[PATCH v22 3/9] arm64: kdump: Remove some redundant checks in map_mem()

Zhen Lei
2022-04-14T11:59:15Z

If the value of crashk_res.end is non-zero in this function, it indicates
that function reserve_crashkernel() has been called under condition
"if (!IS_ENABLED(CONFIG_ZONE_DMA) && !IS_ENABLED(CONFIG_ZONE_DMA32))" in
zone_sizes_init() before. And obviously the command line option
"crashkernel=" must also exist, so crash_mem_map is also true.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
arch/arm64/mm/mmu.c | 31 +++++++++++++------------------
1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 626ec32873c6c36..7666b4955e45cb3 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -528,14 +528,12 @@ static void __init map_mem(pgd_t *pgdp)
memblock_mark_nomap(kernel_start, kernel_end - kernel_start);

#ifdef CONFIG_KEXEC_CORE
- if (crash_mem_map) {
- if (IS_ENABLED(CONFIG_ZONE_DMA) ||
- IS_ENABLED(CONFIG_ZONE_DMA32))
- flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
- else if (crashk_res.end)
- memblock_mark_nomap(crashk_res.start,
- resource_size(&crashk_res));
- }
+ if (crash_mem_map &&
+ (IS_ENABLED(CONFIG_ZONE_DMA) || IS_ENABLED(CONFIG_ZONE_DMA32)))
+ flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
+ else if (crashk_res.end)
+ memblock_mark_nomap(crashk_res.start,
+ resource_size(&crashk_res));
#endif

/* map all the memory banks */
@@ -571,16 +569,13 @@ static void __init map_mem(pgd_t *pgdp)
* through /sys/kernel/kexec_crash_size interface.
*/
#ifdef CONFIG_KEXEC_CORE
- if (crash_mem_map &&
- !IS_ENABLED(CONFIG_ZONE_DMA) && !IS_ENABLED(CONFIG_ZONE_DMA32)) {
- if (crashk_res.end) {
- __map_memblock(pgdp, crashk_res.start,
- crashk_res.end + 1,
- PAGE_KERNEL,
- NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS);
- memblock_clear_nomap(crashk_res.start,
- resource_size(&crashk_res));
- }
+ if (crashk_res.end) {
+ __map_memblock(pgdp, crashk_res.start,
+ crashk_res.end + 1,
+ PAGE_KERNEL,
+ NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS);
+ memblock_clear_nomap(crashk_res.start,
+ resource_size(&crashk_res));
}
#endif
}
--
2.25.1