMC0, not a settable parameter
+	};
+	const int devfd = open(DEVPATH, O_RDWR);
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+
+	FAIL_IF(devfd < 0);
+
+	// Ensure expected error
+	FAIL_IF(ioctl(devfd, PAPR_SYSPARM_IOC_SET, &sp) != -1);
+	SKIP_IF_MSG(errno == EOPNOTSUPP, "operation not supported");
+	FAIL_IF(errno != EPERM);
+
+	FAIL_IF(close(devfd) != 0);
+
+	return 0;
+}
+
+static int set_with_ro_fd(void)
+{
+	struct papr_sysparm_io_block sp = {
+		.parameter = 0, // HMC0, not a settable parameter.
+	};
+	const int devfd = open(DEVPATH, O_RDONLY);
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+
+	FAIL_IF(devfd < 0);
+
+	// Ensure expected error
+	FAIL_IF(ioctl(devfd, PAPR_SYSPARM_IOC_SET, &sp) != -1);
+	SKIP_IF_MSG(errno == EOPNOTSUPP, "operation not supported");
+
+	// HMC0 isn't a settable parameter and we would normally
+	// expect to get EPERM on attempts to modify it. However, when
+	// the file is open read-only, we expect the driver to prevent
+	// the attempt with a distinct error.
+	FAIL_IF(errno != EBADF);
+
+	FAIL_IF(close(devfd) != 0);
+
+	return 0;
+}
+
+struct sysparm_test {
+	int (*function)(void);
+	const char *description;
+};
+
+static const struct sysparm_test sysparm_tests[] = {
+	{
+		.function = open_close,
+		.description = "open and close " DEVPATH " without issuing commands",
+	},
+	{
+		.function = get_splpar,
+		.description = "retrieve SPLPAR characteristics",
+	},
+	{
+		.function = get_bad_parameter,
+		.description = "verify EOPNOTSUPP for known-bad parameter",
+	},
+	{
+		.function = check_efault_get,
+		.description = "PAPR_SYSPARM_IOC_GET returns EFAULT on bad address",
+	},
+	{
+		.function = check_efault_set,
+		.description = "PAPR_SYSPARM_IOC_SET returns EFAULT on bad address",
+	},
+	{
+		.function = set_hmc0,
+		.description = "ensure EPERM on attempt to update HMC0",
+	},
+	{
+		.function = set_with_ro_fd,
+		.description = "PAPR_IOC_SYSPARM_SET returns EACCES on read-only fd",
+	},
+};
+
+int main(void)
+{
+	size_t fails = 0;
+
+	for (size_t i = 0; i < ARRAY_SIZE(sysparm_tests); ++i) {
+		const struct sysparm_test *t = &sysparm_tests[i];
+
+		if (test_harness(t->function, t->description))
+			++fails;
+	}
+
+	return fails == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+}
diff --git a/tools/testing/selftests/powerpc/papr_vpd/.gitignore b/tools/testing/selftests/powerpc/papr_vpd/.gitignore
new file mode 100644
index 0000000000..49285031a6
--- /dev/null
+++ b/tools/testing/selftests/powerpc/papr_vpd/.gitignore
@@ -0,0 +1 @@
+/papr_vpd
diff --git a/tools/testing/selftests/powerpc/papr_vpd/Makefile b/tools/testing/selftests/powerpc/papr_vpd/Makefile
new file mode 100644
index 0000000000..06b719703b
--- /dev/null
+++ b/tools/testing/selftests/powerpc/papr_vpd/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+noarg:
+	$(MAKE) -C ../
+
+TEST_GEN_PROGS := papr_vpd
+
+top_srcdir = ../../../../..
+include ../../lib.mk
+
+$(TEST_GEN_PROGS): ../harness.c ../utils.c
+
+$(OUTPUT)/papr_vpd: CFLAGS += $(KHDR_INCLUDES)
diff --git a/tools/testing/selftests/powerpc/papr_vpd/papr_vpd.c b/tools/testing/selftests/powerpc/papr_vpd/papr_vpd.c
new file mode 100644
index 0000000000..d6f99eb9be
--- /dev/null
+++ b/tools/testing/selftests/powerpc/papr_vpd/papr_vpd.c
@@ -0,0 +1,352 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+#include <asm/papr-vpd.h>
+
+#include "utils.h"
+
+#define DEVPATH "/dev/papr-vpd"
+
+static int dev_papr_vpd_open_close(void)
+{
+	const int devfd = open(DEVPATH, O_RDONLY);
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+
+	FAIL_IF(devfd < 0);
+	FAIL_IF(close(devfd) != 0);
+
+	return 0;
+}
+
+static int dev_papr_vpd_get_handle_all(void)
+{
+	const int devfd = open(DEVPATH, O_RDONLY);
+	struct papr_location_code lc = { .str = "", };
+	off_t size;
+	int fd;
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+
+	FAIL_IF(devfd < 0);
+
+	errno = 0;
+	fd = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, &lc);
+	FAIL_IF(errno != 0);
+	FAIL_IF(fd < 0);
+
+	FAIL_IF(close(devfd) != 0);
+
+	size = lseek(fd, 0, SEEK_END);
+	FAIL_IF(size <= 0);
+
+	void *buf = malloc((size_t)size);
+	FAIL_IF(!buf);
+
+	ssize_t consumed = pread(fd, buf, size, 0);
+	FAIL_IF(consumed != size);
+
+	/* Ensure EOF */
+	FAIL_IF(read(fd, buf, size) != 0);
+	FAIL_IF(close(fd));
+
+	/* Verify that the buffer looks like VPD */
+	static const char needle[] = "System VPD";
+	FAIL_IF(!memmem(buf, size, needle, strlen(needle)));
+
+	return 0;
+}
+
+static int dev_papr_vpd_get_handle_byte_at_a_time(void)
+{
+	const int devfd = open(DEVPATH, O_RDONLY);
+	struct papr_location_code lc = { .str = "", };
+	int fd;
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+
+	FAIL_IF(devfd < 0);
+
+	errno = 0;
+	fd = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, &lc);
+	FAIL_IF(errno != 0);
+	FAIL_IF(fd < 0);
+
+	FAIL_IF(close(devfd) != 0);
+
+	size_t consumed = 0;
+	while (1) {
+		ssize_t res;
+		char c;
+
+		errno = 0;
+		res = read(fd, &c, sizeof(c));
+		FAIL_IF(res > sizeof(c));
+		FAIL_IF(res < 0);
+		FAIL_IF(errno != 0);
+		consumed += res;
+		if (res == 0)
+			break;
+	}
+
+	FAIL_IF(consumed != lseek(fd, 0, SEEK_END));
+
+	FAIL_IF(close(fd));
+
+	return 0;
+}
+
+
+static int dev_papr_vpd_unterm_loc_code(void)
+{
+	const int devfd = open(DEVPATH, O_RDONLY);
+	struct papr_location_code lc = {};
+	int fd;
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+
+	FAIL_IF(devfd < 0);
+
+	/*
+	 * Place a non-null byte in every element of loc_code; the
+	 * driver should reject this input.
+	 */
+	memset(lc.str, 'x', ARRAY_SIZE(lc.str));
+
+	errno = 0;
+	fd = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, &lc);
+	FAIL_IF(fd != -1);
+	FAIL_IF(errno != EINVAL);
+
+	FAIL_IF(close(devfd) != 0);
+	return 0;
+}
+
+static int dev_papr_vpd_null_handle(void)
+{
+	const int devfd = open(DEVPATH, O_RDONLY);
+	int rc;
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+
+	FAIL_IF(devfd < 0);
+
+	errno = 0;
+	rc = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, NULL);
+	FAIL_IF(rc != -1);
+	FAIL_IF(errno != EFAULT);
+
+	FAIL_IF(close(devfd) != 0);
+	return 0;
+}
+
+static int papr_vpd_close_handle_without_reading(void)
+{
+	const int devfd = open(DEVPATH, O_RDONLY);
+	struct papr_location_code lc = { .str = "", };
+	int fd;
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+
+	FAIL_IF(devfd < 0);
+
+	errno = 0;
+	fd = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, &lc);
+	FAIL_IF(errno != 0);
+	FAIL_IF(fd < 0);
+
+	/* close the handle without reading it */
+	FAIL_IF(close(fd) != 0);
+
+	FAIL_IF(close(devfd) != 0);
+	return 0;
+}
+
+static int papr_vpd_reread(void)
+{
+	const int devfd = open(DEVPATH, O_RDONLY);
+	struct papr_location_code lc = { .str = "", };
+	int fd;
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+
+	FAIL_IF(devfd < 0);
+
+	errno = 0;
+	fd = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, &lc);
+	FAIL_IF(errno != 0);
+	FAIL_IF(fd < 0);
+
+	FAIL_IF(close(devfd) != 0);
+
+	const off_t size = lseek(fd, 0, SEEK_END);
+	FAIL_IF(size <= 0);
+
+	char *bufs[2];
+
+	for (size_t i = 0; i < ARRAY_SIZE(bufs); ++i) {
+		bufs[i] = malloc(size);
+		FAIL_IF(!bufs[i]);
+		ssize_t consumed = pread(fd, bufs[i], size, 0);
+		FAIL_IF(consumed != size);
+	}
+
+	FAIL_IF(memcmp(bufs[0], bufs[1], size));
+
+	FAIL_IF(close(fd) != 0);
+
+	return 0;
+}
+
+static int get_system_loc_code(struct papr_location_code *lc)
+{
+	static const char system_id_path[] = "/sys/firmware/devicetree/base/system-id";
+	static const char model_path[] = "/sys/firmware/devicetree/base/model";
+	char *system_id;
+	char *model;
+	int err = -1;
+
+	if (read_file_alloc(model_path, &model, NULL))
+		return err;
+
+	if (read_file_alloc(system_id_path, &system_id, NULL))
+		goto free_model;
+
+	char *mtm;
+	int sscanf_ret = sscanf(model, "IBM,%ms", &mtm);
+	if (sscanf_ret != 1)
+		goto free_system_id;
+
+	char *plant_and_seq;
+	if (sscanf(system_id, "IBM,%*c%*c%ms", &plant_and_seq) != 1)
+		goto free_mtm;
+	/*
+	 * Replace - with . to build location code.
