[PATCH v2 3/3] drm/etnaviv: implement softpin
Guido Günther
agx at sigxcpu.org
Wed Aug 14 12:29:16 UTC 2019
Hi,
nOn Fri, Aug 09, 2019 at 02:05:14PM +0200, Lucas Stach wrote:
> With softpin we allow the userspace to take control over the GPU virtual
> address space. The new capability is relected by a bump of the minor DRM
> version. There are a few restrictions for userspace to take into
> account:
>
> 1. The kernel reserves a bit of the address space to implement zero page
> faulting and mapping of the kernel internal ring buffer. Userspace can
> query the kernel for the first usable GPU VM address via
> ETNAVIV_PARAM_SOFTPIN_START_ADDR.
>
> 2. We only allow softpin on GPUs, which implement proper process
> separation via PPAS. If softpin is not available the softpin start
> address will be set to ~0.
>
> 3. Softpin is all or nothing. A submit using softpin must not use any
> address fixups via relocs.
>
> Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
> Reviewed-by: Philipp Zabel <p.zabel at pengutronix.de>
> ---
> v2: Extend 'presumed' field description to match its softpin use.
> ---
> drivers/gpu/drm/etnaviv/etnaviv_drv.c | 2 +-
> drivers/gpu/drm/etnaviv/etnaviv_drv.h | 2 ++
> drivers/gpu/drm/etnaviv/etnaviv_gem.c | 5 ++--
> drivers/gpu/drm/etnaviv/etnaviv_gem.h | 1 +
> drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c | 26 +++++++++++++++++++-
> drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 9 +++++++
> include/uapi/drm/etnaviv_drm.h | 10 +++++++-
> 7 files changed, 50 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.c b/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> index 80f1edcbbea0..45851d510f62 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> @@ -529,7 +529,7 @@ static struct drm_driver etnaviv_drm_driver = {
> .desc = "etnaviv DRM",
> .date = "20151214",
> .major = 1,
> - .minor = 2,
> + .minor = 3,
> };
>
> /*
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.h b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
> index a488cfdb6bbf..32cfa5a48d42 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.h
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
> @@ -24,6 +24,8 @@ struct etnaviv_gem_object;
> struct etnaviv_gem_submit;
> struct etnaviv_iommu_global;
>
> +#define ETNAVIV_SOFTPIN_START_ADDRESS SZ_4M /* must be >=
> SUBALLOC_SIZE */
what about doing this as code like
#if ETNAVIV_SOFTPIN_START_ADDRESS < SUBALLOC_SIZE
# error "ETNAVIV_SOFTPIN_START_ADDRESS < SUBALLOC_SIZE"
#endif
in e.g. entaviv_cmdbuf.c ?
apart from that
Reviewed-by: Guido Günther <agx at sigxcpu.org>
> +
> struct etnaviv_file_private {
> struct etnaviv_iommu_context *mmu;
> struct drm_sched_entity sched_entity[ETNA_MAX_PIPES];
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
> index 1a64fad55740..be62f1368272 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
> @@ -248,7 +248,8 @@ void etnaviv_gem_mapping_unreference(struct etnaviv_vram_mapping *mapping)
> }
>
> struct etnaviv_vram_mapping *etnaviv_gem_mapping_get(
> - struct drm_gem_object *obj, struct etnaviv_iommu_context *mmu_context)
> + struct drm_gem_object *obj, struct etnaviv_iommu_context *mmu_context,
> + u64 va)
> {
> struct etnaviv_gem_object *etnaviv_obj = to_etnaviv_bo(obj);
> struct etnaviv_vram_mapping *mapping;
> @@ -309,7 +310,7 @@ struct etnaviv_vram_mapping *etnaviv_gem_mapping_get(
>
> ret = etnaviv_iommu_map_gem(mmu_context, etnaviv_obj,
> mmu_context->global->memory_base,
> - mapping, 0);
> + mapping, va);
> if (ret < 0)
> kfree(mapping);
> else
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.h b/drivers/gpu/drm/etnaviv/etnaviv_gem.h
> index 2d01ee1f65c1..f1164934ecdf 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.h
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.h
> @@ -77,6 +77,7 @@ static inline bool is_active(struct etnaviv_gem_object *etnaviv_obj)
>
> struct etnaviv_gem_submit_bo {
> u32 flags;
> + u64 va;
> struct etnaviv_gem_object *obj;
> struct etnaviv_vram_mapping *mapping;
> struct dma_fence *excl;
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
> index 63a1206492d2..75afce42921b 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
> @@ -72,6 +72,14 @@ static int submit_lookup_objects(struct etnaviv_gem_submit *submit,
> }
>
