From b2a815a554a34f0e6fab4526ae762d5528783600 Mon Sep 17 00:00:00 2001 From: Hari Bathini Date: Wed, 11 Sep 2019 20:25:49 +0530 Subject: 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: Hari Bathini Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/156821374440.5656.2945512543806951766.stgit@hbathini.in.ibm.com --- arch/powerpc/kernel/fadump.c | 53 ++++++++++++++++++++++++-------------------- 1 file changed, 29 insertions(+), 24 deletions(-) diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c index 502e49ab4b98..6f52a60bc212 100644 --- a/arch/powerpc/kernel/fadump.c +++ b/arch/powerpc/kernel/fadump.c @@ -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); + } +} -- cgit