From: greg@kroah.com (Greg KH)
To: kernelnewbies@lists.kernelnewbies.org
Subject: Driver to allow DMA from user space
Date: Tue, 20 Dec 2016 10:38:28 +0100 [thread overview]
Message-ID: <20161220093828.GA13045@kroah.com> (raw)
In-Reply-To: <CAJ2oMhLdc0FqxL2KUQYKNey7podoztoZnuWuWMmtTJukfFvp=Q@mail.gmail.com>
On Mon, Dec 19, 2016 at 06:08:47PM +0200, Ran Shalit wrote:
> Hello,
>
> I want to use DMA from userspace.
Why?
> I already use dma in kernel, and now I want can create a character
> device which will be responsible for this.
Why?
> The only problem is that I want to use the same memory which was
> allocated in kernel with dma_alloc_coherent.
Why?
> Is it correct to use mmap in order to use the phsyical memory which
> was allocated with dma_alloc_coherent ?
>
> If it's that simple it can be surely helpful, and the simple driver
> which wraps dma_alloc_coherent can do the job for dmaing from
> userspace.
Have you looked at the uio driver interface?
But again, why? What problem are you trying to solve here?
thanks,
greg k-h
next prev parent reply other threads:[~2016-12-20 9:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-19 16:08 Driver to allow DMA from user space Ran Shalit
2016-12-20 9:38 ` Greg KH [this message]
2016-12-20 10:15 ` Ran Shalit
2016-12-20 10:26 ` Greg KH
2016-12-24 15:47 ` Ran Shalit
2016-12-25 12:37 ` Greg KH
2016-12-30 18:11 ` Ran Shalit
2016-12-31 10:55 ` Greg KH
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