OMAP: iommu: create new api to set valid da range

Some IOMMUs cannot use the whole 0x0 - 0xFFFFFFFF range.
With this new API the valid range can be set.

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

3 files changed, 37 insertions, 7 deletions

diff --git a/arch/arm/plat-omap/include/plat/iommu.h b/arch/arm/plat-omap/include/plat/iommu.h
index 33c7d41cb6a5..69230d685538 100644
--- a/arch/arm/plat-omap/include/plat/iommu.h
+++ b/arch/arm/plat-omap/include/plat/iommu.h
@@ -50,6 +50,8 @@ struct iommu {
         int (*isr)(struct iommu *obj);
 
         void *ctx; /* iommu context: registres saved area */
+        u32 da_start;
+        u32 da_end;
 };
 
 struct cr_regs {
@@ -103,6 +105,8 @@ struct iommu_platform_data {
         const char *name;
         const char *clk_name;
         const int nr_tlb_entries;
+        u32 da_start;
+        u32 da_end;
 };
 
 #if defined(CONFIG_ARCH_OMAP1)
@@ -152,6 +156,7 @@ extern void flush_iotlb_all(struct iommu *obj);
 extern int iopgtable_store_entry(struct iommu *obj, struct iotlb_entry *e);
 extern size_t iopgtable_clear_entry(struct iommu *obj, u32 iova);
 
+extern int iommu_set_da_range(struct iommu *obj, u32 start, u32 end);
 extern struct iommu *iommu_get(const char *name);
 extern void iommu_put(struct iommu *obj);
 
diff --git a/arch/arm/plat-omap/iommu.c b/arch/arm/plat-omap/iommu.c
index 6cd151b31bc5..b1107c08da56 100644
--- a/arch/arm/plat-omap/iommu.c
+++ b/arch/arm/plat-omap/iommu.c
@@ -830,6 +830,28 @@ static int device_match_by_alias(struct device *dev, void *data)
 }
 
 /**
+ * iommu_set_da_range - Set a valid device address range
+ * @obj:                target iommu
+ * @start               Start of valid range
+ * @end                 End of valid range
+ **/
+int iommu_set_da_range(struct iommu *obj, u32 start, u32 end)
+{
+
+        if (!obj)
+                return -EFAULT;
+
+        if (end < start || !PAGE_ALIGN(start | end))
+                return -EINVAL;
+
+        obj->da_start = start;
+        obj->da_end = end;
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(iommu_set_da_range);
+
+/**
  * iommu_get - Get iommu handler
  * @name:       target iommu name
  **/
@@ -922,6 +944,8 @@ static int __devinit omap_iommu_probe(struct platform_device *pdev)
         obj->name = pdata->name;
         obj->dev = &pdev->dev;
         obj->ctx = (void *)obj + sizeof(*obj);
+        obj->da_start = pdata->da_start;
+        obj->da_end = pdata->da_end;
 
         mutex_init(&obj->iommu_lock);
         mutex_init(&obj->mmap_lock);
diff --git a/arch/arm/plat-omap/iovmm.c b/arch/arm/plat-omap/iovmm.c
index fa6e64332a9e..6dc1296c8c77 100644
--- a/arch/arm/plat-omap/iovmm.c
+++ b/arch/arm/plat-omap/iovmm.c
@@ -280,13 +280,14 @@ static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
         alignement = PAGE_SIZE;
 
         if (flags & IOVMF_DA_ANON) {
-                /*
-                 * Reserve the first page for NULL
-                 */
-                start = PAGE_SIZE;
+                start = obj->da_start;
+
                 if (flags & IOVMF_LINEAR)
                         alignement = iopgsz_max(bytes);
                 start = roundup(start, alignement);
+        } else if (start < obj->da_start || start > obj->da_end ||
+                                        obj->da_end - start < bytes) {
+                return ERR_PTR(-EINVAL);
         }
 
         tmp = NULL;
@@ -299,16 +300,16 @@ static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
                 if (prev_end > start)
                         break;
 
-                if (start + bytes <= tmp->da_start)
+                if (tmp->da_start > start && (tmp->da_start - start) >= bytes)
                         goto found;
 
-                if (flags & IOVMF_DA_ANON)
+                if (tmp->da_end >= start && flags & IOVMF_DA_ANON)
                         start = roundup(tmp->da_end + 1, alignement);
 
                 prev_end = tmp->da_end;
         }
 
-        if ((start >= prev_end) && (ULONG_MAX - start + 1 >= bytes))
+        if ((start >= prev_end) && (obj->da_end - start >= bytes))
                 goto found;
 
         dev_dbg(obj->dev, "%s: no space to fit %08x(%x) flags: %08x\n",