From: Keith Busch <kbusch@kernel.org>
Date: Thu, 14 Oct 2021 16:45:42 +0000 (-0700)
Subject: nvme-pci: clear shadow doorbell memory on resets
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=58847f12fe7823c56f844218abcca6920901097d;p=linux.git

nvme-pci: clear shadow doorbell memory on resets

The host memory doorbell and event buffers need to be initialized on
each reset so the driver doesn't observe stale values from the previous
instantiation.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Tested-by: John Levon <john.levon@nutanix.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index ed684874842ff..6e05cfb4879fb 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -245,8 +245,15 @@ static int nvme_dbbuf_dma_alloc(struct nvme_dev *dev)
 {
 	unsigned int mem_size = nvme_dbbuf_size(dev);
 
-	if (dev->dbbuf_dbs)
+	if (dev->dbbuf_dbs) {
+		/*
+		 * Clear the dbbuf memory so the driver doesn't observe stale
+		 * values from the previous instantiation.
+		 */
+		memset(dev->dbbuf_dbs, 0, mem_size);
+		memset(dev->dbbuf_eis, 0, mem_size);
 		return 0;
+	}
 
 	dev->dbbuf_dbs = dma_alloc_coherent(dev->dev, mem_size,
 					    &dev->dbbuf_dbs_dma_addr,