From 448c3de8ac8353fc4447738ae3c56c4eb6c2131d Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Thu, 15 Jul 2021 11:44:35 -0700 Subject: dmaengine: idxd: create user driver for wq 'device' The original architecture of /sys/bus/dsa invented a scheme whereby a single entry in the list of bus drivers, /sys/bus/drivers/dsa, handled all device types and internally routed them to different drivers. Those internal drivers were invisible to userspace. Now, as /sys/bus/dsa wants to grow support for alternate drivers for a given device, for example vfio-mdev instead of kernel-internal-dmaengine, a proper bus device-driver model is needed. The first step in that process is separating the existing omnibus/implicit "dsa" driver into proper individual drivers registered on /sys/bus/dsa. Establish the idxd_user_drv driver that controls the enabling and disabling of the wq and also register and unregister a char device to allow user space to mmap the descriptor submission portal. The cdev related bits are moved to the cdev driver probe/remove and out of the drv_enabe/disable_wq() calls. These bits are exclusive to the cdev operation and not part of the generic enable/disable of the wq device. Reviewed-by: Dan Williams Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/162637467578.744545.10203997610072341376.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Vinod Koul --- drivers/dma/idxd/cdev.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) (limited to 'drivers/dma/idxd/cdev.c') diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c index 18a003b93812..b67bbf24242a 100644 --- a/drivers/dma/idxd/cdev.c +++ b/drivers/dma/idxd/cdev.c @@ -304,6 +304,59 @@ void idxd_wq_del_cdev(struct idxd_wq *wq) put_device(cdev_dev(idxd_cdev)); } +static int idxd_user_drv_probe(struct idxd_dev *idxd_dev) +{ + struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev); + struct idxd_device *idxd = wq->idxd; + int rc; + + if (idxd->state != IDXD_DEV_ENABLED) + return -ENXIO; + + mutex_lock(&wq->wq_lock); + wq->type = IDXD_WQT_USER; + rc = __drv_enable_wq(wq); + if (rc < 0) + goto err; + + rc = idxd_wq_add_cdev(wq); + if (rc < 0) + goto err_cdev; + + mutex_unlock(&wq->wq_lock); + return 0; + +err_cdev: + __drv_disable_wq(wq); +err: + wq->type = IDXD_WQT_NONE; + mutex_unlock(&wq->wq_lock); + return rc; +} + +static void idxd_user_drv_remove(struct idxd_dev *idxd_dev) +{ + struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev); + + mutex_lock(&wq->wq_lock); + idxd_wq_del_cdev(wq); + __drv_disable_wq(wq); + wq->type = IDXD_WQT_NONE; + mutex_unlock(&wq->wq_lock); +} + +static enum idxd_dev_type dev_types[] = { + IDXD_DEV_WQ, + IDXD_DEV_NONE, +}; + +struct idxd_device_driver idxd_user_drv = { + .probe = idxd_user_drv_probe, + .remove = idxd_user_drv_remove, + .name = "user", + .type = dev_types, +}; + int idxd_cdev_register(void) { int rc, i; -- cgit v1.2.3