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>
763d2d8df1