2018-09-11 18:30:50

by Atish Patra

[permalink] [raw]
Subject: [PATCH] RISCV: Fix end PFN for low memory

Use memblock_end_of_DRAM which provides correct last low memory
PFN. Without that, DMA32 region becomes empty resulting in zero
pages being allocated for DMA32.

This patch is based on earlier patch from palmer which never
merged into 4.19. I just edited the commit text to make more
sense.

Signed-off-by: Atish Patra <[email protected]>
Signed-off-by: Palmer Dabbelt <[email protected]>
---
arch/riscv/kernel/setup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index db20dc63..a192bf8a 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -193,7 +193,7 @@ static void __init setup_bootmem(void)
BUG_ON(mem_size == 0);

set_max_mapnr(PFN_DOWN(mem_size));
- max_low_pfn = pfn_base + PFN_DOWN(mem_size);
+ max_low_pfn = memblock_end_of_DRAM();

#ifdef CONFIG_BLK_DEV_INITRD
setup_initrd();
--
2.7.4



2018-09-17 14:10:03

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH] RISCV: Fix end PFN for low memory

On Tue, Sep 11, 2018 at 11:30:18AM -0700, Atish Patra wrote:
> Use memblock_end_of_DRAM which provides correct last low memory
> PFN. Without that, DMA32 region becomes empty resulting in zero
> pages being allocated for DMA32.
>
> This patch is based on earlier patch from palmer which never
> merged into 4.19. I just edited the commit text to make more
> sense.

Looks good,

Reviewed-by: Christoph Hellwig <[email protected]>

Palmer, can you queue this up for 4.19?

2018-09-24 20:56:54

by Atish Patra

[permalink] [raw]
Subject: Re: [PATCH] RISCV: Fix end PFN for low memory

On 9/17/18 7:08 AM, Christoph Hellwig wrote:
> On Tue, Sep 11, 2018 at 11:30:18AM -0700, Atish Patra wrote:
>> Use memblock_end_of_DRAM which provides correct last low memory
>> PFN. Without that, DMA32 region becomes empty resulting in zero
>> pages being allocated for DMA32.
>>
>> This patch is based on earlier patch from palmer which never
>> merged into 4.19. I just edited the commit text to make more
>> sense.
>
> Looks good,
>
> Reviewed-by: Christoph Hellwig <[email protected]>
>
> Palmer, can you queue this up for 4.19?
>
Hi Palmer,
I did not see this one pulled into your rc6 PR.
Not sure if it was intentional or just lost in heap of emails.


Regards,
Atish

2018-09-25 17:04:52

by Palmer Dabbelt

[permalink] [raw]
Subject: Re: [PATCH] RISCV: Fix end PFN for low memory

On Mon, 24 Sep 2018 13:55:04 PDT (-0700), [email protected] wrote:
> On 9/17/18 7:08 AM, Christoph Hellwig wrote:
>> On Tue, Sep 11, 2018 at 11:30:18AM -0700, Atish Patra wrote:
>>> Use memblock_end_of_DRAM which provides correct last low memory
>>> PFN. Without that, DMA32 region becomes empty resulting in zero
>>> pages being allocated for DMA32.
>>>
>>> This patch is based on earlier patch from palmer which never
>>> merged into 4.19. I just edited the commit text to make more
>>> sense.
>>
>> Looks good,
>>
>> Reviewed-by: Christoph Hellwig <[email protected]>
>>
>> Palmer, can you queue this up for 4.19?
>>
> Hi Palmer,
> I did not see this one pulled into your rc6 PR.
> Not sure if it was intentional or just lost in heap of emails.

Looks like it got lost, sorry. It's in my branch now, I might re-spin the rc6
PR because it looks like I may have screwed it up, if not I'll put it in rc7.

Thanks for the ping!