From 2d1b88445064d317e20e86d1897b275a855df9a2 Mon Sep 17 00:00:00 2001 From: Yijing Wang Date: Mon, 16 Mar 2015 11:18:56 +0800 Subject: PCI: Assign resources before drivers claim devices (pci_scan_root_bus()) Previously, pci_scan_root_bus() created a root PCI bus, enumerated the devices on it, and called pci_bus_add_devices(), which made the devices available for drivers to claim them. Most callers assigned resources to devices after pci_scan_root_bus() returns, which may be after drivers have claimed the devices. This is incorrect; the PCI core should not change device resources while a driver is managing the device. Remove pci_bus_add_devices() from pci_scan_root_bus() and do it after any resource assignment in the callers. Note that ARM's pci_common_init_dev() already called pci_bus_add_devices() after pci_scan_root_bus(), so we only need to remove the first call: pci_common_init_dev pcibios_init_hw pci_scan_root_bus pci_bus_add_devices # first call pci_bus_assign_resources pci_bus_add_devices # second call [bhelgaas: changelog, drop "root_bus" var in alpha common_init_pci(), return failure earlier in mn10300, add "return" in x86 pcibios_scan_root(), return early if xtensa platform_pcibios_fixup() fails] Signed-off-by: Yijing Wang Signed-off-by: Bjorn Helgaas CC: Richard Henderson CC: Ivan Kokshaysky CC: Matt Turner CC: David Howells CC: Tony Luck CC: Michal Simek CC: Ralf Baechle CC: Koichi Yasutake CC: Sebastian Ott CC: "David S. Miller" CC: Chris Metcalf CC: Chris Zankel CC: Max Filippov CC: Thomas Gleixner (cherry picked from commit b97ea289cf6aff8d4cbcefe2b707bb9b00a73c73) Signed-off-by: Alex Shi Conflicts solution: add drivers/pci/host/pci-versatile.c --- drivers/pci/host/pci-versatile.c | 238 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 238 insertions(+) create mode 100644 drivers/pci/host/pci-versatile.c (limited to 'drivers/pci/host/pci-versatile.c') diff --git a/drivers/pci/host/pci-versatile.c b/drivers/pci/host/pci-versatile.c new file mode 100644 index 000000000000..e3a2450db2b8 --- /dev/null +++ b/drivers/pci/host/pci-versatile.c @@ -0,0 +1,238 @@ +/* + * Copyright 2004 Koninklijke Philips Electronics NV + * + * Conversion to platform driver and DT: + * Copyright 2014 Linaro Ltd. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * 14/04/2005 Initial version, colin.king@philips.com + */ +#include +#include +#include +#include +#include +#include +#include + +static void __iomem *versatile_pci_base; +static void __iomem *versatile_cfg_base[2]; + +#define PCI_IMAP(m) (versatile_pci_base + ((m) * 4)) +#define PCI_SMAP(m) (versatile_pci_base + 0x14 + ((m) * 4)) +#define PCI_SELFID (versatile_pci_base + 0xc) + +#define VP_PCI_DEVICE_ID 0x030010ee +#define VP_PCI_CLASS_ID 0x0b400000 + +static u32 pci_slot_ignore; + +static int __init versatile_pci_slot_ignore(char *str) +{ + int retval; + int slot; + + while ((retval = get_option(&str, &slot))) { + if ((slot < 0) || (slot > 31)) + pr_err("Illegal slot value: %d\n", slot); + else + pci_slot_ignore |= (1 << slot); + } + return 1; +} +__setup("pci_slot_ignore=", versatile_pci_slot_ignore); + + +static void __iomem *versatile_map_bus(struct pci_bus *bus, + unsigned int devfn, int offset) +{ + unsigned int busnr = bus->number; + + if (pci_slot_ignore & (1 << PCI_SLOT(devfn))) + return NULL; + + return versatile_cfg_base[1] + ((busnr << 16) | (devfn << 8) | offset); +} + +static struct pci_ops pci_versatile_ops = { + .map_bus = versatile_map_bus, + .read = pci_generic_config_read32, + .write = pci_generic_config_write, +}; + +static int versatile_pci_parse_request_of_pci_ranges(struct device *dev, + struct list_head *res) +{ + int err, mem = 1, res_valid = 0; + struct device_node *np = dev->of_node; + resource_size_t iobase; + struct resource_entry *win; + + err = of_pci_get_host_bridge_resources(np, 0, 0xff, res, &iobase); + if (err) + return err; + + resource_list_for_each_entry(win, res, list) { + struct resource *parent, *res = win->res; + + switch (resource_type(res)) { + case IORESOURCE_IO: + parent = &ioport_resource; + err = pci_remap_iospace(res, iobase); + if (err) { + dev_warn(dev, "error %d: failed to map resource %pR\n", + err, res); + continue; + } + break; + case IORESOURCE_MEM: + parent = &iomem_resource; + res_valid |= !