On 3/29/2019 7:28 PM, Sasha Levin wrote:
From: Keith Busch <keith.busch@xxxxxxxxx>
[ Upstream commit 9fe5c59ff6a1e5e26a39b75489a1420e7eaaf0b1 ]
The nvme pci driver had been adding its CMB resource to the P2P DMA
subsystem everytime on on a controller reset. This results in the
following warning:
------------[ cut here ]------------
nvme 0000:00:03.0: Conflicting mapping in same section
WARNING: CPU: 7 PID: 81 at kernel/memremap.c:155 devm_memremap_pages+0xa6/0x380
...
Call Trace:
pci_p2pdma_add_resource+0x153/0x370
nvme_reset_work+0x28c/0x17b1 [nvme]
? add_timer+0x107/0x1e0
? dequeue_entity+0x81/0x660
? dequeue_entity+0x3b0/0x660
? pick_next_task_fair+0xaf/0x610
? __switch_to+0xbc/0x410
process_one_work+0x1cf/0x350
worker_thread+0x215/0x3d0
? process_one_work+0x350/0x350
kthread+0x107/0x120
? kthread_park+0x80/0x80
ret_from_fork+0x1f/0x30
---[ end trace f7ea76ac6ee72727 ]---
nvme nvme0: failed to register the CMB
This patch fixes this by registering the CMB with P2P only once.
Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/nvme/host/pci.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 7b9ef8e734e7..dca87cb485e9 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1649,6 +1649,9 @@ static void nvme_map_cmb(struct nvme_dev *dev)
struct pci_dev *pdev = to_pci_dev(dev->dev);
int bar;
+ if (dev->cmb_size)
+ return;
+
dev->cmbsz = readl(dev->bar + NVME_REG_CMBSZ);
if (!dev->cmbsz)
return;
@@ -2133,7 +2136,6 @@ static void nvme_pci_disable(struct nvme_dev *dev)
{
struct pci_dev *pdev = to_pci_dev(dev->dev);
- nvme_release_cmb(dev);
pci_free_irq_vectors(pdev);
if (pci_is_enabled(pdev)) {
@@ -2585,6 +2587,7 @@ static void nvme_remove(struct pci_dev *pdev)
nvme_stop_ctrl(&dev->ctrl);
nvme_remove_namespaces(&dev->ctrl);
nvme_dev_disable(dev, true);
+ nvme_release_cmb(dev);
nvme_free_host_mem(dev);
nvme_dev_remove_admin(dev);
nvme_free_queues(dev, 0);
There is no P2P support in the 4.19 kernel so I'm not sure this change
is necessary. I would also worry that it might break things if the BARs
need to be remapped after a controller reset.
