On Wed, Sep 30, 2020 at 08:27:04PM -0400, Jonathan Marek wrote:
> Add a new cache mode for creating coherent host-cached BOs.
Reviewed-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
> Signed-off-by: Jonathan Marek <jonathan@xxxxxxxx>
> ---
> drivers/gpu/drm/msm/adreno/adreno_device.c | 1 +
> drivers/gpu/drm/msm/msm_drv.h | 1 +
> drivers/gpu/drm/msm/msm_gem.c | 8 ++++++++
> include/uapi/drm/msm_drm.h | 5 ++---
> 4 files changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c
> index 9eeb46bf2a5d..2aa707546254 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_device.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c
> @@ -410,6 +410,7 @@ static int adreno_bind(struct device *dev, struct device *master, void *data)
> config.rev.minor, config.rev.patchid);
>
> priv->is_a2xx = config.rev.core == 2;
> + priv->has_cached_coherent = config.rev.core >= 6;
>
> gpu = info->init(drm);
> if (IS_ERR(gpu)) {
> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> index 2c3225bc1794..6384844b1696 100644
> --- a/drivers/gpu/drm/msm/msm_drv.h
> +++ b/drivers/gpu/drm/msm/msm_drv.h
> @@ -167,6 +167,7 @@ struct msm_drm_private {
> struct msm_file_private *lastctx;
> /* gpu is only set on open(), but we need this info earlier */
> bool is_a2xx;
> + bool has_cached_coherent;
>
> struct drm_fb_helper *fbdev;
>
> diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
> index b2f49152b4d4..ad9a627493ae 100644
> --- a/drivers/gpu/drm/msm/msm_gem.c
> +++ b/drivers/gpu/drm/msm/msm_gem.c
> @@ -431,6 +431,9 @@ static int msm_gem_pin_iova(struct drm_gem_object *obj,
> if (msm_obj->flags & MSM_BO_MAP_PRIV)
> prot |= IOMMU_PRIV;
>
> + if (msm_obj->flags & MSM_BO_CACHED_COHERENT)
> + prot |= IOMMU_CACHE;
> +
> WARN_ON(!mutex_is_locked(&msm_obj->lock));
>
> if (WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED))
> @@ -998,6 +1001,7 @@ static int msm_gem_new_impl(struct drm_device *dev,
> uint32_t size, uint32_t flags,
> struct drm_gem_object **obj)
> {
> + struct msm_drm_private *priv = dev->dev_private;
> struct msm_gem_object *msm_obj;
>
> switch (flags & MSM_BO_CACHE_MASK) {
> @@ -1005,6 +1009,10 @@ static int msm_gem_new_impl(struct drm_device *dev,
> case MSM_BO_CACHED:
> case MSM_BO_WC:
> break;
> + case MSM_BO_CACHED_COHERENT:
> + if (priv->has_cached_coherent)
> + break;
> + /* fallthrough */
It confused me that this kind of implicitly fell into the else clause in
msm_gem_mmap_obj, but I'm on board. This is a good solution since it only allows
I/O coherence with caching.
> default:
> DRM_DEV_ERROR(dev->dev, "invalid cache flag: %x\n",
> (flags & MSM_BO_CACHE_MASK));
> diff --git a/include/uapi/drm/msm_drm.h b/include/uapi/drm/msm_drm.h
> index a6c1f3eb2623..474497e8743a 100644
> --- a/include/uapi/drm/msm_drm.h
> +++ b/include/uapi/drm/msm_drm.h
> @@ -94,12 +94,11 @@ struct drm_msm_param {
> #define MSM_BO_CACHED 0x00010000
> #define MSM_BO_WC 0x00020000
> #define MSM_BO_UNCACHED 0x00040000
> +#define MSM_BO_CACHED_COHERENT 0x080000
>
> #define MSM_BO_FLAGS (MSM_BO_SCANOUT | \
> MSM_BO_GPU_READONLY | \
> - MSM_BO_CACHED | \
> - MSM_BO_WC | \
> - MSM_BO_UNCACHED)
> + MSM_BO_CACHE_MASK)
>
> struct drm_msm_gem_new {
> __u64 size; /* in */
> --
> 2.26.1
>
--
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