On 11/10/17 14:59, Arnd Bergmann wrote:
> There are two sets of iommu_ops in this driver, and only
> one of them contains a reference to the ipmmu_iotlb_sync
> function. This leads to a compiler warning when these
> operations are not in use:
>
> drivers/iommu/ipmmu-vmsa.c:622:13: error: 'ipmmu_iotlb_sync' defined but not
> used [-Werror=unused-function]
Oh bum, I forgot there was still quite so much #ifdef'd under CONFIG_ARM
in this driver :(
> We either want to use the function in both operations, or
> we should hide it. Without having additional information
> which approach is correct, I'm picking the second one here,
> which avoids the build error.
For correctness I think it needs to be the first one, otherwise
iommu_unmap() will wind up missing a sync on 32-bit ARM.
That said, I think the third option is now viable as well, namely to
shuffle some lines and get rid of the almost-duplicated ops entirely.
I'll have a quick go at that shortly.
Robin.
> Fixes: 32b124492bdf ("iommu/io-pgtable-arm: Convert to IOMMU API TLB sync")
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> drivers/iommu/ipmmu-vmsa.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
> index af8140054273..bdd0d0d20925 100644
> --- a/drivers/iommu/ipmmu-vmsa.c
> +++ b/drivers/iommu/ipmmu-vmsa.c
> @@ -619,14 +619,6 @@ static size_t ipmmu_unmap(struct iommu_domain
> *io_domain, unsigned long iova,
> return domain->iop->unmap(domain->iop, iova, size);
> }
>
> -static void ipmmu_iotlb_sync(struct iommu_domain *io_domain)
> -{
> - struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
> -
> - if (domain->mmu)
> - ipmmu_tlb_flush_all(domain);
> -}
> -
> static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
> dma_addr_t iova)
> {
> @@ -810,6 +802,14 @@ static void ipmmu_domain_free_dma(struct iommu_domain
> *io_domain)
> }
> }
>
> +static void ipmmu_iotlb_sync(struct iommu_domain *io_domain)
> +{
> + struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
> +
> + if (domain->mmu)
> + ipmmu_tlb_flush_all(domain);
> +}
> +
> static int ipmmu_add_device_dma(struct device *dev)
> {
> struct iommu_group *group;
>
