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From c43e4b52cbf2267047f67c9f65de18ee1ab8bfa2 Mon Sep 17 00:00:00 2001
From: Ray Jui <rjui@broadcom.com>
Date: Wed, 27 Jan 2016 16:52:24 -0600
Subject: [PATCH] PCI: iproc: Fix BCMA PCIe bus scanning regression
Commit 943ebae781f5 ("PCI: iproc: Add PAXC interface support") causes
regression on EP device detection on BCMA based platforms.
Fix the issue by allowing multiple devices to be configured on the same
bus, for all PAXB based child buses. In addition, add a check to prevent
non-zero function from being used on bus 0 (root bus).
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>
---
drivers/pci/host/pcie-iproc.c | 28 +++++++++++-----------------
1 file changed, 11 insertions(+), 17 deletions(-)
--- a/drivers/pci/host/pcie-iproc.c
+++ b/drivers/pci/host/pcie-iproc.c
@@ -170,20 +170,6 @@ static inline void iproc_pcie_ob_write(s
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 +185,11 @@ static void __iomem *iproc_pcie_map_cfg_
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 +199,14 @@ static void __iomem *iproc_pcie_map_cfg_
return (pcie->base + offset);
}
+ /*
+ * PAXC is connected to an internally emulated EP within the SoC. It
+ * allows only one device and supports a limited number of functions.
+ */
+ if (pcie->type == IPROC_PCIE_PAXC)
+ if (slot > 0 || fn >= MAX_NUM_PAXC_PF)
+ return NULL;
+
/* EP device access */
val = (busno << CFG_ADDR_BUS_NUM_SHIFT) |
(slot << CFG_ADDR_DEV_NUM_SHIFT) |
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