> submit->bos[i].flags = bo->flags;
> + if (submit->flags & ETNA_SUBMIT_SOFTPIN) {
> + if (bo->presumed < ETNAVIV_SOFTPIN_START_ADDRESS) {
> + DRM_ERROR("invalid softpin address\n");
> + ret = -EINVAL;
> + goto out_unlock;
> + }
> + submit->bos[i].va = bo->presumed;
> + }
>
> /* normally use drm_gem_object_lookup(), but for bulk lookup
> * all under single table_lock just hit object_idr directly:
> @@ -224,11 +232,17 @@ static int submit_pin_objects(struct etnaviv_gem_submit *submit)
> struct etnaviv_vram_mapping *mapping;
>
> mapping = etnaviv_gem_mapping_get(&etnaviv_obj->base,
> - submit->mmu_context);
> + submit->mmu_context,
> + submit->bos[i].va);
> if (IS_ERR(mapping)) {
> ret = PTR_ERR(mapping);
> break;
> }
> +
> + if ((submit->flags & ETNA_SUBMIT_SOFTPIN) &&
> + submit->bos[i].va != mapping->iova)
> + return -EINVAL;
> +
> atomic_inc(&etnaviv_obj->gpu_active);
>
> submit->bos[i].flags |= BO_PINNED;
> @@ -261,6 +275,10 @@ static int submit_reloc(struct etnaviv_gem_submit *submit, void *stream,
> u32 *ptr = stream;
> int ret;
>
> + /* Submits using softpin don't blend with relocs */
> + if ((submit->flags & ETNA_SUBMIT_SOFTPIN) && nr_relocs != 0)
> + return -EINVAL;
> +
> for (i = 0; i < nr_relocs; i++) {
> const struct drm_etnaviv_gem_submit_reloc *r = relocs + i;
> struct etnaviv_gem_submit_bo *bo;
> @@ -445,6 +463,12 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
> return -EINVAL;
> }
>
> + if ((args->flags & ETNA_SUBMIT_SOFTPIN) &&
> + priv->mmu_global->version != ETNAVIV_IOMMU_V2) {
> + DRM_ERROR("softpin requested on incompatible MMU\n");
> + return -EINVAL;
> + }
> +
> /*
> * Copy the command submission and bo array to kernel space in
> * one go, and do this outside of any locks.
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> index d8a83ebfce47..d47d1a8e0219 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> @@ -42,6 +42,8 @@ static const struct platform_device_id gpu_ids[] = {
>
> int etnaviv_gpu_get_param(struct etnaviv_gpu *gpu, u32 param, u64 *value)
> {
> + struct etnaviv_drm_private *priv = gpu->drm->dev_private;
> +
> switch (param) {
> case ETNAVIV_PARAM_GPU_MODEL:
> *value = gpu->identity.model;
> @@ -147,6 +149,13 @@ int etnaviv_gpu_get_param(struct etnaviv_gpu *gpu, u32 param, u64 *value)
> *value = gpu->identity.varyings_count;
> break;
>
> + case ETNAVIV_PARAM_SOFTPIN_START_ADDR:
> + if (priv->mmu_global->version == ETNAVIV_IOMMU_V2)
> + *value = ETNAVIV_SOFTPIN_START_ADDRESS;
> + else
> + *value = ~0ULL;
> + break;
> +
> default:
> DBG("%s: invalid param: %u", dev_name(gpu->dev), param);
> return -EINVAL;
> diff --git a/include/uapi/drm/etnaviv_drm.h b/include/uapi/drm/etnaviv_drm.h
> index 0d5c49dc478c..09d0df8b71c5 100644
> --- a/include/uapi/drm/etnaviv_drm.h
> +++ b/include/uapi/drm/etnaviv_drm.h
> @@ -73,6 +73,7 @@ struct drm_etnaviv_timespec {
> #define ETNAVIV_PARAM_GPU_INSTRUCTION_COUNT 0x18
> #define ETNAVIV_PARAM_GPU_NUM_CONSTANTS 0x19
> #define ETNAVIV_PARAM_GPU_NUM_VARYINGS 0x1a
> +#define ETNAVIV_PARAM_SOFTPIN_START_ADDR 0x1b
>
> #define ETNA_MAX_PIPES 4
>
> @@ -148,6 +149,11 @@ struct drm_etnaviv_gem_submit_reloc {
> * then patching the cmdstream for this entry is skipped. This can
> * avoid kernel needing to map/access the cmdstream bo in the common
> * case.
> + * If the submit is a softpin submit (ETNA_SUBMIT_SOFTPIN) the 'presumed'
> + * field is interpreted as the fixed location to map the bo into the gpu
> + * virtual address space. If the kernel is unable to map the buffer at
> + * this location the submit will fail. This means userspace is responsible
> + * for the whole gpu virtual address management.
> */
> #define ETNA_SUBMIT_BO_READ 0x0001
> #define ETNA_SUBMIT_BO_WRITE 0x0002
> @@ -177,9 +183,11 @@ struct drm_etnaviv_gem_submit_pmr {
> #define ETNA_SUBMIT_NO_IMPLICIT 0x0001
> #define ETNA_SUBMIT_FENCE_FD_IN 0x0002
> #define ETNA_SUBMIT_FENCE_FD_OUT 0x0004
> +#define ETNA_SUBMIT_SOFTPIN 0x0008
> #define ETNA_SUBMIT_FLAGS (ETNA_SUBMIT_NO_IMPLICIT | \
> ETNA_SUBMIT_FENCE_FD_IN | \
> - ETNA_SUBMIT_FENCE_FD_OUT)
> + ETNA_SUBMIT_FENCE_FD_OUT| \
> + ETNA_SUBMIT_SOFTPIN)
> #define ETNA_PIPE_3D 0x00
> #define ETNA_PIPE_2D 0x01
> #define ETNA_PIPE_VG 0x02
> --
> 2.20.1
>
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