Introduce per-file and per-user context for the QDA DRM accelerator driver. A new qda_file_priv structure is stored in file->driver_priv for each open file descriptor, and a qda_user object is allocated per client with a unique client_id generated from an atomic counter in qda_dev.
The DRM driver now provides qda_open() and qda_postclose() callbacks. qda_open() resolves the qda_dev from the drm_device, allocates the qda_file_priv and qda_user structures, and attaches them to the DRM file. qda_postclose() tears down the per-file context and frees the qda_user object when the file is closed.
This prepares the QDA driver to track per-process state for future features such as per-client memory mappings, job submission contexts, and access control over DSP compute resources.
Signed-off-by: Ekansh Gupta ekansh.gupta@oss.qualcomm.com --- drivers/accel/qda/qda_drv.c | 117 ++++++++++++++++++++++++++++++++++++++++++++ drivers/accel/qda/qda_drv.h | 30 ++++++++++++ 2 files changed, 147 insertions(+)
diff --git a/drivers/accel/qda/qda_drv.c b/drivers/accel/qda/qda_drv.c index a9113ec78fa2..bf95fc782cf8 100644 --- a/drivers/accel/qda/qda_drv.c +++ b/drivers/accel/qda/qda_drv.c @@ -12,11 +12,127 @@ #include "qda_drv.h" #include "qda_rpmsg.h"
+static struct qda_drm_priv *get_drm_priv_from_device(struct drm_device *dev) +{ + if (!dev) + return NULL; + + return (struct qda_drm_priv *)dev->dev_private; +} + +static struct qda_dev *get_qdev_from_drm_device(struct drm_device *dev) +{ + struct qda_drm_priv *drm_priv; + + if (!dev) { + qda_dbg(NULL, "Invalid drm_device\n"); + return NULL; + } + + drm_priv = get_drm_priv_from_device(dev); + if (!drm_priv) { + qda_dbg(NULL, "No drm_priv in dev_private\n"); + return NULL; + } + + return drm_priv->qdev; +} + +static struct qda_user *alloc_qda_user(struct qda_dev *qdev) +{ + struct qda_user *qda_user; + + qda_user = kzalloc_obj(*qda_user, GFP_KERNEL); + if (!qda_user) + return NULL; + + qda_user->client_id = atomic_inc_return(&qdev->client_id_counter); + qda_user->qda_dev = qdev; + + qda_dbg(qdev, "Allocated qda_user with client_id=%u\n", qda_user->client_id); + return qda_user; +} + +static void free_qda_user(struct qda_user *qda_user) +{ + if (!qda_user) + return; + + qda_dbg(qda_user->qda_dev, "Freeing qda_user client_id=%u\n", qda_user->client_id); + + kfree(qda_user); +} + +static int qda_open(struct drm_device *dev, struct drm_file *file) +{ + struct qda_user *qda_user; + struct qda_file_priv *qda_file_priv; + struct qda_dev *qdev; + + if (!file) { + qda_dbg(NULL, "Invalid file pointer\n"); + return -EINVAL; + } + + qdev = get_qdev_from_drm_device(dev); + if (!qdev) { + qda_dbg(NULL, "Failed to get qdev from drm_device\n"); + return -EINVAL; + } + + qda_file_priv = kzalloc(sizeof(*qda_file_priv), GFP_KERNEL); + if (!qda_file_priv) + return -ENOMEM; + + qda_file_priv->pid = current->pid; + + qda_user = alloc_qda_user(qdev); + if (!qda_user) { + qda_dbg(qdev, "Failed to allocate qda_user\n"); + kfree(qda_file_priv); + return -ENOMEM; + } + + file->driver_priv = qda_file_priv; + qda_file_priv->qda_user = qda_user; + + qda_dbg(qdev, "Device opened successfully for PID %d\n", current->pid); + + return 0; +} + +static void qda_postclose(struct drm_device *dev, struct drm_file *file) +{ + struct qda_dev *qdev; + struct qda_file_priv *qda_file_priv; + struct qda_user *qda_user; + + qdev = get_qdev_from_drm_device(dev); + if (!qdev || atomic_read(&qdev->removing)) { + qda_dbg(NULL, "Device unavailable or removing\n"); + return; + } + + qda_file_priv = (struct qda_file_priv *)file->driver_priv; + if (qda_file_priv) { + qda_user = qda_file_priv->qda_user; + if (qda_user) + free_qda_user(qda_user); + + kfree(qda_file_priv); + file->driver_priv = NULL; + } + + qda_dbg(qdev, "Device closed for PID %d\n", current->pid); +} + DEFINE_DRM_ACCEL_FOPS(qda_accel_fops);
static struct drm_driver qda_drm_driver = { .driver_features = DRIVER_COMPUTE_ACCEL, .fops = &qda_accel_fops, + .open = qda_open, + .postclose = qda_postclose, .name = DRIVER_NAME, .desc = "Qualcomm DSP Accelerator Driver", }; @@ -58,6 +174,7 @@ static void init_device_resources(struct qda_dev *qdev)
mutex_init(&qdev->lock); atomic_set(&qdev->removing, 0); + atomic_set(&qdev->client_id_counter, 0); }
static int init_memory_manager(struct qda_dev *qdev) diff --git a/drivers/accel/qda/qda_drv.h b/drivers/accel/qda/qda_drv.h index 2b80401a3741..e0ba37702a86 100644 --- a/drivers/accel/qda/qda_drv.h +++ b/drivers/accel/qda/qda_drv.h @@ -10,6 +10,7 @@ #include <linux/list.h> #include <linux/mutex.h> #include <linux/rpmsg.h> +#include <linux/types.h> #include <linux/xarray.h> #include <drm/drm_drv.h> #include <drm/drm_file.h> @@ -20,6 +21,33 @@ /* Driver identification */ #define DRIVER_NAME "qda"
+/** + * struct qda_file_priv - Per-process private data for DRM file + * + * This structure tracks per-process state for each open file descriptor. + * It maintains the IOMMU device assignment and links to the legacy qda_user + * structure for compatibility with existing code. + */ +struct qda_file_priv { + /* Process ID for tracking */ + pid_t pid; + /* Pointer to qda_user structure for backward compatibility */ + struct qda_user *qda_user; +}; + +/** + * struct qda_user - Per-user context for remote processor interaction + * + * This structure maintains per-user state for interactions with the + * remote processor, including memory mappings and pending operations. + */ +struct qda_user { + /* Unique client identifier */ + u32 client_id; + /* Back-pointer to device structure */ + struct qda_dev *qda_dev; +}; + /** * struct qda_drm_priv - DRM device private data for QDA device * @@ -52,6 +80,8 @@ struct qda_dev { struct qda_drm_priv *drm_priv; /* Flag indicating device removal in progress */ atomic_t removing; + /* Atomic counter for generating unique client IDs */ + atomic_t client_id_counter; /* Name of the DSP (e.g., "cdsp", "adsp") */ char dsp_name[16]; /* Compute context-bank (CB) child devices */