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authorZhen Lei <thunder.leizhen@huawei.com>2023-05-27 20:34:37 +0800
committerAndrew Morton <akpm@linux-foundation.org>2023-06-09 17:44:24 -0700
commit8a7db7790a3ff8413bedef886cf135ba301e88d7 (patch)
tree4b3971474b15fe3ce67d2c9a04ec9b6c853186af /kernel/kexec_core.c
parentf7f567b95b12eda7a6a273b8cb82d152491bc0da (diff)
kexec: improve the readability of crash_shrink_memory()
The major adjustments are: 1. end = start + new_size. The 'end' here is not an accurate representation, because it is not the new end of crashk_res, but the start of ram_res, difference 1. So eliminate it and replace it with ram_res->start. 2. Use 'ram_res->start' and 'ram_res->end' as arguments to crash_free_reserved_phys_range() to indicate that the memory covered by 'ram_res' is released from the crashk. And keep it close to insert_resource(). 3. Replace 'if (start == end)' with 'if (!new_size)', clear indication that all crashk memory will be shrunken. No functional change. Link: https://lkml.kernel.org/r/20230527123439.772-5-thunder.leizhen@huawei.com Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Cong Wang <amwang@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel/kexec_core.c')
-rw-r--r--kernel/kexec_core.c15
1 files changed, 5 insertions, 10 deletions
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index bcc86a250ab3..69fe92141b0b 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -1108,7 +1108,6 @@ ssize_t crash_get_memory_size(void)
int crash_shrink_memory(unsigned long new_size)
{
int ret = 0;
- unsigned long start, end;
unsigned long old_size;
struct resource *ram_res;
@@ -1119,9 +1118,7 @@ int crash_shrink_memory(unsigned long new_size)
ret = -ENOENT;
goto unlock;
}
- start = crashk_res.start;
- end = crashk_res.end;
- old_size = (end == 0) ? 0 : end - start + 1;
+ old_size = !crashk_res.end ? 0 : resource_size(&crashk_res);
new_size = roundup(new_size, KEXEC_CRASH_MEM_ALIGN);
if (new_size >= old_size) {
ret = (new_size == old_size) ? 0 : -EINVAL;
@@ -1134,22 +1131,20 @@ int crash_shrink_memory(unsigned long new_size)
goto unlock;
}
- end = start + new_size;
- crash_free_reserved_phys_range(end, crashk_res.end);
-
- ram_res->start = end;
+ ram_res->start = crashk_res.start + new_size;
ram_res->end = crashk_res.end;
ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
ram_res->name = "System RAM";
- if (start == end) {
+ if (!new_size) {
release_resource(&crashk_res);
crashk_res.start = 0;
crashk_res.end = 0;
} else {
- crashk_res.end = end - 1;
+ crashk_res.end = ram_res->start - 1;
}
+ crash_free_reserved_phys_range(ram_res->start, ram_res->end);
insert_resource(&iomem_resource, ram_res);
unlock: