Re: [PATCH v19 01/13] kdump: add helper parse_crashkernel_high_low()
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From: Leizhen (ThunderTown) <hidden>
Date: 2021-12-30 10:15:08
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kexec, linux-arm-kernel, linux-devicetree, lkml
Hi, Dave, Baoquan, Borislav:
What do you think about the introduction of parse_crashkernel_high_low()? If everyone
doesn't object, I'll bring it to the next version. But I'll make some adjustments to the
patches, see below. If there's any objection, I still strongly recommend removing the
parameters "system_ram" and "crash_base" of parse_crashkernel_{high,low}().
How about splitting __parse_crashkernel() into two parts? One for parsing
"crashkernel=X[@offset]", another one for parsing "crashkernel=X,{high,low}" and other
suffixes in the future. So the parameter requirements are clear at the lowest level.
On 2021/12/28 21:26, Zhen Lei wrote:quoted hunk ↗ jump to hunk
The bootup command line option crashkernel=Y,low is valid only when crashkernel=X,high is specified. Putting their parsing into a separate function makes the code logic clearer and easier to understand the strong dependencies between them. Signed-off-by: Zhen Lei <redacted> --- include/linux/crash_core.h | 3 +++ kernel/crash_core.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+)diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h index de62a722431e7db..2d3a64761d18998 100644 --- a/include/linux/crash_core.h +++ b/include/linux/crash_core.h@@ -83,5 +83,8 @@ int parse_crashkernel_high(char *cmdline, unsigned long long system_ram, unsigned long long *crash_size, unsigned long long *crash_base); int parse_crashkernel_low(char *cmdline, unsigned long long system_ram, unsigned long long *crash_size, unsigned long long *crash_base); +int __init parse_crashkernel_high_low(char *cmdline, + unsigned long long *high_size, + unsigned long long *low_size); #endif /* LINUX_CRASH_CORE_H */diff --git a/kernel/crash_core.c b/kernel/crash_core.c index eb53f5ec62c900f..8966beaf7c4fd52 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c@@ -295,6 +295,41 @@ int __init parse_crashkernel_low(char *cmdline, "crashkernel=", suffix_tbl[SUFFIX_LOW]); } +/** + * parse_crashkernel_high_low - Parsing "crashkernel=X,high" and possible + * "crashkernel=Y,low". + * @cmdline: The bootup command line. + * @high_size: Save the memory size specified by "crashkernel=X,high". + * @low_size: Save the memory size specified by "crashkernel=Y,low" or "-1" + * if it's not specified. + * + * Returns 0 on success, else a negative status code. + */ +int __init parse_crashkernel_high_low(char *cmdline, + unsigned long long *high_size, + unsigned long long *low_size) +{ + int ret; + unsigned long long base; + + BUG_ON(!high_size || !low_size); + + /* crashkernel=X,high */ + ret = parse_crashkernel_high(cmdline, 0, high_size, &base); + if (ret) + return ret; + + if (*high_size <= 0) + return -EINVAL; + + /* crashkernel=Y,low */ + ret = parse_crashkernel_low(cmdline, 0, low_size, &base); + if (ret) + *low_size = -1; + + return 0; +} + Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type, void *data, size_t data_len) {
-- Regards, Zhen Lei