diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/powerpc/platforms/pseries/nvram.c')
| -rw-r--r-- | ANDROID_3.4.5/arch/powerpc/platforms/pseries/nvram.c | 679 |
1 files changed, 679 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/arch/powerpc/platforms/pseries/nvram.c b/ANDROID_3.4.5/arch/powerpc/platforms/pseries/nvram.c new file mode 100644 index 00000000..36f957f3 --- /dev/null +++ b/ANDROID_3.4.5/arch/powerpc/platforms/pseries/nvram.c @@ -0,0 +1,679 @@ +/* + * c 2001 PPC 64 Team, IBM Corp + * + * 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. + * + * /dev/nvram driver for PPC64 + * + * This perhaps should live in drivers/char + */ + + +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <linux/kmsg_dump.h> +#include <linux/ctype.h> +#include <linux/zlib.h> +#include <asm/uaccess.h> +#include <asm/nvram.h> +#include <asm/rtas.h> +#include <asm/prom.h> +#include <asm/machdep.h> + +/* Max bytes to read/write in one go */ +#define NVRW_CNT 0x20 + +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 { + int error_type; + unsigned int 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 */ +}; + +static struct nvram_os_partition rtas_log_partition = { + .name = "ibm,rtas-log", + .req_size = 2079, + .min_size = 1055, + .index = -1 +}; + +static struct nvram_os_partition oops_log_partition = { + .name = "lnx,oops-log", + .req_size = 4000, + .min_size = 2000, + .index = -1 +}; + +static const char *pseries_nvram_os_partitions[] = { + "ibm,rtas-log", + "lnx,oops-log", + NULL +}; + +static void oops_to_nvram(struct kmsg_dumper *dumper, + enum kmsg_dump_reason reason, + const char *old_msgs, unsigned long old_len, + const char *new_msgs, unsigned long new_len); + +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 prefix. + * The prefix is just a u16 holding the length of the compressed* text. + * (*Or uncompressed, if compression fails.) oops_buf[] gets written + * to NVRAM. + * + * oops_len points to the prefix. oops_data points to the compressed text. + * + * +- oops_buf + * | +- oops_data + * v v + * +------------+-----------------------------------------------+ + * | length | text | + * | (2 bytes) | (oops_data_sz bytes) | + * +------------+-----------------------------------------------+ + * ^ + * +- oops_len + * + * 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 u16 *oops_len; +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; + +static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index) +{ + unsigned int i; + unsigned long len; + int done; + unsigned long flags; + char *p = buf; + + + if (nvram_size == 0 || nvram_fetch == RTAS_UNKNOWN_SERVICE) + return -ENODEV; + + if (*index >= nvram_size) + return 0; + + i = *index; + if (i + count > nvram_size) + count = nvram_size - i; + + spin_lock_irqsave(&nvram_lock, flags); + + for (; count != 0; count -= len) { + len = count; + if (len > NVRW_CNT) + len = NVRW_CNT; + + if ((rtas_call(nvram_fetch, 3, 2, &done, i, __pa(nvram_buf), + len) != 0) || len != done) { + spin_unlock_irqrestore(&nvram_lock, flags); + return -EIO; + } + + memcpy(p, nvram_buf, len); + + p += len; + i += len; + } + + spin_unlock_irqrestore(&nvram_lock, flags); + + *index = i; + return p - buf; +} + +static ssize_t pSeries_nvram_write(char *buf, size_t count, loff_t *index) +{ + unsigned int i; + unsigned long len; + int done; + unsigned long flags; + const char *p = buf; + + if (nvram_size == 0 || nvram_store == RTAS_UNKNOWN_SERVICE) + return -ENODEV; + + if (*index >= nvram_size) + return 0; + + i = *index; + if (i + count > nvram_size) + count = nvram_size - i; + + spin_lock_irqsave(&nvram_lock, flags); + + for (; count != 0; count -= len) { + len = count; + if (len > NVRW_CNT) + len = NVRW_CNT; + + memcpy(nvram_buf, p, len); + + if ((rtas_call(nvram_store, 3, 2, &done, i, __pa(nvram_buf), + len) != 0) || len != done) { + spin_unlock_irqrestore(&nvram_lock, flags); + return -EIO; + } + + p += len; + i += len; + } + spin_unlock_irqrestore(&nvram_lock, flags); + + *index = i; + return p - buf; +} + +static ssize_t pSeries_nvram_get_size(void) +{ + return nvram_size ? nvram_size : -ENODEV; +} + + +/* nvram_write_os_partition, 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 + */ +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 = err_type; + info.seq_num = 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", __FUNCTION__, rc); + return rc; + } + + rc = ppc_md.nvram_write(buff, length, &tmp_index); + if (rc <= 0) { + pr_err("%s: Failed nvram_write (%d)\n", __FUNCTION__, rc); + return rc; + } + + return 0; +} + +int nvram_write_error_log(char * buff, int length, + unsigned int err_type, unsigned int error_log_cnt) +{ + int rc = nvram_write_os_partition(&rtas_log_partition, buff, length, + err_type, error_log_cnt); + if (!rc) + last_unread_rtas_event = get_seconds(); + return rc; +} + +/* nvram_read_error_log + * + * Reads nvram for error log for at most 'length' + */ +int nvram_read_error_log(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 (rtas_log_partition.index == -1) + return -1; + + if (length > rtas_log_partition.size) + length = rtas_log_partition.size; + + tmp_index = rtas_log_partition.index; + + rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index); + if (rc <= 0) { + printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc); + return rc; + } + + rc = ppc_md.nvram_read(buff, length, &tmp_index); + if (rc <= 0) { + printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc); + return rc; + } + + *error_log_cnt = info.seq_num; + *err_type = info.error_type; + + return 0; +} + +/* This doesn't actually zero anything, but it sets the event_logged + * word to tell that this event is safely in syslog. + */ +int nvram_clear_error_log(void) +{ + loff_t tmp_index; + int clear_word = ERR_FLAG_ALREADY_LOGGED; + int rc; + + if (rtas_log_partition.index == -1) + return -1; + + tmp_index = rtas_log_partition.index; + + rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index); + if (rc <= 0) { + printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc); + return rc; + } + last_unread_rtas_event = 0; + + 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; + + /* Scan nvram for partitions */ + nvram_scan_partitions(); + + /* 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; +} + +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_len = (u16*) oops_buf; + oops_data = oops_buf + sizeof(u16); + oops_data_sz = oops_log_partition.size - sizeof(u16); + + /* + * 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; + + rc = pseries_nvram_init_os_partition(&rtas_log_partition); + nvram_init_oops_partition(rc == 0); + return 0; +} +machine_arch_initcall(pseries, pseries_nvram_init_log_partitions); + +int __init pSeries_nvram_init(void) +{ + struct device_node *nvram; + const unsigned int *nbytes_p; + unsigned int proplen; + + nvram = of_find_node_by_type(NULL, "nvram"); + if (nvram == NULL) + return -ENODEV; + + nbytes_p = of_get_property(nvram, "#bytes", &proplen); + if (nbytes_p == NULL || proplen != sizeof(unsigned int)) { + of_node_put(nvram); + return -EIO; + } + + nvram_size = *nbytes_p; + + nvram_fetch = rtas_token("nvram-fetch"); + nvram_store = rtas_token("nvram-store"); + printk(KERN_INFO "PPC64 nvram contains %d bytes\n", nvram_size); + of_node_put(nvram); + + ppc_md.nvram_read = pSeries_nvram_read; + ppc_md.nvram_write = pSeries_nvram_write; + ppc_md.nvram_size = pSeries_nvram_get_size; + + return 0; +} + +/* + * Try to capture the last capture_len bytes of the printk buffer. Return + * the amount actually captured. + */ +static size_t capture_last_msgs(const char *old_msgs, size_t old_len, + const char *new_msgs, size_t new_len, + char *captured, size_t capture_len) +{ + if (new_len >= capture_len) { + memcpy(captured, new_msgs + (new_len - capture_len), + capture_len); + return capture_len; + } else { + /* Grab the end of old_msgs. */ + size_t old_tail_len = min(old_len, capture_len - new_len); + memcpy(captured, old_msgs + (old_len - old_tail_len), + old_tail_len); + memcpy(captured + old_tail_len, new_msgs, new_len); + return old_tail_len + new_len; + } +} + +/* + * 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 + * hasn't had a chance to read and process? Return 1 if so, else 0. + * + * 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) +{ + return (oops_log_partition.index == rtas_log_partition.index + && last_unread_rtas_event + && get_seconds() - last_unread_rtas_event <= + NVRAM_RTAS_READ_TIMEOUT); +} + +/* Squeeze out each line's <n> severity prefix. */ +static size_t elide_severities(char *buf, size_t len) +{ + char *in, *out, *buf_end = buf + len; + /* Assume a <n> at the very beginning marks the start of a line. */ + int newline = 1; + + in = out = buf; + while (in < buf_end) { + if (newline && in+3 <= buf_end && + *in == '<' && isdigit(in[1]) && in[2] == '>') { + in += 3; + newline = 0; + } else { + newline = (*in == '\n'); + *out++ = *in++; + } + } + return out - buf; +} + +/* 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) +{ + 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_len = (u16) zipped_len; + 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, + const char *old_msgs, unsigned long old_len, + const char *new_msgs, unsigned long new_len) +{ + 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", + __FUNCTION__, (int) reason); + return; + } + + if (clobbering_unread_rtas_event()) + return; + + if (!spin_trylock_irqsave(&lock, flags)) + return; + + if (big_oops_buf) { + text_len = capture_last_msgs(old_msgs, old_len, + new_msgs, new_len, big_oops_buf, big_oops_buf_sz); + text_len = elide_severities(big_oops_buf, text_len); + rc = zip_oops(text_len); + } + if (rc != 0) { + text_len = capture_last_msgs(old_msgs, old_len, + new_msgs, new_len, oops_data, oops_data_sz); + err_type = ERR_TYPE_KERNEL_PANIC; + *oops_len = (u16) text_len; + } + + (void) nvram_write_os_partition(&oops_log_partition, oops_buf, + (int) (sizeof(*oops_len) + *oops_len), err_type, ++oops_count); + + spin_unlock_irqrestore(&lock, flags); +} |