diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/lib/seq_buf.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/lib/seq_buf.c')
-rw-r--r-- | kernel/lib/seq_buf.c | 323 |
1 files changed, 323 insertions, 0 deletions
diff --git a/kernel/lib/seq_buf.c b/kernel/lib/seq_buf.c new file mode 100644 index 000000000..5c94e1012 --- /dev/null +++ b/kernel/lib/seq_buf.c @@ -0,0 +1,323 @@ +/* + * seq_buf.c + * + * Copyright (C) 2014 Red Hat Inc, Steven Rostedt <srostedt@redhat.com> + * + * The seq_buf is a handy tool that allows you to pass a descriptor around + * to a buffer that other functions can write to. It is similar to the + * seq_file functionality but has some differences. + * + * To use it, the seq_buf must be initialized with seq_buf_init(). + * This will set up the counters within the descriptor. You can call + * seq_buf_init() more than once to reset the seq_buf to start + * from scratch. + */ +#include <linux/uaccess.h> +#include <linux/seq_file.h> +#include <linux/seq_buf.h> + +/** + * seq_buf_can_fit - can the new data fit in the current buffer? + * @s: the seq_buf descriptor + * @len: The length to see if it can fit in the current buffer + * + * Returns true if there's enough unused space in the seq_buf buffer + * to fit the amount of new data according to @len. + */ +static bool seq_buf_can_fit(struct seq_buf *s, size_t len) +{ + return s->len + len <= s->size; +} + +/** + * seq_buf_print_seq - move the contents of seq_buf into a seq_file + * @m: the seq_file descriptor that is the destination + * @s: the seq_buf descriptor that is the source. + * + * Returns zero on success, non zero otherwise + */ +int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s) +{ + unsigned int len = seq_buf_used(s); + + return seq_write(m, s->buffer, len); +} + +/** + * seq_buf_vprintf - sequence printing of information. + * @s: seq_buf descriptor + * @fmt: printf format string + * @args: va_list of arguments from a printf() type function + * + * Writes a vnprintf() format into the sequencce buffer. + * + * Returns zero on success, -1 on overflow. + */ +int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args) +{ + int len; + + WARN_ON(s->size == 0); + + if (s->len < s->size) { + len = vsnprintf(s->buffer + s->len, s->size - s->len, fmt, args); + if (s->len + len < s->size) { + s->len += len; + return 0; + } + } + seq_buf_set_overflow(s); + return -1; +} + +/** + * seq_buf_printf - sequence printing of information + * @s: seq_buf descriptor + * @fmt: printf format string + * + * Writes a printf() format into the sequence buffer. + * + * Returns zero on success, -1 on overflow. + */ +int seq_buf_printf(struct seq_buf *s, const char *fmt, ...) +{ + va_list ap; + int ret; + + va_start(ap, fmt); + ret = seq_buf_vprintf(s, fmt, ap); + va_end(ap); + + return ret; +} + +#ifdef CONFIG_BINARY_PRINTF +/** + * seq_buf_bprintf - Write the printf string from binary arguments + * @s: seq_buf descriptor + * @fmt: The format string for the @binary arguments + * @binary: The binary arguments for @fmt. + * + * When recording in a fast path, a printf may be recorded with just + * saving the format and the arguments as they were passed to the + * function, instead of wasting cycles converting the arguments into + * ASCII characters. Instead, the arguments are saved in a 32 bit + * word array that is defined by the format string constraints. + * + * This function will take the format and the binary array and finish + * the conversion into the ASCII string within the buffer. + * + * Returns zero on success, -1 on overflow. + */ +int seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary) +{ + unsigned int len = seq_buf_buffer_left(s); + int ret; + + WARN_ON(s->size == 0); + + if (s->len < s->size) { + ret = bstr_printf(s->buffer + s->len, len, fmt, binary); + if (s->len + ret < s->size) { + s->len += ret; + return 0; + } + } + seq_buf_set_overflow(s); + return -1; +} +#endif /* CONFIG_BINARY_PRINTF */ + +/** + * seq_buf_puts - sequence printing of simple string + * @s: seq_buf descriptor + * @str: simple string to record + * + * Copy a simple string into the sequence buffer. + * + * Returns zero on success, -1 on overflow + */ +int seq_buf_puts(struct seq_buf *s, const char *str) +{ + unsigned int len = strlen(str); + + WARN_ON(s->size == 0); + + if (seq_buf_can_fit(s, len)) { + memcpy(s->buffer + s->len, str, len); + s->len += len; + return 0; + } + seq_buf_set_overflow(s); + return -1; +} + +/** + * seq_buf_putc - sequence printing of simple character + * @s: seq_buf descriptor + * @c: simple character to record + * + * Copy a single character into the sequence buffer. + * + * Returns zero on success, -1 on overflow + */ +int seq_buf_putc(struct seq_buf *s, unsigned char c) +{ + WARN_ON(s->size == 0); + + if (seq_buf_can_fit(s, 1)) { + s->buffer[s->len++] = c; + return 0; + } + seq_buf_set_overflow(s); + return -1; +} + +/** + * seq_buf_putmem - write raw data into the sequenc buffer + * @s: seq_buf descriptor + * @mem: The raw memory to copy into the buffer + * @len: The length of the raw memory to copy (in bytes) + * + * There may be cases where raw memory needs to be written into the + * buffer and a strcpy() would not work. Using this function allows + * for such cases. + * + * Returns zero on success, -1 on overflow + */ +int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len) +{ + WARN_ON(s->size == 0); + + if (seq_buf_can_fit(s, len)) { + memcpy(s->buffer + s->len, mem, len); + s->len += len; + return 0; + } + seq_buf_set_overflow(s); + return -1; +} + +#define MAX_MEMHEX_BYTES 8U +#define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1) + +/** + * seq_buf_putmem_hex - write raw memory into the buffer in ASCII hex + * @s: seq_buf descriptor + * @mem: The raw memory to write its hex ASCII representation of + * @len: The length of the raw memory to copy (in bytes) + * + * This is similar to seq_buf_putmem() except instead of just copying the + * raw memory into the buffer it writes its ASCII representation of it + * in hex characters. + * + * Returns zero on success, -1 on overflow + */ +int seq_buf_putmem_hex(struct seq_buf *s, const void *mem, + unsigned int len) +{ + unsigned char hex[HEX_CHARS]; + const unsigned char *data = mem; + unsigned int start_len; + int i, j; + + WARN_ON(s->size == 0); + + while (len) { + start_len = min(len, HEX_CHARS - 1); +#ifdef __BIG_ENDIAN + for (i = 0, j = 0; i < start_len; i++) { +#else + for (i = start_len-1, j = 0; i >= 0; i--) { +#endif + hex[j++] = hex_asc_hi(data[i]); + hex[j++] = hex_asc_lo(data[i]); + } + if (WARN_ON_ONCE(j == 0 || j/2 > len)) + break; + + /* j increments twice per loop */ + len -= j / 2; + hex[j++] = ' '; + + seq_buf_putmem(s, hex, j); + if (seq_buf_has_overflowed(s)) + return -1; + } + return 0; +} + +/** + * seq_buf_path - copy a path into the sequence buffer + * @s: seq_buf descriptor + * @path: path to write into the sequence buffer. + * @esc: set of characters to escape in the output + * + * Write a path name into the sequence buffer. + * + * Returns the number of written bytes on success, -1 on overflow + */ +int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc) +{ + char *buf; + size_t size = seq_buf_get_buf(s, &buf); + int res = -1; + + WARN_ON(s->size == 0); + + if (size) { + char *p = d_path(path, buf, size); + if (!IS_ERR(p)) { + char *end = mangle_path(buf, p, esc); + if (end) + res = end - buf; + } + } + seq_buf_commit(s, res); + + return res; +} + +/** + * seq_buf_to_user - copy the squence buffer to user space + * @s: seq_buf descriptor + * @ubuf: The userspace memory location to copy to + * @cnt: The amount to copy + * + * Copies the sequence buffer into the userspace memory pointed to + * by @ubuf. It starts from the last read position (@s->readpos) + * and writes up to @cnt characters or till it reaches the end of + * the content in the buffer (@s->len), which ever comes first. + * + * On success, it returns a positive number of the number of bytes + * it copied. + * + * On failure it returns -EBUSY if all of the content in the + * sequence has been already read, which includes nothing in the + * sequence (@s->len == @s->readpos). + * + * Returns -EFAULT if the copy to userspace fails. + */ +int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, int cnt) +{ + int len; + int ret; + + if (!cnt) + return 0; + + if (s->len <= s->readpos) + return -EBUSY; + + len = seq_buf_used(s) - s->readpos; + if (cnt > len) + cnt = len; + ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt); + if (ret == cnt) + return -EFAULT; + + cnt -= ret; + + s->readpos += cnt; + return cnt; +} |