+	 */
+	char *sep = strchr(mtm, '-');
+	if (!sep)
+		goto free_mtm;
+	else
+		*sep = '.';
+
+	snprintf(lc->str, sizeof(lc->str),
+		 "U%s.%s", mtm, plant_and_seq);
+	err = 0;
+
+	free(plant_and_seq);
+free_mtm:
+	free(mtm);
+free_system_id:
+	free(system_id);
+free_model:
+	free(model);
+	return err;
+}
+
+static int papr_vpd_system_loc_code(void)
+{
+	struct papr_location_code lc;
+	const int devfd = open(DEVPATH, O_RDONLY);
+	off_t size;
+	int fd;
+
+	SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
+		    DEVPATH " not present");
+	SKIP_IF_MSG(get_system_loc_code(&lc),
+		    "Cannot determine system location code");
+
+	FAIL_IF(devfd < 0);
+
+	errno = 0;
+	fd = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, &lc);
+	FAIL_IF(errno != 0);
+	FAIL_IF(fd < 0);
+
+	FAIL_IF(close(devfd) != 0);
+
+	size = lseek(fd, 0, SEEK_END);
+	FAIL_IF(size <= 0);
+
+	void *buf = malloc((size_t)size);
+	FAIL_IF(!buf);
+
+	ssize_t consumed = pread(fd, buf, size, 0);
+	FAIL_IF(consumed != size);
+
+	/* Ensure EOF */
+	FAIL_IF(read(fd, buf, size) != 0);
+	FAIL_IF(close(fd));
+
+	/* Verify that the buffer looks like VPD */
+	static const char needle[] = "System VPD";
+	FAIL_IF(!memmem(buf, size, needle, strlen(needle)));
+
+	return 0;
+}
+
+struct vpd_test {
+	int (*function)(void);
+	const char *description;
+};
+
+static const struct vpd_test vpd_tests[] = {
+	{
+		.function = dev_papr_vpd_open_close,
+		.description = "open/close " DEVPATH,
+	},
+	{
+		.function = dev_papr_vpd_unterm_loc_code,
+		.description = "ensure EINVAL on unterminated location code",
+	},
+	{
+		.function = dev_papr_vpd_null_handle,
+		.description = "ensure EFAULT on bad handle addr",
+	},
+	{
+		.function = dev_papr_vpd_get_handle_all,
+		.description = "get handle for all VPD"
+	},
+	{
+		.function = papr_vpd_close_handle_without_reading,
+		.description = "close handle without consuming VPD"
+	},
+	{
+		.function = dev_papr_vpd_get_handle_byte_at_a_time,
+		.description = "read all VPD one byte at a time"
+	},
+	{
+		.function = papr_vpd_reread,
+		.description = "ensure re-read yields same results"
+	},
+	{
+		.function = papr_vpd_system_loc_code,
+		.description = "get handle for system VPD"
+	},
+};
+
+int main(void)
+{
+	size_t fails = 0;
+
+	for (size_t i = 0; i < ARRAY_SIZE(vpd_tests); ++i) {
+		const struct vpd_test *t = &vpd_tests[i];
+
+		if (test_harness(t->function, t->description))
+			++fails;
+	}
+
+	return fails == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+}