Re: [PATCH v2 34/37] drm/nouveau: remove master

[Danilo Krummrich <dakr@redhat.com>]

On Fri, Jul 05, 2024 at 04:37:18AM +1000, Ben Skeggs wrote:
> The only remaining nouveau_drm.master struct member that's being used is
> the mutex that protects its object tree.  Move that into nouveau_drm and
> remove nouveau_drm.master entirely.
> 
> Another patch series will make it possible to also remove the mutex, but
> it's still required for the moment.

It would be good to also mention what we're left with to protect and how we get
rid of that later on.

> 
> Signed-off-by: Ben Skeggs <bskeggs@nvidia.com>
> ---
>  drivers/gpu/drm/nouveau/nouveau_drm.c | 39 +++++++++++----------------
>  drivers/gpu/drm/nouveau/nouveau_drv.h |  3 ++-
>  drivers/gpu/drm/nouveau/nouveau_mem.c | 12 ++++-----
>  3 files changed, 23 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
> index c6c9a528783a..85214d35fd5d 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_drm.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
> @@ -208,11 +208,9 @@ nouveau_cli_fini(struct nouveau_cli *cli)
>  	nvif_mmu_dtor(&cli->mmu);
>  	cli->device.object.map.ptr = NULL;
>  	nvif_device_dtor(&cli->device);
> -	if (cli != &cli->drm->master) {
> -		mutex_lock(&cli->drm->master.lock);
> -		nvif_client_dtor(&cli->base);
> -		mutex_unlock(&cli->drm->master.lock);
> -	}
> +	mutex_lock(&cli->drm->client_mutex);
> +	nvif_client_dtor(&cli->base);
> +	mutex_unlock(&cli->drm->client_mutex);
>  }
>  
>  static int
> @@ -245,11 +243,9 @@ nouveau_cli_init(struct nouveau_drm *drm, const char *sname,
>  	INIT_LIST_HEAD(&cli->worker);
>  	mutex_init(&cli->lock);
>  
> -	if (cli != &drm->master) {
> -		mutex_lock(&drm->master.lock);
> -		ret = nvif_client_ctor(&drm->master.base, cli->name, &cli->base);
> -		mutex_unlock(&drm->master.lock);
> -	}
> +	mutex_lock(&drm->client_mutex);
> +	ret = nvif_client_ctor(&drm->_client, cli->name, &cli->base);
> +	mutex_unlock(&drm->client_mutex);
>  	if (ret) {
>  		NV_PRINTK(err, cli, "Client allocation failed: %d\n", ret);
>  		goto done;
> @@ -602,7 +598,6 @@ nouveau_drm_device_fini(struct nouveau_drm *drm)
>  	mutex_unlock(&drm->clients_lock);
>  
>  	nouveau_cli_fini(&drm->client);
> -	nouveau_cli_fini(&drm->master);
>  	destroy_workqueue(drm->sched_wq);
>  	mutex_destroy(&drm->clients_lock);
>  }
> @@ -618,13 +613,9 @@ nouveau_drm_device_init(struct nouveau_drm *drm)
>  	if (!drm->sched_wq)
>  		return -ENOMEM;
>  
> -	ret = nouveau_cli_init(drm, "DRM-master", &drm->master);
> -	if (ret)
> -		goto fail_wq;
> -
>  	ret = nouveau_cli_init(drm, "DRM", &drm->client);
>  	if (ret)
> -		goto fail_master;
> +		goto fail_wq;
>  
>  	INIT_LIST_HEAD(&drm->clients);
>  	mutex_init(&drm->clients_lock);
> @@ -691,8 +682,6 @@ nouveau_drm_device_init(struct nouveau_drm *drm)
>  fail_ttm:
>  	nouveau_vga_fini(drm);
>  	nouveau_cli_fini(&drm->client);
> -fail_master:
> -	nouveau_cli_fini(&drm->master);
>  fail_wq:
>  	destroy_workqueue(drm->sched_wq);
>  	return ret;
> @@ -706,9 +695,10 @@ nouveau_drm_device_del(struct nouveau_drm *drm)
>  
>  	nvif_mmu_dtor(&drm->mmu);
>  	nvif_device_dtor(&drm->device);
> -	nvif_client_dtor(&drm->master.base);
> +	nvif_client_dtor(&drm->_client);
>  	nvif_parent_dtor(&drm->parent);
>  
> +	mutex_destroy(&drm->client_mutex);
>  	kfree(drm);
>  }
>  
> @@ -733,14 +723,15 @@ nouveau_drm_device_new(const struct drm_driver *drm_driver, struct device *paren
>  	drm->nvkm = device;
>  
>  	nvif_parent_ctor(&nouveau_parent, &drm->parent);
