diff options
author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2014-07-07 10:17:56 +0200 |
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committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2014-07-07 10:17:56 +0200 |
commit | f1615bbe9be4def59c3b3eaddb60722efeed16c2 (patch) | |
tree | ca3020e65447576fc1826e819651e6ba072030b5 /arch/x86/lib/cmdline.c | |
parent | cfb3c0ab0903abb6ea5215b37eebd9c2a1f057eb (diff) | |
parent | cd3de83f147601356395b57a8673e9c5ff1e59d1 (diff) |
Merge tag 'v3.16-rc4' into drm-intel-next-queued
Due to Dave's vacation drm-next hasn't opened yet for 3.17 so I
couldn't move my drm-intel-next queue forward yet like I usually do.
Just pull in the latest upstream -rc to unblock patch merging - I
don't want to needlessly rebase my current patch pile really and void
all the testing we've done already.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'arch/x86/lib/cmdline.c')
-rw-r--r-- | arch/x86/lib/cmdline.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/x86/lib/cmdline.c b/arch/x86/lib/cmdline.c new file mode 100644 index 00000000000..422db000d72 --- /dev/null +++ b/arch/x86/lib/cmdline.c @@ -0,0 +1,84 @@ +/* + * This file is part of the Linux kernel, and is made available under + * the terms of the GNU General Public License version 2. + * + * Misc librarized functions for cmdline poking. + */ +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <asm/setup.h> + +static inline int myisspace(u8 c) +{ + return c <= ' '; /* Close enough approximation */ +} + +/** + * Find a boolean option (like quiet,noapic,nosmp....) + * + * @cmdline: the cmdline string + * @option: option string to look for + * + * Returns the position of that @option (starts counting with 1) + * or 0 on not found. + */ +int cmdline_find_option_bool(const char *cmdline, const char *option) +{ + char c; + int len, pos = 0, wstart = 0; + const char *opptr = NULL; + enum { + st_wordstart = 0, /* Start of word/after whitespace */ + st_wordcmp, /* Comparing this word */ + st_wordskip, /* Miscompare, skip */ + } state = st_wordstart; + + if (!cmdline) + return -1; /* No command line */ + + len = min_t(int, strlen(cmdline), COMMAND_LINE_SIZE); + if (!len) + return 0; + + while (len--) { + c = *(char *)cmdline++; + pos++; + + switch (state) { + case st_wordstart: + if (!c) + return 0; + else if (myisspace(c)) + break; + + state = st_wordcmp; + opptr = option; + wstart = pos; + /* fall through */ + + 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; + else if (!len) /* last word and is matching */ + return wstart; + break; + + case st_wordskip: + if (!c) + return 0; + else if (myisspace(c)) + state = st_wordstart; + break; + } + } + + return 0; /* Buffer overrun */ +} |