(res->flags & IORESOURCE_PREFETCH); + + writel(res->start >> 28, PCI_IMAP(mem)); + writel(PHYS_OFFSET >> 28, PCI_SMAP(mem)); + mem++; + + break; + case IORESOURCE_BUS: + default: + continue; + } + + err = devm_request_resource(dev, parent, res); + if (err) + goto out_release_res; + } + + if (!res_valid) { + dev_err(dev, "non-prefetchable memory resource required\n"); + err = -EINVAL; + goto out_release_res; + } + + return 0; + +out_release_res: + pci_free_resource_list(res); + return err; +} + +/* Unused, temporary to satisfy ARM arch code */ +struct pci_sys_data sys; + +static int versatile_pci_probe(struct platform_device *pdev) +{ + struct resource *res; + int ret, i, myslot = -1; + u32 val; + void __iomem *local_pci_cfg_base; + struct pci_bus *bus; + LIST_HEAD(pci_res); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + versatile_pci_base = devm_ioremap_resource(&pdev->dev, res); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + if (!res) + return -ENODEV; + versatile_cfg_base[0] = devm_ioremap_resource(&pdev->dev, res); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 2); + if (!res) + return -ENODEV; + versatile_cfg_base[1] = devm_ioremap_resource(&pdev->dev, res); + + ret = versatile_pci_parse_request_of_pci_ranges(&pdev->dev, &pci_res); + if (ret) + return ret; + + /* + * We need to discover the PCI core first to configure itself + * before the main PCI probing is performed + */ + for (i = 0; i < 32; i++) { + if ((readl(versatile_cfg_base[0] + (i << 11) + PCI_VENDOR_ID) == VP_PCI_DEVICE_ID) && + (readl(versatile_cfg_base[0] + (i << 11) + PCI_CLASS_REVISION) == VP_PCI_CLASS_ID)) { + myslot = i; + break; + } + } + if (myslot == -1) { + dev_err(&pdev->dev, "Cannot find PCI core!\n"); + return -EIO; + } + /* + * Do not to map Versatile FPGA PCI device into memory space + */ + pci_slot_ignore |= (1 << myslot); + + dev_info(&pdev->dev, "PCI core found (slot %d)\n", myslot); + + writel(myslot, PCI_SELFID); + local_pci_cfg_base = versatile_cfg_base[1] + (myslot << 11); + + val = readl(local_pci_cfg_base + PCI_COMMAND); + val |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE; + writel(val, local_pci_cfg_base + PCI_COMMAND); + + /* + * Configure the PCI inbound memory windows to be 1:1 mapped to SDRAM + */ + writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_0); + writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_1); + writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_2); + + /* + * For many years the kernel and QEMU were symbiotically buggy + * in that they both assumed the same broken IRQ mapping. + * QEMU therefore attempts to auto-detect old broken kernels + * so that they still work on newer QEMU as they did on old + * QEMU. Since we now use the correct (ie matching-hardware) + * IRQ mapping we write a definitely different value to a + * PCI_INTERRUPT_LINE register to tell QEMU that we expect + * real hardware behaviour and it need not be backwards + * compatible for us. This write is harmless on real hardware. + */ + writel(0, versatile_cfg_base[0] + PCI_INTERRUPT_LINE); + + pci_add_flags(PCI_ENABLE_PROC_DOMAINS); + pci_add_flags(PCI_REASSIGN_ALL_BUS | PCI_REASSIGN_ALL_RSRC); + + bus = pci_scan_root_bus(&pdev->dev, 0, &pci_versatile_ops, &sys, &pci_res); + if (!bus) + return -ENOMEM; + + pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci); + pci_assign_unassigned_bus_resources(bus); + pci_bus_add_devices(bus); + + return 0; +} + +static const struct of_device_id versatile_pci_of_match[] = { + { .compatible = "arm,versatile-pci", }, + { }, +}; +MODULE_DEVICE_TABLE(of, versatile_pci_of_match); + +static struct platform_driver versatile_pci_driver = { + .driver = { + .name = "versatile-pci", + .of_match_table = versatile_pci_of_match, + }, + .probe = versatile_pci_probe, +}; +module_platform_driver(versatile_pci_driver); + +MODULE_DESCRIPTION("Versatile PCI driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3