[PATCH 3/3] [RFC] pci: tegra: use new pci_register_host interface

Arnd Bergmann
2016-04-29T23:02:25Z

Tegra is one of the remaining platforms that still use the
traditional pci_common_init_dev() interface for probing PCI
host bridges.

This demonstrates how to convert it to the pci_register_host
interface I just added in a previous patch. This leads to
a more linear probe sequence that can handle errors better
because we avoid callbacks into the driver, and it makes
the driver architecture independent.

As a side note, I should mention that I noticed this driver
does not register any IORESOURCE_IO resource with the bus,
but instead registers the I/O port window as a memory
resource, which is surely a bug.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/pci/host/pci-tegra.c | 67 ++++++++++++++++++++++++--------------------
1 file changed, 36 insertions(+), 31 deletions(-)

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index c388468c202a..ece4f5d0180b 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -265,6 +265,7 @@ static inline struct tegra_msi *to_tegra_msi(struct msi_controller *chip)
}

struct tegra_pcie {
+ struct pci_host_bridge bridge;
struct device *dev;

void __iomem *pads;
@@ -615,14 +616,10 @@ static void tegra_pcie_relax_enable(struct pci_dev *dev)
}
DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, tegra_pcie_relax_enable);

-static int tegra_pcie_setup(int nr, struct pci_sys_data *sys)
+static int tegra_pcie_request_resources(struct tegra_pcie *pcie)
{
- struct tegra_pcie *pcie = sys_to_pcie(sys);
int err;

- sys->mem_offset = pcie->offset.mem;
- sys->io_offset = pcie->offset.io;
-
err = devm_request_resource(pcie->dev, &pcie->all, &pcie->io);
if (err < 0)
return err;
@@ -639,15 +636,15 @@ static int tegra_pcie_setup(int nr, struct pci_sys_data *sys)
if (err)
return err;

- pci_add_resource_offset(&sys->resources, &pcie->pio, sys->io_offset);
- pci_add_resource_offset(&sys->resources, &pcie->mem, sys->mem_offset);
- pci_add_resource_offset(&sys->resources, &pcie->prefetch,
- sys->mem_offset);
- pci_add_resource(&sys->resources, &pcie->busn);
+ pci_add_resource_offset(&pcie->bridge.windows, &pcie->pio, pcie->offset.io);
+ pci_add_resource_offset(&pcie->bridge.windows, &pcie->mem, pcie->offset.mem);
+ pci_add_resource_offset(&pcie->bridge.windows, &pcie->prefetch,
+ pcie->offset.mem);
+ pci_add_resource(&pcie->bridge.windows, &pcie->busn);

pci_ioremap_io(pcie->pio.start, pcie->io.start);

- return 1;
+ return 0;
}

static int tegra_pcie_map_irq(const struct pci_dev *pdev, u8 slot, u8 pin)
@@ -1535,6 +1532,7 @@ static int tegra_pcie_enable_msi(struct tegra_pcie *pcie)
}

/* setup AFI/FPCI range */
+ pcie->bridge.msi = &msi->chip;
msi->pages = __get_free_pages(GFP_KERNEL, 0);
base = virt_to_phys((void *)msi->pages);

@@ -2036,10 +2034,9 @@ retry:
return false;
}

-static int tegra_pcie_enable(struct tegra_pcie *pcie)
+static void tegra_pcie_enable_ports(struct tegra_pcie *pcie)
{
struct tegra_pcie_port *port, *tmp;
- struct hw_pci hw;

list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
dev_info(pcie->dev, "probing port %u, using %u lanes\n",
@@ -2055,22 +2052,6 @@ static int tegra_pcie_enable(struct tegra_pcie *pcie)
tegra_pcie_port_disable(port);
tegra_pcie_port_free(port);
}
-
- memset(&hw, 0, sizeof(hw));
-
-#ifdef CONFIG_PCI_MSI
- hw.msi_ctrl = &pcie->msi.chip;
-#endif
-
- hw.nr_controllers = 1;
- hw.private_data = (void **)&pcie;
- hw.setup = tegra_pcie_setup;
- hw.map_irq = tegra_pcie_map_irq;
- hw.ops = &tegra_pcie_ops;
-
- pci_common_init_dev(pcie->dev, &hw);
-
- return 0;
}

static const struct tegra_pcie_soc_data tegra20_pcie_data = {
@@ -2230,6 +2211,8 @@ static int tegra_pcie_probe(struct platform_device *pdev)
{
const struct of_device_id *match;
struct tegra_pcie *pcie;
+ struct pci_host_bridge *bridge;
+ struct pci_bus *child;
int err;

match = of_match_device(tegra_pcie_of_match, &pdev->dev);
@@ -2244,6 +2227,7 @@ static int tegra_pcie_probe(struct platform_device *pdev)
INIT_LIST_HEAD(&pcie->ports);
pcie->soc_data = match->data;
pcie->dev = &pdev->dev;
+ bridge = &pcie->bridge;

err = tegra_pcie_parse_dt(pcie);
if (err < 0)
@@ -2261,6 +2245,10 @@ static int tegra_pcie_probe(struct platform_device *pdev)
if (err)
goto put_resources;

+ err = tegra_pcie_request_resources(pcie);
+ if (err)
+ goto put_resources;
+
/* setup the AFI address translations */
tegra_pcie_setup_translations(pcie);

@@ -2274,12 +2262,29 @@ static int tegra_pcie_probe(struct platform_device *pdev)
}
}

- err = tegra_pcie_enable(pcie);
+ tegra_pcie_enable_ports(pcie);
+
+ pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
+ bridge->busnr = pcie->busn.start;
+ bridge->dev.parent = &pdev->dev;
+ bridge->sysdata = pcie;
+ bridge->ops = &tegra_pcie_ops;
+ err = pci_register_host(bridge);
+
if (err < 0) {
- dev_err(&pdev->dev, "failed to enable PCIe ports: %d\n", err);
+ dev_err(&pdev->dev, "failed to register host: %d\n", err);
goto disable_msi;
}

+ pci_fixup_irqs(pci_common_swizzle, tegra_pcie_map_irq);
+ pci_bus_size_bridges(bridge->bus);
+ pci_bus_assign_resources(bridge->bus);
+
+ list_for_each_entry(child, &bridge->bus->children, node)
+ pcie_bus_configure_settings(child);
+
+ pci_bus_add_devices(bridge->bus);
+
if (IS_ENABLED(CONFIG_DEBUG_FS)) {
err = tegra_pcie_debugfs_init(pcie);
if (err < 0)
--
2.7.0