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Date:   Fri, 12 Mar 2021 17:13:14 -0500
From:   Sasha Levin <sashal@kernel.org>
To:     Andreas Larsson <andreas@gaisler.com>
Cc:     linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Mike Rapoport <rppt@linux.ibm.com>,
        "David S . Miller" <davem@davemloft.net>,
        sparclinux@vger.kernel.org
Subject: Re: [PATCH AUTOSEL 4.14 06/13] sparc32: Limit memblock allocation to
 low memory
Message-ID: <YEvnenzIKNE1a0FL@sashalap>
References: <20210302115903.63458-1-sashal@kernel.org>
 <20210302115903.63458-6-sashal@kernel.org>
 <ad613de2-6fd4-f7a3-25b1-61f3a093c811@gaisler.com>
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On Wed, Mar 03, 2021 at 09:19:38AM +0100, Andreas Larsson wrote:
>On 2021-03-02 12:58, Sasha Levin wrote:
>>From: Andreas Larsson <andreas@gaisler.com>
>>
>>[ Upstream commit bda166930c37604ffa93f2425426af6921ec575a ]
>>
>>Commit cca079ef8ac29a7c02192d2bad2ffe4c0c5ffdd0 changed sparc32 to use
>>memblocks instead of bootmem, but also made high memory available via
>>memblock allocation which does not work together with e.g. phys_to_virt
>>and can lead to kernel panic.
>>
>>This changes back to only low memory being allocatable in the early
>>stages, now using memblock allocation.
>>
>>Signed-off-by: Andreas Larsson <andreas@gaisler.com>
>>Acked-by: Mike Rapoport <rppt@linux.ibm.com>
>>Signed-off-by: David S. Miller <davem@davemloft.net>
>>Signed-off-by: Sasha Levin <sashal@kernel.org>
>>---
>>  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 95fe4f081ba3..372a4f08ddf8 100644
>>--- a/arch/sparc/mm/init_32.c
>>+++ b/arch/sparc/mm/init_32.c
>>@@ -230,6 +230,9 @@ unsigned long __init bootmem_init(unsigned long *pages_avail)
>>  	reserve_bootmem((bootmap_pfn << PAGE_SHIFT), size, BOOTMEM_DEFAULT);
>>  	*pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
>>+	/* Only allow low memory to be allocated via memblock allocation */
>>+	memblock_set_current_limit(max_low_pfn << PAGE_SHIFT);
>>+
>>  	return max_pfn;
>>  }
>>
>
>This is not needed for 4.14, and will not compile, as the problem it
>fixes was introduced in 4.19.

I'll drop it, thanks!

-- 
Thanks,
Sasha