/****************************************************************************** * platform-pci.c * * Xen platform PCI device driver * * Authors: ssmith@xensource.com and stefano.stabellini@eu.citrix.com * * Copyright (c) 2005, Intel Corporation. * Copyright (c) 2007, XenSource Inc. * Copyright (c) 2010, Citrix * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope 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. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., 59 Temple * Place - Suite 330, Boston, MA 02111-1307 USA. * */ #include #include #include #include #include #include #include #include #include #include #define DRV_NAME "xen-platform-pci" static unsigned long platform_mmio; static unsigned long platform_mmio_alloc; static unsigned long platform_mmiolen; static uint64_t callback_via; static unsigned long alloc_xen_mmio(unsigned long len) { unsigned long addr; addr = platform_mmio + platform_mmio_alloc; platform_mmio_alloc += len; BUG_ON(platform_mmio_alloc > platform_mmiolen); return addr; } static uint64_t get_callback_via(struct pci_dev *pdev) { u8 pin; int irq; irq = pdev->irq; if (irq < 16) return irq; /* ISA IRQ */ pin = pdev->pin; /* We don't know the GSI. Specify the PCI INTx line instead. */ return ((uint64_t)0x01 << HVM_CALLBACK_VIA_TYPE_SHIFT) | /* PCI INTx identifier */ ((uint64_t)pci_domain_nr(pdev->bus) << 32) | ((uint64_t)pdev->bus->number << 16) | ((uint64_t)(pdev->devfn & 0xff) << 8) | ((uint64_t)(pin - 1) & 3); } static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id) { xen_hvm_evtchn_do_upcall(); return IRQ_HANDLED; } static int xen_allocate_irq(struct pci_dev *pdev) { return request_irq(pdev->irq, do_hvm_evtchn_intr, IRQF_NOBALANCING | IRQF_TRIGGER_RISING, "xen-platform-pci", pdev); } static int platform_pci_resume(struct pci_dev *pdev) { int err; if (!xen_pv_domain()) return 0; err = xen_set_callback_via(callback_via); if (err) { dev_err(&pdev->dev, "platform_pci_resume failure!\n"); return err; } return 0; } static int platform_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent) { int i, ret; long ioaddr; long mmio_addr, mmio_len; unsigned int max_nr_gframes; unsigned long grant_frames; if (!xen_domain()) return -ENODEV; i = pci_enable_device(pdev); if (i) return i; ioaddr = pci_resource_start(pdev, 0); mmio_addr = pci_resource_start(pdev, 1); mmio_len = pci_resource_len(pdev, 1); if (mmio_addr == 0 || ioaddr == 0) { dev_err(&pdev->dev, "no resources found\n"); ret = -ENOENT; goto pci_out; } ret = pci_request_region(pdev, 1, DRV_NAME); if (ret < 0) goto pci_out; ret = pci_request_region(pdev, 0, DRV_NAME); if (ret < 0) goto mem_out; platform_mmio = mmio_addr; platform_mmiolen = mmio_len; /* * Xen HVM guests always use the vector callback mechanism. * L1 Dom0 in a nested Xen environment is a PV guest inside in an * HVM environment. It needs the platform-pci driver to get * notifications from L0 Xen, but it cannot use the vector callback * as it is not exported by L1 Xen. */ if (xen_pv_domain()) { ret = xen_allocate_irq(pdev); if (ret) { dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret); goto out; } callback_via = get_callback_via(pdev); ret = xen_set_callback_via(callback_via); if (ret) { dev_warn(&pdev->dev, "Unable to set the evtchn callback " "err=%d\n", ret); goto out; } } max_nr_gframes = gnttab_max_grant_frames(); grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes); ret = gnttab_setup_auto_xlat_frames(grant_frames); if (ret) goto out; ret = gnttab_init(); if (ret) goto grant_out; xenbus_probe(NULL); return 0; grant_out: gnttab_free_auto_xlat_frames(); out: pci_release_region(pdev, 0); mem_out: pci_release_region(pdev, 1); pci_out: pci_disable_device(pdev); return ret; } static struct pci_device_id platform_pci_tbl[] = { {PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, {0,} }; static struct pci_driver platform_driver = { .name = DRV_NAME, .probe = platform_pci_probe, .id_table = platform_pci_tbl, #ifdef CONFIG_PM .resume_early = platform_pci_resume, #endif }; builtin_pci_driver(platform_driver); stat only
authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-29 13:50:06 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-29 13:50:06 -0800
commit39cb2c9a316e77f6dfba96c543e55b6672d5a37e (patch)
tree98fe974ee4e20121253de7f61fc8d01bdb3821c1 /drivers/usb/host/ehci-hcd.c
parent2c5d9555d6d937966d79d4c6529a5f7b9206e405 (diff)
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt() call in intel_unpin_fb_obj() returns NULL, resulting in an oops immediately afterwards as the (inlined) call to i915_vma_unpin_fence() tries to dereference it. It seems to be some race condition where the object is going away at shutdown time, since both times happened when shutting down the X server. The call chains were different: - VT ioctl(KDSETMODE, KD_TEXT): intel_cleanup_plane_fb+0x5b/0xa0 [i915] drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper] intel_atomic_commit_tail+0x749/0xfe0 [i915] intel_atomic_commit+0x3cb/0x4f0 [i915] drm_atomic_commit+0x4b/0x50 [drm] restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper] drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper] intel_fbdev_set_par+0x18/0x70 [i915] fb_set_var+0x236/0x460 fbcon_blank+0x30f/0x350 do_unblank_screen+0xd2/0x1a0 vt_ioctl+0x507/0x12a0 tty_ioctl+0x355/0xc30 do_vfs_ioctl+0xa3/0x5e0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x13/0x94 - i915 unpin_work workqueue: intel_unpin_work_fn+0x58/0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/usb/host/ehci-hcd.c')