On 05/06/22 at 07:43pm, Zhen Lei wrote: ...... > @@ -118,8 +162,7 @@ static void __init reserve_crashkernel(void) > if (crash_base) > crash_max = crash_base + crash_size; > > - /* Current arm64 boot protocol requires 2MB alignment */ > - crash_base = memblock_phys_alloc_range(crash_size, SZ_2M, > + crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, > crash_base, crash_max); > if (!crash_base) { > pr_warn("cannot allocate crashkernel (size:0x%llx)\n", > @@ -127,6 +170,11 @@ static void __init reserve_crashkernel(void) > return; > } > There's corner case missed, e.g 1) ,high and ,low are specified, CONFIG_ZONE_DMA|DMA32 is not enabled; 2) ,high and ,low are specified, the whole system memory is under 4G. Below judgement can filter them away: if (crash_base > arm64_dma_phys_limit && crash_low_size && reserve_crashkernel_low(crash_low_size)) { What's your opinion? Leave it and add document to notice user, or fix it with code change? I would suggest merging this series, Lei can add this corner case handling on top. Since this is a newly added support, we don't have to make it one step. Doing step by step can make reviewing easier. > + if (crash_low_size && reserve_crashkernel_low(crash_low_size)) { > + memblock_phys_free(crash_base, crash_size); > + return; > + } > + > pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n", > crash_base, crash_base + crash_size, crash_size >> 20); > > @@ -135,6 +183,9 @@ static void __init reserve_crashkernel(void) > * map. Inform kmemleak so that it won't try to access it. > */ > kmemleak_ignore_phys(crash_base); > + if (crashk_low_res.end) > + kmemleak_ignore_phys(crashk_low_res.start); > + > crashk_res.start = crash_base; > crashk_res.end = crash_base + crash_size - 1; > insert_resource(&iomem_resource, &crashk_res); > -- > 2.25.1 >