On Tue, Aug 1, 2023 at 4:15 PM Mario Limonciello <mario.limonciello@xxxxxxx> wrote: > > Accessing the blob for amdgpu discovery from debugfs triggers: > > [ 1924.487667] kernel BUG at mm/usercopy.c:102! > > usercopy_abort() explains that it needs to be solved by creating > a cache to store the data. > > Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2748#note_2023519 > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx> > --- > drivers/gpu/drm/amd/amdgpu/amdgpu.h | 7 +++++-- > drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 17 ++++++++++++++++- > drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 2 ++ > 3 files changed, 23 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h > index a3b86b86dc477..66a2251bdeba4 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h > @@ -791,8 +791,11 @@ struct amdgpu_device { > bool accel_working; > struct notifier_block acpi_nb; > struct amdgpu_i2c_chan *i2c_bus[AMDGPU_MAX_I2C_BUS]; > - struct debugfs_blob_wrapper debugfs_vbios_blob; > - struct debugfs_blob_wrapper debugfs_discovery_blob; > +#if defined(CONFIG_DEBUG_FS) > + struct debugfs_blob_wrapper debugfs_vbios_blob; > + struct debugfs_blob_wrapper debugfs_discovery_blob; > + struct kmem_cache *discovery_blob_cache; > +#endif > struct mutex srbm_mutex; > /* GRBM index mutex. Protects concurrent access to GRBM index */ > struct mutex grbm_idx_mutex; > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c > index 56e89e76ff179..55ea5be14b188 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c > @@ -2180,7 +2180,15 @@ int amdgpu_debugfs_init(struct amdgpu_device *adev) > debugfs_create_blob("amdgpu_vbios", 0444, root, > &adev->debugfs_vbios_blob); > > - adev->debugfs_discovery_blob.data = adev->mman.discovery_bin; > + > + adev->discovery_blob_cache = kmem_cache_create_usercopy("amdgpu_discovery", > + adev->mman.discovery_tmr_size, > + 0, 0, 0, > + adev->mman.discovery_tmr_size, > + NULL); > + adev->debugfs_discovery_blob.data = kmem_cache_alloc(adev->discovery_blob_cache, GFP_KERNEL); > + memcpy(adev->debugfs_discovery_blob.data, adev->mman.discovery_bin, > + adev->mman.discovery_tmr_size); > adev->debugfs_discovery_blob.size = adev->mman.discovery_tmr_size; > debugfs_create_blob("amdgpu_discovery", 0444, root, > &adev->debugfs_discovery_blob); > @@ -2188,6 +2196,12 @@ int amdgpu_debugfs_init(struct amdgpu_device *adev) > return 0; > } > > +void amdgpu_debugfs_fini(struct amdgpu_device *adev) > +{ > + kmem_cache_free(adev->discovery_blob_cache, adev->debugfs_discovery_blob.data); > + kmem_cache_destroy(adev->discovery_blob_cache); > +} > + > #else > int amdgpu_debugfs_init(struct amdgpu_device *adev) > { > @@ -2197,4 +2211,5 @@ int amdgpu_debugfs_regs_init(struct amdgpu_device *adev) > { > return 0; > } > +inline void amdgpu_debugfs_fini(struct amdgpu_device *adev) {} > #endif > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c > index 0593ef8fe0a63..1a3b30dff5171 100644 > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c > @@ -2276,6 +2276,8 @@ amdgpu_pci_remove(struct pci_dev *pdev) > struct drm_device *dev = pci_get_drvdata(pdev); > struct amdgpu_device *adev = drm_to_adev(dev); > > + amdgpu_debugfs_fini(adev); > + > amdgpu_xcp_dev_unplug(adev); > drm_dev_unplug(dev); > > -- > 2.34.1 >
