Re: [PATCH 15/15] drm: Upcast struct drm_device.dev to struct pci_device; replace pdev

From: Sam Ravnborg <sam-uyr5N9Q2VtJg9hUCZPvPmw@public.gmane.org>
To: Thomas Zimmermann <tzimmermann-l3A5Bk7waGM@public.gmane.org>
Cc: airlied-cv59FeDIM0c@public.gmane.org,
	nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org,
	intel-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org,
	dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org,
	virtualization-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
	amd-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org,
	daniel-/w4YWyX8dFk@public.gmane.org,
	spice-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org,
	intel-gvt-dev-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org
Subject: Re: [PATCH 15/15] drm: Upcast struct drm_device.dev to struct pci_device; replace pdev
Date: Tue, 24 Nov 2020 22:46:38 +0100	[thread overview]
Message-ID: <20201124214638.GC93095@ravnborg.org> (raw)
In-Reply-To: <20201124113824.19994-16-tzimmermann-l3A5Bk7waGM@public.gmane.org>

Hi Thomas,

On Tue, Nov 24, 2020 at 12:38:24PM +0100, Thomas Zimmermann wrote:
> We have DRM drivers based on USB, SPI and platform devices. All of them
> are fine with storing their device reference in struct drm_device.dev.
> PCI devices should be no exception. Therefore struct drm_device.pdev is
> deprecated.
> 
> Instead upcast from struct drm_device.dev with to_pci_dev(). PCI-specific
> code can use dev_is_pci() to test for a PCI device. This patch changes
> the DRM core code and documentation accordingly. Struct drm_device.pdev
> is being moved to legacy status.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann-l3A5Bk7waGM@public.gmane.org>
> ---
>  drivers/gpu/drm/drm_agpsupport.c |  9 ++++++---
>  drivers/gpu/drm/drm_bufs.c       |  4 ++--
>  drivers/gpu/drm/drm_edid.c       |  7 ++++++-
>  drivers/gpu/drm/drm_irq.c        | 12 +++++++-----
>  drivers/gpu/drm/drm_pci.c        | 26 +++++++++++++++-----------
>  drivers/gpu/drm/drm_vm.c         |  2 +-
>  include/drm/drm_device.h         | 12 +++++++++---
>  7 files changed, 46 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_agpsupport.c b/drivers/gpu/drm/drm_agpsupport.c
> index 4c7ad46fdd21..a4040fe4f4ba 100644
> --- a/drivers/gpu/drm/drm_agpsupport.c
> +++ b/drivers/gpu/drm/drm_agpsupport.c
> @@ -103,11 +103,13 @@ int drm_agp_info_ioctl(struct drm_device *dev, void *data,
>   */
>  int drm_agp_acquire(struct drm_device *dev)
>  {
> +	struct pci_dev *pdev = to_pci_dev(dev->dev);
> +
>  	if (!dev->agp)
>  		return -ENODEV;
>  	if (dev->agp->acquired)
>  		return -EBUSY;
> -	dev->agp->bridge = agp_backend_acquire(dev->pdev);
> +	dev->agp->bridge = agp_backend_acquire(pdev);
>  	if (!dev->agp->bridge)
>  		return -ENODEV;
>  	dev->agp->acquired = 1;
> @@ -402,14 +404,15 @@ int drm_agp_free_ioctl(struct drm_device *dev, void *data,
>   */
>  struct drm_agp_head *drm_agp_init(struct drm_device *dev)
>  {
> +	struct pci_dev *pdev = to_pci_dev(dev->dev);
>  	struct drm_agp_head *head = NULL;
>  
>  	head = kzalloc(sizeof(*head), GFP_KERNEL);
>  	if (!head)
>  		return NULL;
> -	head->bridge = agp_find_bridge(dev->pdev);
> +	head->bridge = agp_find_bridge(pdev);
>  	if (!head->bridge) {
> -		head->bridge = agp_backend_acquire(dev->pdev);
> +		head->bridge = agp_backend_acquire(pdev);
>  		if (!head->bridge) {
>  			kfree(head);
>  			return NULL;
> diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
> index 7a01d0918861..1da8b360b60a 100644
> --- a/drivers/gpu/drm/drm_bufs.c
> +++ b/drivers/gpu/drm/drm_bufs.c
> @@ -325,7 +325,7 @@ static int drm_addmap_core(struct drm_device *dev, resource_size_t offset,
>  		 * As we're limiting the address to 2^32-1 (or less),
>  		 * casting it down to 32 bits is no problem, but we
>  		 * need to point to a 64bit variable first. */
> -		map->handle = dma_alloc_coherent(&dev->pdev->dev,
> +		map->handle = dma_alloc_coherent(dev->dev,
>  						 map->size,
>  						 &map->offset,
>  						 GFP_KERNEL);
> @@ -555,7 +555,7 @@ int drm_legacy_rmmap_locked(struct drm_device *dev, struct drm_local_map *map)
>  	case _DRM_SCATTER_GATHER:
>  		break;
>  	case _DRM_CONSISTENT:
> -		dma_free_coherent(&dev->pdev->dev,
> +		dma_free_coherent(dev->dev,
>  				  map->size,
>  				  map->handle,
>  				  map->offset);
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 74f5a3197214..555a04ce2179 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -32,6 +32,7 @@
>  #include <linux/i2c.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
> +#include <linux/pci.h>
>  #include <linux/slab.h>
>  #include <linux/vga_switcheroo.h>
>  
> @@ -2075,9 +2076,13 @@ EXPORT_SYMBOL(drm_get_edid);
>  struct edid *drm_get_edid_switcheroo(struct drm_connector *connector,
>  				     struct i2c_adapter *adapter)
>  {
> -	struct pci_dev *pdev = connector->dev->pdev;
> +	struct drm_device *dev = connector->dev;
> +	struct pci_dev *pdev = to_pci_dev(dev->dev);
>  	struct edid *edid;

