summaryrefslogtreecommitdiffstats
path: root/arch/s390/hypfs/hypfs_diag.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/s390/hypfs/hypfs_diag.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/s390/hypfs/hypfs_diag.c')
-rw-r--r--arch/s390/hypfs/hypfs_diag.c617
1 files changed, 617 insertions, 0 deletions
diff --git a/arch/s390/hypfs/hypfs_diag.c b/arch/s390/hypfs/hypfs_diag.c
new file mode 100644
index 000000000..3452e18bb
--- /dev/null
+++ b/arch/s390/hypfs/hypfs_diag.c
@@ -0,0 +1,617 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hypervisor filesystem for Linux on s390. Diag 204 and 224
+ * implementation.
+ *
+ * Copyright IBM Corp. 2006, 2008
+ * Author(s): Michael Holzheu <holzheu@de.ibm.com>
+ */
+
+#define KMSG_COMPONENT "hypfs"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <asm/diag.h>
+#include <asm/ebcdic.h>
+#include "hypfs.h"
+
+#define TMP_SIZE 64 /* size of temporary buffers */
+
+#define DBFS_D204_HDR_VERSION 0
+
+static char *diag224_cpu_names; /* diag 224 name table */
+static enum diag204_sc diag204_store_sc; /* used subcode for store */
+static enum diag204_format diag204_info_type; /* used diag 204 data format */
+
+static void *diag204_buf; /* 4K aligned buffer for diag204 data */
+static void *diag204_buf_vmalloc; /* vmalloc pointer for diag204 data */
+static int diag204_buf_pages; /* number of pages for diag204 data */
+
+static struct dentry *dbfs_d204_file;
+
+/*
+ * DIAG 204 member access functions.
+ *
+ * Since we have two different diag 204 data formats for old and new s390
+ * machines, we do not access the structs directly, but use getter functions for
+ * each struct member instead. This should make the code more readable.
+ */
+
+/* Time information block */
+
+static inline int info_blk_hdr__size(enum diag204_format type)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return sizeof(struct diag204_info_blk_hdr);
+ else /* DIAG204_INFO_EXT */
+ return sizeof(struct diag204_x_info_blk_hdr);
+}
+
+static inline __u8 info_blk_hdr__npar(enum diag204_format type, void *hdr)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return ((struct diag204_info_blk_hdr *)hdr)->npar;
+ else /* DIAG204_INFO_EXT */
+ return ((struct diag204_x_info_blk_hdr *)hdr)->npar;
+}
+
+static inline __u8 info_blk_hdr__flags(enum diag204_format type, void *hdr)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return ((struct diag204_info_blk_hdr *)hdr)->flags;
+ else /* DIAG204_INFO_EXT */
+ return ((struct diag204_x_info_blk_hdr *)hdr)->flags;
+}
+
+static inline __u16 info_blk_hdr__pcpus(enum diag204_format type, void *hdr)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return ((struct diag204_info_blk_hdr *)hdr)->phys_cpus;
+ else /* DIAG204_INFO_EXT */
+ return ((struct diag204_x_info_blk_hdr *)hdr)->phys_cpus;
+}
+
+/* Partition header */
+
+static inline int part_hdr__size(enum diag204_format type)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return sizeof(struct diag204_part_hdr);
+ else /* DIAG204_INFO_EXT */
+ return sizeof(struct diag204_x_part_hdr);
+}
+
+static inline __u8 part_hdr__rcpus(enum diag204_format type, void *hdr)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return ((struct diag204_part_hdr *)hdr)->cpus;
+ else /* DIAG204_INFO_EXT */
+ return ((struct diag204_x_part_hdr *)hdr)->rcpus;
+}
+
+static inline void part_hdr__part_name(enum diag204_format type, void *hdr,
+ char *name)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ memcpy(name, ((struct diag204_part_hdr *)hdr)->part_name,
+ DIAG204_LPAR_NAME_LEN);
+ else /* DIAG204_INFO_EXT */
