From d05aafe62f20addf29cd458642496806b97ffc83 Mon Sep 17 00:00:00 2001 From: Ferruh Yigit Date: Tue, 5 Jul 2016 16:00:52 +0100 Subject: [PATCH] igb_uio: fix possible mmap failure with Linux 4.5 mmap the iomem range of the PCI device fails for kernels that enabled CONFIG_IO_STRICT_DEVMEM option: EAL: pci_map_resource(): cannot mmap(39, 0x7f1c51800000, 0x100000, 0x0): Invalid argument (0xffffffffffffffff) CONFIG_IO_STRICT_DEVMEM is introduced in Linux v4.5 and not enabled by default: Linux commit: 90a545e restrict /dev/mem to idle io memory ranges As a workaround igb_uio can stop reserving PCI memory resources, from kernel point of view iomem region looks like idle and mmap works again. This matches uio_pci_generic usage. With this update device iomem range is not protected against any other kernel drivers or userspace access. But this shouldn't be a problem for dpdk usage module since purpose of the igb_uio module is to provide userspace access. Fixes: af75078fece3 ("first public release") Signed-off-by: Ferruh Yigit --- doc/guides/rel_notes/release_16_07.rst | 15 +++++++++++++++ lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 13 ------------- 2 files changed, 15 insertions(+), 13 deletions(-) diff --git a/doc/guides/rel_notes/release_16_07.rst b/doc/guides/rel_notes/release_16_07.rst index 569f562fd8..e2af147439 100644 --- a/doc/guides/rel_notes/release_16_07.rst +++ b/doc/guides/rel_notes/release_16_07.rst @@ -195,6 +195,21 @@ Resolved Issues EAL ~~~ +* **igb_uio: Fixed possible mmap failure for Linux >= 4.5.** + + mmaping the iomem range of the PCI device fails for kernels that + enabled CONFIG_IO_STRICT_DEVMEM option: + + EAL: pci_map_resource(): + cannot mmap(39, 0x7f1c51800000, 0x100000, 0x0): + Invalid argument (0xffffffffffffffff) + + CONFIG_IO_STRICT_DEVMEM is introduced in Linux v4.5 + + Updated igb_uio to stop reserving PCI memory resources, from + kernel point of view iomem region looks like idle and mmap worked + again. This matches uio_pci_generic usage. + Drivers ~~~~~~~ diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c index 45a5720e2d..df41e457ad 100644 --- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c +++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c @@ -342,16 +342,6 @@ igbuio_pci_probe(struct pci_dev *dev, const struct pci_device_id *id) goto fail_free; } - /* - * reserve device's PCI memory regions for use by this - * module - */ - err = pci_request_regions(dev, "igb_uio"); - if (err != 0) { - dev_err(&dev->dev, "Cannot request regions\n"); - goto fail_disable; - } - /* enable bus mastering on the device */ pci_set_master(dev); @@ -441,8 +431,6 @@ fail_release_iomem: igbuio_pci_release_iomem(&udev->info); if (udev->mode == RTE_INTR_MODE_MSIX) pci_disable_msix(udev->pdev); - pci_release_regions(dev); -fail_disable: pci_disable_device(dev); fail_free: kfree(udev); @@ -460,7 +448,6 @@ igbuio_pci_remove(struct pci_dev *dev) igbuio_pci_release_iomem(&udev->info); if (udev->mode == RTE_INTR_MODE_MSIX) pci_disable_msix(dev); - pci_release_regions(dev); pci_disable_device(dev); pci_set_drvdata(dev, NULL); kfree(udev); -- 2.20.1