Re: [linux-next:master 11303/14422] include/linux/io-pgtable.h:172:44: warning: 'struct iommu_dirty_bitmap' declared inside parameter list will not be visible outside of this definition or declaration

[Joao Martins <joao.m.martins@oracle.com>]

On 23/10/2023 14:53, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   e8361b005d7c92997d12f2b85a9e4a525738bd9d
> commit: 14207f68dddf152fd0b2916451a1f4702de886e4 [11303/14422] iommu: Add iommu_domain ops for dirty tracking
> config: sparc64-randconfig-r002-20220915 (https://download.01.org/0day-ci/archive/20231023/202310232131.TOhkKzZa-lkp@intel.com/config)
> compiler: sparc64-linux-gcc (GCC) 13.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231023/202310232131.TOhkKzZa-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202310232131.TOhkKzZa-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>    In file included from drivers/iommu/io-pgtable.c:11:
>>> include/linux/io-pgtable.h:172:44: warning: 'struct iommu_dirty_bitmap' declared inside parameter list will not be visible outside of this definition or declaration
>      172 |                                     struct iommu_dirty_bitmap *dirty);
>          |                                            ^~~~~~~~~~~~~~~~~~
> 
> 
> vim +172 include/linux/io-pgtable.h

'Interesting' randconfig where we build sparc64 with ARM io-pgtable code (also
with IOMMU_API not set but with IOMMU_SUPPORT=y). I have fixed the warning as
below in the ifdef clause for !IOMMU_API following the rest of the style of the
header:

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 9379ceefa5da..291b663c6c05 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -802,6 +802,8 @@ struct iommu_fwspec {};
 struct iommu_device {};
 struct iommu_fault_param {};
 struct iommu_iotlb_gather {};
+struct iommu_dirty_bitmap {};
+struct iommu_dirty_ops {};

 static inline bool iommu_present(const struct bus_type *bus)
 {
@@ -1034,6 +1036,18 @@ static inline bool iommu_iotlb_gather_queued(struct
iommu_iotlb_gather *gather)
        return false;
 }

+static inline void iommu_dirty_bitmap_init(struct iommu_dirty_bitmap *dirty,
+                                          struct iova_bitmap *bitmap,
+                                          struct iommu_iotlb_gather *gather)
+{
+}
+
+static inline void iommu_dirty_bitmap_record(struct iommu_dirty_bitmap *dirty,
+                                            unsigned long iova,
+                                            unsigned long length)
+{
+}
+
 static inline void iommu_device_unregister(struct iommu_device *iommu)
 {
 }