2021-02-04 16:26:54

by Andreas Larsson

Subject: [PATCH] sparc32: Limit memblock allocation to low memory

Commit cca079ef8ac29a7c02192d2bad2ffe4c0c5ffdd0 changed sparc32 to use
memblocks instead of bootmem, but also made high memory available via
memblock allocation which does work together with e.g. phys_to_virt and
leads to crashes.

This changes back to only low memory being allocatable in the early
stages, now using memblock allocation.

Signed-off-by: Andreas Larsson <[email protected]>
---
arch/sparc/mm/init_32.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
index eb2946b1df8a..6139c5700ccc 100644
--- a/arch/sparc/mm/init_32.c
+++ b/arch/sparc/mm/init_32.c
@@ -197,6 +197,9 @@ unsigned long __init bootmem_init(unsigned long *pages_avail)
size = memblock_phys_mem_size() - memblock_reserved_size();
*pages_avail = (size >> PAGE_SHIFT) - high_pages;

+ /* Only allow low memory to be allocated via memblock allocation */
+ memblock_set_current_limit(max_low_pfn << PAGE_SHIFT);
+
return max_pfn;
}

--
2.17.1

2021-02-04 17:28:23

by Mike Rapoport

Subject: Re: [PATCH] sparc32: Limit memblock allocation to low memory

On Thu, Feb 04, 2021 at 05:20:53PM +0100, Andreas Larsson wrote:
> Commit cca079ef8ac29a7c02192d2bad2ffe4c0c5ffdd0 changed sparc32 to use
> memblocks instead of bootmem, but also made high memory available via
> memblock allocation which does work together with e.g. phys_to_virt and
> leads to crashes.
>
> This changes back to only low memory being allocatable in the early
> stages, now using memblock allocation.
>
> Signed-off-by: Andreas Larsson <[email protected]>

Acked-by: Mike Rapoport <[email protected]>

> ---
> arch/sparc/mm/init_32.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
> index eb2946b1df8a..6139c5700ccc 100644
> --- a/arch/sparc/mm/init_32.c
> +++ b/arch/sparc/mm/init_32.c
> @@ -197,6 +197,9 @@ unsigned long __init bootmem_init(unsigned long *pages_avail)
> size = memblock_phys_mem_size() - memblock_reserved_size();
> *pages_avail = (size >> PAGE_SHIFT) - high_pages;
>
> + /* Only allow low memory to be allocated via memblock allocation */
> + memblock_set_current_limit(max_low_pfn << PAGE_SHIFT);
> +
> return max_pfn;
> }
>
> --
> 2.17.1
>

--
Sincerely yours,
Mike.