![Sergei Shtylyov](/assets/img/avatar_default.png)
When testing the R-Car PCIe driver on the Condor board, if the PCIe PHY
driver was left disabled, the kernel crashed with this BUG:
kernel BUG at lib/ioremap.c:72!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 39 Comm: kworker/0:1 Not tainted 4.17.0-dirty #1092
Hardware name: Renesas Condor board based on r8a77980 (DT)
Workqueue: events deferred_probe_work_func
pstate: 80000005 (Nzcv daif -PAN -UAO)
pc : ioremap_page_range+0x370/0x3c8
lr : ioremap_page_range+0x40/0x3c8
sp : ffff000008da39e0
x29: ffff000008da39e0 x28: 00e8000000000f07
x27: ffff7dfffee00000 x26: 0140000000000000
x25: ffff7dfffef00000 x24: 00000000000fe100
x23: ffff80007b906000 x22: ffff000008ab8000
x21: ffff000008bb1d58 x20: ffff7dfffef00000
x19: ffff800009c30fb8 x18: 0000000000000001
x17: 00000000000152d0 x16: 00000000014012d0
x15: 0000000000000000 x14: 0720072007200720
x13: 0720072007200720 x12: 0720072007200720
x11: 0720072007300730 x10: 00000000000000ae
x9 : 0000000000000000 x8 : ffff7dffff000000
x7 : 0000000000000000 x6 : 0000000000000100
x5 : 0000000000000000 x4 : 000000007b906000
x3 : ffff80007c61a880 x2 : ffff7dfffeefffff
x1 : 0000000040000000 x0 : 00e80000fe100f07
Process kworker/0:1 (pid: 39, stack limit = 0x (ptrval))
Call trace:
ioremap_page_range+0x370/0x3c8
pci_remap_iospace+0x7c/0xac
pci_parse_request_of_pci_ranges+0x13c/0x190
rcar_pcie_probe+0x4c/0xb04
platform_drv_probe+0x50/0xbc
driver_probe_device+0x21c/0x308
__device_attach_driver+0x98/0xc8
bus_for_each_drv+0x54/0x94
__device_attach+0xc4/0x12c
device_initial_probe+0x10/0x18
bus_probe_device+0x90/0x98
deferred_probe_work_func+0xb0/0x150
process_one_work+0x12c/0x29c
worker_thread+0x200/0x3fc
kthread+0x108/0x134
ret_from_fork+0x10/0x18
Code: f9004ba2 54000080 aa0003fb 17ffff48 (d4210000)
It turned out that pci_remap_iospace() wasn't undone when the driver's
probe failed, and since devm_phy_optional_get() returned -EPROBE_DEFER,
the probe was retried, finally causing the BUG due to trying to remap
already remapped pages.
The Versatile PCI controller driver has the same issue.
Replace pci_remap_iospace() with the devm_ managed version to fix the bug.
Fixes: b7e78170ef
("PCI: versatile: Add DT-based ARM Versatile PB PCIe host driver")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
[lorenzo.pieralisi@arm.com: updated the commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
240 lines
6.3 KiB
C
240 lines
6.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright 2004 Koninklijke Philips Electronics NV
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*
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* Conversion to platform driver and DT:
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* Copyright 2014 Linaro Ltd.
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*
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* 14/04/2005 Initial version, colin.king@philips.com
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of_address.h>
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#include <linux/of_pci.h>
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#include <linux/of_platform.h>
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#include <linux/pci.h>
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#include <linux/platform_device.h>
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#include "../pci.h"
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static void __iomem *versatile_pci_base;
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static void __iomem *versatile_cfg_base[2];
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#define PCI_IMAP(m) (versatile_pci_base + ((m) * 4))
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#define PCI_SMAP(m) (versatile_pci_base + 0x14 + ((m) * 4))
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#define PCI_SELFID (versatile_pci_base + 0xc)
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#define VP_PCI_DEVICE_ID 0x030010ee
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#define VP_PCI_CLASS_ID 0x0b400000
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static u32 pci_slot_ignore;
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static int __init versatile_pci_slot_ignore(char *str)
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{
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int retval;
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int slot;
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while ((retval = get_option(&str, &slot))) {
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if ((slot < 0) || (slot > 31))
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pr_err("Illegal slot value: %d\n", slot);
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else
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pci_slot_ignore |= (1 << slot);
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}
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return 1;
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}
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__setup("pci_slot_ignore=", versatile_pci_slot_ignore);
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static void __iomem *versatile_map_bus(struct pci_bus *bus,
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unsigned int devfn, int offset)
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{
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unsigned int busnr = bus->number;
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if (pci_slot_ignore & (1 << PCI_SLOT(devfn)))
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return NULL;
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return versatile_cfg_base[1] + ((busnr << 16) | (devfn << 8) | offset);
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}
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static struct pci_ops pci_versatile_ops = {
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.map_bus = versatile_map_bus,
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.read = pci_generic_config_read32,
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.write = pci_generic_config_write,
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};
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static int versatile_pci_parse_request_of_pci_ranges(struct device *dev,
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struct list_head *res)
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{
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int err, mem = 1, res_valid = 0;
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resource_size_t iobase;
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struct resource_entry *win, *tmp;
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err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, res, &iobase);
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if (err)
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return err;
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err = devm_request_pci_bus_resources(dev, res);
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if (err)
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goto out_release_res;
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resource_list_for_each_entry_safe(win, tmp, res) {
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struct resource *res = win->res;
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switch (resource_type(res)) {
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case IORESOURCE_IO:
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err = devm_pci_remap_iospace(dev, res, iobase);
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if (err) {
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dev_warn(dev, "error %d: failed to map resource %pR\n",
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err, res);
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resource_list_destroy_entry(win);
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}
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break;
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case IORESOURCE_MEM:
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res_valid |= !(res->flags & IORESOURCE_PREFETCH);
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writel(res->start >> 28, PCI_IMAP(mem));
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writel(PHYS_OFFSET >> 28, PCI_SMAP(mem));
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mem++;
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break;
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}
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}
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if (res_valid)
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return 0;
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dev_err(dev, "non-prefetchable memory resource required\n");
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err = -EINVAL;
