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BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_TRACE(0.00)[0:+]; ARC_NA(0.00)[]; RCPT_COUNT_TWELVE(0.00)[15]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FREEMAIL_TO(0.00)[ffwll.ch,redhat.com,gmail.com,linux.intel.com,kernel.org,poorly.run,linaro.org,amd.com,kodeit.net,live.com,intel.com]; FUZZY_BLOCKED(0.00)[rspamd.com]; RCVD_TLS_ALL(0.00)[]; DKIM_TRACE(0.00)[suse.de:+]; RCVD_COUNT_TWO(0.00)[2]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:email,suse.de:dkim,suse.de:mid]; ASN(0.00)[asn:25478, ipnet:::/0, country:RU]; RCVD_VIA_SMTP_AUTH(0.00)[]; R_RATELIMIT(0.00)[to_ip_from(RLau4tukfh38qp3nirdnk14qe9)]; FREEMAIL_ENVRCPT(0.00)[gmail.com,live.com] X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Rspamd-Action: no action X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Importing dma-bufs via PRIME requires a DMA-capable device. Devices on peripheral busses, such as USB, often cannot perform DMA by themselves. Without DMA-capable device PRIME import fails. DRM drivers for USB devices already use a separate DMA device for dma-buf imports. Make the mechanism generally available. Besides the case of USB, there are embedded DRM devices without DMA capability. DMA is performed by a separate controller. DRM drivers should set this accordingly. Add the field dma_dev to struct drm_device to refer to the device's DMA device. For USB this should be the USB controller. Use dma_dev in the PRIME import helpers, if set. v2: - acquire internal reference on dma_dev (Jani) - add DMA-controller usecase to docs (Maxime) Signed-off-by: Thomas Zimmermann Reviewed-by: Jani Nikula Reviewed-by: Maxime Ripard --- drivers/gpu/drm/drm_drv.c | 21 +++++++++++++++++++ drivers/gpu/drm/drm_prime.c | 2 +- include/drm/drm_device.h | 41 +++++++++++++++++++++++++++++++++++++ 3 files changed, 63 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 17fc5dc708f4..c9487bc88624 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -500,6 +500,25 @@ void drm_dev_unplug(struct drm_device *dev) } EXPORT_SYMBOL(drm_dev_unplug); +/** + * drm_dev_set_dma_dev - set the DMA device for a DRM device + * @dev: DRM device + * @dma_dev: DMA device or NULL + * + * Sets the DMA device of the given DRM device. Only required if + * the DMA device is different from the DRM device's parent. After + * calling this function, the DRM device holds a reference on + * @dma_dev. Pass NULL to clear the DMA device. + */ +void drm_dev_set_dma_dev(struct drm_device *dev, struct device *dma_dev) +{ + dma_dev = get_device(dma_dev); + + put_device(dev->dma_dev); + dev->dma_dev = dma_dev; +} +EXPORT_SYMBOL(drm_dev_set_dma_dev); + /* * Available recovery methods for wedged device. To be sent along with device * wedged uevent. @@ -654,6 +673,8 @@ static void drm_dev_init_release(struct drm_device *dev, void *res) { drm_fs_inode_free(dev->anon_inode); + put_device(dev->dma_dev); + dev->dma_dev = NULL; put_device(dev->dev); /* Prevent use-after-free in drm_managed_release when debugging is * enabled. Slightly awkward, but can't really be helped. */ diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index bdb51c8f262e..ed4e5f06b79d 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -998,7 +998,7 @@ EXPORT_SYMBOL(drm_gem_prime_import_dev); struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev, struct dma_buf *dma_buf) { - return drm_gem_prime_import_dev(dev, dma_buf, dev->dev); + return drm_gem_prime_import_dev(dev, dma_buf, drm_dev_dma_dev(dev)); } EXPORT_SYMBOL(drm_gem_prime_import); diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h index 6ea54a578cda..e2f894f1b90a 100644 --- a/include/drm/drm_device.h +++ b/include/drm/drm_device.h @@ -64,6 +64,28 @@ struct drm_device { /** @dev: Device structure of bus-device */ struct device *dev; + /** + * @dma_dev: + * + * Device for DMA operations. Only required if the device @dev + * cannot perform DMA by itself. Should be NULL otherwise. Call + * drm_dev_dma_dev() to get the DMA device instead of using this + * field directly. Call drm_dev_set_dma_dev() to set this field. + * + * DRM devices are sometimes bound to virtual devices that cannot + * perform DMA by themselves. Drivers should set this field to the + * respective DMA controller. + * + * Devices on USB and other peripheral busses also cannot perform + * DMA by themselves. The @dma_dev field should point the bus + * controller that does DMA on behalve of such a device. Required + * for importing buffers via dma-buf. + * + * If set, the DRM core automatically releases the reference on the + * device. + */ + struct device *dma_dev; + /** * @managed: * @@ -327,4 +349,23 @@ struct drm_device { struct dentry *debugfs_root; }; +void drm_dev_set_dma_dev(struct drm_device *dev, struct device *dma_dev); + +/** + * drm_dev_dma_dev - returns the DMA device for a DRM device + * @dev: DRM device + * + * Returns the DMA device of the given DRM device. By default, this + * the DRM device's parent. See drm_dev_set_dma_dev(). + * + * Returns: + * A DMA-capable device for the DRM device. + */ +static inline struct device *drm_dev_dma_dev(struct drm_device *dev) +{ + if (dev->dma_dev) + return dev->dma_dev; + return dev->dev; +} + #endif