Re: [PATCH v5] memblock,arm64: Expand the static memblock memory table

[Will Deacon <will@kernel.org>]

On Wed, Jun 15, 2022 at 10:27:42AM +0000, Zhou Guanghui wrote:
> In a system(Huawei Ascend ARM64 SoC) using HBM, a multi-bit ECC error
> occurs, and the BIOS will mark the corresponding area (for example, 2 MB)
> as unusable. When the system restarts next time, these areas are not
> reported or reported as EFI_UNUSABLE_MEMORY. Both cases lead to an
> increase in the number of memblocks, whereas EFI_UNUSABLE_MEMORY
> leads to a larger number of memblocks.
> 
> For example, if the EFI_UNUSABLE_MEMORY type is reported:
> ...
> memory[0x92]    [0x0000200834a00000-0x0000200835bfffff], 0x0000000001200000 bytes on node 7 flags: 0x0
> memory[0x93]    [0x0000200835c00000-0x0000200835dfffff], 0x0000000000200000 bytes on node 7 flags: 0x4
> memory[0x94]    [0x0000200835e00000-0x00002008367fffff], 0x0000000000a00000 bytes on node 7 flags: 0x0
> memory[0x95]    [0x0000200836800000-0x00002008369fffff], 0x0000000000200000 bytes on node 7 flags: 0x4
> memory[0x96]    [0x0000200836a00000-0x0000200837bfffff], 0x0000000001200000 bytes on node 7 flags: 0x0
> memory[0x97]    [0x0000200837c00000-0x0000200837dfffff], 0x0000000000200000 bytes on node 7 flags: 0x4
> memory[0x98]    [0x0000200837e00000-0x000020087fffffff], 0x0000000048200000 bytes on node 7 flags: 0x0
> memory[0x99]    [0x0000200880000000-0x0000200bcfffffff], 0x0000000350000000 bytes on node 6 flags: 0x0
> memory[0x9a]    [0x0000200bd0000000-0x0000200bd01fffff], 0x0000000000200000 bytes on node 6 flags: 0x4
> memory[0x9b]    [0x0000200bd0200000-0x0000200bd07fffff], 0x0000000000600000 bytes on node 6 flags: 0x0
> memory[0x9c]    [0x0000200bd0800000-0x0000200bd09fffff], 0x0000000000200000 bytes on node 6 flags: 0x4
> memory[0x9d]    [0x0000200bd0a00000-0x0000200fcfffffff], 0x00000003ff600000 bytes on node 6 flags: 0x0
> memory[0x9e]    [0x0000200fd0000000-0x0000200fd01fffff], 0x0000000000200000 bytes on node 6 flags: 0x4
> memory[0x9f]    [0x0000200fd0200000-0x0000200fffffffff], 0x000000002fe00000 bytes on node 6 flags: 0x0
> ...
> 
> The EFI memory map is parsed to construct the memblock arrays before
> the memblock arrays can be resized. As the result, memory regions
> beyond INIT_MEMBLOCK_REGIONS are lost.
> 
> Add a new macro INIT_MEMBLOCK_MEMORY_REGTIONS to replace

nit: s/REGTIONS/REGIONS/

> INIT_MEMBLOCK_REGTIONS to define the size of the static memblock.memory
> array.
> 
> Allow overriding memblock.memory array size with architecture defined
> INIT_MEMBLOCK_MEMORY_REGIONS and make arm64 to set
> INIT_MEMBLOCK_MEMORY_REGIONS to 1024 when CONFIG_EFI is enabled.
> 
> Signed-off-by: Zhou Guanghui <zhouguanghui1@huawei.com>
> Acked-by: Mike Rapoport <rppt@linux.ibm.com>
> Tested-by: Darren Hart <darren@os.amperecomputing.com>
> ---
>  arch/arm64/include/asm/memory.h |  9 +++++++++
>  mm/memblock.c                   | 14 +++++++++-----
>  2 files changed, 18 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
> index 0af70d9abede..ce8614fa376a 100644
> --- a/arch/arm64/include/asm/memory.h
> +++ b/arch/arm64/include/asm/memory.h
> @@ -364,6 +364,15 @@ void dump_mem_limit(void);
>  # define INIT_MEMBLOCK_RESERVED_REGIONS	(INIT_MEMBLOCK_REGIONS + NR_CPUS + 1)
>  #endif
>  
> +/*
> + * memory regions which marked with flag MEMBLOCK_NOMAP(for example, the memory
> + * of the EFI_UNUSABLE_MEMORY type) may divide a continuous memory block into
> + * multiple parts. As a result, the number of memory regions is large.
> + */
> +#ifdef CONFIG_EFI
> +#define INIT_MEMBLOCK_MEMORY_REGIONS	(INIT_MEMBLOCK_REGIONS * 8)
> +#endif
> +
>  #include <asm-generic/memory_model.h>
>  
>  #endif /* __ASM_MEMORY_H */

For the arm64 bit:

Acked-by: Will Deacon <will@kernel.org>

I'm assuming Andrew will pick this up, but please yell if you'd prefer it
to go via the arm64 tree.

Will