kexec: add helper __crash_shrink_memory()

No functional change, in preparation for the next patch so that it is
easier to review.

[akpm@linux-foundation.org: make  __crash_shrink_memory() static]
  Link: https://lore.kernel.org/oe-kbuild-all/202305280717.Pw06aLkz-lkp@intel.com/
Link: https://lkml.kernel.org/r/20230527123439.772-6-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>
This commit is contained in:
Zhen Lei 2023-05-27 20:34:38 +08:00 committed by Andrew Morton
parent 8a7db7790a
commit 5b7bfb32cb
1 changed files with 29 additions and 22 deletions

View File

@ -1105,11 +1105,38 @@ ssize_t crash_get_memory_size(void)
return size;
}
static int __crash_shrink_memory(struct resource *old_res,
unsigned long new_size)
{
struct resource *ram_res;
ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
if (!ram_res)
return -ENOMEM;
ram_res->start = old_res->start + new_size;
ram_res->end = old_res->end;
ram_res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
ram_res->name = "System RAM";
if (!new_size) {
release_resource(old_res);
old_res->start = 0;
old_res->end = 0;
} else {
crashk_res.end = ram_res->start - 1;
}
crash_free_reserved_phys_range(ram_res->start, ram_res->end);
insert_resource(&iomem_resource, ram_res);
return 0;
}
int crash_shrink_memory(unsigned long new_size)
{
int ret = 0;
unsigned long old_size;
struct resource *ram_res;
if (!kexec_trylock())
return -EBUSY;
@ -1125,27 +1152,7 @@ int crash_shrink_memory(unsigned long new_size)
goto unlock;
}
ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
if (!ram_res) {
ret = -ENOMEM;
goto unlock;
}
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 (!new_size) {
release_resource(&crashk_res);
crashk_res.start = 0;
crashk_res.end = 0;
} else {
crashk_res.end = ram_res->start - 1;
}
crash_free_reserved_phys_range(ram_res->start, ram_res->end);
insert_resource(&iomem_resource, ram_res);
ret = __crash_shrink_memory(&crashk_res, new_size);
unlock:
kexec_unlock();