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| author | Yijie Yang <yijie.yang@oss.qualcomm.com> | 2026-08-11 16:46:47 +0800 |
|---|---|---|
| committer | Rob Herring (Arm) <robh@kernel.org> | 2026-08-15 15:46:52 -0500 |
| commit | e1c13aed4a1641550e8c9518c96f016e1d52d09b (patch) | |
| tree | 61c2297688373db165cc857b7c7adcb147a5c419 /arch/x86/lib/cmdline.c | |
| download | linux-stable-e1c13aed4a1641550e8c9518c96f016e1d52d09b.tar.gz linux-stable-e1c13aed4a1641550e8c9518c96f016e1d52d09b.zip | |
dt-bindings: interconnect: qcom-bwmon: Add Maili cpu-bwmon compatiblegrafted
Add the Qualcomm Maili SoC compatible string for the CPU bandwidth
monitor (BWMONv4). This falls back to the sdm845-bwmon compatible,
consistent with the existing pattern used by other recent SoCs such as
sm8750 and kaanapali.
Signed-off-by: Yijie Yang <yijie.yang@oss.qualcomm.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Reviewed-by: Jingyi Wang <jingyi.wang@oss.qualcomm.com>
Link: https://patch.msgid.link/20260811-bwmon-v2-1-80f7f150ab9e@oss.qualcomm.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Diffstat (limited to 'arch/x86/lib/cmdline.c')
| -rw-r--r-- | arch/x86/lib/cmdline.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/arch/x86/lib/cmdline.c b/arch/x86/lib/cmdline.c new file mode 100644 index 000000000..c65cd5550 --- /dev/null +++ b/arch/x86/lib/cmdline.c @@ -0,0 +1,235 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * + * Misc librarized functions for cmdline poking. + */ +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/ctype.h> + +#include <asm/setup.h> +#include <asm/cmdline.h> +#include <asm/bug.h> + +static inline int myisspace(u8 c) +{ + return c <= ' '; /* Close enough approximation */ +} + +/* + * Find a boolean option (like quiet,noapic,nosmp....) + * + * @cmdline: the cmdline string + * @max_cmdline_size: the maximum size of cmdline + * @option: option string to look for + * + * Returns the position of that @option (starts counting with 1) + * or 0 on not found. @option will only be found if it is found + * as an entire word in @cmdline. For instance, if @option="car" + * then a cmdline which contains "cart" will not match. + */ +static int +__cmdline_find_option_bool(const char *cmdline, int max_cmdline_size, + const char *option) +{ + char c; + int 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 */ + + /* + * This 'pos' check ensures we do not overrun + * a non-NULL-terminated 'cmdline' + */ + while (pos < max_cmdline_size) { + 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; + fallthrough; + + case st_wordcmp: + if (!*opptr) { + /* + * We matched all the way to the end of the + * option we were looking for. If the + * command-line has a space _or_ ends, then + * we matched! + */ + if (!c || myisspace(c)) + return wstart; + /* + * We hit the end of the option, but _not_ + * the end of a word on the cmdline. Not + * a match. + */ + } else if (!c) { + /* + * Hit the NULL terminator on the end of + * cmdline. + */ + return 0; + } else if (c == *opptr++) { + /* + * We are currently matching, so continue + * to the next character on the cmdline. + */ + break; + } + state = st_wordskip; + fallthrough; + + case st_wordskip: + if (!c) + return 0; + else if (myisspace(c)) + state = st_wordstart; + break; + } + } + + return 0; /* Buffer overrun */ +} + +/* + * Find a non-boolean option (i.e. option=argument). In accordance with + * standard Linux practice, if this option is repeated, this returns the + * last instance on the command line. + * + * @cmdline: the cmdline string + * @max_cmdline_size: the maximum size of cmdline + * @option: option string to look for + * @buffer: memory buffer to return the option argument + * @bufsize: size of the supplied memory buffer + * + * Returns the length of the argument (regardless of if it was + * truncated to fit in the buffer), or -1 on not found. + */ +static int +__cmdline_find_option(const char *cmdline, int max_cmdline_size, + const char *option, char *buffer, int bufsize) +{ + char c; + int pos = 0, len = -1; + const char *opptr = NULL; + char *bufptr = buffer; + enum { + st_wordstart = 0, /* 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) + return -1; /* No command line */ + + /* + * This 'pos' check ensures we do not overrun + * a non-NULL-terminated 'cmdline' + */ + while (pos++ < max_cmdline_size) { + c = *(char *)cmdline++; + if (!c) + break; + + switch (state) { + case st_wordstart: + if (myisspace(c)) + break; + + state = st_wordcmp; + opptr = option; + fallthrough; + + case st_wordcmp: + if ((c == '=') && !*opptr) { + /* + * We matched all the way to the end of the + * option we were looking for, prepare to + * copy the argument. + */ + len = 0; + bufptr = buffer; + state = st_bufcpy; + break; + } else if (c == *opptr++) { + /* + * We are currently matching, so continue + * to the next character on the cmdline. + */ + break; + } + state = st_wordskip; + fallthrough; + + case st_wordskip: + if (myisspace(c)) + state = st_wordstart; + break; + + case st_bufcpy: + if (myisspace(c)) { + state = st_wordstart; + } else { + /* + * Increment len, but don't overrun the + * supplied buffer and leave room for the + * NULL terminator. + */ + if (++len < bufsize) + *bufptr++ = c; + } + break; + } + } + + if (bufsize) + *bufptr = '\0'; + + return len; +} + +int cmdline_find_option_bool(const char *cmdline, const char *option) +{ + int ret; + + ret = __cmdline_find_option_bool(cmdline, COMMAND_LINE_SIZE, option); + if (ret > 0) + return ret; + + if (IS_ENABLED(CONFIG_CMDLINE_BOOL) && !builtin_cmdline_added) + return __cmdline_find_option_bool(builtin_cmdline, COMMAND_LINE_SIZE, option); + + return ret; +} + +int cmdline_find_option(const char *cmdline, const char *option, char *buffer, + int bufsize) +{ + int ret; + + ret = __cmdline_find_option(cmdline, COMMAND_LINE_SIZE, option, buffer, bufsize); + if (ret > 0) + return ret; + + if (IS_ENABLED(CONFIG_CMDLINE_BOOL) && !builtin_cmdline_added) + return __cmdline_find_option(builtin_cmdline, COMMAND_LINE_SIZE, option, buffer, bufsize); + + return ret; +} |
