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, 2 deletions

diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index 15fde52cb5cd..ac8686c853e6 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -106,8 +106,6 @@ struct pnv_phb {
 			 unsigned int hwirq, unsigned int virq,
 			 unsigned int is_64, struct msi_msg *msg);
 	void (*dma_dev_setup)(struct pnv_phb *phb, struct pci_dev *pdev);
-	int (*dma_set_mask)(struct pnv_phb *phb, struct pci_dev *pdev,
-			    u64 dma_mask);
 	u64 (*dma_get_required_mask)(struct pnv_phb *phb,
 				     struct pci_dev *pdev);
 	void (*fixup_phb)(struct pci_controller *hose);