powerpc/nvram: Move generic code for nvram and pstore

With minor checks, we can move most of the code for nvram
under pseries to a common place to be re-used by other
powerpc platforms like powernv. This patch moves such
common code to arch/powerpc/kernel/nvram_64.c file.

Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
[mpe: Move select of ZLIB_DEFLATE to PPC64 to fix the build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

2 files changed, 5 insertions, 662 deletions

diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
index a758a9c..54c87d5 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig
@@ -16,7 +16,6 @@ config PPC_PSERIES
 	select PPC_UDBG_16550
 	select PPC_NATIVE
 	select PPC_PCI_CHOICE if EXPERT
-	select ZLIB_DEFLATE
 	select PPC_DOORBELL
 	select HAVE_CONTEXT_TRACKING
 	select HOTPLUG_CPU if SMP
diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c
index 054a0ed..533807e 100644
--- a/arch/powerpc/platforms/pseries/nvram.c
+++ b/arch/powerpc/platforms/pseries/nvram.c
@@ -20,7 +20,6 @@
 #include <linux/kmsg_dump.h>
 #include <linux/pstore.h>
 #include <linux/ctype.h>
-#include <linux/zlib.h>
 #include <asm/uaccess.h>
 #include <asm/nvram.h>
 #include <asm/rtas.h>
@@ -30,129 +29,17 @@
 /* Max bytes to read/write in one go */
 #define NVRW_CNT 0x20
 
-/*
- * Set oops header version to distinguish between old and new format header.
- * lnx,oops-log partition max size is 4000, header version > 4000 will
- * help in identifying new header.
- */
-#define OOPS_HDR_VERSION 5000
-
 static unsigned int nvram_size;
 static int nvram_fetch, nvram_store;
 static char nvram_buf[NVRW_CNT];	/* assume this is in the first 4GB */
 static DEFINE_SPINLOCK(nvram_lock);
 
-struct err_log_info {
-	__be32 error_type;
-	__be32 seq_num;
-};
-
-struct nvram_os_partition {
-	const char *name;
-	int req_size;	/* desired size, in bytes */
-	int min_size;	/* minimum acceptable size (0 means req_size) */
-	long size;	/* size of data portion (excluding err_log_info) */
-	long index;	/* offset of data portion of partition */
-	bool os_partition; /* partition initialized by OS, not FW */
-};
-
-static struct nvram_os_partition rtas_log_partition = {
-	.name = "ibm,rtas-log",
-	.req_size = 2079,
-	.min_size = 1055,
-	.index = -1,
-	.os_partition = true
-};
-
-static struct nvram_os_partition oops_log_partition = {
-	.name = "lnx,oops-log",
-	.req_size = 4000,
-	.min_size = 2000,
-	.index = -1,
-	.os_partition = true
-};
-
-static const char *pseries_nvram_os_partitions[] = {
-	"ibm,rtas-log",
-	"lnx,oops-log",
-	NULL
-};
-
-struct oops_log_info {
-	__be16 version;
-	__be16 report_length;
-	__be64 timestamp;
-} __attribute__((packed));
-
-static void oops_to_nvram(struct kmsg_dumper *dumper,
-			  enum kmsg_dump_reason reason);
-
-static struct kmsg_dumper nvram_kmsg_dumper = {
-	.dump = oops_to_nvram
-};
-
 /* See clobbering_unread_rtas_event() */
 #define NVRAM_RTAS_READ_TIMEOUT 5		/* seconds */
 static unsigned long last_unread_rtas_event;	/* timestamp */
 
