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>

arch/powerpc/platforms/powernv/pci-ioda.c

@@ -1601,9 +1601,10 @@ static void pnv_pci_ioda_dma_dev_setup(struct pnv_phb *phb, struct pci_dev *pdev
 	set_iommu_table_base_and_group(&pdev->dev, pe->tce32_table);
 }
 
-static int pnv_pci_ioda_dma_set_mask(struct pnv_phb *phb,
-				     struct pci_dev *pdev, u64 dma_mask)
+static int pnv_pci_ioda_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;
 	struct pci_dn *pdn = pci_get_pdn(pdev);
 	struct pnv_ioda_pe *pe;
 	uint64_t top;
@@ -2657,6 +2658,7 @@ static const struct pci_controller_ops pnv_pci_ioda_controller_ops = {
        .enable_device_hook = pnv_pci_enable_device_hook,
        .window_alignment = pnv_pci_window_alignment,
        .reset_secondary_bus = pnv_pci_reset_secondary_bus,
+       .dma_set_mask = pnv_pci_ioda_dma_set_mask,
 };
 
 static void __init pnv_pci_init_ioda_phb(struct device_node *np,
@@ -2802,7 +2804,6 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
 
 	/* Setup TCEs */
 	phb->dma_dev_setup = pnv_pci_ioda_dma_dev_setup;
-	phb->dma_set_mask = pnv_pci_ioda_dma_set_mask;
 	phb->dma_get_required_mask = pnv_pci_ioda_dma_get_required_mask;
 
 	/* Setup shutdown function for kexec */

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);

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);

arch/powerpc/platforms/powernv/powernv.h

@@ -12,17 +12,11 @@ struct pci_dev;
 #ifdef CONFIG_PCI
 extern void pnv_pci_init(void);
 extern void pnv_pci_shutdown(void);
-extern int pnv_pci_dma_set_mask(struct pci_dev *pdev, u64 dma_mask);
 extern u64 pnv_pci_dma_get_required_mask(struct pci_dev *pdev);
 #else
 static inline void pnv_pci_init(void) { }
 static inline void pnv_pci_shutdown(void) { }
 
-static inline int pnv_pci_dma_set_mask(struct pci_dev *pdev, u64 dma_mask)
-{
-	return -ENODEV;
-}
-
 static inline u64 pnv_pci_dma_get_required_mask(struct pci_dev *pdev)
 {
 	return 0;

arch/powerpc/platforms/powernv/setup.c

@@ -165,13 +165,6 @@ static void pnv_progress(char *s, unsigned short hex)
 {
 }
 
-static int pnv_dma_set_mask(struct device *dev, u64 dma_mask)
-{
-	if (dev_is_pci(dev))
-		return pnv_pci_dma_set_mask(to_pci_dev(dev), dma_mask);
-	return __dma_set_mask(dev, dma_mask);
-}
-
 static u64 pnv_dma_get_required_mask(struct device *dev)
 {
 	if (dev_is_pci(dev))
@@ -321,7 +314,6 @@ define_machine(powernv) {
 	.machine_shutdown	= pnv_shutdown,
 	.power_save             = power7_idle,
 	.calibrate_decr		= generic_calibrate_decr,
-	.dma_set_mask		= pnv_dma_set_mask,
 	.dma_get_required_mask	= pnv_dma_get_required_mask,
 #ifdef CONFIG_KEXEC
 	.kexec_cpu_down		= pnv_kexec_cpu_down,