Commit 83f706ec authored by Matthew Auld's avatar Matthew Auld
Browse files

drm/gpusvm: export drm_gpusvm_pages API 



Export get/unmap/free pages API. We also need to tweak the SVM init to
allow skipping much of the unneeded parts.

Signed-off-by: default avatarMatthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: default avatarMatthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250828142430.615826-15-matthew.auld@intel.com
parent 6364afd5

drivers/gpu/drm/drm_gpusvm.c

+51 −15
Original line number Diff line number Diff line
@@ -373,6 +373,12 @@ static const struct mmu_interval_notifier_ops drm_gpusvm_notifier_ops = { 
 *

 * This function initializes the GPU SVM.

 *

 * Note: If only using the simple drm_gpusvm_pages API (get/unmap/free),

 * then only @gpusvm, @name, and @drm are expected. However, the same base

 * @gpusvm can also be used with both modes together in which case the full

 * setup is needed, where the core drm_gpusvm_pages API will simply never use

 * the other fields.

 *

 * Return: 0 on success, a negative error code on failure.

 */

int drm_gpusvm_init(struct drm_gpusvm *gpusvm,
@@ -383,8 +389,16 @@ int drm_gpusvm_init(struct drm_gpusvm *gpusvm, 
		    const struct drm_gpusvm_ops *ops,

		    const unsigned long *chunk_sizes, int num_chunks)

{

	if (mm) {

		if (!ops->invalidate || !num_chunks)

			return -EINVAL;

		mmgrab(mm);

	} else {

		/* No full SVM mode, only core drm_gpusvm_pages API. */

		if (ops || num_chunks || mm_range || notifier_size ||

		    device_private_page_owner)

			return -EINVAL;

	}



	gpusvm->name = name;

	gpusvm->drm = drm;
@@ -397,7 +411,6 @@ int drm_gpusvm_init(struct drm_gpusvm *gpusvm, 
	gpusvm->chunk_sizes = chunk_sizes;

	gpusvm->num_chunks = num_chunks;



	mmgrab(mm);

	gpusvm->root = RB_ROOT_CACHED;

	INIT_LIST_HEAD(&gpusvm->notifier_list);
@@ -489,6 +502,7 @@ void drm_gpusvm_fini(struct drm_gpusvm *gpusvm) 
			drm_gpusvm_range_remove(gpusvm, range);

	}



	if (gpusvm->mm)

		mmdrop(gpusvm->mm);

	WARN_ON(!RB_EMPTY_ROOT(&gpusvm->root.rb_root));

}
@@ -1044,6 +1058,27 @@ static void __drm_gpusvm_free_pages(struct drm_gpusvm *gpusvm, 
	}

}



/**

 * drm_gpusvm_free_pages() - Free dma-mapping associated with GPU SVM pages

 * struct

 * @gpusvm: Pointer to the GPU SVM structure

 * @svm_pages: Pointer to the GPU SVM pages structure

 * @npages: Number of mapped pages

 *

 * This function unmaps and frees the dma address array associated with a GPU

 * SVM pages struct.

 */

void drm_gpusvm_free_pages(struct drm_gpusvm *gpusvm,

			   struct drm_gpusvm_pages *svm_pages,

			   unsigned long npages)

{

	drm_gpusvm_notifier_lock(gpusvm);

	__drm_gpusvm_unmap_pages(gpusvm, svm_pages, npages);

	__drm_gpusvm_free_pages(gpusvm, svm_pages);

	drm_gpusvm_notifier_unlock(gpusvm);

}

EXPORT_SYMBOL_GPL(drm_gpusvm_free_pages);



/**

 * drm_gpusvm_range_remove() - Remove GPU SVM range

 * @gpusvm: Pointer to the GPU SVM structure
@@ -1220,12 +1255,11 @@ static bool drm_gpusvm_pages_valid_unlocked(struct drm_gpusvm *gpusvm, 
 *

 * Return: 0 on success, negative error code on failure.

 */

static int drm_gpusvm_get_pages(struct drm_gpusvm *gpusvm,

int drm_gpusvm_get_pages(struct drm_gpusvm *gpusvm,

			 struct drm_gpusvm_pages *svm_pages,

			 struct mm_struct *mm,

			 struct mmu_interval_notifier *notifier,

				unsigned long pages_start,

				unsigned long pages_end,

			 unsigned long pages_start, unsigned long pages_end,

			 const struct drm_gpusvm_ctx *ctx)

{

	struct hmm_range hmm_range = {
@@ -1415,6 +1449,7 @@ static int drm_gpusvm_get_pages(struct drm_gpusvm *gpusvm, 
		goto retry;

	return err;

}

EXPORT_SYMBOL_GPL(drm_gpusvm_get_pages);



/**

 * drm_gpusvm_range_get_pages() - Get pages for a GPU SVM range
@@ -1451,7 +1486,7 @@ EXPORT_SYMBOL_GPL(drm_gpusvm_range_get_pages); 
 * Must be called in the invalidate() callback of the corresponding notifier for

 * IOMMU security model.

 */

static void drm_gpusvm_unmap_pages(struct drm_gpusvm *gpusvm,

void drm_gpusvm_unmap_pages(struct drm_gpusvm *gpusvm,

			    struct drm_gpusvm_pages *svm_pages,

			    unsigned long npages,

			    const struct drm_gpusvm_ctx *ctx)
@@ -1466,6 +1501,7 @@ static void drm_gpusvm_unmap_pages(struct drm_gpusvm *gpusvm, 
	if (!ctx->in_notifier)

		drm_gpusvm_notifier_unlock(gpusvm);

}

EXPORT_SYMBOL_GPL(drm_gpusvm_unmap_pages);



/**

 * drm_gpusvm_range_unmap_pages() - Unmap pages associated with a GPU SVM range

include/drm/drm_gpusvm.h

+16 −0
Original line number Diff line number Diff line
@@ -307,6 +307,22 @@ drm_gpusvm_range_find(struct drm_gpusvm_notifier *notifier, unsigned long start, 
void drm_gpusvm_range_set_unmapped(struct drm_gpusvm_range *range,

				   const struct mmu_notifier_range *mmu_range);



int drm_gpusvm_get_pages(struct drm_gpusvm *gpusvm,

			 struct drm_gpusvm_pages *svm_pages,

			 struct mm_struct *mm,

			 struct mmu_interval_notifier *notifier,

			 unsigned long pages_start, unsigned long pages_end,

			 const struct drm_gpusvm_ctx *ctx);



void drm_gpusvm_unmap_pages(struct drm_gpusvm *gpusvm,

			    struct drm_gpusvm_pages *svm_pages,

			    unsigned long npages,

			    const struct drm_gpusvm_ctx *ctx);



void drm_gpusvm_free_pages(struct drm_gpusvm *gpusvm,

			   struct drm_gpusvm_pages *svm_pages,

			   unsigned long npages);



#ifdef CONFIG_LOCKDEP

/**

 * drm_gpusvm_driver_set_lock() - Set the lock protecting accesses to GPU SVM