[PATCH 6.1 0794/1146] dmaengine: idxd: Make max batch size attributes in sysfs invisible for Intel IAA

Greg Kroah-Hartman
2022-12-28T16:35:19Z

From: Xiaochen Shen <xiaochen.shen@intel.com>

[ Upstream commit 91123b37e8a99cc489d5bdcfebd1c25f29382504 ]

In current code, dev.max_batch_size and wq.max_batch_size attributes in
sysfs are exposed to user to show or update the values.

>From Intel IAA spec [1], Intel IAA does not support batch processing. So
these sysfs attributes should not be supported on IAA device.

Fix this issue by making the attributes of max_batch_size invisible in
sysfs through is_visible() filter when the device is IAA.

Add description in the ABI documentation to mention that the attributes
are not visible when the device does not support batch.

[1]: https://cdrdv2.intel.com/v1/dl/getContent/721858

Fixes: e7184b159dd3 ("dmaengine: idxd: add support for configurable max wq batch size")
Fixes: c52ca478233c ("dmaengine: idxd: add configuration component of driver")
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20220930201528.18621-3-xiaochen.shen@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../ABI/stable/sysfs-driver-dma-idxd | 2 ++
drivers/dma/idxd/sysfs.c | 32 +++++++++++++++++++
2 files changed, 34 insertions(+)

diff --git a/Documentation/ABI/stable/sysfs-driver-dma-idxd b/Documentation/ABI/stable/sysfs-driver-dma-idxd
index 8e2c2c405db2..69e2d9155e0d 100644
--- a/Documentation/ABI/stable/sysfs-driver-dma-idxd
+++ b/Documentation/ABI/stable/sysfs-driver-dma-idxd
@@ -22,6 +22,7 @@ Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The largest number of work descriptors in a batch.
+ It's not visible when the device does not support batch.

What: /sys/bus/dsa/devices/dsa<m>/max_work_queues_size
Date: Oct 25, 2019
@@ -205,6 +206,7 @@ KernelVersion: 5.10.0
Contact: dmaengine@vger.kernel.org
Description: The max batch size for this workqueue. Cannot exceed device
max batch size. Configurable parameter.
+ It's not visible when the device does not support batch.

What: /sys/bus/dsa/devices/wq<m>.<n>/ats_disable
Date: Nov 13, 2020
diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 7269bd54554f..7909767e9836 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -1233,6 +1233,14 @@ static bool idxd_wq_attr_op_config_invisible(struct attribute *attr,
!idxd->hw.wq_cap.op_config;
}

+static bool idxd_wq_attr_max_batch_size_invisible(struct attribute *attr,
+ struct idxd_device *idxd)
+{
+ /* Intel IAA does not support batch processing, make it invisible */
+ return attr == &dev_attr_wq_max_batch_size.attr &&
+ idxd->data->type == IDXD_TYPE_IAX;
+}
+
static umode_t idxd_wq_attr_visible(struct kobject *kobj,
struct attribute *attr, int n)
{
@@ -1243,6 +1251,9 @@ static umode_t idxd_wq_attr_visible(struct kobject *kobj,
if (idxd_wq_attr_op_config_invisible(attr, idxd))
return 0;

+ if (idxd_wq_attr_max_batch_size_invisible(attr, idxd))
+ return 0;
+
return attr->mode;
}

@@ -1533,6 +1544,26 @@ static ssize_t cmd_status_store(struct device *dev, struct device_attribute *att
}
static DEVICE_ATTR_RW(cmd_status);

+static bool idxd_device_attr_max_batch_size_invisible(struct attribute *attr,
+ struct idxd_device *idxd)
+{
+ /* Intel IAA does not support batch processing, make it invisible */
+ return attr == &dev_attr_max_batch_size.attr &&
+ idxd->data->type == IDXD_TYPE_IAX;
+}
+
+static umode_t idxd_device_attr_visible(struct kobject *kobj,
+ struct attribute *attr, int n)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ struct idxd_device *idxd = confdev_to_idxd(dev);
+
+ if (idxd_device_attr_max_batch_size_invisible(attr, idxd))
+ return 0;
+
+ return attr->mode;
+}
+
static struct attribute *idxd_device_attributes[] = {
&dev_attr_version.attr,
&dev_attr_max_groups.attr,
@@ -1560,6 +1591,7 @@ static struct attribute *idxd_device_attributes[] = {

static const struct attribute_group idxd_device_attribute_group = {
.attrs = idxd_device_attributes,
+ .is_visible = idxd_device_attr_visible,
};

static const struct attribute_group *idxd_attribute_groups[] = {
--
2.35.1