block: Add PCI P2P flag for request queue

Add QUEUE_FLAG_PCI_P2P, meaning a driver's request queue supports targeting
P2P memory.  This will be used by P2P providers and orchestrators (in
subsequent patches) to ensure block devices can support P2P memory before
submitting P2P-backed pages to submit_bio().

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jens Axboe <axboe@kernel.dk>

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6980014357d477793079164ce67393659def6052..c32f7171899be46fb82edae93c6ab78ed19c2a26 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -699,6 +699,7 @@ struct request_queue {
 #define QUEUE_FLAG_SCSI_PASSTHROUGH 27 /* queue supports SCSI commands */
 #define QUEUE_FLAG_QUIESCED    28      /* queue has been quiesced */
 #define QUEUE_FLAG_PREEMPT_ONLY        29      /* only process REQ_PREEMPT requests */
+#define QUEUE_FLAG_PCI_P2PDMA  30      /* device supports PCI p2p requests */
 
 #define QUEUE_FLAG_DEFAULT     ((1 << QUEUE_FLAG_IO_STAT) |            \
                                 (1 << QUEUE_FLAG_SAME_COMP)    |       \
@@ -731,6 +732,8 @@ bool blk_queue_flag_test_and_clear(unsigned int flag, struct request_queue *q);
 #define blk_queue_dax(q)       test_bit(QUEUE_FLAG_DAX, &(q)->queue_flags)
 #define blk_queue_scsi_passthrough(q)  \
        test_bit(QUEUE_FLAG_SCSI_PASSTHROUGH, &(q)->queue_flags)
+#define blk_queue_pci_p2pdma(q)        \
+       test_bit(QUEUE_FLAG_PCI_P2PDMA, &(q)->queue_flags)
 
 #define blk_noretry_request(rq) \
        ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \