When testing the R-Car PCIe driver on the Condor board, I noticed that iff I left the PCIe PHY driver disabled, the kernel crashed with this BUG: [ 1.225819] kernel BUG at lib/ioremap.c:72! [ 1.230007] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 1.235496] Modules linked in: [ 1.238561] CPU: 0 PID: 39 Comm: kworker/0:1 Not tainted 4.17.0-dirty #1092 [ 1.245526] Hardware name: Renesas Condor board based on r8a77980 (DT) [ 1.252075] Workqueue: events deferred_probe_work_func [ 1.257220] pstate: 80000005 (Nzcv daif -PAN -UAO) [ 1.262024] pc : ioremap_page_range+0x370/0x3c8 [ 1.266558] lr : ioremap_page_range+0x40/0x3c8 [ 1.271002] sp : ffff000008da39e0 [ 1.274317] x29: ffff000008da39e0 x28: 00e8000000000f07 [ 1.279636] x27: ffff7dfffee00000 x26: 0140000000000000 [ 1.284954] x25: ffff7dfffef00000 x24: 00000000000fe100 [ 1.290272] x23: ffff80007b906000 x22: ffff000008ab8000 [ 1.295590] x21: ffff000008bb1d58 x20: ffff7dfffef00000 [ 1.300909] x19: ffff800009c30fb8 x18: 0000000000000001 [ 1.306226] x17: 00000000000152d0 x16: 00000000014012d0 [ 1.311544] x15: 0000000000000000 x14: 0720072007200720 [ 1.316862] x13: 0720072007200720 x12: 0720072007200720 [ 1.322180] x11: 0720072007300730 x10: 00000000000000ae [ 1.327498] x9 : 0000000000000000 x8 : ffff7dffff000000 [ 1.332816] x7 : 0000000000000000 x6 : 0000000000000100 [ 1.338134] x5 : 0000000000000000 x4 : 000000007b906000 [ 1.343452] x3 : ffff80007c61a880 x2 : ffff7dfffeefffff [ 1.348770] x1 : 0000000040000000 x0 : 00e80000fe100f07 [ 1.354090] Process kworker/0:1 (pid: 39, stack limit = 0x (ptrval)) [ 1.361056] Call trace: [ 1.363504] ioremap_page_range+0x370/0x3c8 [ 1.367695] pci_remap_iospace+0x7c/0xac [ 1.371624] pci_parse_request_of_pci_ranges+0x13c/0x190 [ 1.376945] rcar_pcie_probe+0x4c/0xb04 [ 1.380786] platform_drv_probe+0x50/0xbc [ 1.384799] driver_probe_device+0x21c/0x308 [ 1.389072] __device_attach_driver+0x98/0xc8 [ 1.393431] bus_for_each_drv+0x54/0x94 [ 1.397269] __device_attach+0xc4/0x12c [ 1.401107] device_initial_probe+0x10/0x18 [ 1.405292] bus_probe_device+0x90/0x98 [ 1.409130] deferred_probe_work_func+0xb0/0x150 [ 1.413756] process_one_work+0x12c/0x29c [ 1.417768] worker_thread+0x200/0x3fc [ 1.421522] kthread+0x108/0x134 [ 1.424755] ret_from_fork+0x10/0x18 [ 1.428334] 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 most feasible solution seems to introduce devm_pci_remap_iospace() and call it instead of pci_remap_iospace(), so that the pages get unmapped automagically on any probe failure. And while fixing pci_parse_request_of_pci_ranges(), aslo fix the other drivers that have probably copied the bad example... Fixes: 4e64dbe226e7 ("PCI: generic: Expose pci_host_common_probe() for use by other drivers") Fixes: cbce7900598c ("PCI: designware: Make driver arch-agnostic") Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver") Fixes: d3c68e0a7e34 ("PCI: faraday: Add Faraday Technology FTPCI100 PCI Host Bridge driver") Fixes: 68a15eb7bd0c ("PCI: v3-semi: Add V3 Semiconductor PCI host driver") Fixes: b7e78170efd4 ("PCI: versatile: Add DT-based ARM Versatile PB PCIe host driver") Fixes: 5f6b6ccdbe1c ("PCI: xgene: Add APM X-Gene PCIe driver") Fixes: 637cfacae96f ("PCI: mediatek: Add MediaTek PCIe host controller support") Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- The patch is against the 'master' branch of Bjorn Helgaas' 'pci.git' repo... It has only been tested with the R-Car PCIe driver... drivers/pci/controller/dwc/pcie-designware-host.c | 3 + drivers/pci/controller/pci-aardvark.c | 2 - drivers/pci/controller/pci-ftpci100.c | 2 - drivers/pci/controller/pci-v3-semi.c | 2 - drivers/pci/controller/pci-versatile.c | 2 - drivers/pci/controller/pci-xgene.c | 2 - drivers/pci/controller/pcie-mediatek.c | 2 - drivers/pci/of.c | 2 - drivers/pci/pci.c | 38 ++++++++++++++++++++++ include/linux/pci.h | 2 + 10 files changed, 49 insertions(+), 8 deletions(-) Index: pci/drivers/pci/controller/dwc/pcie-designware-host.c =================================================================== --- pci.orig/drivers/pci/controller/dwc/pcie-designware-host.c +++ pci/drivers/pci/controller/dwc/pcie-designware-host.c @@ -363,7 +363,8 @@ int dw_pcie_host_init(struct pcie_port * resource_list_for_each_entry_safe(win, tmp, &bridge->windows) { switch (resource_type(win->res)) { case IORESOURCE_IO: - ret = pci_remap_iospace(win->res, pp->io_base); + ret = devm_pci_remap_iospace(dev, win->res, + pp->io_base); if (ret) { dev_warn(dev, "Error %d: failed to map resource %pR\n", ret, win->res); Index: pci/drivers/pci/controller/pci-aardvark.c =================================================================== --- pci.orig/drivers/pci/controller/pci-aardvark.c +++ pci/drivers/pci/controller/pci-aardvark.c @@ -849,7 +849,7 @@ static int advk_pcie_parse_request_of_pc 0, 0xF8000000, 0, lower_32_bits(res->start), OB_PCIE_IO); - err = pci_remap_iospace(res, iobase); + err = devm_pci_remap_iospace(dev, res, iobase); if (err) { dev_warn(dev, "error %d: failed to map resource %pR\n", err, res); Index: pci/drivers/pci/controller/pci-ftpci100.c =================================================================== --- pci.orig/drivers/pci/controller/pci-ftpci100.c +++ pci/drivers/pci/controller/pci-ftpci100.c @@ -501,7 +501,7 @@ static int faraday_pci_probe(struct plat dev_err(dev, "illegal IO mem size\n"); return -EINVAL; } - ret = pci_remap_iospace(io, io_base); + ret = devm_pci_remap_iospace(dev, io, io_base); if (ret) { dev_warn(dev, "error %d: failed to map resource %pR\n", ret, io); Index: pci/drivers/pci/controller/pci-v3-semi.c =================================================================== --- pci.orig/drivers/pci/controller/pci-v3-semi.c +++ pci/drivers/pci/controller/pci-v3-semi.c @@ -537,7 +537,7 @@ static int v3_pci_setup_resource(struct v3->io_bus_addr = io->start - win->offset; dev_dbg(dev, "I/O window %pR, bus addr %pap\n", io, &v3->io_bus_addr); - ret = pci_remap_iospace(io, io_base); + ret = devm_pci_remap_iospace(dev, io, io_base); if (ret) { dev_warn(dev, "error %d: failed to map resource %pR\n", Index: pci/drivers/pci/controller/pci-versatile.c =================================================================== --- pci.orig/drivers/pci/controller/pci-versatile.c +++ pci/drivers/pci/controller/pci-versatile.c @@ -82,7 +82,7 @@ static int versatile_pci_parse_request_o switch (resource_type(res)) { case IORESOURCE_IO: - err = pci_remap_iospace(res, iobase); + err = devm_pci_remap_iospace(dev, res, iobase); if (err) { dev_warn(dev, "error %d: failed