From: Christoph Hellwig <hch@lst.de>
Date: Wed, 6 Sep 2017 12:19:57 +0200
Subject: nvme-pci: propagate (some) errors from host memory buffer setup
Patch-mainline: v4.14-rc1
Git-commit: 9620cfba97a8b88ae91f0e275e8ff110b578bb6e
References: FATE#323952, FATE#322506

We want to catch command execution errors when resetting the device, so
propagate errors from the Set Features when setting up the host memory
buffer.  We keep ignoring memory allocation failures, as the spec
clearly says that the controller must work without a host memory buffer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Cc: stable@vger.kernel.org
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/nvme/host/pci.c |   18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1693,12 +1693,13 @@ static int nvme_alloc_host_mem(struct nv
 	return -ENOMEM;
 }
 
-static void nvme_setup_host_mem(struct nvme_dev *dev)
+static int nvme_setup_host_mem(struct nvme_dev *dev)
 {
 	u64 max = (u64)max_host_mem_size_mb * SZ_1M;
 	u64 preferred = (u64)dev->ctrl.hmpre * 4096;
 	u64 min = (u64)dev->ctrl.hmmin * 4096;
 	u32 enable_bits = NVME_HOST_MEM_ENABLE;
+	int ret = 0;
 
 	preferred = min(preferred, max);
 	if (min > max) {
@@ -1706,7 +1707,7 @@ static void nvme_setup_host_mem(struct n
 			"min host memory (%lld MiB) above limit (%d MiB).\n",
 			min >> ilog2(SZ_1M), max_host_mem_size_mb);
 		nvme_free_host_mem(dev);
-		return;
+		return 0;
 	}
 
 	/*
@@ -1723,7 +1724,7 @@ static void nvme_setup_host_mem(struct n
 		if (nvme_alloc_host_mem(dev, min, preferred)) {
 			dev_warn(dev->ctrl.device,
 				"failed to allocate host memory buffer.\n");
-			return;
+			return 0; /* controller must work without HMB */
 		}
 
 		dev_info(dev->ctrl.device,
@@ -1731,8 +1732,10 @@ static void nvme_setup_host_mem(struct n
 			dev->host_mem_size >> ilog2(SZ_1M));
 	}
 
-	if (nvme_set_host_mem(dev, enable_bits))
+	ret = nvme_set_host_mem(dev, enable_bits);
+	if (ret)
 		nvme_free_host_mem(dev);
+	return ret;
 }
 
 static int nvme_setup_io_queues(struct nvme_dev *dev)
@@ -2176,8 +2179,11 @@ static void nvme_reset_work(struct work_
 				 "unable to allocate dma for dbbuf\n");
 	}
 
-	if (dev->ctrl.hmpre)
-		nvme_setup_host_mem(dev);
+	if (dev->ctrl.hmpre) {
+		result = nvme_setup_host_mem(dev);
+		if (result < 0)
+			goto out;
+	}
 
 	result = nvme_setup_io_queues(dev);
 	if (result)