powerpc/powernv: Move dma_set_mask() from pnv_phb to pci_controller_ops

Previously, dma_set_mask() on powernv was convoluted:
 0) Call dma_set_mask() (a/p/kernel/dma.c)
 1) In dma_set_mask(), ppc_md.dma_set_mask() exists, so call it.
 2) On powernv, that function pointer is pnv_dma_set_mask().
    In pnv_dma_set_mask(), the device is pci, so call pnv_pci_dma_set_mask().
 3) In pnv_pci_dma_set_mask(), call pnv_phb->set_dma_mask() if it exists.
 4) It only exists in the ioda case, where it points to
    pnv_pci_ioda_dma_set_mask(), which is the final function.

So the call chain is:
 dma_set_mask() ->
  pnv_dma_set_mask() ->
   pnv_pci_dma_set_mask() ->
    pnv_pci_ioda_dma_set_mask()

Both ppc_md and pnv_phb function pointers are used.

Rip out the ppc_md call, pnv_dma_set_mask() and pnv_pci_dma_set_mask().

Instead:
 0) Call dma_set_mask() (a/p/kernel/dma.c)
 1) In dma_set_mask(), the device is pci, and pci_controller_ops.dma_set_mask()
    exists, so call pci_controller_ops.dma_set_mask()
 2) In the ioda case, that points to pnv_pci_ioda_dma_set_mask().

The new call chain is
 dma_set_mask() ->
  pnv_pci_ioda_dma_set_mask()

Now only the pci_controller_ops function pointer is used.

The fallback paths for p5ioc2 are the same.

Previously, pnv_pci_dma_set_mask() would find no pnv_phb->set_dma_mask()
function, to it would call __set_dma_mask().

Now, dma_set_mask() finds no ppc_md call or pci_controller_ops call,
so it calls __set_dma_mask().

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 0 insertions, 10 deletions

diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index dfad2ba13bdf..8a557b5aabf7 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -689,16 +689,6 @@ void pnv_pci_dma_dev_setup(struct pci_dev *pdev)
 		phb->dma_dev_setup(phb, pdev);
 }
 
-int pnv_pci_dma_set_mask(struct pci_dev *pdev, u64 dma_mask)
-{
-	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
-	struct pnv_phb *phb = hose->private_data;
-
-	if (phb && phb->dma_set_mask)
-		return phb->dma_set_mask(phb, pdev, dma_mask);
-	return __dma_set_mask(&pdev->dev, dma_mask);
-}
-
 u64 pnv_pci_dma_get_required_mask(struct pci_dev *pdev)
 {
 	struct pci_controller *hose = pci_bus_to_host(pdev->bus);