From 329d8d3b474923087f6988737ff12137b58e55cc Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Fri, 2 Sep 2011 13:32:30 -0400 Subject: [PATCH] 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: Laurent Pinchart Acked-by: Hiroshi DOYU [ohad@wizery.com: rebased, but tested only with aligned buffers] [ohad@wizery.com: slightly edited the commit log] Signed-off-by: Ohad Ben-Cohen Signed-off-by: Joerg Roedel --- drivers/iommu/omap-iovmm.c | 36 ++++++++++++++++++++++++++---------- 1 file changed, 26 insertions(+), 10 deletions(-) diff --git a/drivers/iommu/omap-iovmm.c b/drivers/iommu/omap-iovmm.c index 5e7f97dc76ef..39bdb92aa96f 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; @@ -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) -- 2.39.5