+ memcpy(name, ((struct diag204_x_part_hdr *)hdr)->part_name,
+ DIAG204_LPAR_NAME_LEN);
+ EBCASC(name, DIAG204_LPAR_NAME_LEN);
+ name[DIAG204_LPAR_NAME_LEN] = 0;
+ strim(name);
+}
+
+/* CPU info block */
+
+static inline int cpu_info__size(enum diag204_format type)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return sizeof(struct diag204_cpu_info);
+ else /* DIAG204_INFO_EXT */
+ return sizeof(struct diag204_x_cpu_info);
+}
+
+static inline __u8 cpu_info__ctidx(enum diag204_format type, void *hdr)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return ((struct diag204_cpu_info *)hdr)->ctidx;
+ else /* DIAG204_INFO_EXT */
+ return ((struct diag204_x_cpu_info *)hdr)->ctidx;
+}
+
+static inline __u16 cpu_info__cpu_addr(enum diag204_format type, void *hdr)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return ((struct diag204_cpu_info *)hdr)->cpu_addr;
+ else /* DIAG204_INFO_EXT */
+ return ((struct diag204_x_cpu_info *)hdr)->cpu_addr;
+}
+
+static inline __u64 cpu_info__acc_time(enum diag204_format type, void *hdr)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return ((struct diag204_cpu_info *)hdr)->acc_time;
+ else /* DIAG204_INFO_EXT */
+ return ((struct diag204_x_cpu_info *)hdr)->acc_time;
+}
+
+static inline __u64 cpu_info__lp_time(enum diag204_format type, void *hdr)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return ((struct diag204_cpu_info *)hdr)->lp_time;
+ else /* DIAG204_INFO_EXT */
+ return ((struct diag204_x_cpu_info *)hdr)->lp_time;
+}
+
+static inline __u64 cpu_info__online_time(enum diag204_format type, void *hdr)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return 0; /* online_time not available in simple info */
+ else /* DIAG204_INFO_EXT */
+ return ((struct diag204_x_cpu_info *)hdr)->online_time;
+}
+
+/* Physical header */
+
+static inline int phys_hdr__size(enum diag204_format type)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return sizeof(struct diag204_phys_hdr);
+ else /* DIAG204_INFO_EXT */
+ return sizeof(struct diag204_x_phys_hdr);
+}
+
+static inline __u8 phys_hdr__cpus(enum diag204_format type, void *hdr)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return ((struct diag204_phys_hdr *)hdr)->cpus;
+ else /* DIAG204_INFO_EXT */
+ return ((struct diag204_x_phys_hdr *)hdr)->cpus;
+}
+
+/* Physical CPU info block */
+
+static inline int phys_cpu__size(enum diag204_format type)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return sizeof(struct diag204_phys_cpu);
+ else /* DIAG204_INFO_EXT */
+ return sizeof(struct diag204_x_phys_cpu);
+}
+
+static inline __u16 phys_cpu__cpu_addr(enum diag204_format type, void *hdr)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return ((struct diag204_phys_cpu *)hdr)->cpu_addr;
+ else /* DIAG204_INFO_EXT */
+ return ((struct diag204_x_phys_cpu *)hdr)->cpu_addr;
+}
+
+static inline __u64 phys_cpu__mgm_time(enum diag204_format type, void *hdr)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return ((struct diag204_phys_cpu *)hdr)->mgm_time;
+ else /* DIAG204_INFO_EXT */
+ return ((struct diag204_x_phys_cpu *)hdr)->mgm_time;
+}
+
+static inline __u64 phys_cpu__ctidx(enum diag204_format type, void *hdr)
+{
+ if (type == DIAG204_INFO_SIMPLE)
+ return ((struct diag204_phys_cpu *)hdr)->ctidx;
+ else /* DIAG204_INFO_EXT */
+ return ((struct diag204_x_phys_cpu *)hdr)->ctidx;
+}
+
+/* Diagnose 204 functions */
+/*
+ * For the old diag subcode 4 with simple data format we have to use real
+ * memory. If we use subcode 6 or 7 with extended data format, we can (and
+ * should) use vmalloc, since we need a lot of memory in that case. Currently
+ * up to 93 pages!
