On Thu, Sep 27, 2012 at 02:14:22PM +0200, Daniel Vetter wrote:
> On Thu, Sep 27, 2012 at 09:27:57AM +0100, Chris Wilson wrote:
> > As SandyBridge returns garbage when decoding certain addresses through
> > the GTT (all memory below 1MiB and a very small number of individual
> > pages) we need to prevent the GPU from utilizing those pages. The
> > ultimate goal would be to prevent our allocator from handing us those
> > pages, but that is a longer term project. In the short term, we can
> > detect when we attempt to bind those pages to the GPU and return an
> > error to the application rather than hang the GPU and potentially the
> > system.
> >
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > ---
> > drivers/gpu/drm/i915/i915_gem_gtt.c | 40 ++++++++++++++++++++++++++++++++---
> > 1 file changed, 37 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> > index d9d3fc7..5c7ccfd 100644
> > --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> > +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> > @@ -306,17 +306,51 @@ void i915_gem_restore_gtt_mappings(struct drm_device *dev)
> > intel_gtt_chipset_flush();
> > }
> >
> > +static bool
> > +gen6_valid_addresses(struct drm_i915_gem_object *obj)
> > +{
> > + struct scatterlist *sg;
> > + int i;
> > +
> > + for_each_sg(obj->pages->sgl, sg, obj->pages->nents, i) {
> > + dma_addr_t addr = sg_dma_address(sg);
> > + if (WARN(addr < 0x100000 ||
> > + addr == 0x20050000 ||
> > + addr == 0x20110000 ||
> > + addr == 0x20130000 ||
> > + addr == 0x20138000 ||
> > + addr == 0x40004000,
> > + "object references unaddressable physical pages: addr=%x",
> > + (u32)addr))
> > + return false;
>
> Iirc the bug is about the physical address, no the remapped one after
> dmar. We'd need to check the windows code for that though ...
Also maybe don't fail, but only smash some dirt into dmesg - otherwise
we'll score a neat regression report and probably angry users.
-Daniel
>
> > + }
> > +
> > + return true;
> > +}
> > +
> > int i915_gem_gtt_prepare_object(struct drm_i915_gem_object *obj)
> > {
> > - if (obj->has_dma_mapping)
> > - return 0;
> > + int ret;
> >
> > - if (!dma_map_sg(&obj->base.dev->pdev->dev,
> > + if (!obj->has_dma_mapping &&
> > + !dma_map_sg(&obj->base.dev->pdev->dev,
> > obj->pages->sgl, obj->pages->nents,
> > PCI_DMA_BIDIRECTIONAL))
> > return -ENOSPC;
> >
> > + if (IS_GEN6(obj->base.dev) && !gen6_valid_addresses(obj)) {
> > + ret = -EFAULT;
> > + goto unmap;
> > + }
> > +
> > return 0;
> > +
> > +unmap:
> > + if (!obj->has_dma_mapping)
> > + dma_unmap_sg(&obj->base.dev->pdev->dev,
> > + obj->pages->sgl, obj->pages->nents,
> > + PCI_DMA_BIDIRECTIONAL);
> > + return ret;
> > }
> >
> > void i915_gem_gtt_bind_object(struct drm_i915_gem_object *obj,
> > --
> > 1.7.10.4
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
