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pci: mvebu: no longer fake the slot location of downstream devices 

By default, the Marvell hardware, for each PCIe interface, exhibits
the following devices:

 * On slot 0, a "Marvell Memory controller", identical on all PCIe
   interfaces, and which isn't useful when the Marvell SoC is the PCIe
   root complex (i.e, the normal case when we run Linux on the Marvell
   SoC).

 * On slot 1, the real PCIe card connected into the PCIe slot of the
   board.

So, what the Marvell PCIe driver was doing in its PCI-to-PCI bridge
emulation is that when the Linux PCI core was trying to access the
device in slot 0, we were in fact forwarding the configuration
transaction to the device in slot 1. For all other slots, we were
telling the Linux PCI core that there was no device connected.

However, new versions of bootloaders from Marvell change the default
PCIe configuration, and make the real device appear in slot 0, and the
"Marvell Memory controller" in slot 1.

Therefore, this commit modifies the Marvell PCIe driver to adjust the
PCIe hardware configuration to make sure that this behavior (real
device in slot 0, "Marvell Memory controller" in slot 1) is the one
we'll see regardless of what the bootloader has done. It allows to
remove the little hack that was forwarding configuration transactions
on slot 0 to slot 1, which is nice.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
This commit is contained in:
Thomas Petazzoni 2013-05-23 16:32:51 +02:00 committed by Jason Cooper
parent 3d9939c92e
commit f4ac99011e
1 changed files with 15 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
drivers/pci/host/pci-mvebu.c
View File

@ -51,6 +51,7 @@
#define PCIE_CTRL_X1_MODE 0x0001
#define PCIE_STAT_OFF 0x1a04
#define PCIE_STAT_BUS 0xff00
#define PCIE_STAT_DEV 0x1f0000
#define PCIE_STAT_LINK_DOWN BIT(0)
#define PCIE_DEBUG_CTRL 0x1a60
#define PCIE_DEBUG_SOFT_RESET BIT(20)
@ -148,6 +149,16 @@ static void mvebu_pcie_set_local_bus_nr(struct mvebu_pcie_port *port, int nr)
writel(stat, port->base + PCIE_STAT_OFF);
}
static void mvebu_pcie_set_local_dev_nr(struct mvebu_pcie_port *port, int nr)
{
u32 stat;
stat = readl(port->base + PCIE_STAT_OFF);
stat &= ~PCIE_STAT_DEV;
stat |= nr << 16;
writel(stat, port->base + PCIE_STAT_OFF);
}
/*
* Setup PCIE BARs and Address Decode Wins:
* BAR[0,2] -> disabled, BAR[1] -> covers all DRAM banks
@ -572,8 +583,7 @@ static int mvebu_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
/* Access the real PCIe interface */
spin_lock_irqsave(&port->conf_lock, flags);
ret = mvebu_pcie_hw_wr_conf(port, bus,
PCI_DEVFN(1, PCI_FUNC(devfn)),
ret = mvebu_pcie_hw_wr_conf(port, bus, devfn,
where, size, val);
spin_unlock_irqrestore(&port->conf_lock, flags);
@ -606,8 +616,7 @@ static int mvebu_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
/* Access the real PCIe interface */
spin_lock_irqsave(&port->conf_lock, flags);
ret = mvebu_pcie_hw_rd_conf(port, bus,
PCI_DEVFN(1, PCI_FUNC(devfn)),
ret = mvebu_pcie_hw_rd_conf(port, bus, devfn,
where, size, val);
spin_unlock_irqrestore(&port->conf_lock, flags);
@ -817,6 +826,8 @@ static int __init mvebu_pcie_probe(struct platform_device *pdev)
continue;
}
mvebu_pcie_set_local_dev_nr(port, 1);
if (mvebu_pcie_link_up(port)) {
port->haslink = 1;
dev_info(&pdev->dev, "PCIe%d.%d: link up\n",