-/*
- * For capturing and compressing an oops or panic report...
-
- * big_oops_buf[] holds the uncompressed text we're capturing.
- *
- * oops_buf[] holds the compressed text, preceded by a oops header.
- * oops header has u16 holding the version of oops header (to differentiate
- * between old and new format header) followed by u16 holding the length of
- * the compressed* text (*Or uncompressed, if compression fails.) and u64
- * holding the timestamp. oops_buf[] gets written to NVRAM.
- *
- * oops_log_info points to the header. oops_data points to the compressed text.
- *
- * +- oops_buf
- * |                                   +- oops_data
- * v                                   v
- * +-----------+-----------+-----------+------------------------+
- * | version   | length    | timestamp | text                   |
- * | (2 bytes) | (2 bytes) | (8 bytes) | (oops_data_sz bytes)   |
- * +-----------+-----------+-----------+------------------------+
- * ^
- * +- oops_log_info
- *
- * We preallocate these buffers during init to avoid kmalloc during oops/panic.
- */
-static size_t big_oops_buf_sz;
-static char *big_oops_buf, *oops_buf;
-static char *oops_data;
-static size_t oops_data_sz;
-
-/* Compression parameters */
-#define COMPR_LEVEL 6
-#define WINDOW_BITS 12
-#define MEM_LEVEL 4
-static struct z_stream_s stream;
-
 #ifdef CONFIG_PSTORE
-static struct nvram_os_partition of_config_partition = {
-	.name = "of-config",
-	.index = -1,
-	.os_partition = false
-};
-
-static struct nvram_os_partition common_partition = {
-	.name = "common",
-	.index = -1,
-	.os_partition = false
-};
-
-static enum pstore_type_id nvram_type_ids[] = {
-	PSTORE_TYPE_DMESG,
-	PSTORE_TYPE_PPC_RTAS,
-	PSTORE_TYPE_PPC_OF,
-	PSTORE_TYPE_PPC_COMMON,
-	-1
-};
-static int read_type;
-static unsigned long last_rtas_event;
+unsigned long last_rtas_event;
 #endif
 
 static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index)
@@ -246,73 +133,11 @@ static ssize_t pSeries_nvram_get_size(void)
 	return nvram_size ? nvram_size : -ENODEV;
 }
 
-
-/* nvram_write_os_partition, nvram_write_error_log
+/* nvram_write_error_log
  *
  * We need to buffer the error logs into nvram to ensure that we have
- * the failure information to decode.  If we have a severe error there
- * is no way to guarantee that the OS or the machine is in a state to
- * get back to user land and write the error to disk.  For example if
- * the SCSI device driver causes a Machine Check by writing to a bad
- * IO address, there is no way of guaranteeing that the device driver
- * is in any state that is would also be able to write the error data
- * captured to disk, thus we buffer it in NVRAM for analysis on the
- * next boot.
- *
- * In NVRAM the partition containing the error log buffer will looks like:
- * Header (in bytes):
- * +-----------+----------+--------+------------+------------------+
- * | signature | checksum | length | name       | data             |
- * |0          |1         |2      3|4         15|16        length-1|
- * +-----------+----------+--------+------------+------------------+
- *
- * The 'data' section would look like (in bytes):
- * +--------------+------------+-----------------------------------+
- * | event_logged | sequence # | error log                         |
- * |0            3|4          7|8                  error_log_size-1|
- * +--------------+------------+-----------------------------------+
- *
- * event_logged: 0 if event has not been logged to syslog, 1 if it has
- * sequence #: The unique sequence # for each event. (until it wraps)
- * error log: The error log from event_scan
+ * the failure information to decode.
  */
-static int nvram_write_os_partition(struct nvram_os_partition *part,
-				    char *buff, int length,
-				    unsigned int err_type,
-				    unsigned int error_log_cnt)
-{
-	int rc;
-	loff_t tmp_index;
-	struct err_log_info info;
-	
-	if (part->index == -1) {
-		return -ESPIPE;
-	}
-
-	if (length > part->size) {
-		length = part->size;
-	}
-
-	info.error_type = cpu_to_be32(err_type);
-	info.seq_num = cpu_to_be32(error_log_cnt);
-
-	tmp_index = part->index;
-
-	rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index);
-	if (rc <= 0) {
-		pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
-		return rc;
-	}
-
-	rc = ppc_md.nvram_write(buff, length, &tmp_index);
-	if (rc <= 0) {
-		pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
-		return rc;
-	}
-	
-	return 0;
-}
-
 int nvram_write_error_log(char * buff, int length,
                           unsigned int err_type, unsigned int error_log_cnt)
 {
@@ -328,50 +153,6 @@ int nvram_write_error_log(char * buff, int length,
 	return rc;
 }
 
