Re: [PATCH v18 04/17] x86/setup: Add helper parse_crashkernel_in_order()
From: Leizhen (ThunderTown) <hidden>
Date: 2021-12-25 01:59:03
Also in:
kexec, linux-arm-kernel, linux-devicetree, lkml
On 2021/12/22 21:08, Zhen Lei wrote:
quoted hunk ↗ jump to hunk
Currently, there are two possible combinations of configurations. (1) crashkernel=X[@offset] (2) crashkernel=X,high, with or without crashkernel=X,low (1) has the highest priority, if it is configured correctly, (2) will be ignored. Similarly, in combination (2), crashkernel=X,low is valid only when crashkernel=X,high is valid. Putting the operations of parsing all "crashkernel=" configurations in one function helps to sort out the strong dependency. So add helper parse_crashkernel_in_order(). The "__maybe_unused" will be removed in the next patch. Signed-off-by: Zhen Lei <redacted> --- arch/x86/kernel/setup.c | 51 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+)diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index d9080bfa131a654..f997074d36f2484 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c@@ -439,6 +439,57 @@ static int __init reserve_crashkernel_low(void) } #endif +#define CRASHKERNEL_MEM_NONE 0x0 /* crashkernel= is not exist or invalid */ +#define CRASHKERNEL_MEM_CLASSIC 0x1 /* crashkernel=X[@offset] is valid */ +#define CRASHKERNEL_MEM_HIGH 0x2 /* crashkernel=X,high is valid */ +#define CRASHKERNEL_MEM_LOW 0x4 /* crashkernel=X,low is valid */ + +/** + * parse_crashkernel_in_order - Parse all "crashkernel=" configurations in + * priority order until a valid combination is found. + * @cmdline: The bootup command line. + * @system_ram: Total system memory size. + * @crash_size: Save the memory size specified by "crashkernel=X[@offset]" or + * "crashkernel=X,high". + * @crash_base: Save the base address specified by "crashkernel=X@offset" + * @low_size: Save the memory size specified by "crashkernel=X,low" + * + * Returns the status flag of the parsing result of "crashkernel=", such as + * CRASHKERNEL_MEM_NONE, CRASHKERNEL_MEM_HIGH. + */ +__maybe_unused +static int __init parse_crashkernel_in_order(char *cmdline, + unsigned long long system_ram, + unsigned long long *crash_size, + unsigned long long *crash_base, + unsigned long long *low_size)
I rethought yesterday that this function name is not self-annotated. In addition, the meaning of the return value is not mainstream. It would be better to change it to parse_crashkernel_high_low().
+{
+ int ret, flag = CRASHKERNEL_MEM_NONE;
+
+ BUG_ON(!crash_size || !crash_base || !low_size);
+
+ /* crashkernel=X[@offset] */
+ ret = parse_crashkernel(cmdline, system_ram, crash_size, crash_base);
+ if (!ret && crash_size > 0)
+ return CRASHKERNEL_MEM_CLASSIC;
+
+#ifdef CONFIG_X86_64
+ /* crashkernel=X,high */
+ ret = parse_crashkernel_high(cmdline, system_ram, crash_size, crash_base);
+ if (ret || crash_size <= 0)
+ return CRASHKERNEL_MEM_NONE;
+
+ flag = CRASHKERNEL_MEM_HIGH;
+
+ /* crashkernel=Y,low */
+ ret = parse_crashkernel_low(cmdline, system_ram, low_size, crash_base);
+ if (!ret)
+ flag |= CRASHKERNEL_MEM_LOW;
+#endif
+
+ return flag;
+}
+
static void __init reserve_crashkernel(void)
{
unsigned long long crash_size, crash_base, total_mem;