diff options
Diffstat (limited to 'drivers/gpu/drm/drm_prime.c')
| -rw-r--r-- | drivers/gpu/drm/drm_prime.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 1693aa7c14b5..4ed5ed1f078c 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -826,6 +826,37 @@ out: EXPORT_SYMBOL(drm_prime_pages_to_sg); /** + * drm_prime_get_contiguous_size - returns the contiguous size of the buffer + * @sgt: sg_table describing the buffer to check + * + * This helper calculates the contiguous size in the DMA address space + * of the the buffer described by the provided sg_table. + * + * This is useful for implementing + * &drm_gem_object_funcs.gem_prime_import_sg_table. + */ +unsigned long drm_prime_get_contiguous_size(struct sg_table *sgt) +{ + dma_addr_t expected = sg_dma_address(sgt->sgl); + struct scatterlist *sg; + unsigned long size = 0; + int i; + + for_each_sgtable_dma_sg(sgt, sg, i) { + unsigned int len = sg_dma_len(sg); + + if (!len) + break; + if (sg_dma_address(sg) != expected) + break; + expected += len; + size += len; + } + return size; +} +EXPORT_SYMBOL(drm_prime_get_contiguous_size); + +/** * drm_gem_prime_export - helper library implementation of the export callback * @obj: GEM object to export * @flags: flags like DRM_CLOEXEC and DRM_RDWR |