devicetree.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
To: "Rafał Miłecki" <rafal@milecki.pl>,
	"Rafał Miłecki" <zajec5@gmail.com>,
	"Rob Herring" <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-mips@vger.kernel.org,
	Florian Fainelli <f.fainelli@gmail.com>,
	Vivek Unune <npcomplete13@gmail.com>,
	bcm-kernel-feedback-list@broadcom.com,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] nvmem: iomap: new driver exposing NVMEM accessible using I/O mapping
Date: Fri, 5 Mar 2021 10:33:35 +0000	[thread overview]
Message-ID: <35e498b6-3b2c-d154-db00-d755af339b60@linaro.org> (raw)
In-Reply-To: <93708a21-3444-f68e-c834-a4f769a0acba@milecki.pl>



On 05/03/2021 10:24, Rafał Miłecki wrote:
>>>
>>> +static int iomap_read(void *context, unsigned int offset, void *val,
>>> +              size_t bytes)
>>> +{
>>> +    struct iomap *priv = context;
>>> +    u8 *src = priv->base + offset;
>>> +    u8 *dst = val;
>>> +    size_t tmp;
>>> +
>>> +    tmp = offset % 4;
>>> +    memcpy_fromio(dst, src, tmp);
>>> +    dst += tmp;
>>> +    src += tmp;
>>> +    bytes -= tmp;
>>> +
>>> +    tmp = rounddown(bytes, 4);
>>> +    __ioread32_copy(dst, src, tmp / 4);
>>> +    dst += tmp;
>>> +    src += tmp;
>>> +    bytes -= tmp;
>>> +
>>> +    memcpy_fromio(dst, src, bytes);
>>> +
>>
>>
>> You could just do this!
>>
>>      while (bytes--)
>>          *val++ = readb(priv->base + offset + i++);
> 
> Do you mean that as replacement for "memcpy_fromio" or the whole
> function code?

Yes please!

> The reason for using __ioread32_copy() was to improve reading
> performance (using aligned 32 bit access where possible). I'm not sure
> if that really matters?

Just simple while loop is much readable than the previous code TBH!

> 

> P.S.
> Please don't yell at me in every sentence :( Makes me a bit sad :(
Sorry!! I did not mean anything as such! :-)

--srini

  reply	other threads:[~2021-03-05 10:34 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-04 14:41 [PATCH 1/2] dt-bindings: nvmem: add binding for I/O mapped NVMEM Rafał Miłecki
2021-03-04 14:41 ` [PATCH 2/2] nvmem: iomap: new driver exposing NVMEM accessible using I/O mapping Rafał Miłecki
2021-03-05 10:02   ` Srinivas Kandagatla
2021-03-05 10:24     ` Rafał Miłecki
2021-03-05 10:33       ` Srinivas Kandagatla [this message]
2021-03-05 10:39         ` Rafał Miłecki

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=35e498b6-3b2c-d154-db00-d755af339b60@linaro.org \
    --to=srinivas.kandagatla@linaro.org \
    --cc=bcm-kernel-feedback-list@broadcom.com \
    --cc=devicetree@vger.kernel.org \
    --cc=f.fainelli@gmail.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mips@vger.kernel.org \
    --cc=npcomplete13@gmail.com \
    --cc=rafal@milecki.pl \
    --cc=robh+dt@kernel.org \
    --cc=zajec5@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).