Re: [PATCH v4 18/22] drm/pagemap, drm/xe: Clean up the use of the device-private page owner

["Ghimiray, Himal Prasad" <himal.prasad.ghimiray@intel.com>]

On 11-12-2025 22:29, Thomas Hellström wrote:
> Use the dev_pagemap->owner field wherever possible, simplifying
> the code slightly.
> 
> v3: New patch

LGTM
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>

> 
> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> ---
>   drivers/gpu/drm/drm_pagemap.c | 32 +++++++++++---------------------
>   drivers/gpu/drm/xe/xe_svm.c   |  3 +--
>   include/drm/drm_pagemap.h     |  3 +--
>   3 files changed, 13 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
> index 5b4337011924..77f8ea5ed802 100644
> --- a/drivers/gpu/drm/drm_pagemap.c
> +++ b/drivers/gpu/drm/drm_pagemap.c
> @@ -65,7 +65,6 @@
>    * @refcount: Reference count for the zdd
>    * @devmem_allocation: device memory allocation
>    * @dpagemap: Refcounted pointer to the underlying struct drm_pagemap.
> - * @device_private_page_owner: Device private pages owner
>    *
>    * This structure serves as a generic wrapper installed in
>    * page->zone_device_data. It provides infrastructure for looking up a device
> @@ -78,13 +77,11 @@ struct drm_pagemap_zdd {
>   	struct kref refcount;
>   	struct drm_pagemap_devmem *devmem_allocation;
>   	struct drm_pagemap *dpagemap;
> -	void *device_private_page_owner;
>   };
>   
>   /**
>    * drm_pagemap_zdd_alloc() - Allocate a zdd structure.
>    * @dpagemap: Pointer to the underlying struct drm_pagemap.
> - * @device_private_page_owner: Device private pages owner
>    *
>    * This function allocates and initializes a new zdd structure. It sets up the
>    * reference count and initializes the destroy work.
> @@ -92,7 +89,7 @@ struct drm_pagemap_zdd {
>    * Return: Pointer to the allocated zdd on success, ERR_PTR() on failure.
>    */
>   static struct drm_pagemap_zdd *
> -drm_pagemap_zdd_alloc(struct drm_pagemap *dpagemap, void *device_private_page_owner)
> +drm_pagemap_zdd_alloc(struct drm_pagemap *dpagemap)
>   {
>   	struct drm_pagemap_zdd *zdd;
>   
> @@ -102,7 +99,6 @@ drm_pagemap_zdd_alloc(struct drm_pagemap *dpagemap, void *device_private_page_ow
>   
>   	kref_init(&zdd->refcount);
>   	zdd->devmem_allocation = NULL;
> -	zdd->device_private_page_owner = device_private_page_owner;
>   	zdd->dpagemap = drm_pagemap_get(dpagemap);
>   
>   	return zdd;
> @@ -307,7 +303,6 @@ npages_in_range(unsigned long start, unsigned long end)
>    * @end: End of the virtual address range to migrate.
>    * @timeslice_ms: The time requested for the migrated pagemap pages to
>    * be present in @mm before being allowed to be migrated back.
> - * @pgmap_owner: Not used currently, since only system memory is considered.
>    *
>    * This function migrates the specified virtual address range to device memory.
>    * It performs the necessary setup and invokes the driver-specific operations for
> @@ -325,14 +320,15 @@ npages_in_range(unsigned long start, unsigned long end)
>   int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
>   				  struct mm_struct *mm,
>   				  unsigned long start, unsigned long end,
> -				  unsigned long timeslice_ms,
> -				  void *pgmap_owner)
> +				  unsigned long timeslice_ms)
>   {
>   	const struct drm_pagemap_devmem_ops *ops = devmem_allocation->ops;
> +	struct drm_pagemap *dpagemap = devmem_allocation->dpagemap;
> +	struct dev_pagemap *pagemap = dpagemap->pagemap;
>   	struct migrate_vma migrate = {
>   		.start		= start,
>   		.end		= end,
> -		.pgmap_owner	= pgmap_owner,
> +		.pgmap_owner	= pagemap->owner,
