Re: [PATCH v18 04/17] x86/setup: Add helper parse_crashkernel_in_order()

2021-12-24 Thread Leizhen (ThunderTown)



On 2021/12/22 21:08, Zhen Lei wrote:
> 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 
> ---
>  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;
> 

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[PATCH v18 04/17] x86/setup: Add helper parse_crashkernel_in_order()

2021-12-22 Thread Zhen Lei
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 
---
 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_CLASSIC0x1 /* 
crashkernel=X[@offset] is valid */
+#define CRASHKERNEL_MEM_HIGH   0x2 /* crashkernel=X,high is valid 
*/
+#define CRASHKERNEL_MEM_LOW0x4 /* 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)
+{
+   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;
-- 
2.25.1


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