To be able to keep track of drm_pagemap usage, add a refcounted backpointer to struct drm_pagemap_zdd. This will keep the drm_pagemap reference count from dropping to zero as long as there are drm_pagemap pages present in a CPU address space.
Signed-off-by: Thomas Hellström <[email protected]> Reviewed-by: Matthew Brost <[email protected]> --- drivers/gpu/drm/drm_pagemap.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c index 4b8692f0b2a2..173b3ecb07d5 100644 --- a/drivers/gpu/drm/drm_pagemap.c +++ b/drivers/gpu/drm/drm_pagemap.c @@ -62,6 +62,7 @@ * * @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 @@ -74,11 +75,13 @@ 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 @@ -87,7 +90,7 @@ 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(void *device_private_page_owner) +drm_pagemap_zdd_alloc(struct drm_pagemap *dpagemap, void *device_private_page_owner) { struct drm_pagemap_zdd *zdd; @@ -98,6 +101,7 @@ drm_pagemap_zdd_alloc(void *device_private_page_owner) 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; } @@ -127,6 +131,7 @@ static void drm_pagemap_zdd_destroy(struct kref *ref) struct drm_pagemap_zdd *zdd = container_of(ref, struct drm_pagemap_zdd, refcount); struct drm_pagemap_devmem *devmem = zdd->devmem_allocation; + struct drm_pagemap *dpagemap = zdd->dpagemap; if (devmem) { complete_all(&devmem->detached); @@ -134,6 +139,7 @@ static void drm_pagemap_zdd_destroy(struct kref *ref) devmem->ops->devmem_release(devmem); } kfree(zdd); + drm_pagemap_put(dpagemap); } /** @@ -366,7 +372,7 @@ 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(pgmap_owner); + zdd = drm_pagemap_zdd_alloc(devmem_allocation->dpagemap, pgmap_owner); if (!zdd) { err = -ENOMEM; goto err_free; -- 2.51.1
