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authorChristoph Hellwig <hch@lst.de>2020-04-14 09:42:24 +0200
committerJens Axboe <axboe@kernel.dk>2020-04-22 10:47:35 -0600
commitcc97923a5bccc776851c242b61015faf288d5c22 (patch)
treed6510d4f326674e96bdf70c4f07472f492537db8 /include/scsi
parent0475bd6c65976c390e3805a1e5f10fc30ca8def2 (diff)
block: move dma drain handling to scsi
Don't burden the common block code with with specifics of the libata DMA draining mechanism. Instead move most of the code to the scsi midlayer. That also means the nr_phys_segments adjustments in the blk-mq fast path can go away entirely, given that SCSI never looks at nr_phys_segments after mapping the request to a scatterlist. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/scsi')
-rw-r--r--include/scsi/scsi_device.h3
-rw-r--r--include/scsi/scsi_host.h7
2 files changed, 10 insertions, 0 deletions
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index c3cba2aaf934..bc5909033d13 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -229,6 +229,9 @@ struct scsi_device {
struct scsi_device_handler *handler;
void *handler_data;
+ size_t dma_drain_len;
+ void *dma_drain_buf;
+
unsigned char access_state;
struct mutex state_mutex;
enum scsi_device_state sdev_state;
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 822e8cda8d9b..46ef8cccc982 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -271,6 +271,13 @@ struct scsi_host_template {
int (* map_queues)(struct Scsi_Host *shost);
/*
+ * Check if scatterlists need to be padded for DMA draining.
+ *
+ * Status: OPTIONAL
+ */
+ bool (* dma_need_drain)(struct request *rq);
+
+ /*
* This function determines the BIOS parameters for a given
* harddisk. These tend to be numbers that are made up by
* the host adapter. Parameters: