[PATCH] drivers: iommu: constify iommu_gather_ops structures

[Bhumika Goyal <bhumirks@gmail.com>]

Check for iommu_gather_ops structures that are only stored in the tlb
field of an io_pgtable_cfg structure. The tlb field is of type
const struct iommu_gather_ops *, so iommu_gather_ops structures
having this property can be declared as const.
Done using Coccinelle:

@r1 disable optional_qualifier @
identifier i;
position p;
@@
static struct iommu_gather_ops i@p = {...};

@ok1@
identifier r1.i;
position p;
struct io_pgtable_cfg q;
@@
q.tlb=&i@p;

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
static
+const
struct iommu_gather_ops i={...};

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct iommu_gather_ops i;

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
---
 drivers/iommu/io-pgtable-arm-v7s.c | 2 +-
 drivers/iommu/ipmmu-vmsa.c         | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index f50e51c..1465bbc 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -741,7 +741,7 @@ static void dummy_tlb_sync(void *cookie)
 	WARN_ON(cookie != cfg_cookie);
 }
 
-static struct iommu_gather_ops dummy_tlb_ops = {
+static const struct iommu_gather_ops dummy_tlb_ops = {
 	.tlb_flush_all	= dummy_tlb_flush_all,
 	.tlb_add_flush	= dummy_tlb_add_flush,
 	.tlb_sync	= dummy_tlb_sync,
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index ace331d..b8bcf18 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -283,7 +283,7 @@ static void ipmmu_tlb_add_flush(unsigned long iova, size_t size,
 	/* The hardware doesn't support selective TLB flush. */
 }
 
-static struct iommu_gather_ops ipmmu_gather_ops = {
+static const struct iommu_gather_ops ipmmu_gather_ops = {
 	.tlb_flush_all = ipmmu_tlb_flush_all,
 	.tlb_add_flush = ipmmu_tlb_add_flush,
 	.tlb_sync = ipmmu_tlb_flush_all,
-- 
1.9.1