linux-kernel - RE: [EXT] Re: [PATCH 3/4] dmaengine: fsl-edma: support little endian for edma driver

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

Date:   Wed, 22 May 2019 06:33:12 +0000
From:   Peng Ma <peng.ma@....com>
To:     Vinod Koul <vkoul@...nel.org>
CC:     "robh+dt@...nel.org" <robh+dt@...nel.org>,
        "shawnguo@...nel.org" <shawnguo@...nel.org>,
        "mark.rutland@....com" <mark.rutland@....com>,
        Leo Li <leoyang.li@....com>,
        "dan.j.williams@...el.com" <dan.j.williams@...el.com>,
        "dmaengine@...r.kernel.org" <dmaengine@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>
Subject: RE: [EXT] Re: [PATCH 3/4] dmaengine: fsl-edma: support little endian
 for edma driver

Hi Vinod,

Thank for you reply.
the registers (CHCFG0 - CHCFG15) on big endian socs as fallows:
CHCFG0		0x0
CHCFG1		0x1
CHCFG2		0x2
CHCFG3		0x3
......
CHCFG12		0xC
CHCFG13		0xD
CHCFG14		0xE
CHCFG15		0xF

On little endian socs as fallows:
CHCFG3		0x0
CHCFG2		0x1
CHCFG1		0x2
CHCFG0		0x3
......
CHCFG15		0xC
CHCFG14		0xD
CHCFG13		0xE
CHCFG12		0xF

To fit this map we should add this patch.

Best Regards,
Peng
>-----Original Message-----
>From: Vinod Koul <vkoul@...nel.org>
>Sent: 2019年5月21日 12:38
>To: Peng Ma <peng.ma@....com>
>Cc: robh+dt@...nel.org; shawnguo@...nel.org; mark.rutland@....com; Leo
>Li <leoyang.li@....com>; dan.j.williams@...el.com;
>dmaengine@...r.kernel.org; devicetree@...r.kernel.org;
>linux-kernel@...r.kernel.org; linux-arm-kernel@...ts.infradead.org
>Subject: [EXT] Re: [PATCH 3/4] dmaengine: fsl-edma: support little endian for
>edma driver
>
>Caution: EXT Email
>
>On 06-05-19, 09:03, Peng Ma wrote:
>> improve edma driver to support little endian.
>
>Can you explain a bit more how adding the below lines adds little endian
>support...
>
>>
>> Signed-off-by: Peng Ma <peng.ma@....com>
>> ---
>>  drivers/dma/fsl-edma-common.c |    5 +++++
>>  1 files changed, 5 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/dma/fsl-edma-common.c
>> b/drivers/dma/fsl-edma-common.c index 680b2a0..6bf238e 100644
>> --- a/drivers/dma/fsl-edma-common.c
>> +++ b/drivers/dma/fsl-edma-common.c
>> @@ -83,9 +83,14 @@ void fsl_edma_chan_mux(struct fsl_edma_chan
>*fsl_chan,
>>       u32 ch = fsl_chan->vchan.chan.chan_id;
>>       void __iomem *muxaddr;
>>       unsigned int chans_per_mux, ch_off;
>> +     int endian_diff[4] = {3, 1, -1, -3};
>>
>>       chans_per_mux = fsl_chan->edma->n_chans / DMAMUX_NR;
>>       ch_off = fsl_chan->vchan.chan.chan_id % chans_per_mux;
>> +
>> +     if (!fsl_chan->edma->big_endian)
>> +             ch_off += endian_diff[ch_off % 4];
>> +
>>       muxaddr = fsl_chan->edma->muxbase[ch / chans_per_mux];
>>       slot = EDMAMUX_CHCFG_SOURCE(slot);
>>
>> --
>> 1.7.1
>
>--
>~Vinod