Commit b2a815a5 authored by Hari Bathini's avatar Hari Bathini Committed by Michael Ellerman
Browse files

powerpc/fadump: improve how crashed kernel's memory is reserved 



The size parameter to fadump_reserve_crash_area() function is not needed
as all the memory above boot memory size must be preserved anyway. Update
the function by dropping this redundant parameter.

Signed-off-by: default avatarHari Bathini <hbathini@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821374440.5656.2945512543806951766.stgit@hbathini.in.ibm.com
parent dda9dbfe

arch/powerpc/kernel/fadump.c

+29 −24
Original line number Diff line number Diff line
@@ -34,6 +34,8 @@ 


static struct fw_dump fw_dump;



static void __init fadump_reserve_crash_area(u64 base);



static DEFINE_MUTEX(fadump_mutex);

struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0 };

struct fadump_mrange_info reserved_mrange_info = { "reserved", NULL, 0, 0, 0 };
@@ -318,26 +320,6 @@ static unsigned long get_fadump_area_size(void) 
	return size;

}



static void __init fadump_reserve_crash_area(unsigned long base,

					     unsigned long size)

{

	struct memblock_region *reg;

	unsigned long mstart, mend, msize;



	for_each_memblock(memory, reg) {

		mstart = max_t(unsigned long, base, reg->base);

		mend = reg->base + reg->size;

		mend = min(base + size, mend);



		if (mstart < mend) {

			msize = mend - mstart;

			memblock_reserve(mstart, msize);

			pr_info("Reserved %ldMB of memory at %#016lx for saving crash dump\n",

				(msize >> 20), mstart);

		}

	}

}



int __init fadump_reserve_mem(void)

{

	bool is_memblock_bottom_up = memblock_bottom_up();
@@ -406,12 +388,11 @@ int __init fadump_reserve_mem(void) 
#endif

		/*

		 * If last boot has crashed then reserve all the memory

		 * above boot_memory_size so that we don't touch it until

		 * above boot memory size so that we don't touch it until

		 * dump is written to disk by userspace tool. This memory

		 * will be released for general use once the dump is saved.

		 * can be released for general use by invalidating fadump.

		 */

		size = mem_boundary - base;

		fadump_reserve_crash_area(base, size);

		fadump_reserve_crash_area(base);



		pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr);

		pr_debug("Reserve dump area start address: 0x%lx\n",
@@ -1377,3 +1358,27 @@ int __init setup_fadump(void) 
	return 1;

}

subsys_initcall(setup_fadump);



/* Preserve everything above the base address */

static void __init fadump_reserve_crash_area(u64 base)

{

	struct memblock_region *reg;

	u64 mstart, msize;



	for_each_memblock(memory, reg) {

		mstart = reg->base;

		msize  = reg->size;



		if ((mstart + msize) < base)

			continue;



		if (mstart < base) {

			msize -= (base - mstart);

			mstart = base;

		}



		pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",

			(msize >> 20), mstart);

		memblock_reserve(mstart, msize);

	}

}