> -	drm->master.base.object.parent = &drm->parent;
> +	mutex_init(&drm->client_mutex);
> +	drm->_client.object.parent = &drm->parent;
>  
>  	ret = nvif_driver_init(NULL, nouveau_config, nouveau_debug, "drm",
> -			       nouveau_name(parent), &drm->master.base);
> +			       nouveau_name(parent), &drm->_client);
>  	if (ret)
>  		goto done;
>  
> -	ret = nvif_device_ctor(&drm->master.base, "drmDevice", &drm->device);
> +	ret = nvif_device_ctor(&drm->_client, "drmDevice", &drm->device);
>  	if (ret) {
>  		NV_ERROR(drm, "Device allocation failed: %d\n", ret);
>  		goto done;
> @@ -966,7 +957,7 @@ nouveau_do_suspend(struct nouveau_drm *drm, bool runtime)
>  	}
>  
>  	NV_DEBUG(drm, "suspending object tree...\n");
> -	ret = nvif_client_suspend(&drm->master.base);
> +	ret = nvif_client_suspend(&drm->_client);
>  	if (ret)
>  		goto fail_client;
>  
> @@ -991,7 +982,7 @@ nouveau_do_resume(struct nouveau_drm *drm, bool runtime)
>  	int ret = 0;
>  
>  	NV_DEBUG(drm, "resuming object tree...\n");
> -	ret = nvif_client_resume(&drm->master.base);
> +	ret = nvif_client_resume(&drm->_client);
>  	if (ret) {
>  		NV_ERROR(drm, "Client resume failed with error: %d\n", ret);
>  		return ret;
> diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
> index 2535a50b99f3..630463668a76 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_drv.h
> +++ b/drivers/gpu/drm/nouveau/nouveau_drv.h
> @@ -203,10 +203,11 @@ u_memcpya(uint64_t user, unsigned int nmemb, unsigned int size)
>  struct nouveau_drm {
>  	struct nvkm_device *nvkm;
>  	struct nvif_parent parent;
> +	struct mutex client_mutex;
> +	struct nvif_client _client;
>  	struct nvif_device device;
>  	struct nvif_mmu mmu;
>  
> -	struct nouveau_cli master;
>  	struct nouveau_cli client;
>  	struct drm_device *dev;
>  
> diff --git a/drivers/gpu/drm/nouveau/nouveau_mem.c b/drivers/gpu/drm/nouveau/nouveau_mem.c
> index b112b62dca3c..fac92fdbf9cc 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_mem.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_mem.c
> @@ -80,9 +80,9 @@ nouveau_mem_fini(struct nouveau_mem *mem)
>  {
>  	nvif_vmm_put(&mem->drm->client.vmm.vmm, &mem->vma[1]);
>  	nvif_vmm_put(&mem->drm->client.vmm.vmm, &mem->vma[0]);
> -	mutex_lock(&mem->drm->master.lock);
> +	mutex_lock(&mem->drm->client_mutex);
>  	nvif_mem_dtor(&mem->mem);
> -	mutex_unlock(&mem->drm->master.lock);
> +	mutex_unlock(&mem->drm->client_mutex);
>  }
>  
>  int
> @@ -113,11 +113,11 @@ nouveau_mem_host(struct ttm_resource *reg, struct ttm_tt *tt)
>  	else
>  		args.dma = tt->dma_address;
>  
> -	mutex_lock(&drm->master.lock);
> +	mutex_lock(&drm->client_mutex);
>  	ret = nvif_mem_ctor_type(mmu, "ttmHostMem", mmu->mem, type, PAGE_SHIFT,
>  				 reg->size,
>  				 &args, sizeof(args), &mem->mem);
> -	mutex_unlock(&drm->master.lock);
> +	mutex_unlock(&drm->client_mutex);
>  	return ret;
>  }
>  
> @@ -130,7 +130,7 @@ nouveau_mem_vram(struct ttm_resource *reg, bool contig, u8 page)
>  	u64 size = ALIGN(reg->size, 1 << page);
>  	int ret;
>  
> -	mutex_lock(&drm->master.lock);
> +	mutex_lock(&drm->client_mutex);
>  	switch (mmu->mem) {
>  	case NVIF_CLASS_MEM_GF100:
>  		ret = nvif_mem_ctor_type(mmu, "ttmVram", mmu->mem,
> @@ -154,7 +154,7 @@ nouveau_mem_vram(struct ttm_resource *reg, bool contig, u8 page)
>  		WARN_ON(1);
>  		break;
>  	}
> -	mutex_unlock(&drm->master.lock);
> +	mutex_unlock(&drm->client_mutex);
>  
>  	reg->start = mem->mem.addr >> PAGE_SHIFT;
>  	return ret;
> -- 
> 2.45.1
>