[kernel,07/15] powerpc/iommu: Cleanup iommu_table disposal

At the moment iommu_table could be disposed by either calling
iommu_table_free() directly or it_ops::free() which only implementation
for IODA2 calls iommu_table_free() anyway.

As we are going to have reference counting on tables, we need an unified
way of disposing tables.

This moves it_ops::free() call into iommu_free_table() and makes use
of the latter everywhere. The free() callback now handles only
platform-specific data.

This should cause no behavioral change.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/kernel/iommu.c               | 4 ++++
 arch/powerpc/platforms/powernv/pci-ioda.c | 6 ++----
 drivers/vfio/vfio_iommu_spapr_tce.c       | 2 +-
 3 files changed, 7 insertions(+), 5 deletions(-)

On Wed, Aug 03, 2016 at 06:40:48PM +1000, Alexey Kardashevskiy wrote:
> At the moment iommu_table could be disposed by either calling
> iommu_table_free() directly or it_ops::free() which only implementation
> for IODA2 calls iommu_table_free() anyway.
> 
> As we are going to have reference counting on tables, we need an unified
> way of disposing tables.
> 
> This moves it_ops::free() call into iommu_free_table() and makes use
> of the latter everywhere. The free() callback now handles only
> platform-specific data.
> 
> This should cause no behavioral change.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  arch/powerpc/kernel/iommu.c               | 4 ++++
>  arch/powerpc/platforms/powernv/pci-ioda.c | 6 ++----
>  drivers/vfio/vfio_iommu_spapr_tce.c       | 2 +-
>  3 files changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
> index a8e3490..13263b0 100644
> --- a/arch/powerpc/kernel/iommu.c
> +++ b/arch/powerpc/kernel/iommu.c
> @@ -718,6 +718,9 @@ void iommu_free_table(struct iommu_table *tbl, const char *node_name)
>  	if (!tbl)
>  		return;
>  
> +	if (tbl->it_ops->free)
> +		tbl->it_ops->free(tbl);
> +
>  	if (!tbl->it_map) {
>  		kfree(tbl);
>  		return;
> @@ -744,6 +747,7 @@ void iommu_free_table(struct iommu_table *tbl, const char *node_name)
>  	/* free table */
>  	kfree(tbl);
>  }
> +EXPORT_SYMBOL_GPL(iommu_free_table);
>  
>  /* Creates TCEs for a user provided buffer.  The user buffer must be
>   * contiguous real kernel storage (not vmalloc).  The address passed here
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index 59c7e7d..74ab8382 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -1394,7 +1394,6 @@ static void pnv_pci_ioda2_release_dma_pe(struct pci_dev *dev, struct pnv_ioda_pe
>  		iommu_group_put(pe->table_group.group);
>  		BUG_ON(pe->table_group.group);
>  	}
> -	pnv_pci_ioda2_table_free_pages(tbl);
>  	iommu_free_table(tbl, of_node_full_name(dev->dev.of_node));
>  }
>  
> @@ -1987,7 +1986,6 @@ static void pnv_ioda2_tce_free(struct iommu_table *tbl, long index,
>  static void pnv_ioda2_table_free(struct iommu_table *tbl)
>  {
>  	pnv_pci_ioda2_table_free_pages(tbl);
> -	iommu_free_table(tbl, "pnv");
>  }
>  
>  static struct iommu_table_ops pnv_ioda2_iommu_ops = {
> @@ -2313,7 +2311,7 @@ static long pnv_pci_ioda2_setup_default_config(struct pnv_ioda_pe *pe)
>  	if (rc) {
>  		pe_err(pe, "Failed to configure 32-bit TCE table, err %ld\n",
>  				rc);
> -		pnv_ioda2_table_free(tbl);
> +		iommu_free_table(tbl, "");
>  		return rc;
>  	}
>  
> @@ -2399,7 +2397,7 @@ static void pnv_ioda2_take_ownership(struct iommu_table_group *table_group)
>  
>  	pnv_pci_ioda2_set_bypass(pe, false);
>  	pnv_pci_ioda2_unset_window(&pe->table_group, 0);
> -	pnv_ioda2_table_free(tbl);
> +	iommu_free_table(tbl, "pnv");
>  }
>  
>  static void pnv_ioda2_release_ownership(struct iommu_table_group *table_group)
> diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
> index 40e71a0..79f26c7 100644
> --- a/drivers/vfio/vfio_iommu_spapr_tce.c
> +++ b/drivers/vfio/vfio_iommu_spapr_tce.c
> @@ -660,7 +660,7 @@ static void tce_iommu_free_table(struct iommu_table *tbl)
>  	unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT;
>  
>  	tce_iommu_userspace_view_free(tbl);
> -	tbl->it_ops->free(tbl);
> +	iommu_free_table(tbl, "");
>  	decrement_locked_vm(pages);
>  }
>