From: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
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: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
Acked-by: Hiroshi DOYU <hiroshi.d...@nokia.com>
[o...@wizery.com: slightly edited the commit log]
Signed-off-by: Ohad Ben-Cohen <o...@wizery.com>
---
A fix by Laurent that was waiting until omap's iommu lands in drivers/.
Generally we're not extending omap-iovmm anymore, but this fixes a real
breakage for omap3isp users, so there's no point in delaying it until
the generic DMA API is ready and we've migrated.
Thanks Laurent!
drivers/iommu/omap-iovmm.c | 32 ++++++++++++++++++++++++--------
1 files changed, 24 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/omap-iovmm.c b/drivers/iommu/omap-iovmm.c
index 5e7f97d..d28a256 100644
--- a/drivers/iommu/omap-iovmm.c
+++ b/drivers/iommu/omap-iovmm.c
@@ -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;
@@ -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)
--
1.7.4.1
--
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