-/* nvram_read_partition
- *
- * Reads nvram partition for at most 'length'
- */
-static int nvram_read_partition(struct nvram_os_partition *part, char *buff,
-				int length, unsigned int *err_type,
-				unsigned int *error_log_cnt)
-{
-	int rc;
-	loff_t tmp_index;
-	struct err_log_info info;
-	
-	if (part->index == -1)
-		return -1;
-
-	if (length > part->size)
-		length = part->size;
-
-	tmp_index = part->index;
-
-	if (part->os_partition) {
-		rc = ppc_md.nvram_read((char *)&info,
-					sizeof(struct err_log_info),
-					&tmp_index);
-		if (rc <= 0) {
-			pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
-			return rc;
-		}
-	}
-
-	rc = ppc_md.nvram_read(buff, length, &tmp_index);
-	if (rc <= 0) {
-		pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
-		return rc;
-	}
-
-	if (part->os_partition) {
-		*error_log_cnt = be32_to_cpu(info.seq_num);
-		*err_type = be32_to_cpu(info.error_type);
-	}
-
-	return 0;
-}
-
 /* nvram_read_error_log
  *
  * Reads nvram for error log for at most 'length'
@@ -407,67 +188,6 @@ int nvram_clear_error_log(void)
 	return 0;
 }
 
-/* pseries_nvram_init_os_partition
- *
- * This sets up a partition with an "OS" signature.
- *
- * The general strategy is the following:
- * 1.) If a partition with the indicated name already exists...
- *	- If it's large enough, use it.
- *	- Otherwise, recycle it and keep going.
- * 2.) Search for a free partition that is large enough.
- * 3.) If there's not a free partition large enough, recycle any obsolete
- * OS partitions and try again.
- * 4.) Will first try getting a chunk that will satisfy the requested size.
- * 5.) If a chunk of the requested size cannot be allocated, then try finding
- * a chunk that will satisfy the minum needed.
- *
- * Returns 0 on success, else -1.
- */
-static int __init pseries_nvram_init_os_partition(struct nvram_os_partition
-									*part)
-{
-	loff_t p;
-	int size;
-
-	/* Look for ours */
-	p = nvram_find_partition(part->name, NVRAM_SIG_OS, &size);
-
-	/* Found one but too small, remove it */
-	if (p && size < part->min_size) {
-		pr_info("nvram: Found too small %s partition,"
-					" removing it...\n", part->name);
-		nvram_remove_partition(part->name, NVRAM_SIG_OS, NULL);
-		p = 0;
-	}
-
-	/* Create one if we didn't find */
-	if (!p) {
-		p = nvram_create_partition(part->name, NVRAM_SIG_OS,
-					part->req_size, part->min_size);
-		if (p == -ENOSPC) {
-			pr_info("nvram: No room to create %s partition, "
-				"deleting any obsolete OS partitions...\n",
-				part->name);
-			nvram_remove_partition(NULL, NVRAM_SIG_OS,
-						pseries_nvram_os_partitions);
-			p = nvram_create_partition(part->name, NVRAM_SIG_OS,
-					part->req_size, part->min_size);
-		}
-	}
-
-	if (p <= 0) {
-		pr_err("nvram: Failed to find or create %s"
-		       " partition, err %d\n", part->name, (int)p);
-		return -1;
-	}
-
-	part->index = p;
-	part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info);
-	
-	return 0;
-}
-
 /*
  * Are we using the ibm,rtas-log for oops/panic reports?  And if so,
  * would logging this oops/panic overwrite an RTAS event that rtas_errd
@@ -476,7 +196,7 @@ static int __init pseries_nvram_init_os_partition(struct nvram_os_partition
  * We assume that if rtas_errd hasn't read the RTAS event in
  * NVRAM_RTAS_READ_TIMEOUT seconds, it's probably not going to.
  */
-static int clobbering_unread_rtas_event(void)
+int clobbering_unread_rtas_event(void)
 {
 	return (oops_log_partition.index == rtas_log_partition.index
 		&& last_unread_rtas_event
@@ -484,313 +204,6 @@ static int clobbering_unread_rtas_event(void)
 						NVRAM_RTAS_READ_TIMEOUT);
 }
 