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out_release_res:
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pci_free_resource_list(res);
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return err;
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}
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static int versatile_pci_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct resource *res;
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int ret, i, myslot = -1;
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u32 val;
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void __iomem *local_pci_cfg_base;
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struct pci_bus *bus, *child;
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struct pci_host_bridge *bridge;
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LIST_HEAD(pci_res);
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bridge = devm_pci_alloc_host_bridge(dev, 0);
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if (!bridge)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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versatile_pci_base = devm_ioremap_resource(dev, res);
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if (IS_ERR(versatile_pci_base))
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return PTR_ERR(versatile_pci_base);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
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versatile_cfg_base[0] = devm_ioremap_resource(dev, res);
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if (IS_ERR(versatile_cfg_base[0]))
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return PTR_ERR(versatile_cfg_base[0]);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
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versatile_cfg_base[1] = devm_pci_remap_cfg_resource(dev, res);
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if (IS_ERR(versatile_cfg_base[1]))
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return PTR_ERR(versatile_cfg_base[1]);
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ret = versatile_pci_parse_request_of_pci_ranges(dev, &pci_res);
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if (ret)
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return ret;
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/*
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* We need to discover the PCI core first to configure itself
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* before the main PCI probing is performed
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*/
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for (i = 0; i < 32; i++) {
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if ((readl(versatile_cfg_base[0] + (i << 11) + PCI_VENDOR_ID) == VP_PCI_DEVICE_ID) &&
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(readl(versatile_cfg_base[0] + (i << 11) + PCI_CLASS_REVISION) == VP_PCI_CLASS_ID)) {
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myslot = i;
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break;
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}
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}
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if (myslot == -1) {
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dev_err(dev, "Cannot find PCI core!\n");
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return -EIO;
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}
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/*
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* Do not to map Versatile FPGA PCI device into memory space
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*/
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pci_slot_ignore |= (1 << myslot);
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dev_info(dev, "PCI core found (slot %d)\n", myslot);
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writel(myslot, PCI_SELFID);
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local_pci_cfg_base = versatile_cfg_base[1] + (myslot << 11);
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val = readl(local_pci_cfg_base + PCI_COMMAND);
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val |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE;
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writel(val, local_pci_cfg_base + PCI_COMMAND);
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/*
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* Configure the PCI inbound memory windows to be 1:1 mapped to SDRAM
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*/
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writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_0);
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writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_1);
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writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_2);
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/*
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* For many years the kernel and QEMU were symbiotically buggy
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* in that they both assumed the same broken IRQ mapping.
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* QEMU therefore attempts to auto-detect old broken kernels
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* so that they still work on newer QEMU as they did on old
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* QEMU. Since we now use the correct (ie matching-hardware)
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* IRQ mapping we write a definitely different value to a
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* PCI_INTERRUPT_LINE register to tell QEMU that we expect
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* real hardware behaviour and it need not be backwards
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* compatible for us. This write is harmless on real hardware.
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*/
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writel(0, versatile_cfg_base[0] + PCI_INTERRUPT_LINE);
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pci_add_flags(PCI_ENABLE_PROC_DOMAINS);
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pci_add_flags(PCI_REASSIGN_ALL_BUS);
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list_splice_init(&pci_res, &bridge->windows);
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bridge->dev.parent = dev;
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bridge->sysdata = NULL;
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bridge->busnr = 0;
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bridge->ops = &pci_versatile_ops;
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bridge->map_irq = of_irq_parse_and_map_pci;
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bridge->swizzle_irq = pci_common_swizzle;
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ret = pci_scan_root_bus_bridge(bridge);
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if (ret < 0)
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return ret;
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bus = bridge->bus;
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pci_assign_unassigned_bus_resources(bus);
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list_for_each_entry(child, &bus->children, node)
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pcie_bus_configure_settings(child);
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pci_bus_add_devices(bus);
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return 0;
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}
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static const struct of_device_id versatile_pci_of_match[] = {
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{ .compatible = "arm,versatile-pci", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, versatile_pci_of_match);
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static struct platform_driver versatile_pci_driver = {
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.driver = {
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.name = "versatile-pci",
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.of_match_table = versatile_pci_of_match,
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.suppress_bind_attrs = true,
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},
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.probe = versatile_pci_probe,
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};
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module_platform_driver(versatile_pci_driver);
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MODULE_DESCRIPTION("Versatile PCI driver");
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MODULE_LICENSE("GPL v2");
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