linux-kernel - Re: [PATCH 1/1] dmaengine: dw-edma: Removed redundant #ifdef check for 64-bit

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20220512103955.abihluliakytznae@mobilestation>
Date:   Thu, 12 May 2022 13:39:55 +0300
From:   Serge Semin <fancer.lancer@...il.com>
To:     Ruiqi Li <guywithanaxe42@...il.com>
Cc:     Serge Semin <Sergey.Semin@...kalelectronics.ru>,
        gustavo.pimentel@...opsys.com, vkoul@...nel.org,
        dmaengine@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/1] dmaengine: dw-edma: Removed redundant #ifdef check
 for 64-bit

Hello Ruiqu

On Tue, May 10, 2022 at 11:31:17AM -0500, Ruiqi Li wrote:
> Commit at 8fc5133d fixed unaligned memory access, which caused both 32
> and 64 bit to be the same.
> 
>     #ifdef CONFIG_64BIT
>     /* llp is not aligned on 64bit -> keep 32bit accesses */
>     SET_CH_32(dw, chan->dir, chan->id, llp.lsb,
>               lower_32_bits(chunk->ll_region.paddr));
>     SET_CH_32(dw, chan->dir, chan->id, llp.msb,
>               upper_32_bits(chunk->ll_region.paddr));
>     #else /* CONFIG_64BIT */
>     SET_CH_32(dw, chan->dir, chan->id, llp.lsb,
>               lower_32_bits(chunk->ll_region.paddr));
>     SET_CH_32(dw, chan->dir, chan->id, llp.msb,
>               upper_32_bits(chunk->ll_region.paddr));
>     #endif /* CONFIG_64BIT */
> 
> This patch removes redundant preprocessor check for 64 bit.

A similar fix but with another reasoning has already been submitted:
Link: https://lore.kernel.org/linux-pci/20220503225104.12108-21-Sergey.Semin@baikalelectronics.ru/
So not only the denoted but all 64BIT-ifdef's will be dropped from the
driver.

-Sergey

> 
> Signed-off-by: Ruiqi Li <guywithanaxe42@...il.com>
> ---
>  drivers/dma/dw-edma/dw-edma-v0-core.c | 7 -------
>  1 file changed, 7 deletions(-)
> 
> diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c
> index 33bc1e6c4cf2..d34f344a094b 100644
> --- a/drivers/dma/dw-edma/dw-edma-v0-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-v0-core.c
> @@ -415,18 +415,11 @@ void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
>  			  (DW_EDMA_V0_CCS | DW_EDMA_V0_LLE));
>  		/* Linked list */
>  
> -		#ifdef CONFIG_64BIT
>  		/* llp is not aligned on 64bit -> keep 32bit accesses */
>  		SET_CH_32(dw, chan->dir, chan->id, llp.lsb,
>  			  lower_32_bits(chunk->ll_region.paddr));
>  		SET_CH_32(dw, chan->dir, chan->id, llp.msb,
>  			  upper_32_bits(chunk->ll_region.paddr));
> -		#else /* CONFIG_64BIT */
> -		SET_CH_32(dw, chan->dir, chan->id, llp.lsb,
> -			  lower_32_bits(chunk->ll_region.paddr));
> -		SET_CH_32(dw, chan->dir, chan->id, llp.msb,
> -			  upper_32_bits(chunk->ll_region.paddr));
> -		#endif /* CONFIG_64BIT */
>  	}
>  	/* Doorbell */
>  	SET_RW_32(dw, chan->dir, doorbell,
> -- 
> 2.36.1
>