2023-10-02 22:45:48

by Fenghua Yu

[permalink] [raw]
Subject: Re: [PATCH] dmaengine: idxd: add wq driver name support for accel-config user tool

Hi, Vinod,

I see you applied a couple of IDXD patches to dmaengine tree last week.
Really appreciate that!

This patch and another patch that fixes a split lock issue:
https://lore.kernel.org/dmaengine/[email protected]/
are not applied yet.

Any concern on these two patches? Are they good to be applied to
dmaengine tree?

Thank you very much!

-Fenghua


On 9/8/23 13:10, Fenghua Yu wrote:
> From: Dave Jiang <[email protected]>
>
> With the possibility of multiple wq drivers that can be bound to the wq,
> the user config tool accel-config needs a way to know which wq driver to
> bind to the wq. Introduce per wq driver_name sysfs attribute where the user
> can indicate the driver to be bound to the wq. This allows accel-config to
> just bind to the driver using wq->driver_name.
>
> Signed-off-by: Dave Jiang <[email protected]>
> Signed-off-by: Tom Zanussi <[email protected]>
> Reviewed-by: Fenghua Yu <[email protected]>
> Acked-by: Vinod Koul <[email protected]>
> ---
>
> Hi, Vinod,
>
> This patch is part of IAA crypto patch series:
> https://lore.kernel.org/all/[email protected]/
> I'm sending this patch indepentantly here because:
> 1. the IAA crypto patch series is unlikely to be merged into 6.7
> 2. this patch is useful by itself in a few other places
> 3. this patch doesn't depend on the IAA crypto patch set and can
> be used and applied cleanly by itself
> 4. this patch has only dmaengine code
>
> So it would be good to merge this patch into 6.7 first. An updated
> IAA crypto patch set will be submitted later after 6.7 time frame
> and merged in a later kernel version.
>
> .../ABI/stable/sysfs-driver-dma-idxd | 6 ++++
> drivers/dma/idxd/cdev.c | 7 ++++
> drivers/dma/idxd/dma.c | 6 ++++
> drivers/dma/idxd/idxd.h | 9 +++++
> drivers/dma/idxd/sysfs.c | 34 +++++++++++++++++++
> include/uapi/linux/idxd.h | 1 +
> 6 files changed, 63 insertions(+)
>
> diff --git a/Documentation/ABI/stable/sysfs-driver-dma-idxd b/Documentation/ABI/stable/sysfs-driver-dma-idxd
> index 825e619250bf..982e9f3b80e2 100644
> --- a/Documentation/ABI/stable/sysfs-driver-dma-idxd
> +++ b/Documentation/ABI/stable/sysfs-driver-dma-idxd
> @@ -270,6 +270,12 @@ Description: Shows the operation capability bits displayed in bitmap format
> correlates to the operations allowed. It's visible only
> on platforms that support the capability.
>
> +What: /sys/bus/dsa/devices/wq<m>.<n>/driver_name
> +Date: Sept 8, 2023
> +KernelVersion: 6.7.0
> +Contact: [email protected]
> +Description: Name of driver to be bounded to the wq.
> +
> What: /sys/bus/dsa/devices/engine<m>.<n>/group_id
> Date: Oct 25, 2019
> KernelVersion: 5.6.0
> diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c
> index d32deb9b4e3d..0423655f5a88 100644
> --- a/drivers/dma/idxd/cdev.c
> +++ b/drivers/dma/idxd/cdev.c
> @@ -509,6 +509,7 @@ void idxd_wq_del_cdev(struct idxd_wq *wq)
>
> static int idxd_user_drv_probe(struct idxd_dev *idxd_dev)
> {
> + struct device *dev = &idxd_dev->conf_dev;
> struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
> struct idxd_device *idxd = wq->idxd;
> int rc;
> @@ -536,6 +537,12 @@ static int idxd_user_drv_probe(struct idxd_dev *idxd_dev)
>
> mutex_lock(&wq->wq_lock);
>
> + if (!idxd_wq_driver_name_match(wq, dev)) {
> + idxd->cmd_status = IDXD_SCMD_WQ_NO_DRV_NAME;
> + rc = -ENODEV;
> + goto wq_err;
> + }
> +
> wq->wq = create_workqueue(dev_name(wq_confdev(wq)));
> if (!wq->wq) {
> rc = -ENOMEM;
> diff --git a/drivers/dma/idxd/dma.c b/drivers/dma/idxd/dma.c
