[PATCH] nvme: Support user mode processing of ZNS Zone Changed AEN

[clay.mayers at kioxia.com]

From: Clay Mayers <clay.mayers at kioxia.com>

The ZNS Zone-Descriptor-Changes AEN is of type notify and uses CQE.DW1
to convey the namespace of the log page to read. Unhandled notify AENs
now generate an NVME_AEN uevent and include the value of CQE.DW1 as a
new property when non-zero.

All unhandled notify events are include to avoid command set specific
code in the aen handling.  This support is planned to be used by both
zone based applications and another unreleased device with an alternate
command set.

Signed-off-by: Clay Mayers <clay.mayers at kioxia.com>
---
 drivers/nvme/host/core.c | 19 +++++++++++--------
 drivers/nvme/host/nvme.h |  1 +
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 66446f1e06cf..fa865b8da1d3 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4615,17 +4615,20 @@ static void nvme_change_uevent(struct nvme_ctrl *ctrl, char *envdata)
 
 static void nvme_aen_uevent(struct nvme_ctrl *ctrl)
 {
-	char *envp[2] = { NULL, NULL };
+	char *envp[3] = { NULL, NULL, NULL };
 	u32 aen_result = ctrl->aen_result;
+	u32 aen_data = ctrl->aen_data;
 
 	ctrl->aen_result = 0;
+	ctrl->aen_data = 0;
 	if (!aen_result)
 		return;
 
 	envp[0] = kasprintf(GFP_KERNEL, "NVME_AEN=%#08x", aen_result);
-	if (!envp[0])
-		return;
-	kobject_uevent_env(&ctrl->device->kobj, KOBJ_CHANGE, envp);
+	envp[1] = kasprintf(GFP_KERNEL, "NVME_AEN_DATA=%#08x", aen_data);
+	if (envp[0] && envp[1])
+		kobject_uevent_env(&ctrl->device->kobj, KOBJ_CHANGE, envp);
+	kfree(envp[1]);
 	kfree(envp[0]);
 }
 
@@ -4748,11 +4751,9 @@ static bool nvme_handle_aen_notice(struct nvme_ctrl *ctrl, u32 result)
 		queue_work(nvme_wq, &ctrl->ana_work);
 		break;
 #endif
-	case NVME_AER_NOTICE_DISC_CHANGED:
+	default:
 		ctrl->aen_result = result;
 		break;
-	default:
-		dev_warn(ctrl->device, "async event result %08x\n", result);
 	}
 	return requeue;
 }
@@ -4799,8 +4800,10 @@ void nvme_complete_async_event(struct nvme_ctrl *ctrl, __le16 status,
 		break;
 	}
 
-	if (requeue)
+	if (requeue) {
+		ctrl->aen_data = le64_to_cpu(res->u64) >> 32;
 		queue_work(nvme_wq, &ctrl->async_event_work);
+	}
 }
 EXPORT_SYMBOL_GPL(nvme_complete_async_event);
 
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 1bdf714dcd9e..a1bab447dc65 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -299,6 +299,7 @@ struct nvme_ctrl {
 	u16 cctemp;
 	u32 oaes;
 	u32 aen_result;
+	u32 aen_data;
 	u32 ctratt;
 	unsigned int shutdown_timeout;
 	unsigned int kato;
-- 
2.27.0