>   		.flags		= MIGRATE_VMA_SELECT_SYSTEM,
>   	};
>   	unsigned long i, npages = npages_in_range(start, end);
> @@ -374,7 +370,7 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
>   	pagemap_addr = buf + (2 * sizeof(*migrate.src) * npages);
>   	pages = buf + (2 * sizeof(*migrate.src) + sizeof(*pagemap_addr)) * npages;
>   
> -	zdd = drm_pagemap_zdd_alloc(devmem_allocation->dpagemap, pgmap_owner);
> +	zdd = drm_pagemap_zdd_alloc(dpagemap);
>   	if (!zdd) {
>   		err = -ENOMEM;
>   		goto err_free;
> @@ -787,8 +783,7 @@ EXPORT_SYMBOL_GPL(drm_pagemap_evict_to_ram);
>   /**
>    * __drm_pagemap_migrate_to_ram() - Migrate GPU SVM range to RAM (internal)
>    * @vas: Pointer to the VM area structure
> - * @device_private_page_owner: Device private pages owner
> - * @page: Pointer to the page for fault handling (can be NULL)
> + * @page: Pointer to the page for fault handling.
>    * @fault_addr: Fault address
>    * @size: Size of migration
>    *
> @@ -799,14 +794,13 @@ EXPORT_SYMBOL_GPL(drm_pagemap_evict_to_ram);
>    * Return: 0 on success, negative error code on failure.
>    */
>   static int __drm_pagemap_migrate_to_ram(struct vm_area_struct *vas,
> -					void *device_private_page_owner,
>   					struct page *page,
>   					unsigned long fault_addr,
>   					unsigned long size)
>   {
>   	struct migrate_vma migrate = {
>   		.vma		= vas,
> -		.pgmap_owner	= device_private_page_owner,
> +		.pgmap_owner	= page_pgmap(page)->owner,
>   		.flags		= MIGRATE_VMA_SELECT_DEVICE_PRIVATE |
>   		MIGRATE_VMA_SELECT_DEVICE_COHERENT,
>   		.fault_page	= page,
> @@ -821,12 +815,9 @@ static int __drm_pagemap_migrate_to_ram(struct vm_area_struct *vas,
>   	void *buf;
>   	int i, err = 0;
>   
> -	if (page) {
> -		zdd = page->zone_device_data;
> -		if (time_before64(get_jiffies_64(),
> -				  zdd->devmem_allocation->timeslice_expiration))
> -			return 0;
> -	}
> +	zdd = page->zone_device_data;
> +	if (time_before64(get_jiffies_64(), zdd->devmem_allocation->timeslice_expiration))
> +		return 0;
>   
>   	start = ALIGN_DOWN(fault_addr, size);
>   	end = ALIGN(fault_addr + 1, size);
> @@ -940,7 +931,6 @@ static vm_fault_t drm_pagemap_migrate_to_ram(struct vm_fault *vmf)
>   	int err;
>   
>   	err = __drm_pagemap_migrate_to_ram(vmf->vma,
> -					   zdd->device_private_page_owner,
>   					   vmf->page, vmf->address,
>   					   zdd->devmem_allocation->size);
>   
> diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
> index 489b3e3e38dc..2fa73143fcd5 100644
> --- a/drivers/gpu/drm/xe/xe_svm.c
> +++ b/drivers/gpu/drm/xe/xe_svm.c
> @@ -1110,8 +1110,7 @@ static int xe_drm_pagemap_populate_mm(struct drm_pagemap *dpagemap,
>   		/* Ensure the device has a pm ref while there are device pages active. */
>   		xe_pm_runtime_get_noresume(xe);
>   		err = drm_pagemap_migrate_to_devmem(&bo->devmem_allocation, mm,
> -						    start, end, timeslice_ms,
> -						    xpagemap->pagemap.owner);
> +						    start, end, timeslice_ms);
>   		if (err)
>   			xe_svm_devmem_release(&bo->devmem_allocation);
>   		xe_bo_unlock(bo);
> diff --git a/include/drm/drm_pagemap.h b/include/drm/drm_pagemap.h
> index 78cc9011829f..f73afece42ba 100644
> --- a/include/drm/drm_pagemap.h
> +++ b/include/drm/drm_pagemap.h
> @@ -320,8 +320,7 @@ struct drm_pagemap_devmem {
>   int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
>   				  struct mm_struct *mm,
>   				  unsigned long start, unsigned long end,
> -				  unsigned long timeslice_ms,
> -				  void *pgmap_owner);
> +				  unsigned long timeslice_ms);
>   
>   int drm_pagemap_evict_to_ram(struct drm_pagemap_devmem *devmem_allocation);
>