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Commit 2b5f6980 authored by Tarun Karra's avatar Tarun Karra Committed by Matt Wagantall
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msm: kgsl: Allow SMMU mappings over 64K pages 



On previous targets there was a SMMU hardware bug that restricted us to
64K page mappings. This is fixed now on all targets supported on
current mainline. Allow SMMU mappings over 64K pages.

Change-Id: I9b3ac7c7ef88415ffe98199e3178ed9c7746ca40
Signed-off-by: default avatarTarun Karra <tkarra@codeaurora.org>
parent 17c13708

drivers/gpu/msm/kgsl_iommu.c

+2 −79
Original line number Diff line number Diff line
@@ -1107,70 +1107,6 @@ kgsl_iommu_unmap(struct kgsl_pagetable *pt, 
	return ret;

}



/*

 * _create_sg_no_large_pages - Create a sg list from a given sg list w/o

 * greater that 64K pages

 * @memdesc - The memory descriptor containing the sg

 * @nents - [output] the number of entries in the new scatterlist

 *

 * Returns the new sg list else error pointer on failure

 */

struct scatterlist *_create_sg_no_large_pages(struct kgsl_memdesc *memdesc,

					int *nents)

{

	struct page *page;

	struct scatterlist *s, *s_temp, *sg_temp;

	unsigned int sglen_alloc = 0, offset, i, len;

	uint64_t gpuaddr = memdesc->gpuaddr;



	for_each_sg(memdesc->sgt->sgl, s, memdesc->sgt->nents, i) {

		/*

		 * We need to unchunk any fully aligned 1M chunks

		 * to trick the iommu driver into not using 1M

		 * PTEs

		 */

		if (SZ_1M <= s->length

			&& IS_ALIGNED(gpuaddr, SZ_1M)

			&& IS_ALIGNED(sg_phys(s), SZ_1M))

			sglen_alloc += ALIGN(s->length, SZ_64K)/SZ_64K;

		else

			sglen_alloc++;

		gpuaddr += s->length;

	}

	/* No large pages were detected */

	if (sglen_alloc == memdesc->sgt->nents)

		return NULL;



	sg_temp = kgsl_malloc(sglen_alloc * sizeof(struct scatterlist));

	if (NULL == sg_temp)

		return ERR_PTR(-ENOMEM);



	sg_init_table(sg_temp, sglen_alloc);

	s_temp = sg_temp;



	gpuaddr = memdesc->gpuaddr;

	for_each_sg(memdesc->sgt->sgl, s, memdesc->sgt->nents, i) {

		page = sg_page(s);

		if (SZ_1M <= s->length

			&& IS_ALIGNED(gpuaddr, SZ_1M)

			&& IS_ALIGNED(sg_phys(s), SZ_1M)) {

			for (offset = 0; offset < s->length; s_temp++) {

				/* the last chunk might be smaller than 64K */

				len = min_t(unsigned int, SZ_64K,

					s->length - offset);

				sg_set_page(s_temp, page, len, offset);

				offset += len;

			}

		} else {

			sg_set_page(s_temp, page, s->length, 0);

			s_temp++;

		}

		gpuaddr += s->length;

	}

	*nents = sglen_alloc;

	return sg_temp;

}



/**

 * _iommu_add_guard_page - Add iommu guard page

 * @pt - Pointer to kgsl pagetable structure
@@ -1269,22 +1205,9 @@ kgsl_iommu_map(struct kgsl_pagetable *pt, 
			kgsl_active_count_put(device);

		}

		mutex_unlock(&device->mutex);

	} else {

		struct scatterlist *sg_temp = NULL;

		int sg_temp_nents;



		sg_temp = _create_sg_no_large_pages(memdesc, &sg_temp_nents);



		if (IS_ERR(sg_temp))

			return PTR_ERR(sg_temp);



	} else

		mapped = iommu_map_sg(iommu_pt->domain, addr,

				sg_temp ? sg_temp : memdesc->sgt->sgl,

				sg_temp ? sg_temp_nents : memdesc->sgt->nents,

				flags);



		kgsl_free(sg_temp);

	}

				memdesc->sgt->sgl, memdesc->sgt->nents, flags);



	if (mapped != size) {

		KGSL_CORE_ERR("iommu_map_sg(%p, %016llX, %lld, %x) err: %zd\n",