Commit 329d8d3b authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Joerg Roedel
Browse files

iommu/omap-iovmm: support non page-aligned buffers in iommu_vmap 



omap_iovmm requires page-aligned buffers, and that sometimes causes
omap3isp failures (i.e. whenever the buffer passed from userspace is not
page-aligned).

Remove this limitation by rounding the address of the first page entry
down, and adding the offset back to the device address.

Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: default avatarHiroshi DOYU <Hiroshi.DOYU@nokia.com>
[ohad@wizery.com: rebased, but tested only with aligned buffers]
[ohad@wizery.com: slightly edited the commit log]
Signed-off-by: default avatarOhad Ben-Cohen <ohad@wizery.com>
Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent 024ae884

drivers/iommu/omap-iovmm.c

+26 −10
Original line number Diff line number Diff line
@@ -27,6 +27,15 @@ 


static struct kmem_cache *iovm_area_cachep;



/* return the offset of the first scatterlist entry in a sg table */

static unsigned int sgtable_offset(const struct sg_table *sgt)

{

	if (!sgt || !sgt->nents)

		return 0;



	return sgt->sgl->offset;

}



/* return total bytes of sg buffers */

static size_t sgtable_len(const struct sg_table *sgt)

{
@@ -39,11 +48,17 @@ static size_t sgtable_len(const struct sg_table *sgt) 
	for_each_sg(sgt->sgl, sg, sgt->nents, i) {

		size_t bytes;



		bytes = sg->length;

		bytes = sg->length + sg->offset;



		if (!iopgsz_ok(bytes)) {

			pr_err("%s: sg[%d] not iommu pagesize(%x)\n",

			       __func__, i, bytes);

			pr_err("%s: sg[%d] not iommu pagesize(%u %u)\n",

			       __func__, i, bytes, sg->offset);

			return 0;

		}



		if (i && sg->offset) {

			pr_err("%s: sg[%d] offset not allowed in internal "

					"entries\n", __func__, i);

			return 0;

		}
@@ -164,8 +179,8 @@ static void *vmap_sg(const struct sg_table *sgt) 
		u32 pa;

		int err;



		pa = sg_phys(sg);

		bytes = sg->length;

		pa = sg_phys(sg) - sg->offset;

		bytes = sg->length + sg->offset;



		BUG_ON(bytes != PAGE_SIZE);
@@ -405,8 +420,8 @@ static int map_iovm_area(struct iommu_domain *domain, struct iovm_struct *new, 
		u32 pa;

		size_t bytes;



		pa = sg_phys(sg);

		bytes = sg->length;

		pa = sg_phys(sg) - sg->offset;

		bytes = sg->length + sg->offset;



		flags &= ~IOVMF_PGSZ_MASK;
@@ -432,7 +447,7 @@ err_out: 
	for_each_sg(sgt->sgl, sg, i, j) {

		size_t bytes;



		bytes = sg->length;

		bytes = sg->length + sg->offset;

		order = get_order(bytes);



		/* ignore failures.. we're already handling one */
@@ -461,7 +476,7 @@ static void unmap_iovm_area(struct iommu_domain *domain, struct omap_iommu *obj, 
		size_t bytes;

		int order;



		bytes = sg->length;

		bytes = sg->length + sg->offset;

		order = get_order(bytes);



		err = iommu_unmap(domain, start, order);
@@ -600,7 +615,7 @@ u32 omap_iommu_vmap(struct iommu_domain *domain, struct omap_iommu *obj, u32 da, 
	if (IS_ERR_VALUE(da))

		vunmap_sg(va);



	return da;

	return da + sgtable_offset(sgt);

}

EXPORT_SYMBOL_GPL(omap_iommu_vmap);
@@ -620,6 +635,7 @@ omap_iommu_vunmap(struct iommu_domain *domain, struct omap_iommu *obj, u32 da) 
	 * 'sgt' is allocated before 'omap_iommu_vmalloc()' is called.

	 * Just returns 'sgt' to the caller to free

	 */

	da &= PAGE_MASK;

	sgt = unmap_vm_area(domain, obj, da, vunmap_sg,

					IOVMF_DISCONT | IOVMF_MMIO);

	if (!sgt)

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