Re: [PATCH v19 02/13] x86/setup: Use parse_crashkernel_high_low() to simplify code

john.p.donnelly
2022-01-11T15:04:55Z

On 12/28/21 7:26 AM, Zhen Lei wrote:
> Use parse_crashkernel_high_low() to bring the parsing of
> "crashkernel=X,high" and the parsing of "crashkernel=Y,low" together, they
> are strongly dependent, make code logic clear and more readable.
>
> Suggested-by: Borislav Petkov <bp@alien8.de>
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
>
Acked-by: John Donnelly <john.p.donnelly@oracle.com>
> ---
> arch/x86/kernel/setup.c | 21 +++++++++------------
> 1 file changed, 9 insertions(+), 12 deletions(-)
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 6a190c7f4d71b05..93d78aae1937db3 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -416,18 +416,16 @@ static void __init memblock_x86_reserve_range_setup_data(void)
> # define CRASH_ADDR_HIGH_MAX SZ_64T
> #endif
>
> -static int __init reserve_crashkernel_low(void)
> +static int __init reserve_crashkernel_low(unsigned long long low_size)
> {
> #ifdef CONFIG_X86_64
> - unsigned long long base, low_base = 0, low_size = 0;
> + unsigned long long low_base = 0;
> unsigned long low_mem_limit;
> - int ret;
>
> low_mem_limit = min(memblock_phys_mem_size(), CRASH_ADDR_LOW_MAX);
>
> - /* crashkernel=Y,low */
> - ret = parse_crashkernel_low(boot_command_line, low_mem_limit, &low_size, &base);
> - if (ret) {
> + /* crashkernel=Y,low is not specified */
> + if ((long)low_size < 0) {
> /*
> * two parts from kernel/dma/swiotlb.c:
> * -swiotlb size: user-specified with swiotlb= or default.
> @@ -465,7 +463,7 @@ static int __init reserve_crashkernel_low(void)
>
> static void __init reserve_crashkernel(void)
> {
> - unsigned long long crash_size, crash_base, total_mem;
> + unsigned long long crash_size, crash_base, total_mem, low_size;
> bool high = false;
> int ret;
>
> @@ -474,10 +472,9 @@ static void __init reserve_crashkernel(void)
> /* crashkernel=XM */
> ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base);
> if (ret != 0 || crash_size <= 0) {
> - /* crashkernel=X,high */
> - ret = parse_crashkernel_high(boot_command_line, total_mem,
> - &crash_size, &crash_base);
> - if (ret != 0 || crash_size <= 0)
> + /* crashkernel=X,high and possible crashkernel=Y,low */
> + ret = parse_crashkernel_high_low(boot_command_line, &crash_size, &low_size);
> + if (ret)
> return;
> high = true;
> }
> @@ -520,7 +517,7 @@ static void __init reserve_crashkernel(void)
> }
> }
>
> - if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
> + if (crash_base >= (1ULL << 32) && reserve_crashkernel_low(low_size)) {
> memblock_phys_free(crash_base, crash_size);
> return;
> }