nvme-pci: fix conflicting p2p resource adds
authorKeith Busch <keith.busch@intel.com>
Wed, 31 Oct 2018 19:15:29 +0000 (13:15 -0600)
committerJens Axboe <axboe@kernel.dk>
Fri, 2 Nov 2018 14:14:46 +0000 (08:14 -0600)
commit9fe5c59ff6a1e5e26a39b75489a1420e7eaaf0b1
tree4e5a5edf35e507d531ee778d75930e51df696b59
parentd19b8bc82fc232d17ec45ca148388e4ba05ac4b9
nvme-pci: fix conflicting p2p resource adds

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@intel.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
drivers/nvme/host/pci.c