Make the sg_tablesize used by SRP adjustable at module load time via a
module parameter. Calculate the corresponding IU length required to
support this.
Signed-off-by: Vu Pham <vu@mellanox.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The SRP driver never sleeps while holding target_mutex, and it's just
used to protect some simple list operations, so hold times will be
short. So just convert it to a spinlock, which is smaller and faster.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Create an SRP FMR pool on HCAs that support FMRs, and use FMRs to map
gather/scatter lists that have more than one entry into a single
memory region that appears virtually contiguous to the SRP target
(which is the RDMA initiator).
This patch bails out on FMR mapping for SCSI commands where the
gather/scatter list cannot be mapped into a single FMR because there
are sub-page-sized entries in middle of the list. An unaligned
start or end of the list is OK.
Based on a patch by Vu Pham <vuhuong@mellanox.com>.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
If a SCSI abort completes, or the command completes successfully, then
the driver must remove the command from its queue of pending
commands. Similarly, if a device reset succeeds, then all commands
queued for the given device must be removed from the queue.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Since the SCSI midlayer is moving towards entirely getting rid of
commands with use_sg == 0, we should treat this case as an exception.
Therefore, change the IB SRP initiator to create a fake scatterlist
for these commands with sg_init_one(). This simplifies the flow of
DMA mapping and unmapping, since SRP can just use dma_map_sg() and
dma_unmap_sg() unconditionally, rather than having to choose between
the dma_{map,unmap}_sg() and dma_{map,unmap}_single() variants.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Convert srp_host->target_mutex from a semaphore to a mutex.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Increase SRP max_luns to 512 to match the kernel's default, since SRP
storage targets can have lots of LUNs and the SRP initiator itself
doesn't have any particular limit.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add an InfiniBand SCSI RDMA Protocol (SRP) initiator. This driver is
used to talk talk to InfiniBand SRP targets (storage devices).
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Vu Pham