From ba69f224817437b5280f4c8ef511d09f17ab1305 Mon Sep 17 00:00:00 2001
From: Dmitry Fomichev
Date: Wed, 9 Dec 2020 05:03:58 +0900
Subject: hw/block/nvme: Process controller reset and shutdown differently

Controller reset ans subsystem shutdown are handled very much the same
in the current code, but some of the steps should be different in these
two cases.

Introduce two new functions, nvme_reset_ctrl() and nvme_shutdown_ctrl(),
to separate some portions of the code from nvme_clear_ctrl(). The steps
that are made different between reset and shutdown are that BAR.CC is not
reset to zero upon the shutdown and namespace data is flushed to
backing storage as a part of shutdown handling, but not upon reset.

Suggested-by: Klaus Jensen <k.jensen@samsung.com>
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
---
 hw/block/nvme-ns.c |  2 +-
 hw/block/nvme-ns.h |  2 +-
 hw/block/nvme.c    | 24 ++++++++++++++++++------
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/hw/block/nvme-ns.c b/hw/block/nvme-ns.c
index 37f95951a6..a0de53e718 100644
--- a/hw/block/nvme-ns.c
+++ b/hw/block/nvme-ns.c
@@ -129,7 +129,7 @@ void nvme_ns_drain(NvmeNamespace *ns)
     blk_drain(ns->blkconf.blk);
 }
 
-void nvme_ns_flush(NvmeNamespace *ns)
+void nvme_ns_shutdown(NvmeNamespace *ns)
 {
     blk_flush(ns->blkconf.blk);
 }
diff --git a/hw/block/nvme-ns.h b/hw/block/nvme-ns.h
index 44bf6271b7..ed3d7e65d5 100644
--- a/hw/block/nvme-ns.h
+++ b/hw/block/nvme-ns.h
@@ -73,6 +73,6 @@ typedef struct NvmeCtrl NvmeCtrl;
 
 int nvme_ns_setup(NvmeCtrl *n, NvmeNamespace *ns, Error **errp);
 void nvme_ns_drain(NvmeNamespace *ns);
-void nvme_ns_flush(NvmeNamespace *ns);
+void nvme_ns_shutdown(NvmeNamespace *ns);
 
 #endif /* NVME_NS_H */
diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index de52487aaf..f54c5c6ea4 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -2295,6 +2295,20 @@ static void nvme_clear_ctrl(NvmeCtrl *n)
     n->aer_queued = 0;
     n->outstanding_aers = 0;
     n->qs_created = false;
+}
+
+static void nvme_ctrl_reset(NvmeCtrl *n)
+{
+    nvme_clear_ctrl(n);
+    n->bar.cc = 0;
+}
+
+static void nvme_ctrl_shutdown(NvmeCtrl *n)
+{
+    NvmeNamespace *ns;
+    int i;
+
+    nvme_clear_ctrl(n);
 
     for (i = 1; i <= n->num_namespaces; i++) {
         ns = nvme_ns(n, i);
@@ -2302,10 +2316,8 @@ static void nvme_clear_ctrl(NvmeCtrl *n)
             continue;
         }
 
-        nvme_ns_flush(ns);
+        nvme_ns_shutdown(ns);
     }
-
-    n->bar.cc = 0;
 }
 
 static int nvme_start_ctrl(NvmeCtrl *n)
@@ -2472,12 +2484,12 @@ static void nvme_write_bar(NvmeCtrl *n, hwaddr offset, uint64_t data,
             }
         } else if (!NVME_CC_EN(data) && NVME_CC_EN(n->bar.cc)) {
             trace_pci_nvme_mmio_stopped();
-            nvme_clear_ctrl(n);
+            nvme_ctrl_reset(n);
             n->bar.csts &= ~NVME_CSTS_READY;
         }
         if (NVME_CC_SHN(data) && !(NVME_CC_SHN(n->bar.cc))) {
             trace_pci_nvme_mmio_shutdown_set();
-            nvme_clear_ctrl(n);
+            nvme_ctrl_shutdown(n);
             n->bar.cc = data;
             n->bar.csts |= NVME_CSTS_SHST_COMPLETE;
         } else if (!NVME_CC_SHN(data) && NVME_CC_SHN(n->bar.cc)) {
@@ -3088,7 +3100,7 @@ static void nvme_exit(PCIDevice *pci_dev)
 {
     NvmeCtrl *n = NVME(pci_dev);
 
-    nvme_clear_ctrl(n);
+    nvme_ctrl_shutdown(n);
     g_free(n->cq);
     g_free(n->sq);
     g_free(n->aer_reqs);
-- 
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