[PATCH u-boot-marvell 4/5] pci: pci_mvebu: refactor validation of addresses for config access

[Marek Behún]

Refactor validation of bdf parameter in mvebu_pcie_read/write_config
functions.

We can simplify the code by putting the validation into separate
function.

Also there are always only two devices visible on local bus:
* on slot configured by function mvebu_pcie_set_local_dev_nr()
  (by default this register is set to 0) there is a
  "Marvell Memory controller", which isn't useful in root complex
  mode,
* on all other slots the real PCIe card connected to the PCIe slot.

We can simplify the code even more by simply allowing access only to
the real PCIe card.

Signed-off-by: Marek Behún <marek.behun at nic.cz>
Cc: Stefan Roese <sr at denx.de>
Cc: Phil Sutter <phil at nwl.cc>
Cc: Mario Six <mario.six at gdsys.cc>
Cc: Baruch Siach <baruch at tkos.co.il>
---
 drivers/pci/pci_mvebu.c | 59 ++++++++++++++++++++++-------------------
 1 file changed, 31 insertions(+), 28 deletions(-)

diff --git a/drivers/pci/pci_mvebu.c b/drivers/pci/pci_mvebu.c
index 4ad73512a6..2d923b7d8d 100644
--- a/drivers/pci/pci_mvebu.c
+++ b/drivers/pci/pci_mvebu.c
@@ -78,7 +78,8 @@ struct mvebu_pcie {
 	u32 lane;
 	int devfn;
 	u32 lane_mask;
-	pci_dev_t dev;
+	int first_busno;
+	int local_dev;
 	char name[16];
 	unsigned int mem_target;
 	unsigned int mem_attr;
@@ -143,27 +144,36 @@ static inline struct mvebu_pcie *hose_to_pcie(struct pci_controller *hose)
 	return container_of(hose, struct mvebu_pcie, hose);
 }
 
+static int mvebu_pcie_valid_addr(struct mvebu_pcie *pcie, pci_dev_t bdf)
+{
+	/*
+	 * There are two devices visible on local bus:
+	 *   * on slot configured by function mvebu_pcie_set_local_dev_nr()
+	 *     (by default this register is set to 0) there is a
+	 *     "Marvell Memory controller", which isn't useful in root complex
+	 *     mode,
+	 *   * on all other slots the real PCIe card connected to the PCIe slot.
+	 *
+	 * We therefore allow access only to the real PCIe card.
+	 */
+	if (PCI_BUS(bdf) == pcie->first_busno &&
+	    PCI_DEV(bdf) != !pcie->local_dev)
+		return 0;
+
+	return 1;
+}
+
 static int mvebu_pcie_read_config(const struct udevice *bus, pci_dev_t bdf,
 				  uint offset, ulong *valuep,
 				  enum pci_size_t size)
 {
 	struct mvebu_pcie *pcie = dev_get_plat(bus);
-	int local_bus = PCI_BUS(pcie->dev);
-	int local_dev = PCI_DEV(pcie->dev);
 	u32 data;
 
-	debug("PCIE CFG read:  loc_bus=%d loc_dev=%d (b,d,f)=(%2d,%2d,%2d) ",
-	      local_bus, local_dev, PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
+	debug("PCIE CFG read: (b,d,f)=(%2d,%2d,%2d) ",
+	      PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
 
-	/* Don't access the local host controller via this API */
-	if (PCI_BUS(bdf) == local_bus && PCI_DEV(bdf) == local_dev) {
-		debug("- skipping host controller\n");
-		*valuep = pci_get_ff(size);
-		return 0;
-	}
-
-	/* If local dev is 0, the first other dev can only be 1 */
-	if (PCI_BUS(bdf) == local_bus && local_dev == 0 && PCI_DEV(bdf) != 1) {
+	if (!mvebu_pcie_valid_addr(pcie, bdf)) {
 		debug("- out of range\n");
 		*valuep = pci_get_ff(size);
 		return 0;
@@ -185,22 +195,13 @@ static int mvebu_pcie_write_config(struct udevice *bus, pci_dev_t bdf,
 				   enum pci_size_t size)
 {
 	struct mvebu_pcie *pcie = dev_get_plat(bus);
-	int local_bus = PCI_BUS(pcie->dev);
-	int local_dev = PCI_DEV(pcie->dev);
 	u32 data;
 
-	debug("PCIE CFG write: loc_bus=%d loc_dev=%d (b,d,f)=(%2d,%2d,%2d) ",
-	      local_bus, local_dev, PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
+	debug("PCIE CFG write: (b,d,f)=(%2d,%2d,%2d) ",
+	      PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
 	debug("(addr,size,val)=(0x%04x, %d, 0x%08lx)\n", offset, size, value);
 
-	/* Don't access the local host controller via this API */
-	if (PCI_BUS(bdf) == local_bus && PCI_DEV(bdf) == local_dev) {
-		debug("- skipping host controller\n");
-		return 0;
-	}
-
-	/* If local dev is 0, the first other dev can only be 1 */
-	if (PCI_BUS(bdf) == local_bus && local_dev == 0 && PCI_DEV(bdf) != 1) {
+	if (!mvebu_pcie_valid_addr(pcie, bdf)) {
 		debug("- out of range\n");
 		return 0;
 	}
@@ -286,9 +287,11 @@ static int mvebu_pcie_probe(struct udevice *dev)
 	      readl(pcie->base), mvebu_pcie_get_local_bus_nr(pcie),
 	      mvebu_pcie_get_local_dev_nr(pcie));
 
+	pcie->first_busno = bus;
+	pcie->local_dev = 0;
+
 	mvebu_pcie_set_local_bus_nr(pcie, bus);
-	mvebu_pcie_set_local_dev_nr(pcie, 0);
-	pcie->dev = PCI_BDF(bus, 0, 0);
+	mvebu_pcie_set_local_dev_nr(pcie, pcie->local_dev);
 
 	pcie->mem.start = (u32)mvebu_pcie_membase;
 	pcie->mem.end = pcie->mem.start + PCIE_MEM_SIZE - 1;
-- 
2.26.2