On Wed, Jun 03, 2026 at 11:21:43AM +0530, Ekansh Gupta wrote: > On 20-05-2026 19:59, Dmitry Baryshkov wrote: > > On Tue, May 19, 2026 at 11:45:58AM +0530, Ekansh Gupta via B4 Relay wrote: > >> From: Ekansh Gupta <[email protected]> > >> > >> Introduce the DRM_IOCTL_QDA_QUERY IOCTL, which allows user-space to > >> identify which DSP domain a given /dev/accel/accel* node represents > >> (e.g. "cdsp", "adsp"). > >> > >> include/uapi/drm/qda_accel.h > >> Defines the QDA IOCTL command numbers and the associated data > >> structures. The header follows the standard DRM UAPI conventions: > >> __u8/__u32 types, a C++ extern "C" guard, and GPL-2.0-only WITH > >> Linux-syscall-note licensing. > >> > >> drivers/accel/qda/qda_ioctl.c / qda_ioctl.h > >> Implements qda_ioctl_query(), which copies the DSP domain name > >> stored in qda_dev.dsp_name into the user-supplied drm_qda_query > >> buffer using strscpy(). > >> > >> drivers/accel/qda/qda_drv.c > >> Registers the qda_ioctls[] table with the drm_driver so that the > >> DRM core dispatches DRM_IOCTL_QDA_QUERY to qda_ioctl_query(). > >> > >> Assisted-by: Claude:claude-4-6-sonnet > >> Signed-off-by: Ekansh Gupta <[email protected]> > >> --- > >> drivers/accel/qda/Makefile | 1 + > >> drivers/accel/qda/qda_drv.c | 8 +++++++ > >> drivers/accel/qda/qda_ioctl.c | 26 +++++++++++++++++++++++ > >> drivers/accel/qda/qda_ioctl.h | 13 ++++++++++++ > >> include/uapi/drm/qda_accel.h | 49 > >> +++++++++++++++++++++++++++++++++++++++++++ > >> 5 files changed, 97 insertions(+) > >> > >> diff --git a/drivers/accel/qda/Makefile b/drivers/accel/qda/Makefile > >> index 701fad5ffb50..b658dad35fee 100644 > >> --- a/drivers/accel/qda/Makefile > >> +++ b/drivers/accel/qda/Makefile > >> @@ -8,6 +8,7 @@ obj-$(CONFIG_DRM_ACCEL_QDA) := qda.o > >> qda-y := \ > >> qda_cb.o \ > >> qda_drv.o \ > >> + qda_ioctl.o \ > >> qda_memory_manager.o \ > >> qda_rpmsg.o > >> > >> diff --git a/drivers/accel/qda/qda_drv.c b/drivers/accel/qda/qda_drv.c > >> index 0ad5d9873d7e..becd831d10be 100644 > >> --- a/drivers/accel/qda/qda_drv.c > >> +++ b/drivers/accel/qda/qda_drv.c > >> @@ -8,8 +8,10 @@ > >> #include <drm/drm_gem.h> > >> #include <drm/drm_ioctl.h> > >> #include <drm/drm_print.h> > >> +#include <drm/qda_accel.h> > >> > >> #include "qda_drv.h" > >> +#include "qda_ioctl.h" > >> #include "qda_rpmsg.h" > >> > >> static int qda_open(struct drm_device *dev, struct drm_file *file) > >> @@ -36,11 +38,17 @@ static void qda_postclose(struct drm_device *dev, > >> struct drm_file *file) > >> > >> DEFINE_DRM_ACCEL_FOPS(qda_accel_fops); > >> > >> +static const struct drm_ioctl_desc qda_ioctls[] = { > >> + DRM_IOCTL_DEF_DRV(QDA_QUERY, qda_ioctl_query, 0), > >> +}; > >> + > >> static const struct drm_driver qda_drm_driver = { > >> .driver_features = DRIVER_COMPUTE_ACCEL, > >> .fops = &qda_accel_fops, > >> .open = qda_open, > >> .postclose = qda_postclose, > >> + .ioctls = qda_ioctls, > >> + .num_ioctls = ARRAY_SIZE(qda_ioctls), > >> .name = QDA_DRIVER_NAME, > >> .desc = "Qualcomm DSP Accelerator Driver", > >> }; > >> diff --git a/drivers/accel/qda/qda_ioctl.c b/drivers/accel/qda/qda_ioctl.c > >> new file mode 100644 > >> index 000000000000..761d3567c33f > >> --- /dev/null > >> +++ b/drivers/accel/qda/qda_ioctl.c > >> @@ -0,0 +1,26 @@ > >> +// SPDX-License-Identifier: GPL-2.0-only > >> +// Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. > >> +#include <drm/drm_ioctl.h> > >> +#include <drm/qda_accel.h> > >> +#include "qda_drv.h" > >> +#include "qda_ioctl.h" > >> + > >> +/** > >> + * qda_ioctl_query() - Query DSP device information > >> + * @dev: DRM device structure > >> + * @data: User-space data (struct drm_qda_query) > >> + * @file_priv: DRM file private data > >> + * > >> + * Return: 0 on success, negative error code on failure > >> + */ > >> +int qda_ioctl_query(struct drm_device *dev, void *data, struct drm_file > >> *file_priv) > >> +{ > >> + struct drm_qda_query *args = data; > >> + struct qda_dev *qdev; > >> + > >> + qdev = qda_dev_from_drm(dev); > >> + > >> + strscpy(args->dsp_name, qdev->dsp_name, sizeof(args->dsp_name)); > >> + > >> + return 0; > >> +} > >> diff --git a/drivers/accel/qda/qda_ioctl.h b/drivers/accel/qda/qda_ioctl.h > >> new file mode 100644 > >> index 000000000000..b8fd536a111f > >> --- /dev/null > >> +++ b/drivers/accel/qda/qda_ioctl.h > >> @@ -0,0 +1,13 @@ > >> +/* SPDX-License-Identifier: GPL-2.0-only */ > >> +/* > >> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. > >> + */ > >> + > >> +#ifndef __QDA_IOCTL_H__ > >> +#define __QDA_IOCTL_H__ > >> + > >> +#include "qda_drv.h" > >> + > >> +int qda_ioctl_query(struct drm_device *dev, void *data, struct drm_file > >> *file_priv); > >> + > >> +#endif /* __QDA_IOCTL_H__ */ > >> diff --git a/include/uapi/drm/qda_accel.h b/include/uapi/drm/qda_accel.h > >> new file mode 100644 > >> index 000000000000..1971a4263065 > >> --- /dev/null > >> +++ b/include/uapi/drm/qda_accel.h > >> @@ -0,0 +1,49 @@ > >> +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ > >> +/* > >> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. > >> + */ > >> + > >> +#ifndef __QDA_ACCEL_H__ > >> +#define __QDA_ACCEL_H__ > >> + > >> +#include "drm.h" > >> + > >> +#if defined(__cplusplus) > >> +extern "C" { > >> +#endif > >> + > >> +/* > >> + * QDA IOCTL command numbers > >> + * > >> + * These define the command numbers for QDA-specific IOCTLs. > >> + * They are used with DRM_COMMAND_BASE to create the full IOCTL numbers. > >> + */ > >> +#define DRM_QDA_QUERY 0x00 > >> + > >> +/* > >> + * QDA IOCTL definitions > >> + * > >> + * These macros define the actual IOCTL numbers used by userspace > >> applications. > >> + * They combine the command numbers with DRM_COMMAND_BASE and specify the > >> + * data structure and direction (read/write) for each IOCTL. > >> + */ > >> +#define DRM_IOCTL_QDA_QUERY DRM_IOR(DRM_COMMAND_BASE + > >> DRM_QDA_QUERY, \ > >> + struct drm_qda_query) > >> + > >> +/** > >> + * struct drm_qda_query - Device information query structure > >> + * @dsp_name: Name of DSP (e.g., "adsp", "cdsp", "cdsp1", "gdsp0", > >> "gdsp1") > >> + * > >> + * This structure is used with DRM_IOCTL_QDA_QUERY to query device type, > >> + * allowing userspace to identify which DSP a device node represents. The > >> + * kernel provides the DSP name directly as a null-terminated string. > >> + */ > >> +struct drm_qda_query { > >> + __u8 dsp_name[16]; > > > > Are you sure that you want to query only the name? No extra options, no > > attributes, no hardware capabilities? > There are plans to extend this ioctl to support DSP capabilities and few > other query options, but as per my understanding, I don't need to add > reserved IOCTLs in drm case and I can extend it in future. Please > correct me if my understanding is wrong and I should add reserved fields. > > Copying the statement from the doc[1]. > "Note that drm_ioctl() automatically zero-extends structures, hence make > sure you can add more stuff at the end, i.e. don’t put a variable sized > array there."
I'd rather have a query type as an input here, to be able to return one of querried params. > > [1] > https://www.kernel.org/doc/html/v7.0/gpu/drm-uapi.html#ioctl-support-on-device-nodes> > > >> +}; > >> + > >> +#if defined(__cplusplus) > >> +} > >> +#endif > >> + > >> +#endif /* __QDA_ACCEL_H__ */ > >> > >> -- > >> 2.34.1 > >> > >> > > > -- With best wishes Dmitry