+ */
+
+static void diag204_free_buffer(void)
+{
+ if (!diag204_buf)
+ return;
+ if (diag204_buf_vmalloc) {
+ vfree(diag204_buf_vmalloc);
+ diag204_buf_vmalloc = NULL;
+ } else {
+ free_pages((unsigned long) diag204_buf, 0);
+ }
+ diag204_buf = NULL;
+}
+
+static void *page_align_ptr(void *ptr)
+{
+ return (void *) PAGE_ALIGN((unsigned long) ptr);
+}
+
+static void *diag204_alloc_vbuf(int pages)
+{
+ /* The buffer has to be page aligned! */
+ diag204_buf_vmalloc = vmalloc(array_size(PAGE_SIZE, (pages + 1)));
+ if (!diag204_buf_vmalloc)
+ return ERR_PTR(-ENOMEM);
+ diag204_buf = page_align_ptr(diag204_buf_vmalloc);
+ diag204_buf_pages = pages;
+ return diag204_buf;
+}
+
+static void *diag204_alloc_rbuf(void)
+{
+ diag204_buf = (void*)__get_free_pages(GFP_KERNEL,0);
+ if (!diag204_buf)
+ return ERR_PTR(-ENOMEM);
+ diag204_buf_pages = 1;
+ return diag204_buf;
+}
+
+static void *diag204_get_buffer(enum diag204_format fmt, int *pages)
+{
+ if (diag204_buf) {
+ *pages = diag204_buf_pages;
+ return diag204_buf;
+ }
+ if (fmt == DIAG204_INFO_SIMPLE) {
+ *pages = 1;
+ return diag204_alloc_rbuf();
+ } else {/* DIAG204_INFO_EXT */
+ *pages = diag204((unsigned long)DIAG204_SUBC_RSI |
+ (unsigned long)DIAG204_INFO_EXT, 0, NULL);
+ if (*pages <= 0)
+ return ERR_PTR(-ENOSYS);
+ else
+ return diag204_alloc_vbuf(*pages);
+ }
+}
+
+/*
+ * diag204_probe() has to find out, which type of diagnose 204 implementation
+ * we have on our machine. Currently there are three possible scanarios:
+ * - subcode 4 + simple data format (only one page)
+ * - subcode 4-6 + extended data format
+ * - subcode 4-7 + extended data format
+ *
+ * Subcode 5 is used to retrieve the size of the data, provided by subcodes
+ * 6 and 7. Subcode 7 basically has the same function as subcode 6. In addition
+ * to subcode 6 it provides also information about secondary cpus.
+ * In order to get as much information as possible, we first try
+ * subcode 7, then 6 and if both fail, we use subcode 4.
