Introduce DRM_IOCTL_QDA_QUERY, a query IOCTL that lets user-space retrieve information about the DSP a given /dev/accel/accel* node represents.
The IOCTL takes a query_type selector as input, so it can be extended to return additional parameters (capabilities, attributes) in the future without adding new IOCTLs: drm_ioctl() zero-extends the argument structure, so new fields can be appended to struct drm_qda_query as long as they go at the end. The first supported query, QDA_QUERY_DSP_NAME, returns the DSP domain name (e.g. "cdsp", "adsp"). The UAPI header include/uapi/drm/qda_accel.h defines the command number, the DRM_IOWR IOCTL definition, the query_type values, and struct drm_qda_query. It follows the standard DRM UAPI conventions: fixed-width types, a C++ extern "C" guard, and GPL-2.0-only WITH Linux-syscall-note licensing. qda_ioctl_query() validates the reserved pad field, dispatches on query_type, and copies the DSP name from qda_dev.dsp_name into the user-supplied buffer with strscpy(). Unknown query types are rejected with -EINVAL. qda_drv.c registers the qda_ioctls[] table with the drm_driver so the DRM core dispatches DRM_IOCTL_QDA_QUERY to qda_ioctl_query(). Assisted-by: Claude:claude-sonnet-5 Signed-off-by: Ekansh Gupta <[email protected]> --- Changes in v2: - Add a query_type input selector so the IOCTL can return different parameters in future, and switch DRM_IOR -> DRM_IOWR so the input reaches the kernel (Dmitry Baryshkov) - Reject unknown query types and a non-zero pad with -EINVAL --- drivers/accel/qda/Makefile | 1 + drivers/accel/qda/qda_drv.c | 8 +++++++ drivers/accel/qda/qda_ioctl.c | 35 +++++++++++++++++++++++++++ drivers/accel/qda/qda_ioctl.h | 13 ++++++++++ include/uapi/drm/qda_accel.h | 55 +++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 112 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 fdc909facd95..e1fd8bfa12d7 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" static int qda_open(struct drm_device *dev, struct drm_file *file) { @@ -35,11 +37,17 @@ 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..c1d6c9bc0465 --- /dev/null +++ b/drivers/accel/qda/qda_ioctl.c @@ -0,0 +1,35 @@ +// 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; + + if (args->pad) + return -EINVAL; + + qdev = qda_dev_from_drm(dev); + + switch (args->query_type) { + case QDA_QUERY_DSP_NAME: + strscpy(args->dsp_name, qdev->dsp_name, sizeof(args->dsp_name)); + break; + default: + return -EINVAL; + } + + 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..fe695347762c --- /dev/null +++ b/include/uapi/drm/qda_accel.h @@ -0,0 +1,55 @@ +/* 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_IOWR(DRM_COMMAND_BASE + DRM_QDA_QUERY, \ + struct drm_qda_query) + +/* Query type definitions for drm_qda_query */ +#define QDA_QUERY_DSP_NAME 1 + +/** + * struct drm_qda_query - Device information query structure + * @query_type: Type of query (input) + * @pad: Padding for 64-bit alignment (must be zero) + * @dsp_name: Null-terminated name of the DSP (returned when query_type is QDA_QUERY_DSP_NAME) + * + * This structure is used with DRM_IOCTL_QDA_QUERY to query device attributes + * based on @query_type. + */ +struct drm_qda_query { + __u32 query_type; + __u32 pad; + __u8 dsp_name[16]; +}; + +#if defined(__cplusplus) +} +#endif + +#endif /* __QDA_ACCEL_H__ */ -- 2.34.1
