[PATCH v3 0/2] omap: iovmm: Fix IOVMM check for fixed 'da'

[PATCH v3 0/2] omap: iovmm: Fix IOVMM check for fixed 'da'

[David Cohen]

Hi,

Previous patch 2/3 was dropped in this new version. Patch 1 was updated
according to a comment it got.

---
IOVMM driver checks input 'da == 0' when mapping address to determine whether
user wants fixed 'da' or not. At the same time, it doesn't disallow address
0x0 to be used, what creates an ambiguous situation. This patch set moves
fixed 'da' check to the input flags.

Br,

David Cohen
---

David Cohen (1):
  omap: iovmm: don't check 'da' to set IOVMF_DA_FIXED flag

Michael Jones (1):
  omap: iovmm: disallow mapping NULL address when IOVMF_DA_ANON is set

 arch/arm/plat-omap/include/plat/iovmm.h |    2 --
 arch/arm/plat-omap/iovmm.c              |   27 ++++++++++++---------------
 2 files changed, 12 insertions(+), 17 deletions(-)

-- 
1.7.4.1

[PATCH v3 1/2] omap: iovmm: disallow mapping NULL address when IOVMF_DA_ANON is set

[David Cohen]

From: Michael Jones <michael.jones@matrix-vision.de>

commit c7f4ab26e3bcdaeb3e19ec658e3ad9092f1a6ceb allowed mapping the NULL
address if da_start==0, which would then not get unmapped. Disallow
this again if IOVMF_DA_ANON is set. And spell variable 'alignment'
correctly.

Signed-off-by: Michael Jones <michael.jones@matrix-vision.de>
---
 arch/arm/plat-omap/iovmm.c |   13 +++++++------
 1 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/arch/arm/plat-omap/iovmm.c b/arch/arm/plat-omap/iovmm.c
index 6dc1296..ea7eab9 100644
--- a/arch/arm/plat-omap/iovmm.c
+++ b/arch/arm/plat-omap/iovmm.c
@@ -271,20 +271,21 @@ static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
 					   size_t bytes, u32 flags)
 {
 	struct iovm_struct *new, *tmp;
-	u32 start, prev_end, alignement;
+	u32 start, prev_end, alignment;
 
 	if (!obj || !bytes)
 		return ERR_PTR(-EINVAL);
 
 	start = da;
-	alignement = PAGE_SIZE;
+	alignment = PAGE_SIZE;
 
 	if (flags & IOVMF_DA_ANON) {
-		start = obj->da_start;
+		/* Don't map address 0 */
+		start = obj->da_start ? obj->da_start : alignment;
 
 		if (flags & IOVMF_LINEAR)
-			alignement = iopgsz_max(bytes);
-		start = roundup(start, alignement);
+			alignment = iopgsz_max(bytes);
+		start = roundup(start, alignment);
 	} else if (start < obj->da_start || start > obj->da_end ||
 					obj->da_end - start < bytes) {
 		return ERR_PTR(-EINVAL);
@@ -304,7 +305,7 @@ static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
 			goto found;
 
 		if (tmp->da_end >= start && flags & IOVMF_DA_ANON)
-			start = roundup(tmp->da_end + 1, alignement);
+			start = roundup(tmp->da_end + 1, alignment);
 
 		prev_end = tmp->da_end;
 	}
-- 
1.7.4.1

[PATCH v3 2/2] omap: iovmm: don't check 'da' to set IOVMF_DA_FIXED flag

[David Cohen]

Currently IOVMM driver sets IOVMF_DA_FIXED/IOVMF_DA_ANON flags according
to input 'da' address when mapping memory:
da == 0: IOVMF_DA_ANON
da != 0: IOVMF_DA_FIXED

It prevents IOMMU to map first page with fixed 'da'. To avoid such
issue, IOVMM will not automatically set IOVMF_DA_FIXED. It should now
come from the user throught 'flags' parameter when mapping memory.
As IOVMF_DA_ANON and IOVMF_DA_FIXED are mutually exclusive, IOVMF_DA_ANON
can be removed. The driver will now check internally if IOVMF_DA_FIXED
is set or not.

Signed-off-by: David Cohen <dacohen@gmail.com>
---
 arch/arm/plat-omap/include/plat/iovmm.h |    2 --
 arch/arm/plat-omap/iovmm.c              |   14 +++++---------
 2 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/arch/arm/plat-omap/include/plat/iovmm.h b/arch/arm/plat-omap/include/plat/iovmm.h
index bdc7ce5..32a2f6c 100644
--- a/arch/arm/plat-omap/include/plat/iovmm.h
+++ b/arch/arm/plat-omap/include/plat/iovmm.h
@@ -71,8 +71,6 @@ struct iovm_struct {
 #define IOVMF_LINEAR_MASK	(3 << (2 + IOVMF_SW_SHIFT))
 
 #define IOVMF_DA_FIXED		(1 << (4 + IOVMF_SW_SHIFT))
-#define IOVMF_DA_ANON		(2 << (4 + IOVMF_SW_SHIFT))
-#define IOVMF_DA_MASK		(3 << (4 + IOVMF_SW_SHIFT))
 
 
 extern struct iovm_struct *find_iovm_area(struct iommu *obj, u32 da);
diff --git a/arch/arm/plat-omap/iovmm.c b/arch/arm/plat-omap/iovmm.c
index ea7eab9..51ef43e 100644
--- a/arch/arm/plat-omap/iovmm.c
+++ b/arch/arm/plat-omap/iovmm.c
@@ -279,7 +279,7 @@ static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
 	start = da;
 	alignment = PAGE_SIZE;
 
-	if (flags & IOVMF_DA_ANON) {
+	if (~flags & IOVMF_DA_FIXED) {
 		/* Don't map address 0 */
 		start = obj->da_start ? obj->da_start : alignment;
 
@@ -304,7 +304,7 @@ static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
 		if (tmp->da_start > start && (tmp->da_start - start) >= bytes)
 			goto found;
 
-		if (tmp->da_end >= start && flags & IOVMF_DA_ANON)
+		if (tmp->da_end >= start && ~flags & IOVMF_DA_FIXED)
 			start = roundup(tmp->da_end + 1, alignment);
 
 		prev_end = tmp->da_end;
@@ -651,7 +651,6 @@ u32 iommu_vmap(struct iommu *obj, u32 da, const struct sg_table *sgt,
 	flags &= IOVMF_HW_MASK;
 	flags |= IOVMF_DISCONT;
 	flags |= IOVMF_MMIO;
-	flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 
 	da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
 	if (IS_ERR_VALUE(da))
@@ -691,7 +690,7 @@ EXPORT_SYMBOL_GPL(iommu_vunmap);
  * @flags:	iovma and page property
  *
  * Allocate @bytes linearly and creates 1-n-1 mapping and returns
- * @da again, which might be adjusted if 'IOVMF_DA_ANON' is set.
+ * @da again, which might be adjusted if 'IOVMF_DA_FIXED' is not set.
  */
 u32 iommu_vmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
 {
@@ -710,7 +709,6 @@ u32 iommu_vmalloc(struct iommu *obj, u32 da, size_t bytes, u32 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)) {
@@ -781,7 +779,7 @@ static u32 __iommu_kmap(struct iommu *obj, u32 da, u32 pa, void *va,
  * @flags:	iovma and page property
  *
  * Creates 1-1-1 mapping and returns @da again, which can be
- * adjusted if 'IOVMF_DA_ANON' is set.
+ * adjusted if 'IOVMF_DA_FIXED' is not set.
  */
 u32 iommu_kmap(struct iommu *obj, u32 da, u32 pa, size_t bytes,
 		 u32 flags)
@@ -800,7 +798,6 @@ u32 iommu_kmap(struct iommu *obj, u32 da, u32 pa, size_t bytes,
 	flags &= IOVMF_HW_MASK;
 	flags |= IOVMF_LINEAR;
 	flags |= IOVMF_MMIO;
-	flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 
 	da = __iommu_kmap(obj, da, pa, va, bytes, flags);
 	if (IS_ERR_VALUE(da))
@@ -839,7 +836,7 @@ EXPORT_SYMBOL_GPL(iommu_kunmap);
  * @flags:	iovma and page property
  *
  * Allocate @bytes linearly and creates 1-1-1 mapping and returns
- * @da again, which might be adjusted if 'IOVMF_DA_ANON' is set.
+ * @da again, which might be adjusted if 'IOVMF_DA_FIXED' is not set.
  */
 u32 iommu_kmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
 {
@@ -859,7 +856,6 @@ u32 iommu_kmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
 	flags &= IOVMF_HW_MASK;
 	flags |= IOVMF_LINEAR;
 	flags |= IOVMF_ALLOC;
-	flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 
 	da = __iommu_kmap(obj, da, pa, va, bytes, flags);
 	if (IS_ERR_VALUE(da))
-- 
1.7.4.1

Re: [PATCH v3 0/2] omap: iovmm: Fix IOVMM check for fixed 'da'

[Tony Lindgren]

* David Cohen <dacohen@gmail.com> [110309 01:16]:
> Hi,
> 
> Previous patch 2/3 was dropped in this new version. Patch 1 was updated
> according to a comment it got.
> 
> ---
> IOVMM driver checks input 'da == 0' when mapping address to determine whether
> user wants fixed 'da' or not. At the same time, it doesn't disallow address
> 0x0 to be used, what creates an ambiguous situation. This patch set moves
> fixed 'da' check to the input flags.

Applying these.

Tony