[PATCH v4 07/16] dmaengine: idxd: create kmem cache for event log fault items

[Fenghua Yu]

From: Dave Jiang <dave.jiang@xxxxxxxxx>

Add a kmem cache per device for allocating event log fault context. The
context allows an event log entry to be copied and passed to a software
workqueue to be processed. Due to each device can have different sized
event log entry depending on device type, it's not possible to have a
global kmem cache.

Tested-by: Tony Zhu <tony.zhu@xxxxxxxxx>
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Co-developed-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
 drivers/dma/idxd/idxd.h  | 10 ++++++++++
 drivers/dma/idxd/init.c  |  9 +++++++++
 drivers/dma/idxd/sysfs.c |  1 +
 3 files changed, 20 insertions(+)

diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index 6e56361ae658..c5d99c179902 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -274,6 +274,15 @@ struct idxd_evl {
 	u16 head;
 };
 
+struct idxd_evl_fault {
+	struct work_struct work;
+	struct idxd_wq *wq;
+	u8 status;
+
+	/* make this last member always */
+	struct __evl_entry entry[];
+};
+
 struct idxd_device {
 	struct idxd_dev idxd_dev;
 	struct idxd_driver_data *data;
@@ -331,6 +340,7 @@ struct idxd_device {
 
 	unsigned long *opcap_bmap;
 	struct idxd_evl *evl;
+	struct kmem_cache *evl_cache;
 
 	struct dentry *dbgfs_dir;
 	struct dentry *dbgfs_evl_file;
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index d19bc6389221..a7c98fac7a85 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -346,6 +346,15 @@ static int idxd_init_evl(struct idxd_device *idxd)
 
 	spin_lock_init(&evl->lock);
 	evl->size = IDXD_EVL_SIZE_MIN;
+
+	idxd->evl_cache = kmem_cache_create(dev_name(idxd_confdev(idxd)),
+					    sizeof(struct idxd_evl_fault) + evl_ent_size(idxd),
+					    0, 0, NULL);
+	if (!idxd->evl_cache) {
+		kfree(evl);
+		return -ENOMEM;
+	}
+
 	idxd->evl = evl;
 	return 0;
 }
diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 163fdfaa5022..8b9dfa0d2b99 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -1718,6 +1718,7 @@ static void idxd_conf_device_release(struct device *dev)
 	kfree(idxd->wqs);
 	kfree(idxd->engines);
 	kfree(idxd->evl);
+	kmem_cache_destroy(idxd->evl_cache);
 	ida_free(&idxd_ida, idxd->id);
 	bitmap_free(idxd->opcap_bmap);
 	kfree(idxd);
-- 
2.37.1