Merge tag 'powerpc-6.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Add initial support to recognise the HeXin C2000 processor.

 - Add papr-vpd and papr-sysparm character device drivers for VPD &
   sysparm retrieval, so userspace tools can be adapted to avoid doing
   raw firmware calls from userspace.

 - Sched domains optimisations for shared processor partitions on
   P9/P10.

 - A series of optimisations for KVM running as a nested HV under
   PowerVM.

 - Other small features and fixes.

Thanks to Aditya Gupta, Aneesh Kumar K.V, Arnd Bergmann, Christophe
Leroy, Colin Ian King, Dario Binacchi, David Heidelberg, Geoff Levand,
Gustavo A. R. Silva, Haoran Liu, Jordan Niethe, Kajol Jain, Kevin Hao,
Kunwu Chan, Li kunyu, Li zeming, Masahiro Yamada, Michal Suchánek,
Nathan Lynch, Naveen N Rao, Nicholas Piggin, Randy Dunlap, Sathvika
Vasireddy, Srikar Dronamraju, Stephen Rothwell, Vaibhav Jain, and
Zhao Ke.

* tag 'powerpc-6.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (96 commits)
  powerpc/ps3_defconfig: Disable PPC64_BIG_ENDIAN_ELF_ABI_V2
  powerpc/86xx: Drop unused CONFIG_MPC8610
  powerpc/powernv: Add error handling to opal_prd_range_is_valid
  selftests/powerpc: Fix spelling mistake "EACCESS" -> "EACCES"
  powerpc/hvcall: Reorder Nestedv2 hcall opcodes
  powerpc/ps3: Add missing set_freezable() for ps3_probe_thread()
  powerpc/mpc83xx: Use wait_event_freezable() for freezable kthread
  powerpc/mpc83xx: Add the missing set_freezable() for agent_thread_fn()
  powerpc/fsl: Fix fsl,tmu-calibration to match the schema
  powerpc/smp: Dynamically build Powerpc topology
  powerpc/smp: Avoid asym packing within thread_group of a core
  powerpc/smp: Add __ro_after_init attribute
  powerpc/smp: Disable MC domain for shared processor
  powerpc/smp: Enable Asym packing for cores on shared processor
  powerpc/sched: Cleanup vcpu_is_preempted()
  powerpc: add cpu_spec.cpu_features to vmcoreinfo
  powerpc/imc-pmu: Add a null pointer check in update_events_in_group()
  powerpc/powernv: Add a null pointer check in opal_powercap_init()
  powerpc/powernv: Add a null pointer check in opal_event_init()
  powerpc/powernv: Add a null pointer check to scom_debug_init_one()
  ...

12 files changed, 666 insertions, 31 deletions

diff --git a/tools/testing/selftests/powerpc/Makefile b/tools/testing/selftests/powerpc/Makefile
index 7ea42fa02eab..c376151982c4 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 000000000000..a8ad0d42604e
--- /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 9dc0c158f871..efe1e1be4695 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 5235bdc8c0b1..9ddede0770ed 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
@@ -30,26 +30,22 @@
 #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;
 
-extern void preempt_fpu(double *darray, int *threads_starting, int *running);
+extern int preempt_fpu(double *darray, int *threads_starting, int *running);
 
 void *preempt_fpu_c(void *p)
 {
-	int i;
-	srand(pthread_self());
-	for (i = 0; i < 21; i++)
-		darray[i] = rand();
+	long rc;
 
-	/* Test failed if it ever returns */
-	preempt_fpu(darray, &threads_starting, &running);
+	srand(pthread_self());
+	randomise_darray(darray, ARRAY_SIZE(darray));
+	rc = preempt_fpu(darray, &threads_starting, &running);
 
-	return p;
+	return (void *)rc;
 }
 
 int test_preempt_fpu(void)
diff --git a/tools/testing/selftests/powerpc/math/fpu_syscall.c b/tools/testing/selftests/powerpc/math/fpu_syscall.c
index 694f225c7e45..751d46b133fc 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/math/vmx_preempt.c b/tools/testing/selftests/powerpc/math/vmx_preempt.c
index 6761d6ce30ec..6f7cf400c687 100644
--- a/tools/testing/selftests/powerpc/math/vmx_preempt.c
+++ b/tools/testing/selftests/powerpc/math/vmx_preempt.c
@@ -37,19 +37,21 @@ __thread vector int varray[] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10,11,12},
 int threads_starting;
 int running;
 
-extern void preempt_vmx(vector int *varray, int *threads_starting, int *running);
+extern int preempt_vmx(vector int *varray, int *threads_starting, int *running);
 
 void *preempt_vmx_c(void *p)
 {
 	int i, j;
+	long rc;
+
 	srand(pthread_self());
 	for (i = 0; i < 12; i++)
 		for (j = 0; j < 4; j++)
 			varray[i][j] = rand();
 
-	/* Test fails if it ever returns */
-	preempt_vmx(varray, &threads_starting, &running);
-	return p;
+	rc = preempt_vmx(varray, &threads_starting, &running);
+
+	return (void *)rc;
 }
 
 int test_preempt_vmx(void)
diff --git a/tools/testing/selftests/powerpc/papr_sysparm/.gitignore b/tools/testing/selftests/powerpc/papr_sysparm/.gitignore
new file mode 100644
index 000000000000..f2a69bf59d40
--- /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 000000000000..7f79e437634a
--- /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 000000000000..f56c15a11e2f
--- /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 000000000000..49285031a656
--- /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 000000000000..06b719703bfd
--- /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 000000000000..98cbb9109ee6
--- /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;
+	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(get_system_loc_code(&lc),
+		    "Cannot determine system location code");
+	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;
+}
+
+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;
+}