Patch series "kdump: use generic functions to simplify crashkernel
reservation in arch", v3.

In the current arm64, crashkernel=,high support has been finished after
several rounds of posting and careful reviewing.  The code in arm64 which
parses crashkernel kernel parameters firstly, then reserve memory can be a
good example for other ARCH to refer to.

Whereas in x86_64, the code mixing crashkernel parameter parsing and
memory reserving is twisted, and looks messy.  Refactoring the code to
make it more readable maintainable is necessary.

Here, firstly abstract the crashkernel parameter parsing code into
parse_crashkernel() to make it be able to parse crashkernel=,high|low. 
Then abstract the crashkernel memory reserving code into a generic
function reserve_crashkernel_generic().  Finally, in ARCH which
crashkernel=,high support is needed, a simple arch_reserve_crashkernel()
can be added to call above two functions.  This can remove the duplicated
implmentation code in each ARCH, like arm64, x86_64 and riscv.

crashkernel=512M,high
crashkernel=512M,high crashkernel=256M,low
crashkernel=512M,high crashkernel=0M,low
crashkernel=0M,high crashkernel=256M,low
crashkernel=512M
crashkernel=512M@0x4f000000
crashkernel=1G-4G:256M,4G-64G:320M,64G-:576M
crashkernel=0M


This patch (of 9):

In all call sites of __parse_crashkernel(), the parameter 'name' is
hardcoded as "crashkernel=".  So remove the unnecessary parameter 'name',
add local varibale 'name' inside __parse_crashkernel() instead.

Link: https://lkml.kernel.org/r/20230914033142.676708-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20230914033142.676708-2-bhe@redhat.comSigned-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>