mirror of
https://github.com/torvalds/linux.git
synced 2024-11-13 23:51:39 +00:00
df561f6688
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
157 lines
3.1 KiB
C
157 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/* -*- linux-c -*- ------------------------------------------------------- *
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
* Copyright 2007 rPath, Inc. - All Rights Reserved
|
|
*
|
|
* ----------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* Simple command-line parser for early boot.
|
|
*/
|
|
|
|
#include "boot.h"
|
|
|
|
static inline int myisspace(u8 c)
|
|
{
|
|
return c <= ' '; /* Close enough approximation */
|
|
}
|
|
|
|
/*
|
|
* Find a non-boolean option, that is, "option=argument". In accordance
|
|
* with standard Linux practice, if this option is repeated, this returns
|
|
* the last instance on the command line.
|
|
*
|
|
* Returns the length of the argument (regardless of if it was
|
|
* truncated to fit in the buffer), or -1 on not found.
|
|
*/
|
|
int __cmdline_find_option(unsigned long cmdline_ptr, const char *option, char *buffer, int bufsize)
|
|
{
|
|
addr_t cptr;
|
|
char c;
|
|
int len = -1;
|
|
const char *opptr = NULL;
|
|
char *bufptr = buffer;
|
|
enum {
|
|
st_wordstart, /* Start of word/after whitespace */
|
|
st_wordcmp, /* Comparing this word */
|
|
st_wordskip, /* Miscompare, skip */
|
|
st_bufcpy /* Copying this to buffer */
|
|
} state = st_wordstart;
|
|
|
|
if (!cmdline_ptr)
|
|
return -1; /* No command line */
|
|
|
|
cptr = cmdline_ptr & 0xf;
|
|
set_fs(cmdline_ptr >> 4);
|
|
|
|
while (cptr < 0x10000 && (c = rdfs8(cptr++))) {
|
|
switch (state) {
|
|
case st_wordstart:
|
|
if (myisspace(c))
|
|
break;
|
|
|
|
/* else */
|
|
state = st_wordcmp;
|
|
opptr = option;
|
|
fallthrough;
|
|
|
|
case st_wordcmp:
|
|
if (c == '=' && !*opptr) {
|
|
len = 0;
|
|
bufptr = buffer;
|
|
state = st_bufcpy;
|
|
} else if (myisspace(c)) {
|
|
state = st_wordstart;
|
|
} else if (c != *opptr++) {
|
|
state = st_wordskip;
|
|
}
|
|
break;
|
|
|
|
case st_wordskip:
|
|
if (myisspace(c))
|
|
state = st_wordstart;
|
|
break;
|
|
|
|
case st_bufcpy:
|
|
if (myisspace(c)) {
|
|
state = st_wordstart;
|
|
} else {
|
|
if (len < bufsize-1)
|
|
*bufptr++ = c;
|
|
len++;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (bufsize)
|
|
*bufptr = '\0';
|
|
|
|
return len;
|
|
}
|
|
|
|
/*
|
|
* Find a boolean option (like quiet,noapic,nosmp....)
|
|
*
|
|
* Returns the position of that option (starts counting with 1)
|
|
* or 0 on not found
|
|
*/
|
|
int __cmdline_find_option_bool(unsigned long cmdline_ptr, const char *option)
|
|
{
|
|
addr_t cptr;
|
|
char c;
|
|
int pos = 0, wstart = 0;
|
|
const char *opptr = NULL;
|
|
enum {
|
|
st_wordstart, /* Start of word/after whitespace */
|
|
st_wordcmp, /* Comparing this word */
|
|
st_wordskip, /* Miscompare, skip */
|
|
} state = st_wordstart;
|
|
|
|
if (!cmdline_ptr)
|
|
return -1; /* No command line */
|
|
|
|
cptr = cmdline_ptr & 0xf;
|
|
set_fs(cmdline_ptr >> 4);
|
|
|
|
while (cptr < 0x10000) {
|
|
c = rdfs8(cptr++);
|
|
pos++;
|
|
|
|
switch (state) {
|
|
case st_wordstart:
|
|
if (!c)
|
|
return 0;
|
|
else if (myisspace(c))
|
|
break;
|
|
|
|
state = st_wordcmp;
|
|
opptr = option;
|
|
wstart = pos;
|
|
fallthrough;
|
|
|
|
case st_wordcmp:
|
|
if (!*opptr)
|
|
if (!c || myisspace(c))
|
|
return wstart;
|
|
else
|
|
state = st_wordskip;
|
|
else if (!c)
|
|
return 0;
|
|
else if (c != *opptr++)
|
|
state = st_wordskip;
|
|
break;
|
|
|
|
case st_wordskip:
|
|
if (!c)
|
|
return 0;
|
|
else if (myisspace(c))
|
|
state = st_wordstart;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return 0; /* Buffer overrun */
|
|
}
|