dmaengine: idxd: add event log size sysfs attribute

Add support for changing of the event log size. Event log is a
feature added to DSA 2.0 hardware to improve error reporting.
It supersedes the SWERROR register on DSA 1.0 hardware and hope
to prevent loss of reported errors.

The error log size determines how many error entries supported for
the device. It can be configured by the user via sysfs attribute.

Tested-by: Tony Zhu <tony.zhu@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20230407203143.2189681-3-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 52 insertions, 0 deletions

diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 2eba8cab25a1..85644e5bde83 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -1573,6 +1573,46 @@ static ssize_t iaa_cap_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(iaa_cap);
 
+static ssize_t event_log_size_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct idxd_device *idxd = confdev_to_idxd(dev);
+
+	if (!idxd->evl)
+		return -EOPNOTSUPP;
+
+	return sysfs_emit(buf, "%u\n", idxd->evl->size);
+}
+
+static ssize_t event_log_size_store(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	struct idxd_device *idxd = confdev_to_idxd(dev);
+	unsigned long val;
+	int rc;
+
+	if (!idxd->evl)
+		return -EOPNOTSUPP;
+
+	rc = kstrtoul(buf, 10, &val);
+	if (rc < 0)
+		return -EINVAL;
+
+	if (idxd->state == IDXD_DEV_ENABLED)
+		return -EPERM;
+
+	if (!test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
+		return -EPERM;
+
+	if (val < IDXD_EVL_SIZE_MIN || val > IDXD_EVL_SIZE_MAX)
+		return -EINVAL;
+
+	idxd->evl->size = val;
+	return count;
+}
+static DEVICE_ATTR_RW(event_log_size);
+
 static bool idxd_device_attr_max_batch_size_invisible(struct attribute *attr,
 						      struct idxd_device *idxd)
 {
@@ -1603,6 +1643,13 @@ static bool idxd_device_attr_iaa_cap_invisible(struct attribute *attr,
 	       idxd->hw.version < DEVICE_VERSION_2);
 }
 
+static bool idxd_device_attr_event_log_size_invisible(struct attribute *attr,
+						      struct idxd_device *idxd)
+{
+	return (attr == &dev_attr_event_log_size.attr &&
+		!idxd->hw.gen_cap.evl_support);
+}
+
 static umode_t idxd_device_attr_visible(struct kobject *kobj,
 					struct attribute *attr, int n)
 {
@@ -1618,6 +1665,9 @@ static umode_t idxd_device_attr_visible(struct kobject *kobj,
 	if (idxd_device_attr_iaa_cap_invisible(attr, idxd))
 		return 0;
 
+	if (idxd_device_attr_event_log_size_invisible(attr, idxd))
+		return 0;
+
 	return attr->mode;
 }
 
@@ -1644,6 +1694,7 @@ static struct attribute *idxd_device_attributes[] = {
 	&dev_attr_cdev_major.attr,
 	&dev_attr_cmd_status.attr,
 	&dev_attr_iaa_cap.attr,
+	&dev_attr_event_log_size.attr,
 	NULL,
 };
 
@@ -1665,6 +1716,7 @@ static void idxd_conf_device_release(struct device *dev)
 	bitmap_free(idxd->wq_enable_map);
 	kfree(idxd->wqs);
 	kfree(idxd->engines);
+	kfree(idxd->evl);
 	ida_free(&idxd_ida, idxd->id);
 	bitmap_free(idxd->opcap_bmap);
 	kfree(idxd);