diff mbox series

[11/18] iommu/fsl_pamu: remove the snoop_id field

Message ID 20210316153825.135976-12-hch@lst.de (mailing list archive)
State Not Applicable
Delegated to: Netdev Maintainers
Headers show
Series [01/18] iommu: remove the unused domain_window_disable method | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Christoph Hellwig March 16, 2021, 3:38 p.m. UTC
The snoop_id is always set to ~(u32)0.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Li Yang <leoyang.li@nxp.com>
---
 drivers/iommu/fsl_pamu_domain.c | 5 ++---
 drivers/iommu/fsl_pamu_domain.h | 1 -
 2 files changed, 2 insertions(+), 4 deletions(-)

Comments

Will Deacon March 30, 2021, 12:58 p.m. UTC | #1
On Tue, Mar 16, 2021 at 04:38:17PM +0100, Christoph Hellwig wrote:
> The snoop_id is always set to ~(u32)0.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Acked-by: Li Yang <leoyang.li@nxp.com>
> ---
>  drivers/iommu/fsl_pamu_domain.c | 5 ++---
>  drivers/iommu/fsl_pamu_domain.h | 1 -
>  2 files changed, 2 insertions(+), 4 deletions(-)

pamu_config_ppaace() takes quite a few useless parameters at this stage,
but anyway:

Acked-by: Will Deacon <will@kernel.org>

Do you know if this driver is actually useful? Once the complexity has been
stripped back, the stubs and default values really stand out.

Will
Christoph Hellwig April 1, 2021, 9:36 a.m. UTC | #2
On Tue, Mar 30, 2021 at 01:58:17PM +0100, Will Deacon wrote:
> pamu_config_ppaace() takes quite a few useless parameters at this stage,
> but anyway:

I'll see it it makes sense to throw in another patch at the end to cut
it down a bit more.

> Acked-by: Will Deacon <will@kernel.org>
> 
> Do you know if this driver is actually useful? Once the complexity has been
> stripped back, the stubs and default values really stand out.

Yeah.  No idea what the usefulness of this driver is.  Bascially all it
seems to do is to setup a few registers to allow access to the whole
physical memory.  But maybe that is required on this hardware to allow
for any DMA access?
diff mbox series

Patch

diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
index 21c6d9e79eddf9..701fc3f187a100 100644
--- a/drivers/iommu/fsl_pamu_domain.c
+++ b/drivers/iommu/fsl_pamu_domain.c
@@ -97,12 +97,12 @@  static int pamu_set_liodn(struct fsl_dma_domain *dma_domain, struct device *dev,
 		goto out_unlock;
 	ret = pamu_config_ppaace(liodn, geom->aperture_start,
 				 geom->aperture_end - 1, omi_index, 0,
-				 dma_domain->snoop_id, dma_domain->stash_id, 0);
+				 ~(u32)0, dma_domain->stash_id, 0);
 	if (ret)
 		goto out_unlock;
 	ret = pamu_config_ppaace(liodn, geom->aperture_start,
 				 geom->aperture_end - 1, ~(u32)0,
-				 0, dma_domain->snoop_id, dma_domain->stash_id,
+				 0, ~(u32)0, dma_domain->stash_id,
 				 PAACE_AP_PERMS_QUERY | PAACE_AP_PERMS_UPDATE);
 out_unlock:
 	spin_unlock_irqrestore(&iommu_lock, flags);
@@ -210,7 +210,6 @@  static struct iommu_domain *fsl_pamu_domain_alloc(unsigned type)
 		return NULL;
 
 	dma_domain->stash_id = ~(u32)0;
-	dma_domain->snoop_id = ~(u32)0;
 	INIT_LIST_HEAD(&dma_domain->devices);
 	spin_lock_init(&dma_domain->domain_lock);
 
diff --git a/drivers/iommu/fsl_pamu_domain.h b/drivers/iommu/fsl_pamu_domain.h
index 5f4ed253f61b31..95ac1b3cab3b69 100644
--- a/drivers/iommu/fsl_pamu_domain.h
+++ b/drivers/iommu/fsl_pamu_domain.h
@@ -13,7 +13,6 @@  struct fsl_dma_domain {
 	/* list of devices associated with the domain */
 	struct list_head		devices;
 	u32				stash_id;
-	u32				snoop_id;
 	struct iommu_domain		iommu_domain;
 	spinlock_t			domain_lock;
 };