Maybe add a comment that explain why this can trigger - so people are
helped it they are catched by this.
As it is now it is not even mentioned in the changelog.

> +	if (drm_WARN_ON_ONCE(dev, !dev_is_pci(dev->dev)))
> +		return NULL;
> +
>  	vga_switcheroo_lock_ddc(pdev);
>  	edid = drm_get_edid(connector, adapter);
>  	vga_switcheroo_unlock_ddc(pdev);
> diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
> index 09d6e9e2e075..22986a9a593b 100644
> --- a/drivers/gpu/drm/drm_irq.c
> +++ b/drivers/gpu/drm/drm_irq.c
> @@ -122,7 +122,7 @@ int drm_irq_install(struct drm_device *dev, int irq)
>  		dev->driver->irq_preinstall(dev);
>  
>  	/* PCI devices require shared interrupts. */
> -	if (dev->pdev)
> +	if (dev_is_pci(dev->dev))
>  		sh_flags = IRQF_SHARED;
>  
>  	ret = request_irq(irq, dev->driver->irq_handler,
> @@ -140,7 +140,7 @@ int drm_irq_install(struct drm_device *dev, int irq)
>  	if (ret < 0) {
>  		dev->irq_enabled = false;
>  		if (drm_core_check_feature(dev, DRIVER_LEGACY))
> -			vga_client_register(dev->pdev, NULL, NULL, NULL);
> +			vga_client_register(to_pci_dev(dev->dev), NULL, NULL, NULL);
>  		free_irq(irq, dev);
>  	} else {
>  		dev->irq = irq;
> @@ -203,7 +203,7 @@ int drm_irq_uninstall(struct drm_device *dev)
>  	DRM_DEBUG("irq=%d\n", dev->irq);
>  
>  	if (drm_core_check_feature(dev, DRIVER_LEGACY))
> -		vga_client_register(dev->pdev, NULL, NULL, NULL);
> +		vga_client_register(to_pci_dev(dev->dev), NULL, NULL, NULL);
>  
>  	if (dev->driver->irq_uninstall)
>  		dev->driver->irq_uninstall(dev);
> @@ -220,6 +220,7 @@ int drm_legacy_irq_control(struct drm_device *dev, void *data,
>  {
>  	struct drm_control *ctl = data;
>  	int ret = 0, irq;
> +	struct pci_dev *pdev;
>  
>  	/* if we haven't irq we fallback for compatibility reasons -
>  	 * this used to be a separate function in drm_dma.h
> @@ -230,12 +231,13 @@ int drm_legacy_irq_control(struct drm_device *dev, void *data,
>  	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
>  		return 0;
>  	/* UMS was only ever supported on pci devices. */
> -	if (WARN_ON(!dev->pdev))
> +	if (WARN_ON(!dev_is_pci(dev->dev)))
>  		return -EINVAL;
>  
>  	switch (ctl->func) {
>  	case DRM_INST_HANDLER:
> -		irq = dev->pdev->irq;
> +		pdev = to_pci_dev(dev->dev);
> +		irq = pdev->irq;
>  
>  		if (dev->if_version < DRM_IF_VERSION(1, 2) &&
>  		    ctl->irq != irq)
> diff --git a/drivers/gpu/drm/drm_pci.c b/drivers/gpu/drm/drm_pci.c
> index 6dba4b8ce4fe..c7868418e36d 100644
> --- a/drivers/gpu/drm/drm_pci.c
> +++ b/drivers/gpu/drm/drm_pci.c
> @@ -65,7 +65,7 @@ drm_dma_handle_t *drm_pci_alloc(struct drm_device * dev, size_t size, size_t ali
>  		return NULL;
>  
>  	dmah->size = size;
> -	dmah->vaddr = dma_alloc_coherent(&dev->pdev->dev, size,
> +	dmah->vaddr = dma_alloc_coherent(dev->dev, size,
>  					 &dmah->busaddr,
>  					 GFP_KERNEL);
>  
> @@ -88,7 +88,7 @@ EXPORT_SYMBOL(drm_pci_alloc);
>   */
>  void drm_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
>  {
> -	dma_free_coherent(&dev->pdev->dev, dmah->size, dmah->vaddr,
> +	dma_free_coherent(dev->dev, dmah->size, dmah->vaddr,
>  			  dmah->busaddr);
>  	kfree(dmah);
>  }
> @@ -107,16 +107,18 @@ static int drm_get_pci_domain(struct drm_device *dev)
>  		return 0;
>  #endif /* __alpha__ */
>  
> -	return pci_domain_nr(dev->pdev->bus);
> +	return pci_domain_nr(to_pci_dev(dev->dev)->bus);
>  }
>  
>  int drm_pci_set_busid(struct drm_device *dev, struct drm_master *master)