+ */
+
+static int diag204_probe(void)
+{
+ void *buf;
+ int pages, rc;
+
+ buf = diag204_get_buffer(DIAG204_INFO_EXT, &pages);
+ if (!IS_ERR(buf)) {
+ if (diag204((unsigned long)DIAG204_SUBC_STIB7 |
+ (unsigned long)DIAG204_INFO_EXT, pages, buf) >= 0) {
+ diag204_store_sc = DIAG204_SUBC_STIB7;
+ diag204_info_type = DIAG204_INFO_EXT;
+ goto out;
+ }
+ if (diag204((unsigned long)DIAG204_SUBC_STIB6 |
+ (unsigned long)DIAG204_INFO_EXT, pages, buf) >= 0) {
+ diag204_store_sc = DIAG204_SUBC_STIB6;
+ diag204_info_type = DIAG204_INFO_EXT;
+ goto out;
+ }
+ diag204_free_buffer();
+ }
+
+ /* subcodes 6 and 7 failed, now try subcode 4 */
+
+ buf = diag204_get_buffer(DIAG204_INFO_SIMPLE, &pages);
+ if (IS_ERR(buf)) {
+ rc = PTR_ERR(buf);
+ goto fail_alloc;
+ }
+ if (diag204((unsigned long)DIAG204_SUBC_STIB4 |
+ (unsigned long)DIAG204_INFO_SIMPLE, pages, buf) >= 0) {
+ diag204_store_sc = DIAG204_SUBC_STIB4;
+ diag204_info_type = DIAG204_INFO_SIMPLE;
+ goto out;
+ } else {
+ rc = -ENOSYS;
+ goto fail_store;
+ }
+out:
+ rc = 0;
+fail_store:
+ diag204_free_buffer();
+fail_alloc:
+ return rc;
+}
+
+static int diag204_do_store(void *buf, int pages)
+{
+ int rc;
+
+ rc = diag204((unsigned long) diag204_store_sc |
+ (unsigned long) diag204_info_type, pages, buf);
+ return rc < 0 ? -ENOSYS : 0;
+}
+
+static void *diag204_store(void)
+{
+ void *buf;
+ int pages, rc;
+
+ buf = diag204_get_buffer(diag204_info_type, &pages);
+ if (IS_ERR(buf))
+ goto out;
+ rc = diag204_do_store(buf, pages);
+ if (rc)
+ return ERR_PTR(rc);
+out:
+ return buf;
+}
+
+/* Diagnose 224 functions */
+
+static int diag224_get_name_table(void)
+{
+ /* memory must be below 2GB */
+ diag224_cpu_names = (char *) __get_free_page(GFP_KERNEL | GFP_DMA);
+ if (!diag224_cpu_names)
+ return -ENOMEM;
+ if (diag224(diag224_cpu_names)) {
+ free_page((unsigned long) diag224_cpu_names);
+ return -EOPNOTSUPP;
+ }
+ EBCASC(diag224_cpu_names + 16, (*diag224_cpu_names + 1) * 16);
+ return 0;
+}
+
+static void diag224_delete_name_table(void)
+{
+ free_page((unsigned long) diag224_cpu_names);
+}
+
+static int diag224_idx2name(int index, char *name)
+{
+ memcpy(name, diag224_cpu_names + ((index + 1) * DIAG204_CPU_NAME_LEN),
+ DIAG204_CPU_NAME_LEN);
+ name[DIAG204_CPU_NAME_LEN] = 0;
+ strim(name);
+ return 0;
+}
+
+struct dbfs_d204_hdr {
+ u64 len; /* Length of d204 buffer without header */
+ u16 version; /* Version of header */
+ u8 sc; /* Used subcode */
+ char reserved[53];
+} __attribute__ ((packed));
+
+struct dbfs_d204 {
+ struct dbfs_d204_hdr hdr; /* 64 byte header */
+ char buf[]; /* d204 buffer */
+} __attribute__ ((packed));
+
+static int dbfs_d204_create(void **data, void **data_free_ptr, size_t *size)
+{
+ struct dbfs_d204 *d204;
+ int rc, buf_size;
+ void *base;
+
+ buf_size = PAGE_SIZE * (diag204_buf_pages + 1) + sizeof(d204->hdr);
+ base = vzalloc(buf_size);
+ if (!base)
+ return -ENOMEM;
+ d204 = page_align_ptr(base + sizeof(d204->hdr)) - sizeof(d204->hdr);
+ rc = diag204_do_store(d204->buf, diag204_buf_pages);
+ if (rc) {
+ vfree(base);
+ return rc;
+ }
+ d204->hdr.version = DBFS_D204_HDR_VERSION;
+ d204->hdr.len = PAGE_SIZE * diag204_buf_pages;
+ d204->hdr.sc = diag204_store_sc;
+ *data = d204;
+ *data_free_ptr = base;
+ *size = d204->hdr.len + sizeof(struct dbfs_d204_hdr);
+ return 0;
+}
+
+static struct hypfs_dbfs_file dbfs_file_d204 = {
+ .name = "diag_204",
+ .data_create = dbfs_d204_create,
+ .data_free = vfree,
+};
+
+__init int hypfs_diag_init(void)
+{
+ int rc;
+
+ if (diag204_probe()) {
+ pr_err("The hardware system does not support hypfs\n");
+ return -ENODATA;
+ }
+ if (diag204_info_type == DIAG204_INFO_EXT) {
+ rc = hypfs_dbfs_create_file(&dbfs_file_d204);
+ if (rc)
+ return rc;
+ }
+ if (MACHINE_IS_LPAR) {
+ rc = diag224_get_name_table();
+ if (rc) {
+ pr_err("The hardware system does not provide all "
+ "functions required by hypfs\n");
+ debugfs_remove(dbfs_d204_file);
+ return rc;
+ }
+ }
+ return 0;
+}
+
+void hypfs_diag_exit(void)
+{
+ debugfs_remove(dbfs_d204_file);
+ diag224_delete_name_table();
+ diag204_free_buffer();
+ hypfs_dbfs_remove_file(&dbfs_file_d204);
+}
+
+/*
+ * Functions to create the directory structure
+ * *******************************************
+ */
+
+static int hypfs_create_cpu_files(struct dentry *cpus_dir, void *cpu_info)
+{
+ struct dentry *cpu_dir;
+ char buffer[TMP_SIZE];
+ void *rc;
+
+ snprintf(buffer, TMP_SIZE, "%d", cpu_info__cpu_addr(diag204_info_type,
+ cpu_info));
+ cpu_dir = hypfs_mkdir(cpus_dir, buffer);
+ rc = hypfs_create_u64(cpu_dir, "mgmtime",
+ cpu_info__acc_time(diag204_info_type, cpu_info) -
+ cpu_info__lp_time(diag204_info_type, cpu_info));
+ if (IS_ERR(rc))
+ return PTR_ERR(rc);
+ rc = hypfs_create_u64(cpu_dir, "cputime",
+ cpu_info__lp_time(diag204_info_type, cpu_info));
+ if (IS_ERR(rc))
+ return PTR_ERR(rc);
+ if (diag204_info_type == DIAG204_INFO_EXT) {
+ rc = hypfs_create_u64(cpu_dir, "onlinetime",
+ cpu_info__online_time(diag204_info_type,
+ cpu_info));
+ if (IS_ERR(rc))
+ return PTR_ERR(rc);
+ }
+ diag224_idx2name(cpu_info__ctidx(diag204_info_type, cpu_info), buffer);
+ rc = hypfs_create_str(cpu_dir, "type", buffer);
+ return PTR_ERR_OR_ZERO(rc);
+}
+
+static void *hypfs_create_lpar_files(struct dentry *systems_dir, void *part_hdr)
+{
+ struct dentry *cpus_dir;
+ struct dentry *lpar_dir;
+ char lpar_name[DIAG204_LPAR_NAME_LEN + 1];
+ void *cpu_info;
+ int i;
+
+ part_hdr__part_name(diag204_info_type, part_hdr, lpar_name);
+ lpar_name[DIAG204_LPAR_NAME_LEN] = 0;
+ lpar_dir = hypfs_mkdir(systems_dir, lpar_name);
