From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ander Conselvan de Oliveira Subject: Re: [PATCH v3] drm/i915: Implement dma-buf mmap() for userspace access Date: Mon, 23 Jun 2014 14:25:25 +0300 Message-ID: <53A80EA5.3030203@gmail.com> References: <1403181274-7167-1-git-send-email-conselvan2@gmail.com> <20140619123701.GT5821@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTP id CC1B36E2D1 for ; Mon, 23 Jun 2014 04:25:23 -0700 (PDT) In-Reply-To: <20140619123701.GT5821@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On 06/19/2014 03:37 PM, Daniel Vetter wrote: > On Thu, Jun 19, 2014 at 03:34:34PM +0300, Ander Conselvan de Oliveira wrote: >> From: Rob Bradford >> >> The aim is that this is functionally equivalent to using the >> I915_GEM_MMAP ioctl. >> >> v2: Add aperture check limit, limit to SNB+ and improve error handling. >> >> v3 (anderco): Map without using the GTT. > > Why that? This means you'll have a non-coherent mapping and atm dma-buf > doesn't expose and invalidate/flushing ioctls. Which really you want for > this. Hmm. I completely overlooked that important detail. In a discussion with Rob, we came to the conclusion we didn't want to use the GTT because of the performance penalty. Now I see that just modifying the mmap() support is not enough. Thanks, Ander > -Daniel > >> >> Signed-off-by: Rob Bradford >> Signed-off-by: Ander Conselvan de Oliveira >> --- >> drivers/gpu/drm/i915/i915_gem_dmabuf.c | 19 ++++++++++++++++++- >> 1 file changed, 18 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c >> index 580aa42..2d31fca 100644 >> --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c >> +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c >> @@ -193,7 +193,24 @@ static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_n >> >> static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma) >> { >> - return -EINVAL; >> + struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); >> + struct drm_device *dev = obj->base.dev; >> + struct drm_i915_private *dev_priv = dev->dev_private; >> + int ret; >> + >> + if (INTEL_INFO(dev)->gen < 6) >> + return -EINVAL; >> + >> + ret = i915_mutex_lock_interruptible(dev); >> + if (ret) >> + return ret; >> + >> + ret = obj->base.filp->f_op->mmap(obj->base.filp, vma); >> + fput(vma->vm_file); >> + vma->vm_file = get_file(obj->base.filp); >> + >> + mutex_unlock(&dev->struct_mutex); >> + return ret; >> } >> >> static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t length, enum dma_data_direction direction) >> -- >> 1.8.3.2 >> >> _______________________________________________ >> Intel-gfx mailing list >> Intel-gfx@lists.freedesktop.org >> http://lists.freedesktop.org/mailman/listinfo/intel-gfx >