-/* Derived from logfs_compress() */
-static int nvram_compress(const void *in, void *out, size_t inlen,
-							size_t outlen)
-{
-	int err, ret;
-
-	ret = -EIO;
-	err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
-						MEM_LEVEL, Z_DEFAULT_STRATEGY);
-	if (err != Z_OK)
-		goto error;
-
-	stream.next_in = in;
-	stream.avail_in = inlen;
-	stream.total_in = 0;
-	stream.next_out = out;
-	stream.avail_out = outlen;
-	stream.total_out = 0;
-
-	err = zlib_deflate(&stream, Z_FINISH);
-	if (err != Z_STREAM_END)
-		goto error;
-
-	err = zlib_deflateEnd(&stream);
-	if (err != Z_OK)
-		goto error;
-
-	if (stream.total_out >= stream.total_in)
-		goto error;
-
-	ret = stream.total_out;
-error:
-	return ret;
-}
-
-/* Compress the text from big_oops_buf into oops_buf. */
-static int zip_oops(size_t text_len)
-{
-	struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
-	int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len,
-								oops_data_sz);
-	if (zipped_len < 0) {
-		pr_err("nvram: compression failed; returned %d\n", zipped_len);
-		pr_err("nvram: logging uncompressed oops/panic report\n");
-		return -1;
-	}
-	oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
-	oops_hdr->report_length = cpu_to_be16(zipped_len);
-	oops_hdr->timestamp = cpu_to_be64(get_seconds());
-	return 0;
-}
-
-#ifdef CONFIG_PSTORE
-static int nvram_pstore_open(struct pstore_info *psi)
-{
-	/* Reset the iterator to start reading partitions again */
-	read_type = -1;
-	return 0;
-}
-
-/**
- * nvram_pstore_write - pstore write callback for nvram
- * @type:               Type of message logged
- * @reason:             reason behind dump (oops/panic)
- * @id:                 identifier to indicate the write performed
- * @part:               pstore writes data to registered buffer in parts,
- *                      part number will indicate the same.
- * @count:              Indicates oops count
- * @compressed:         Flag to indicate the log is compressed
- * @size:               number of bytes written to the registered buffer
- * @psi:                registered pstore_info structure
- *
- * Called by pstore_dump() when an oops or panic report is logged in the
- * printk buffer.
- * Returns 0 on successful write.
- */
-static int nvram_pstore_write(enum pstore_type_id type,
-				enum kmsg_dump_reason reason,
-				u64 *id, unsigned int part, int count,
-				bool compressed, size_t size,
-				struct pstore_info *psi)
-{
-	int rc;
-	unsigned int err_type = ERR_TYPE_KERNEL_PANIC;
-	struct oops_log_info *oops_hdr = (struct oops_log_info *) oops_buf;
-
-	/* part 1 has the recent messages from printk buffer */
-	if (part > 1 || type != PSTORE_TYPE_DMESG ||
-				clobbering_unread_rtas_event())
-		return -1;
-
-	oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
-	oops_hdr->report_length = cpu_to_be16(size);
-	oops_hdr->timestamp = cpu_to_be64(get_seconds());
-
-	if (compressed)
-		err_type = ERR_TYPE_KERNEL_PANIC_GZ;
-
-	rc = nvram_write_os_partition(&oops_log_partition, oops_buf,
-		(int) (sizeof(*oops_hdr) + size), err_type, count);
-
-	if (rc != 0)
-		return rc;
-
-	*id = part;
-	return 0;
-}
-
-/*
- * Reads the oops/panic report, rtas, of-config and common partition.
- * Returns the length of the data we read from each partition.
- * Returns 0 if we've been called before.
- */
-static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
-				int *count, struct timespec *time, char **buf,
-				bool *compressed, struct pstore_info *psi)
-{
-	struct oops_log_info *oops_hdr;
-	unsigned int err_type, id_no, size = 0;
-	struct nvram_os_partition *part = NULL;
-	char *buff = NULL;
-	int sig = 0;
-	loff_t p;
-
-	read_type++;
-
-	switch (nvram_type_ids[read_type]) {
-	case PSTORE_TYPE_DMESG:
-		part = &oops_log_partition;
-		*type = PSTORE_TYPE_DMESG;
-		break;
-	case PSTORE_TYPE_PPC_RTAS:
-		part = &rtas_log_partition;
-		*type = PSTORE_TYPE_PPC_RTAS;
-		time->tv_sec = last_rtas_event;
-		time->tv_nsec = 0;
-		break;
-	case PSTORE_TYPE_PPC_OF:
-		sig = NVRAM_SIG_OF;
-		part = &of_config_partition;
-		*type = PSTORE_TYPE_PPC_OF;
-		*id = PSTORE_TYPE_PPC_OF;
-		time->tv_sec = 0;
-		time->tv_nsec = 0;
-		break;
-	case PSTORE_TYPE_PPC_COMMON:
-		sig = NVRAM_SIG_SYS;
-		part = &common_partition;
-		*type = PSTORE_TYPE_PPC_COMMON;
-		*id = PSTORE_TYPE_PPC_COMMON;
-		time->tv_sec = 0;
-		time->tv_nsec = 0;
-		break;
-	default:
-		return 0;
-	}
-
-	if (!part->os_partition) {
-		p = nvram_find_partition(part->name, sig, &size);
-		if (p <= 0) {
-			pr_err("nvram: Failed to find partition %s, "
-				"err %d\n", part->name, (int)p);
-			return 0;
-		}
-		part->index = p;
-		part->size = size;
-	}
-
-	buff = kmalloc(part->size, GFP_KERNEL);
-
-	if (!buff)
-		return -ENOMEM;
-
-	if (nvram_read_partition(part, buff, part->size, &err_type, &id_no)) {
-		kfree(buff);
-		return 0;
-	}
-
-	*count = 0;
-
-	if (part->os_partition)
-		*id = id_no;
-
-	if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
-		size_t length, hdr_size;
-
-		oops_hdr = (struct oops_log_info *)buff;
-		if (be16_to_cpu(oops_hdr->version) < OOPS_HDR_VERSION) {
-			/* Old format oops header had 2-byte record size */
-			hdr_size = sizeof(u16);
-			length = be16_to_cpu(oops_hdr->version);
-			time->tv_sec = 0;
-			time->tv_nsec = 0;
-		} else {
-			hdr_size = sizeof(*oops_hdr);
-			length = be16_to_cpu(oops_hdr->report_length);
-			time->tv_sec = be64_to_cpu(oops_hdr->timestamp);
-			time->tv_nsec = 0;
-		}
-		*buf = kmalloc(length, GFP_KERNEL);
-		if (*buf == NULL)
-			return -ENOMEM;
-		memcpy(*buf, buff + hdr_size, length);
-		kfree(buff);
-
-		if (err_type == ERR_TYPE_KERNEL_PANIC_GZ)
-			*compressed = true;
-		else
-			*compressed = false;
-		return length;
-	}
-
-	*buf = buff;
-	return part->size;
-}
-
-static struct pstore_info nvram_pstore_info = {
-	.owner = THIS_MODULE,
-	.name = "nvram",
-	.open = nvram_pstore_open,
-	.read = nvram_pstore_read,
-	.write = nvram_pstore_write,
-};
-
-static int nvram_pstore_init(void)
-{
-	int rc = 0;
-
-	nvram_pstore_info.buf = oops_data;
-	nvram_pstore_info.bufsize = oops_data_sz;
-
-	spin_lock_init(&nvram_pstore_info.buf_lock);
-
-	rc = pstore_register(&nvram_pstore_info);
-	if (rc != 0)
-		pr_err("nvram: pstore_register() failed, defaults to "
-				"kmsg_dump; returned %d\n", rc);
-
-	return rc;
-}
-#else
-static int nvram_pstore_init(void)
-{
-	return -1;
-}
-#endif
-
-static void __init nvram_init_oops_partition(int rtas_partition_exists)
-{
-	int rc;
-
-	rc = pseries_nvram_init_os_partition(&oops_log_partition);
-	if (rc != 0) {
-		if (!rtas_partition_exists)
-			return;
-		pr_notice("nvram: Using %s partition to log both"
-			" RTAS errors and oops/panic reports\n",
-			rtas_log_partition.name);
-		memcpy(&oops_log_partition, &rtas_log_partition,
-						sizeof(rtas_log_partition));
-	}
-	oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL);
-	if (!oops_buf) {
-		pr_err("nvram: No memory for %s partition\n",
-						oops_log_partition.name);
-		return;
-	}
-	oops_data = oops_buf + sizeof(struct oops_log_info);
-	oops_data_sz = oops_log_partition.size - sizeof(struct oops_log_info);
-
-	rc = nvram_pstore_init();
-
-	if (!rc)
-		return;
-
-	/*
-	 * Figure compression (preceded by elimination of each line's <n>
-	 * severity prefix) will reduce the oops/panic report to at most
-	 * 45% of its original size.
-	 */
-	big_oops_buf_sz = (oops_data_sz * 100) / 45;
-	big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
-	if (big_oops_buf) {
-		stream.workspace =  kmalloc(zlib_deflate_workspacesize(
-					WINDOW_BITS, MEM_LEVEL), GFP_KERNEL);
-		if (!stream.workspace) {
-			pr_err("nvram: No memory for compression workspace; "
-				"skipping compression of %s partition data\n",
-				oops_log_partition.name);
-			kfree(big_oops_buf);
-			big_oops_buf = NULL;
-		}
-	} else {
-		pr_err("No memory for uncompressed %s data; "
-			"skipping compression\n", oops_log_partition.name);
-		stream.workspace = NULL;
-	}
-
-	rc = kmsg_dump_register(&nvram_kmsg_dumper);
-	if (rc != 0) {
-		pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc);
-		kfree(oops_buf);
-		kfree(big_oops_buf);
-		kfree(stream.workspace);
-	}
-}
-
 static int __init pseries_nvram_init_log_partitions(void)
 {
 	int rc;
@@ -798,7 +211,7 @@ static int __init pseries_nvram_init_log_partitions(void)
 	/* Scan nvram for partitions */
 	nvram_scan_partitions();
 