+ if (IS_ERR(lpar_dir))
+ return lpar_dir;
+ cpus_dir = hypfs_mkdir(lpar_dir, "cpus");
+ if (IS_ERR(cpus_dir))
+ return cpus_dir;
+ cpu_info = part_hdr + part_hdr__size(diag204_info_type);
+ for (i = 0; i < part_hdr__rcpus(diag204_info_type, part_hdr); i++) {
+ int rc;
+ rc = hypfs_create_cpu_files(cpus_dir, cpu_info);
+ if (rc)
+ return ERR_PTR(rc);
+ cpu_info += cpu_info__size(diag204_info_type);
+ }
+ return cpu_info;
+}
+
+static int hypfs_create_phys_cpu_files(struct dentry *cpus_dir, void *cpu_info)
+{
+ struct dentry *cpu_dir;
+ char buffer[TMP_SIZE];
+ void *rc;
+
+ snprintf(buffer, TMP_SIZE, "%i", phys_cpu__cpu_addr(diag204_info_type,
+ cpu_info));
+ cpu_dir = hypfs_mkdir(cpus_dir, buffer);
+ if (IS_ERR(cpu_dir))
+ return PTR_ERR(cpu_dir);
+ rc = hypfs_create_u64(cpu_dir, "mgmtime",
+ phys_cpu__mgm_time(diag204_info_type, cpu_info));
+ if (IS_ERR(rc))
+ return PTR_ERR(rc);
+ diag224_idx2name(phys_cpu__ctidx(diag204_info_type, cpu_info), buffer);
+ rc = hypfs_create_str(cpu_dir, "type", buffer);
+ return PTR_ERR_OR_ZERO(rc);
+}
+
+static void *hypfs_create_phys_files(struct dentry *parent_dir, void *phys_hdr)
+{
+ int i;
+ void *cpu_info;
+ struct dentry *cpus_dir;
+
+ cpus_dir = hypfs_mkdir(parent_dir, "cpus");
+ if (IS_ERR(cpus_dir))
+ return cpus_dir;
+ cpu_info = phys_hdr + phys_hdr__size(diag204_info_type);
+ for (i = 0; i < phys_hdr__cpus(diag204_info_type, phys_hdr); i++) {
+ int rc;
+ rc = hypfs_create_phys_cpu_files(cpus_dir, cpu_info);
+ if (rc)
+ return ERR_PTR(rc);
+ cpu_info += phys_cpu__size(diag204_info_type);
+ }
+ return cpu_info;
+}
+
+int hypfs_diag_create_files(struct dentry *root)
+{
+ struct dentry *systems_dir, *hyp_dir;
+ void *time_hdr, *part_hdr;
+ int i, rc;
+ void *buffer, *ptr;
+
+ buffer = diag204_store();
+ if (IS_ERR(buffer))
+ return PTR_ERR(buffer);
+
+ systems_dir = hypfs_mkdir(root, "systems");
+ if (IS_ERR(systems_dir)) {
+ rc = PTR_ERR(systems_dir);
+ goto err_out;
+ }
+ time_hdr = (struct x_info_blk_hdr *)buffer;
+ part_hdr = time_hdr + info_blk_hdr__size(diag204_info_type);
+ for (i = 0; i < info_blk_hdr__npar(diag204_info_type, time_hdr); i++) {
+ part_hdr = hypfs_create_lpar_files(systems_dir, part_hdr);
+ if (IS_ERR(part_hdr)) {
+ rc = PTR_ERR(part_hdr);
+ goto err_out;
+ }
+ }
+ if (info_blk_hdr__flags(diag204_info_type, time_hdr) &
+ DIAG204_LPAR_PHYS_FLG) {
+ ptr = hypfs_create_phys_files(root, part_hdr);
+ if (IS_ERR(ptr)) {
+ rc = PTR_ERR(ptr);
+ goto err_out;
+ }
+ }
+ hyp_dir = hypfs_mkdir(root, "hyp");
+ if (IS_ERR(hyp_dir)) {
+ rc = PTR_ERR(hyp_dir);
+ goto err_out;
+ }
+ ptr = hypfs_create_str(hyp_dir, "type", "LPAR Hypervisor");
+ if (IS_ERR(ptr)) {
+ rc = PTR_ERR(ptr);
+ goto err_out;
+ }
+ rc = 0;
+
+err_out:
+ return rc;
+}