to map resource %pR\n", err, res); Index: pci/drivers/pci/controller/pci-xgene.c =================================================================== --- pci.orig/drivers/pci/controller/pci-xgene.c +++ pci/drivers/pci/controller/pci-xgene.c @@ -423,7 +423,7 @@ static int xgene_pcie_map_ranges(struct case IORESOURCE_IO: xgene_pcie_setup_ob_reg(port, res, OMR3BARL, io_base, res->start - window->offset); - ret = pci_remap_iospace(res, io_base); + ret = devm_pci_remap_iospace(dev, res, io_base); if (ret < 0) return ret; break; Index: pci/drivers/pci/controller/pcie-mediatek.c =================================================================== --- pci.orig/drivers/pci/controller/pcie-mediatek.c +++ pci/drivers/pci/controller/pcie-mediatek.c @@ -1109,7 +1109,7 @@ static int mtk_pcie_request_resources(st if (err < 0) return err; - pci_remap_iospace(&pcie->pio, pcie->io.start); + devm_pci_remap_iospace(dev, &pcie->pio, pcie->io.start); return 0; } Index: pci/drivers/pci/of.c =================================================================== --- pci.orig/drivers/pci/of.c +++ pci/drivers/pci/of.c @@ -612,7 +612,7 @@ int pci_parse_request_of_pci_ranges(stru switch (resource_type(res)) { case IORESOURCE_IO: - err = pci_remap_iospace(res, iobase); + err = devm_pci_remap_iospace(dev, res, iobase); if (err) { dev_warn(dev, "error %d: failed to map resource %pR\n", err, res); Index: pci/drivers/pci/pci.c =================================================================== --- pci.orig/drivers/pci/pci.c +++ pci/drivers/pci/pci.c @@ -3579,6 +3579,44 @@ void pci_unmap_iospace(struct resource * } EXPORT_SYMBOL(pci_unmap_iospace); +static void devm_pci_unmap_iospace(struct device *dev, void *ptr) +{ + struct resource **res = ptr; + + pci_unmap_iospace(*res); +} + +/** + * devm_pci_remap_iospace - Managed pci_remap_iospace() + * @dev: Generic device to remap IO address for + * @res: Resource describing the I/O space + * @phys_addr: physical address of range to be mapped + * + * Managed pci_remap_iospace(). Map is automatically unmapped on driver + * detach. + */ +int devm_pci_remap_iospace(struct device *dev, const struct resource *res, + phys_addr_t phys_addr) +{ + const struct resource **ptr; + int error; + + ptr = devres_alloc(devm_pci_unmap_iospace, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return -ENOMEM; + + error = pci_remap_iospace(res, phys_addr); + if (error) { + devres_free(ptr); + } else { + *ptr = res; + devres_add(dev, ptr); + } + + return error; +} +EXPORT_SYMBOL(devm_pci_remap_iospace); + /** * devm_pci_remap_cfgspace - Managed pci_remap_cfgspace() * @dev: Generic device to remap IO address for Index: pci/include/linux/pci.h =================================================================== --- pci.orig/include/linux/pci.h +++ pci/include/linux/pci.h @@ -1240,6 +1240,8 @@ int pci_register_io_range(struct fwnode_ unsigned long pci_address_to_pio(phys_addr_t addr); phys_addr_t pci_pio_to_address(unsigned long pio); int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr); +int devm_pci_remap_iospace(struct device *dev, const struct resource *res, + phys_addr_t phys_addr); void pci_unmap_iospace(struct resource *res); void __iomem *devm_pci_remap_cfgspace(struct device *dev, resource_size_t offset,