4 files changed, 86 insertions, 1 deletions

diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index eca2c9d76db6..2a71273f1822 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -261,6 +261,10 @@ struct idxd_driver_data {
 	int align;
 };
 
+struct idxd_evl {
+	u16 size;
+};
+
 struct idxd_device {
 	struct idxd_dev idxd_dev;
 	struct idxd_driver_data *data;
@@ -317,6 +321,7 @@ struct idxd_device {
 	struct idxd_pmu *idxd_pmu;
 
 	unsigned long *opcap_bmap;
+	struct idxd_evl *evl;
 };
 
 /* IDXD software descriptor */
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index a78cfd361c04..525de59df82a 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -331,6 +331,23 @@ static void idxd_cleanup_internals(struct idxd_device *idxd)
 	destroy_workqueue(idxd->wq);
 }
 
+static int idxd_init_evl(struct idxd_device *idxd)
+{
+	struct device *dev = &idxd->pdev->dev;
+	struct idxd_evl *evl;
+
+	if (idxd->hw.gen_cap.evl_support == 0)
+		return 0;
+
+	evl = kzalloc_node(sizeof(*evl), GFP_KERNEL, dev_to_node(dev));
+	if (!evl)
+		return -ENOMEM;
+
+	evl->size = IDXD_EVL_SIZE_MIN;
+	idxd->evl = evl;
+	return 0;
+}
+
 static int idxd_setup_internals(struct idxd_device *idxd)
 {
 	struct device *dev = &idxd->pdev->dev;
@@ -356,8 +373,14 @@ static int idxd_setup_internals(struct idxd_device *idxd)
 		goto err_wkq_create;
 	}
 
+	rc = idxd_init_evl(idxd);
+	if (rc < 0)
+		goto err_evl;
+
 	return 0;
 
+ err_evl:
+	destroy_workqueue(idxd->wq);
  err_wkq_create:
 	for (i = 0; i < idxd->max_groups; i++)
 		put_device(group_confdev(idxd->groups[i]));
diff --git a/drivers/dma/idxd/registers.h b/drivers/dma/idxd/registers.h
index 338289a66f00..ea3a499a3c3c 100644
--- a/drivers/dma/idxd/registers.h
+++ b/drivers/dma/idxd/registers.h
@@ -31,7 +31,9 @@ union gen_cap_reg {
 		u64 rsvd:3;
 		u64 dest_readback:1;
 		u64 drain_readback:1;
-		u64 rsvd2:6;
+		u64 rsvd2:3;
+		u64 evl_support:2;
+		u64 rsvd4:1;
 		u64 max_xfer_shift:5;
 		u64 max_batch_shift:4;
 		u64 max_ims_mult:6;
@@ -297,6 +299,9 @@ union iaa_cap_reg {
 
 #define IDXD_IAACAP_OFFSET	0x180
 
+#define IDXD_EVL_SIZE_MIN	0x0040
+#define IDXD_EVL_SIZE_MAX	0xffff
+
 union msix_perm {
 	struct {
 		u32 rsvd:2;
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);