On 20-05-2026 19:48, Dmitry Baryshkov wrote: > On Tue, May 19, 2026 at 11:45:53AM +0530, Ekansh Gupta via B4 Relay wrote: >> From: Ekansh Gupta <[email protected]> >> >> Add the foundational driver files for the Qualcomm DSP Accelerator >> (QDA), a DRM accel driver for Qualcomm DSPs. The driver integrates >> with the DRM accel subsystem (drivers/accel/) and provides: >> >> - A standard /dev/accel/accel* character device node via DRM. >> - GEM-based buffer management with DMA-BUF import/export (PRIME). >> - IOMMU context bank management for per-session memory isolation. >> - Standard DRM IOCTLs for device management and job submission. >> >> qda_drv.c / qda_drv.h: Core DRM driver registration. Defines the >> drm_driver ops table, per-file private state (qda_file_priv), and the >> main device structure (qda_dev) which embeds drm_device. >> >> qda_rpmsg.c / qda_rpmsg.h: RPMsg transport layer. Registers an >> rpmsg_driver matching the "qcom,fastrpc" compatible string. On probe >> it allocates a qda_dev, reads the DSP domain name from the "label" DT >> property, and registers the DRM device. >> >> Assisted-by: Claude:claude-4-6-sonnet >> Signed-off-by: Ekansh Gupta <[email protected]> >> --- >> drivers/accel/Kconfig | 1 + >> drivers/accel/Makefile | 1 + >> drivers/accel/qda/Kconfig | 30 +++++++++++++ >> drivers/accel/qda/Makefile | 10 +++++ >> drivers/accel/qda/qda_drv.c | 97 >> ++++++++++++++++++++++++++++++++++++++++++ >> drivers/accel/qda/qda_drv.h | 62 +++++++++++++++++++++++++++ >> drivers/accel/qda/qda_rpmsg.c | 99 >> +++++++++++++++++++++++++++++++++++++++++++ >> drivers/accel/qda/qda_rpmsg.h | 13 ++++++ >> 8 files changed, 313 insertions(+) >> >> diff --git a/drivers/accel/Kconfig b/drivers/accel/Kconfig >> index bdf48ccafcf2..74ac0f71bc9d 100644 >> --- a/drivers/accel/Kconfig >> +++ b/drivers/accel/Kconfig >> @@ -29,6 +29,7 @@ source "drivers/accel/ethosu/Kconfig" >> source "drivers/accel/habanalabs/Kconfig" >> source "drivers/accel/ivpu/Kconfig" >> source "drivers/accel/qaic/Kconfig" >> +source "drivers/accel/qda/Kconfig" >> source "drivers/accel/rocket/Kconfig" >> >> endif >> diff --git a/drivers/accel/Makefile b/drivers/accel/Makefile >> index 1d3a7251b950..58c08dd5f389 100644 >> --- a/drivers/accel/Makefile >> +++ b/drivers/accel/Makefile >> @@ -5,4 +5,5 @@ obj-$(CONFIG_DRM_ACCEL_ARM_ETHOSU) += ethosu/ >> obj-$(CONFIG_DRM_ACCEL_HABANALABS) += habanalabs/ >> obj-$(CONFIG_DRM_ACCEL_IVPU) += ivpu/ >> obj-$(CONFIG_DRM_ACCEL_QAIC) += qaic/ >> +obj-$(CONFIG_DRM_ACCEL_QDA) += qda/ >> obj-$(CONFIG_DRM_ACCEL_ROCKET) += rocket/ >> \ No newline at end of file >> diff --git a/drivers/accel/qda/Kconfig b/drivers/accel/qda/Kconfig >> new file mode 100644 >> index 000000000000..484d21ff1b55 >> --- /dev/null >> +++ b/drivers/accel/qda/Kconfig >> @@ -0,0 +1,30 @@ >> +# SPDX-License-Identifier: GPL-2.0-only >> +# >> +# Qualcomm DSP accelerator driver >> +# >> + >> +config DRM_ACCEL_QDA >> + tristate "Qualcomm DSP accelerator" >> + depends on DRM_ACCEL >> + depends on ARCH_QCOM || COMPILE_TEST >> + depends on RPMSG >> + help >> + Enables the DRM-based accelerator driver for Qualcomm's Hexagon DSPs. >> + This driver provides a standardized interface for offloading >> computational >> + tasks to the DSP, including audio