PCI: iproc: Allow multiple devices except on PAXC

Commit 943ebae781f5 ("PCI: iproc: Add PAXC interface support") only allowed
device 0, which is a regression on BCMA-based platforms.

All systems support only one device, a Root Port at 00:00.0, on the root
bus.  PAXC-based systems support only the Root Port (00:00.0) and a single
device (with multiple functions) below it, e.g., 01:00.0, 01:00.1, etc.
Non-PAXC systems support arbitrary devices below the Root Port.

[bhelgaas: changelog, fold in removal of MAX_NUM_PAXC_PF check]
Fixes: 943ebae781f5 ("PCI: iproc: Add PAXC interface support")
Reported-by: Rafal Milecki <zajec5@gmail.com>
Signed-off-by: Ray Jui <rjui@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c
index 5816bceddb650c24576464913f9b7044d38be585..a576aeeb22da6cec1a01784328e209a66e96e8df 100644 (file)
--- a/drivers/pci/host/pcie-iproc.c
+++ b/drivers/pci/host/pcie-iproc.c
@@ -64,7 +64,6 @@
 #define OARR_SIZE_CFG                BIT(OARR_SIZE_CFG_SHIFT)
 
 #define MAX_NUM_OB_WINDOWS           2
-#define MAX_NUM_PAXC_PF              4
 
 #define IPROC_PCIE_REG_INVALID 0xffff
 
@@ -170,20 +169,6 @@ static inline void iproc_pcie_ob_write(struct iproc_pcie *pcie,
        writel(val, pcie->base + offset + (window * 8));
 }
 
-static inline bool iproc_pcie_device_is_valid(struct iproc_pcie *pcie,
-                                             unsigned int slot,
-                                             unsigned int fn)
-{
-       if (slot > 0)
-               return false;
-
-       /* PAXC can only support limited number of functions */
-       if (pcie->type == IPROC_PCIE_PAXC && fn >= MAX_NUM_PAXC_PF)
-               return false;
-
-       return true;
-}
-
 /**
  * Note access to the configuration registers are protected at the higher layer
  * by 'pci_lock' in drivers/pci/access.c
@@ -199,11 +184,11 @@ static void __iomem *iproc_pcie_map_cfg_bus(struct pci_bus *bus,
        u32 val;
        u16 offset;
 
-       if (!iproc_pcie_device_is_valid(pcie, slot, fn))
-               return NULL;
-
        /* root complex access */
        if (busno == 0) {
+               if (slot > 0 || fn > 0)
+                       return NULL;
+
                iproc_pcie_write_reg(pcie, IPROC_PCIE_CFG_IND_ADDR,
                                     where & CFG_IND_ADDR_MASK);
                offset = iproc_pcie_reg_offset(pcie, IPROC_PCIE_CFG_IND_DATA);
@@ -213,6 +198,14 @@ static void __iomem *iproc_pcie_map_cfg_bus(struct pci_bus *bus,
                        return (pcie->base + offset);
        }
 
+       /*
+        * PAXC is connected to an internally emulated EP within the SoC.  It
+        * allows only one device.
+        */
+       if (pcie->type == IPROC_PCIE_PAXC)
+               if (slot > 0)
+                       return NULL;
+
        /* EP device access */
        val = (busno << CFG_ADDR_BUS_NUM_SHIFT) |
                (slot << CFG_ADDR_DEV_NUM_SHIFT) |