> index 07623fb0f52f..47a01893cfdb 100644
> --- a/drivers/dma/idxd/dma.c
> +++ b/drivers/dma/idxd/dma.c
> @@ -306,6 +306,12 @@ static int idxd_dmaengine_drv_probe(struct idxd_dev *idxd_dev)
> return -ENXIO;
>
> mutex_lock(&wq->wq_lock);
> + if (!idxd_wq_driver_name_match(wq, dev)) {
> + idxd->cmd_status = IDXD_SCMD_WQ_NO_DRV_NAME;
> + rc = -ENODEV;
> + goto err;
> + }
> +
> wq->type = IDXD_WQT_KERNEL;
>
> rc = drv_enable_wq(wq);
> diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
> index e269ca1f4862..1e89c80a07fc 100644
> --- a/drivers/dma/idxd/idxd.h
> +++ b/drivers/dma/idxd/idxd.h
> @@ -159,6 +159,8 @@ struct idxd_cdev {
> int minor;
> };
>
> +#define DRIVER_NAME_SIZE 128
> +
> #define IDXD_ALLOCATED_BATCH_SIZE 128U
> #define WQ_NAME_SIZE 1024
> #define WQ_TYPE_SIZE 10
> @@ -227,6 +229,8 @@ struct idxd_wq {
> /* Lock to protect upasid_xa access. */
> struct mutex uc_lock;
> struct xarray upasid_xa;
> +
> + char driver_name[DRIVER_NAME_SIZE + 1];
> };
>
> struct idxd_engine {
> @@ -646,6 +650,11 @@ static inline void idxd_wqcfg_set_max_batch_shift(int idxd_type, union wqcfg *wq
> wqcfg->max_batch_shift = max_batch_shift;
> }
>
> +static inline int idxd_wq_driver_name_match(struct idxd_wq *wq, struct device *dev)
> +{
> + return (strncmp(wq->driver_name, dev->driver->name, strlen(dev->driver->name)) == 0);
> +}
> +
> int __must_check __idxd_driver_register(struct idxd_device_driver *idxd_drv,
> struct module *module, const char *mod_name);
> #define idxd_driver_register(driver) \
> diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
> index 7caba90d85b3..523ae0dff7d4 100644
> --- a/drivers/dma/idxd/sysfs.c
> +++ b/drivers/dma/idxd/sysfs.c
> @@ -1259,6 +1259,39 @@ static ssize_t wq_op_config_store(struct device *dev, struct device_attribute *a
> static struct device_attribute dev_attr_wq_op_config =
> __ATTR(op_config, 0644, wq_op_config_show, wq_op_config_store);
>
> +static ssize_t wq_driver_name_show(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct idxd_wq *wq = confdev_to_wq(dev);
> +
> + return sysfs_emit(buf, "%s\n", wq->driver_name);
> +}
> +
> +static ssize_t wq_driver_name_store(struct device *dev, struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct idxd_wq *wq = confdev_to_wq(dev);
> + char *input, *pos;
> +
> + if (wq->state != IDXD_WQ_DISABLED)
> + return -EPERM;
> +
> + if (strlen(buf) > DRIVER_NAME_SIZE || strlen(buf) == 0)
> + return -EINVAL;
> +
> + input = kstrndup(buf, count, GFP_KERNEL);
> + if (!input)
> + return -ENOMEM;
> +
> + pos = strim(input);
> + memset(wq->driver_name, 0, DRIVER_NAME_SIZE + 1);
> + sprintf(wq->driver_name, "%s", pos);
> + kfree(input);
> + return count;
> +}
> +
> +static struct device_attribute dev_attr_wq_driver_name =
> + __ATTR(driver_name, 0644, wq_driver_name_show, wq_driver_name_store);
> +
> static struct attribute *idxd_wq_attributes[] = {
> &dev_attr_wq_clients.attr,
> &dev_attr_wq_state.attr,
> @@ -1278,6 +1311,7 @@ static struct attribute *idxd_wq_attributes[] = {
> &dev_attr_wq_occupancy.attr,
> &dev_attr_wq_enqcmds_retries.attr,
> &dev_attr_wq_op_config.attr,
> + &dev_attr_wq_driver_name.attr,
> NULL,
> };
>
> diff --git a/include/uapi/linux/idxd.h b/include/uapi/linux/idxd.h
> index 606b52e88ce3..3d1987e1bb2d 100644
> --- a/include/uapi/linux/idxd.h
> +++ b/include/uapi/linux/idxd.h
> @@ -31,6 +31,7 @@ enum idxd_scmd_stat {
> IDXD_SCMD_WQ_IRQ_ERR = 0x80100000,
> IDXD_SCMD_WQ_USER_NO_IOMMU = 0x80110000,
> IDXD_SCMD_DEV_EVL_ERR = 0x80120000,
> + IDXD_SCMD_WQ_NO_DRV_NAME = 0x80200000,
> };
>
> #define IDXD_SCMD_SOFTERR_MASK 0x80000000