-	rc = pseries_nvram_init_os_partition(&rtas_log_partition);
+	rc = nvram_init_os_partition(&rtas_log_partition);
 	nvram_init_oops_partition(rc == 0);
 	return 0;
 }
@@ -834,72 +247,3 @@ int __init pSeries_nvram_init(void)
 	return 0;
 }
 
-
-/*
- * This is our kmsg_dump callback, called after an oops or panic report
- * has been written to the printk buffer.  We want to capture as much
- * of the printk buffer as possible.  First, capture as much as we can
- * that we think will compress sufficiently to fit in the lnx,oops-log
- * partition.  If that's too much, go back and capture uncompressed text.
- */
-static void oops_to_nvram(struct kmsg_dumper *dumper,
-			  enum kmsg_dump_reason reason)
-{
-	struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
-	static unsigned int oops_count = 0;
-	static bool panicking = false;
-	static DEFINE_SPINLOCK(lock);
-	unsigned long flags;
-	size_t text_len;
-	unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ;
-	int rc = -1;
-
-	switch (reason) {
-	case KMSG_DUMP_RESTART:
-	case KMSG_DUMP_HALT:
-	case KMSG_DUMP_POWEROFF:
-		/* These are almost always orderly shutdowns. */
-		return;
-	case KMSG_DUMP_OOPS:
-		break;
-	case KMSG_DUMP_PANIC:
-		panicking = true;
-		break;
-	case KMSG_DUMP_EMERG:
-		if (panicking)
-			/* Panic report already captured. */
-			return;
-		break;
-	default:
-		pr_err("%s: ignoring unrecognized KMSG_DUMP_* reason %d\n",
-		       __func__, (int) reason);
-		return;
-	}
-
-	if (clobbering_unread_rtas_event())
-		return;
-
-	if (!spin_trylock_irqsave(&lock, flags))
-		return;
-
-	if (big_oops_buf) {
-		kmsg_dump_get_buffer(dumper, false,
-				     big_oops_buf, big_oops_buf_sz, &text_len);
-		rc = zip_oops(text_len);
-	}
-	if (rc != 0) {
-		kmsg_dump_rewind(dumper);
-		kmsg_dump_get_buffer(dumper, false,
-				     oops_data, oops_data_sz, &text_len);
-		err_type = ERR_TYPE_KERNEL_PANIC;
-		oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
-		oops_hdr->report_length = cpu_to_be16(text_len);
-		oops_hdr->timestamp = cpu_to_be64(get_seconds());
-	}
-
-	(void) nvram_write_os_partition(&oops_log_partition, oops_buf,
-		(int) (sizeof(*oops_hdr) + text_len), err_type,
-		++oops_count);
-
-	spin_unlock_irqrestore(&lock, flags);
-}