Hello,
On Wed, 20 Jun 2018 20:51:37 +0300, Sergei Shtylyov wrote:
> 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 -
For the Aardvark chunk:
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxx>
Thanks!
Thomas Petazzoni
--
Thomas Petazzoni, CTO, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
