Messages in this thread | | | Subject | Re: sparc32: boot fails with > 256 MB memory after switch to NO_BOOTMEM | From | Andreas Larsson <> | Date | Thu, 28 Jan 2021 12:05:28 +0100 |
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On 2021-01-28 10:35, Mike Rapoport wrote: > On Wed, Jan 27, 2021 at 04:03:00PM +0100, Andreas Larsson wrote: >> >> >> Commit cca079ef8ac29a7c02192d2bad2ffe4c0c5ffdd0 makes sparc32 use >> memblocks instead of the previous bootmem solution. Unfortunately, due >> to this: >> >> #define PAGE_OFFSET 0xf0000000 >> #define __va(x) ((void *)((unsigned long) (x) - phys_base + >> PAGE_OFFSET)) >> #define phys_to_virt __va >> >> it makes physical addresses >= 0x10000000 past phys_base wrap around the >> 32-bit memory space when converted to virtual addresses, e.g. in >> memblock_alloc_try_nid. Physical memory exactly 0x10000000 past >> phys_base is returned as an unintended NULL pointer, leading to a panic >> in my boot when percpu memory allocation fails due to it. >> >> Unfortunately I have had 256 MB memory or less in a lot of my testing, >> so this old one has slipped by me. >> >> Does anyone has any ideas or pointers on how to resolve this? > > I think the simplest way to work around this is to limit early allocations > to 256M with addition of > > memblock_set_current_limit(SZ_256M); > > somewhere at setup_arch(). > > The page allocator will anyway see the entire memory, so I cannot think of > any downside here.
That works like a charm! Thank you! I'll submit a patch.
-- Andreas Larsson Cobham Gaisler
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