Messages in this thread | | | Subject | Re: [PATCH 2/2] arm64: mm: fix kdump broken with ZONE_DMA reintroduced | From | chenzhou <> | Date | Mon, 28 Dec 2020 15:32:35 +0800 |
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Hi Nicolas,
Thanks for your review.
On 2020/12/26 18:34, Nicolas Saenz Julienne wrote: > Hi Chen, thanks for looking at this. > > On Sat, 2020-12-26 at 11:35 +0800, Chen Zhou wrote: >> If the memory reserved for crash dump kernel falled in ZONE_DMA32, >> the devices in crash dump kernel need to use ZONE_DMA will alloc fail. >> >> Fix this by reserving low memory in ZONE_DMA if CONFIG_ZONE_DMA is >> enabled, otherwise, reserving in ZONE_DMA32. >> >> Fixes: bff3b04460a8 ("arm64: mm: reserve CMA and crashkernel in ZONE_DMA32") > I'm not so sure this counts as a fix, if someone backports it it'll probably > break things as it depends on the series that dynamically sizes DMA zones. I write this just because kdump is broken from this commit. > >> Signed-off-by: Chen Zhou <chenzhou10@huawei.com> >> --- > Why not doing the same with CMA? You'll probably have to move the > dma_contiguous_reserve() call into bootmem_init() so as to make sure that > arm64_dma_phys_limit is populated. You are right, CMA also need this. I will do this in next version.
Thanks, Chen Zhou > > Regards, > Nicolas > >> arch/arm64/mm/init.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c >> index 7b9809e39927..5074e945f1a6 100644 >> --- a/arch/arm64/mm/init.c >> +++ b/arch/arm64/mm/init.c >> @@ -85,7 +85,8 @@ static void __init reserve_crashkernel(void) >> >> >> if (crash_base == 0) { >> /* Current arm64 boot protocol requires 2MB alignment */ >> - crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit, >> + crash_base = memblock_find_in_range(0, >> + arm64_dma_phys_limit ? : arm64_dma32_phys_limit, >> crash_size, SZ_2M); >> if (crash_base == 0) { >> pr_warn("cannot allocate crashkernel (size:0x%llx)\n", >
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