While booting with amd,imageon on a headless target the GPU probe was failing with -ENOSPC in get_pages() from msm_gem.c. Investigation showed that the driver was using the default 16MB VRAM carveout because msm_use_mmu() was returning false since headless devices use a dummy parent device. Avoid this by extending the existing is_a2xx priv member to check the GPU IOMMU state on all platforms and use that check in msm_use_mmu(). This works for memory allocations but it doesn't prevent the VRAM carveout from being created because that happens before we have a chance to check the GPU IOMMU state in adreno_bind. There are a number of possible options to resolve this but none of them are very clean. The easiest way is to likely specify vram=0 as module parameter on headless devices so that the memory doesn't get wasted. Signed-off-by: Jordan Crouse <jorcrous@xxxxxxxxxx> --- drivers/gpu/drm/msm/adreno/adreno_device.c | 6 +++++- drivers/gpu/drm/msm/msm_drv.c | 7 +++---- drivers/gpu/drm/msm/msm_drv.h | 2 +- 3 files changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c index 36f062c7582f..4f19da28f80f 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_device.c +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c @@ -539,7 +539,11 @@ static int adreno_bind(struct device *dev, struct device *master, void *data) DBG("Found GPU: %u.%u.%u.%u", config.rev.core, config.rev.major, config.rev.minor, config.rev.patchid); - priv->is_a2xx = config.rev.core == 2; + /* + * A2xx has a built in IOMMU and all other IOMMU enabled targets will + * have an ARM IOMMU attached + */ + priv->has_gpu_iommu = config.rev.core == 2 || device_iommu_mapped(dev); priv->has_cached_coherent = config.rev.core >= 6; gpu = info->init(drm); diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index aca48c868c14..a125a351ec90 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -318,11 +318,10 @@ bool msm_use_mmu(struct drm_device *dev) struct msm_drm_private *priv = dev->dev_private; /* - * a2xx comes with its own MMU - * On other platforms IOMMU can be declared specified either for the - * MDP/DPU device or for its parent, MDSS device. + * Return true if the GPU or the MDP/DPU or parent MDSS device has an + * IOMMU */ - return priv->is_a2xx || + return priv->has_gpu_iommu || device_iommu_mapped(dev->dev) || device_iommu_mapped(dev->dev->parent); } diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h index 9f0c184b02a0..f33f94acd1b9 100644 --- a/drivers/gpu/drm/msm/msm_drv.h +++ b/drivers/gpu/drm/msm/msm_drv.h @@ -126,7 +126,7 @@ struct msm_drm_private { struct msm_gpu *gpu; /* gpu is only set on open(), but we need this info earlier */ - bool is_a2xx; + bool has_gpu_iommu; bool has_cached_coherent; struct drm_fb_helper *fbdev; -- 2.34.1