processing, sensor offload, computer >> + vision, and AI inference workloads. >> + >> + The driver supports all DSP domains (ADSP, CDSP, SDSP, GDSP) and >> + implements the FastRPC protocol for communication between the >> application >> + processor and DSP. It integrates with the Linux kernel's Compute >> + Accelerators subsystem (drivers/accel/) and provides a modern >> alternative >> + to the legacy FastRPC driver found in drivers/misc/. >> + >> + Key features include DMA-BUF interoperability for seamless buffer >> sharing > > Key features of what? Consider distro maintainers reading your help text > in order to identify whether to enable it or not. ack> >> + with other multimedia subsystems, IOMMU-based memory isolation, and >> + standard DRM IOCTLs for device management and job submission. >> + >> + If unsure, say N. >> + >> + To compile this driver as a module, choose M here: the >> + module will be called qda. >> diff --git a/drivers/accel/qda/Makefile b/drivers/accel/qda/Makefile >> new file mode 100644 >> index 000000000000..dbe809067a8b >> --- /dev/null >> +++ b/drivers/accel/qda/Makefile >> @@ -0,0 +1,10 @@ >> +# SPDX-License-Identifier: GPL-2.0-only >> +# >> +# Makefile for Qualcomm DSP accelerator driver >> +# >> + >> +obj-$(CONFIG_DRM_ACCEL_QDA) := qda.o >> + >> +qda-y := \ >> + qda_drv.o \ >> + qda_rpmsg.o >> diff --git a/drivers/accel/qda/qda_drv.c b/drivers/accel/qda/qda_drv.c >> new file mode 100644 >> index 000000000000..1c1bab68d445 >> --- /dev/null >> +++ b/drivers/accel/qda/qda_drv.c >> @@ -0,0 +1,97 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +// Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. >> +#include <linux/module.h> >> +#include <linux/slab.h> >> +#include <drm/drm_accel.h> >> +#include <drm/drm_drv.h> >> +#include <drm/drm_file.h> >> +#include <drm/drm_gem.h> >> +#include <drm/drm_ioctl.h> >> +#include <drm/drm_print.h> >> + >> +#include "qda_drv.h" >> +#include "qda_rpmsg.h" >> + >> +static int qda_open(struct drm_device *dev, struct drm_file *file) >> +{ >> + struct qda_file_priv *qda_file_priv; >> + >> + qda_file_priv = kzalloc_obj(*qda_file_priv); >> + if (!qda_file_priv) >> + return -ENOMEM; >> + >> + qda_file_priv->qda_dev = qda_dev_from_drm(dev); >> + file->driver_priv = qda_file_priv; >> + >> + return 0; >> +} >> + >> +static void qda_postclose(struct drm_device *dev, struct drm_file *file) >> +{ >> + struct qda_file_priv *qda_file_priv = file->driver_priv; >> + >> + kfree(qda_file_priv); >> + file->driver_priv = NULL; >> +} >> + >> +DEFINE_DRM_ACCEL_FOPS(qda_accel_fops); >> + >> +static const struct drm_driver qda_drm_driver = { >> + .driver_features = DRIVER_COMPUTE_ACCEL, >> + .fops = &qda_accel_fops, >> + .open = qda_open, >> + .postclose = qda_postclose, >> + .name = QDA_DRIVER_NAME, >> + .desc = "Qualcomm DSP Accelerator Driver", >> +}; >> + >> +struct qda_dev *qda_alloc_device(struct device *dev) >> +{ >> + struct qda_dev *qdev; >> + >> + qdev = devm_drm_dev_alloc(dev, &qda_drm_driver, struct qda_dev, >> drm_dev); >> + if (IS_ERR(qdev)) >> + return ERR_CAST(qdev); >> + >> + return qdev; >> +} >> + >> +void qda_unregister_device(struct qda_dev *qdev) >> +{ >> + drm_dev_unregister(&qdev->drm_dev); >> +} >> + >> +int qda_register_device(struct qda_dev *qdev) >> +{ >> + int ret; >> + >> + ret = drm_dev_register(&qdev->drm_dev, 0); >> + if (ret) >> + drm_err(&qdev->drm_dev, "Failed to register DRM device: %d\n", >> ret); >> + >> + return ret; >> +} >> + >> +static int __init qda_core_init(void) >> +{ >> + int ret; >> + >> + ret = qda_rpmsg_register(); >> + if (ret) >> + return ret; >> + >> + pr_info("qda: QDA driver initialization complete\n"); >> + return 0; >> +} >> + >> +static void __exit qda_core_exit(void) >> +{ >> + qda_rpmsg_unregister(); >> +} >> + >> +module_init(qda_core_init); >> +module_exit(qda_core_exit); >> + >> +MODULE_AUTHOR("Qualcomm AI Infra Team"); >> +MODULE_DESCRIPTION("Qualcomm DSP Accelerator Driver"); >> +MODULE_LICENSE("GPL"); >> diff --git a/drivers/accel/qda/qda_drv.h b/drivers/accel/qda/qda_drv.h >> new file mode 100644 >> index 000000000000..7ba2ef19a411 >> --- /dev/null >> +++ b/drivers/accel/qda/qda_drv.h >> @@ -0,0 +1,62 @@ >> +/* SPDX-License-Identifier: GPL-2.0-only */ >> +/* >> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. >> + */ >> + >> +#ifndef __QDA_DRV_H__ >> +#define __QDA_DRV_H__ >> + >> +#include <linux/device.h> >> +#include <linux/rpmsg.h> >> +#include <linux/types.h> >> +#include <drm/drm_device.h> >> +#include <drm/drm_drv.h> >> +#include <drm/drm_file.h> >> + >> +/* Driver identification */ >> +#define QDA_DRIVER_NAME "qda" >> + >> +/** >> + * struct qda_file_priv - Per-process private data for DRM file >> + */ >> +struct qda_file_priv { >> + /** @qda_dev: Back-pointer to device structure */ >> + struct qda_dev *qda_dev; >> +}; >> + >> +/** >> + * struct qda_dev - Main device structure for QDA driver >> + * >> + * The DRM device is embedded as the first member so that container_of() >> + * can recover the qda_dev from any drm_device pointer. >> + */ >> +struct qda_dev { >> + /** @drm_dev: Embedded DRM device; recover via qda_dev_from_drm() */ >> + struct drm_device drm_dev; >> + /** @rpdev: RPMsg device for communication with the remote processor */ >> + struct rpmsg_device *rpdev; >> + /** @dev: Underlying Linux device */ >> + struct device *dev; >> + /** @dsp_name: Name of the DSP domain (e.g. "cdsp", "adsp") */ >> + const char *dsp_name; >> +}; >> + >> +/** >> + * qda_dev_from_drm - Recover qda_dev from an embedded drm_device pointer >> + * @dev: Pointer to the embedded drm_device >> + * >> + * Return: Pointer to the enclosing qda_dev. >> + */ >> +static inline struct qda_dev *qda_dev_from_drm(struct drm_device *dev) >> +{ >> + return container_of(dev, struct qda_dev, drm_dev); >> +} >> + >> +/* Device allocation (uses devm_drm_dev_alloc internally) */ >> +struct qda_dev *qda_alloc_device(struct device *dev); >> + >> +/* Core device lifecycle */ >> +int qda_register_device(struct qda_dev *qdev); >> +void qda_unregister_device(struct qda_dev *qdev); >> + >> +#endif /* __QDA_DRV_H__ */ >> diff --git a/drivers/accel/qda/qda_rpmsg.c b/drivers/accel/qda/qda_rpmsg.c >> new file mode 100644 >> index 000000000000..6eaf1b145f8a >> --- /dev/null >> +++ b/drivers/accel/qda/qda_rpmsg.c >> @@ -0,0 +1,99 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +// Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. >> +#include <linux/module.h> >> +#include <linux/of.h> >> +#include <linux/rpmsg.h> >> +#include <drm/drm_print.h> >> + >> +#include "qda_drv.h" >> +#include "qda_rpmsg.h" >> + >> +static struct qda_dev *alloc_and_init_qdev(struct rpmsg_device *rpdev) > > Use the prefix uniformly. > ack>> +{ >> + struct qda_dev *qdev; >> + >> + qdev = qda_alloc_device(&rpdev->dev); >> + if (IS_ERR(qdev)) >> + return qdev; >> + >> + qdev->dev = &rpdev->dev; >> + qdev->rpdev = rpdev; >> + dev_set_drvdata(&rpdev->dev, qdev); >> + >> + return qdev; >> +} >> + >> +static int qda_rpmsg_cb(struct rpmsg_device *rpdev, void *data, int len, >> + void *priv, u32 src) >> +{ >> + /* Placeholder: responses will be dispatched here */ >> + return 0; >> +} >> + >> +static void qda_rpmsg_remove(struct rpmsg_device *rpdev) >> +{ >> + struct qda_dev *qdev = dev_get_drvdata(&rpdev->dev); >> + >> + drm_dev_unplug(&qdev->drm_dev); >> + qdev->rpdev = NULL; >> + qda_unregister_device(qdev); >> + dev_info(qdev->dev, "RPMsg device removed\n"); > > Drop the spamming. And useless (where it is useless) drm_dbg() / dev_dbg() > spamming too. ack> >> +} >> + >> +static int qda_rpmsg_probe(struct rpmsg_device *rpdev) >> +{ >> + struct qda_dev *qdev; >> + const char *label; >> + int ret; >> + >> + dev_dbg(&rpdev->dev, "QDA RPMsg probe starting\n"); >> + >> + qdev = alloc_and_init_qdev(rpdev); >> + if (IS_ERR(qdev)) >> + return PTR_ERR(qdev); >> + >> + ret = of_property_read_string(rpdev->dev.of_node, "label", &label); >> + if (ret) { >> + dev_err(qdev->dev, "Missing 'label' property in DT node: %d\n", >> ret); >> + return ret; >> + } >> + qdev->dsp_name = label; > > Why not just of_property_read_string(...., &qdev->dsp_name)? > >> + >> + ret = qda_register_device(qdev); > > return qda_register_device(); ack> >> + if (ret) >> + return ret; >> + >> + drm_info(&qdev->drm_dev, "QDA RPMsg probe complete for %s\n", >> qdev->dsp_name); >> + return 0; >> +} >> + >> +static const struct of_device_id qda_rpmsg_id_table[] = { >> + { .compatible = "qcom,fastrpc" }, >> + {}, >> +}; >> +MODULE_DEVICE_TABLE(of, qda_rpmsg_id_table); >> + >> +static struct rpmsg_driver qda_rpmsg_driver = { >> + .probe = qda_rpmsg_probe, >> + .remove = qda_rpmsg_remove, >> + .callback = qda_rpmsg_cb, >> + .drv = { >> + .name = "qcom,fastrpc", >> + .of_match_table = qda_rpmsg_id_table, >> + }, >> +}; >> + >> +int qda_rpmsg_register(void) >> +{ >> + int ret = register_rpmsg_driver(&qda_rpmsg_driver); >> + >> + if (ret) >> + pr_err("qda: Failed to register RPMsg driver: %d\n", ret); >> + >> + return ret; >> +} >> + >> +void qda_rpmsg_unregister(void) >> +{ >> + unregister_rpmsg_driver(&qda_rpmsg_driver); >> +} > > Just use module_rpmsg_driver(), drop all the wrappers and module_init() > / exit(). I'll check and update this.> >> diff --git a/drivers/accel/qda/qda_rpmsg.h b/drivers/accel/qda/qda_rpmsg.h >> new file mode 100644 >> index 000000000000..5229d834b34b >> --- /dev/null >> +++ b/drivers/accel/qda/qda_rpmsg.h >> @@ -0,0 +1,13 @@ >> +/* SPDX-License-Identifier: GPL-2.0-only */ >> +/* >> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. >> + */ >> + >> +#ifndef __QDA_RPMSG_H__ >> +#define __QDA_RPMSG_H__ >> + >> +/* RPMsg transport layer registration */ >> +int qda_rpmsg_register(void); >> +void qda_rpmsg_unregister(void); >> + >> +#endif /* __QDA_RPMSG_H__ */ >> >> -- >> 2.34.1 >> >> >
