Commit 5b7bfb32 authored by Zhen Lei's avatar Zhen Lei Committed by Andrew Morton
Browse files

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: default avatarZhen Lei <thunder.leizhen@huawei.com>
Acked-by: default avatarBaoquan 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: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 8a7db779

kernel/kexec_core.c

+29 −22
Original line number Diff line number Diff line
@@ -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();