• Dave Gordon's avatar
    drm/i915/guc: keep GuC doorbell & process descriptor mapped in kernel · 0d92a6a4
    Dave Gordon authored
    Don't use kmap_atomic() for doorbell & process descriptor access.
    This patch fixes the BUG shown below, where the thread could sleep
    while holding a kmap_atomic mapping. In order not to need to call
    kmap_atomic() in this code path, we now set up a permanent kernel
    mapping of the shared doorbell and process-descriptor page, and
    use that in all doorbell and process-descriptor related code.
    
      BUG: scheduling while atomic: gem_close_race/1941/0x00000002
      Modules linked in: hid_generic usbhid i915 asix usbnet libphy mii
        i2c_algo_bit drm_kms_helper cfbfillrect syscopyarea cfbimgblt
        sysfillrect sysimgblt fb_sys_fops cfbcopyarea drm coretemp i2c_hid
        hid video pinctrl_sunrisepoint pinctrl_intel acpi_pad nls_iso8859_1
        e1000e ptp psmouse pps_core ahci libahci
      CPU: 0 PID: 1941 Comm: gem_close_race Tainted: G     U 4.4.0-160121+ #123
      Hardware name: Intel Corporation Skylake Client platform/Skylake AIO
        DDR3L RVP10, BIOS SKLSE2R1.R00.X100.B01.1509220551 09/22/2015
        0000000000013e40 ffff880166c27a78 ffffffff81280d02 ffff880172c13e40
        ffff880166c27a88 ffffffff810c203a ffff880166c27ac8 ffffffff814ec808
        ffff88016b7c6000 ffff880166c28000 00000000000f4240 0000000000000001
      Call Trace:
        [<ffffffff81280d02>] dump_stack+0x4b/0x79
        [<ffffffff810c203a>] __schedule_bug+0x41/0x4f
        [<ffffffff814ec808>] __schedule+0x5a8/0x690
        [<ffffffff814ec927>] schedule+0x37/0x80
        [<ffffffff814ef3fd>] schedule_hrtimeout_range_clock+0xad/0x130
        [<ffffffff81090be0>] ? hrtimer_init+0x10/0x10
        [<ffffffff814ef3f1>] ?  schedule_hrtimeout_range_clock+0xa1/0x130
        [<ffffffff814ef48e>] schedule_hrtimeout_range+0xe/0x10
        [<ffffffff814eef9b>] usleep_range+0x3b/0x40
        [<ffffffffa01ec109>] i915_guc_wq_check_space+0x119/0x210 [i915]
        [<ffffffffa01da47c>] intel_logical_ring_alloc_request_extras+0x5c/0x70 [i915]
        [<ffffffffa01cdbf1>] i915_gem_request_alloc+0x91/0x170 [i915]
        [<ffffffffa01c1c07>] i915_gem_do_execbuffer.isra.25+0xbc7/0x12a0 [i915]
        [<ffffffffa01cb785>] ?  i915_gem_object_get_pages_gtt+0x225/0x3c0 [i915]
        [<ffffffffa01d1fb6>] ? i915_gem_pwrite_ioctl+0xd6/0x9f0 [i915]
        [<ffffffffa01c2e68>] i915_gem_execbuffer2+0xa8/0x250 [i915]
        [<ffffffffa00f65d8>] drm_ioctl+0x258/0x4f0 [drm]
        [<ffffffffa01c2dc0>] ? i915_gem_execbuffer+0x340/0x340 [i915]
        [<ffffffff8111590d>] do_vfs_ioctl+0x2cd/0x4a0
        [<ffffffff8111eac2>] ? __fget+0x72/0xb0
        [<ffffffff81115b1c>] SyS_ioctl+0x3c/0x70
        [<ffffffff814effd7>] entry_SYSCALL_64_fastpath+0x12/0x6a
      ------------[ cut here ]------------
    
    v4:
      Only tear down doorbell & kunmap() client object if we actually
      succeeded in allocating a client object (Tvrtko Ursulin)
    
    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93847Original-version-by: default avatarAlex Dai <yu.dai@intel.com>
    Signed-off-by: default avatarDave Gordon <david.s.gordon@intel.com>
    Cc: Tvtrko Ursulin <tvrtko.ursulin@intel.com>
    Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
    Signed-off-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
    0d92a6a4
intel_guc.h 4.13 KB