[PATCH v6 09/13] lib: test_hmm add ioctl to get zone device type

[Alex Sierra <alex.sierra@xxxxxxx>]

new ioctl cmd added to query zone device type. This will be
used once the test_hmm adds zone device generic type.

Signed-off-by: Alex Sierra <alex.sierra@xxxxxxx>
---
 lib/test_hmm.c      | 15 ++++++++++++++-
 lib/test_hmm_uapi.h |  7 +++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index 6998f10350ea..3cd91ca31dd7 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -82,6 +82,7 @@ struct dmirror_chunk {
 struct dmirror_device {
 	struct cdev		cdevice;
 	struct hmm_devmem	*devmem;
+	unsigned int            zone_device_type;
 
 	unsigned int		devmem_capacity;
 	unsigned int		devmem_count;
@@ -468,6 +469,7 @@ static bool dmirror_allocate_chunk(struct dmirror_device *mdevice,
 	if (IS_ERR(res))
 		goto err_devmem;
 
+	mdevice->zone_device_type = HMM_DMIRROR_MEMORY_DEVICE_PRIVATE;
 	devmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
 	devmem->pagemap.range.start = res->start;
 	devmem->pagemap.range.end = res->end;
@@ -912,6 +914,15 @@ static int dmirror_snapshot(struct dmirror *dmirror,
 	return ret;
 }
 
+static int dmirror_get_device_type(struct dmirror *dmirror,
+			    struct hmm_dmirror_cmd *cmd)
+{
+	mutex_lock(&dmirror->mutex);
+	cmd->zone_device_type = dmirror->mdevice->zone_device_type;
+	mutex_unlock(&dmirror->mutex);
+
+	return 0;
+}
 static long dmirror_fops_unlocked_ioctl(struct file *filp,
 					unsigned int command,
 					unsigned long arg)
@@ -952,7 +963,9 @@ static long dmirror_fops_unlocked_ioctl(struct file *filp,
 	case HMM_DMIRROR_SNAPSHOT:
 		ret = dmirror_snapshot(dmirror, &cmd);
 		break;
-
+	case HMM_DMIRROR_GET_MEM_DEV_TYPE:
+		ret = dmirror_get_device_type(dmirror, &cmd);
+		break;
 	default:
 		return -EINVAL;
 	}
diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h
index 670b4ef2a5b6..ee88701793d5 100644
--- a/lib/test_hmm_uapi.h
+++ b/lib/test_hmm_uapi.h
@@ -26,6 +26,7 @@ struct hmm_dmirror_cmd {
 	__u64		npages;
 	__u64		cpages;
 	__u64		faults;
+	__u64		zone_device_type;
 };
 
 /* Expose the address space of the calling process through hmm device file */
@@ -33,6 +34,7 @@ struct hmm_dmirror_cmd {
 #define HMM_DMIRROR_WRITE		_IOWR('H', 0x01, struct hmm_dmirror_cmd)
 #define HMM_DMIRROR_MIGRATE		_IOWR('H', 0x02, struct hmm_dmirror_cmd)
 #define HMM_DMIRROR_SNAPSHOT		_IOWR('H', 0x03, struct hmm_dmirror_cmd)
+#define HMM_DMIRROR_GET_MEM_DEV_TYPE	_IOWR('H', 0x04, struct hmm_dmirror_cmd)
 
 /*
  * Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT.
@@ -60,4 +62,9 @@ enum {
 	HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE	= 0x30,
 };
 
+enum {
+	/* 0 is reserved to catch uninitialized type fields */
+	HMM_DMIRROR_MEMORY_DEVICE_PRIVATE = 1,
+};
+
 #endif /* _LIB_TEST_HMM_UAPI_H */
-- 
2.32.0