>  {
> +	struct pci_dev *pdev = to_pci_dev(dev->dev);
> +
>  	master->unique = kasprintf(GFP_KERNEL, "pci:%04x:%02x:%02x.%d",
>  					drm_get_pci_domain(dev),
> -					dev->pdev->bus->number,
> -					PCI_SLOT(dev->pdev->devfn),
> -					PCI_FUNC(dev->pdev->devfn));
> +					pdev->bus->number,
> +					PCI_SLOT(pdev->devfn),
> +					PCI_FUNC(pdev->devfn));
>  	if (!master->unique)
>  		return -ENOMEM;
>  
> @@ -126,12 +128,14 @@ int drm_pci_set_busid(struct drm_device *dev, struct drm_master *master)
>  
>  static int drm_pci_irq_by_busid(struct drm_device *dev, struct drm_irq_busid *p)
>  {
> +	struct pci_dev *pdev = to_pci_dev(dev->dev);
> +
>  	if ((p->busnum >> 8) != drm_get_pci_domain(dev) ||
> -	    (p->busnum & 0xff) != dev->pdev->bus->number ||
> -	    p->devnum != PCI_SLOT(dev->pdev->devfn) || p->funcnum != PCI_FUNC(dev->pdev->devfn))
> +	    (p->busnum & 0xff) != pdev->bus->number ||
> +	    p->devnum != PCI_SLOT(pdev->devfn) || p->funcnum != PCI_FUNC(pdev->devfn))
>  		return -EINVAL;
>  
> -	p->irq = dev->pdev->irq;
> +	p->irq = pdev->irq;
>  
>  	DRM_DEBUG("%d:%d:%d => IRQ %d\n", p->busnum, p->devnum, p->funcnum,
>  		  p->irq);
> @@ -159,7 +163,7 @@ int drm_legacy_irq_by_busid(struct drm_device *dev, void *data,
>  		return -EOPNOTSUPP;
>  
>  	/* UMS was only ever support on PCI devices. */
> -	if (WARN_ON(!dev->pdev))
> +	if (WARN_ON(!dev_is_pci(dev->dev)))
>  		return -EINVAL;
>  
>  	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
> @@ -183,7 +187,7 @@ void drm_pci_agp_destroy(struct drm_device *dev)
>  static void drm_pci_agp_init(struct drm_device *dev)
>  {
>  	if (drm_core_check_feature(dev, DRIVER_USE_AGP)) {
> -		if (pci_find_capability(dev->pdev, PCI_CAP_ID_AGP))
> +		if (pci_find_capability(to_pci_dev(dev->dev), PCI_CAP_ID_AGP))
>  			dev->agp = drm_agp_init(dev);
>  		if (dev->agp) {
>  			dev->agp->agp_mtrr = arch_phys_wc_add(
> diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
> index 6d5a03b32238..9b3b989d7cad 100644
> --- a/drivers/gpu/drm/drm_vm.c
> +++ b/drivers/gpu/drm/drm_vm.c
> @@ -278,7 +278,7 @@ static void drm_vm_shm_close(struct vm_area_struct *vma)
>  			case _DRM_SCATTER_GATHER:
>  				break;
>  			case _DRM_CONSISTENT:
> -				dma_free_coherent(&dev->pdev->dev,
> +				dma_free_coherent(dev->dev,
>  						  map->size,
>  						  map->handle,
>  						  map->offset);
> diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
> index 283a93ce4617..9d9db178119a 100644
> --- a/include/drm/drm_device.h
> +++ b/include/drm/drm_device.h
> @@ -290,9 +290,6 @@ struct drm_device {
>  	/** @agp: AGP data */
>  	struct drm_agp_head *agp;
>  
> -	/** @pdev: PCI device structure */
> -	struct pci_dev *pdev;
> -
>  #ifdef __alpha__
>  	/** @hose: PCI hose, only used on ALPHA platforms. */
>  	struct pci_controller *hose;
> @@ -336,6 +333,15 @@ struct drm_device {
>  	/* Everything below here is for legacy driver, never use! */
>  	/* private: */
>  #if IS_ENABLED(CONFIG_DRM_LEGACY)
> +	/**
> +	 * @pdev: PCI device structure
> +	 *
> +	 * This is deprecated. to get the PCI device, upcast from @dev
Capital T after '.'

> +	 * with to_pci_dev(). To test if the hardware is a PCI device,
> +	 * use dev_is_pci() with @dev.
> +	 */
> +	struct pci_dev *pdev;
> +
>  	/* Context handle management - linked list of context handles */
>  	struct list_head ctxlist;
>  
> -- 
> 2.29.2
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel