OMAP: iovmm: add superpages support to fixed da address

This patch adds superpages support to fixed ad address
inside iommu_kmap function.

Signed-off-by: Fernando Guzman Lugo <x0095840@ti.com>
Acked-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>

diff --git a/arch/arm/plat-omap/iovmm.c b/arch/arm/plat-omap/iovmm.c
index 34f0012b56762d45050113c313c4a7cb6528fd45..93a34d92b3a2206517c65bbc86d2e0bf183c41b5 100644 (file)
--- a/arch/arm/plat-omap/iovmm.c
+++ b/arch/arm/plat-omap/iovmm.c
@@ -87,35 +87,43 @@ static size_t sgtable_len(const struct sg_table *sgt)
 }
 #define sgtable_ok(x)  (!!sgtable_len(x))
 
+static unsigned max_alignment(u32 addr)
+{
+       int i;
+       unsigned pagesize[] = { SZ_16M, SZ_1M, SZ_64K, SZ_4K, };
+       for (i = 0; i < ARRAY_SIZE(pagesize) && addr & (pagesize[i] - 1); i++)
+               ;
+       return (i < ARRAY_SIZE(pagesize)) ? pagesize[i] : 0;
+}
+
 /*
  * calculate the optimal number sg elements from total bytes based on
  * iommu superpages
  */
-static unsigned int sgtable_nents(size_t bytes)
+static unsigned sgtable_nents(size_t bytes, u32 da, u32 pa)
 {
-       int i;
-       unsigned int nr_entries;
-       const unsigned long pagesize[] = { SZ_16M, SZ_1M, SZ_64K, SZ_4K, };
+       unsigned nr_entries = 0, ent_sz;
 
        if (!IS_ALIGNED(bytes, PAGE_SIZE)) {
                pr_err("%s: wrong size %08x\n", __func__, bytes);
                return 0;
        }
 
-       nr_entries = 0;
-       for (i = 0; i < ARRAY_SIZE(pagesize); i++) {
-               if (bytes >= pagesize[i]) {
-                       nr_entries += (bytes / pagesize[i]);
-                       bytes %= pagesize[i];
-               }
+       while (bytes) {
+               ent_sz = max_alignment(da | pa);
+               ent_sz = min_t(unsigned, ent_sz, iopgsz_max(bytes));
+               nr_entries++;
+               da += ent_sz;
+               pa += ent_sz;
+               bytes -= ent_sz;
        }
-       BUG_ON(bytes);
 
        return nr_entries;
 }
 
 /* allocate and initialize sg_table header(a kind of 'superblock') */
-static struct sg_table *sgtable_alloc(const size_t bytes, u32 flags)
+static struct sg_table *sgtable_alloc(const size_t bytes, u32 flags,
+                                                       u32 da, u32 pa)
 {
        unsigned int nr_entries;
        int err;
@@ -127,9 +135,8 @@ static struct sg_table *sgtable_alloc(const size_t bytes, u32 flags)
        if (!IS_ALIGNED(bytes, PAGE_SIZE))
                return ERR_PTR(-EINVAL);
 
-       /* FIXME: IOVMF_DA_FIXED should support 'superpages' */
-       if ((flags & IOVMF_LINEAR) && (flags & IOVMF_DA_ANON)) {
-               nr_entries = sgtable_nents(bytes);
+       if (flags & IOVMF_LINEAR) {
+               nr_entries = sgtable_nents(bytes, da, pa);
                if (!nr_entries)
                        return ERR_PTR(-EINVAL);
        } else
@@ -409,7 +416,8 @@ static inline void sgtable_drain_vmalloc(struct sg_table *sgt)
        BUG_ON(!sgt);
 }
 
-static void sgtable_fill_kmalloc(struct sg_table *sgt, u32 pa, size_t len)
+static void sgtable_fill_kmalloc(struct sg_table *sgt, u32 pa, u32 da,
+                                                               size_t len)
 {
        unsigned int i;
        struct scatterlist *sg;
@@ -418,9 +426,10 @@ static void sgtable_fill_kmalloc(struct sg_table *sgt, u32 pa, size_t len)
        va = phys_to_virt(pa);
 
        for_each_sg(sgt->sgl, sg, sgt->nents, i) {
-               size_t bytes;
+               unsigned bytes;
 
-               bytes = iopgsz_max(len);
+               bytes = max_alignment(da | pa);
+               bytes = min_t(unsigned, bytes, iopgsz_max(len));
 
                BUG_ON(!iopgsz_ok(bytes));
 
@@ -429,6 +438,7 @@ static void sgtable_fill_kmalloc(struct sg_table *sgt, u32 pa, size_t len)
                 * 'pa' is cotinuous(linear).
                 */
                pa += bytes;
+               da += bytes;
                len -= bytes;
        }
        BUG_ON(len);
@@ -695,18 +705,18 @@ u32 iommu_vmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
        if (!va)
                return -ENOMEM;
 
-       sgt = sgtable_alloc(bytes, flags);
+       flags &= IOVMF_HW_MASK;
+       flags |= IOVMF_DISCONT;
+       flags |= IOVMF_ALLOC;
+       flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
+
+       sgt = sgtable_alloc(bytes, flags, da, 0);
        if (IS_ERR(sgt)) {
                da = PTR_ERR(sgt);
                goto err_sgt_alloc;
        }
        sgtable_fill_vmalloc(sgt, va);
 
-       flags &= IOVMF_HW_MASK;
-       flags |= IOVMF_DISCONT;
-       flags |= IOVMF_ALLOC;
-       flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
-
        da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
        if (IS_ERR_VALUE(da))
                goto err_iommu_vmap;
@@ -746,11 +756,11 @@ static u32 __iommu_kmap(struct iommu *obj, u32 da, u32 pa, void *va,
 {
        struct sg_table *sgt;
 
-       sgt = sgtable_alloc(bytes, flags);
+       sgt = sgtable_alloc(bytes, flags, da, pa);
        if (IS_ERR(sgt))
                return PTR_ERR(sgt);
 
-       sgtable_fill_kmalloc(sgt, pa, bytes);
+       sgtable_fill_kmalloc(sgt, pa, da, bytes);
 
        da = map_iommu_region(obj, da, sgt, va, bytes, flags);
        if (IS_ERR_VALUE(da)) {