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Diffstat (limited to 'drivers/target/target_core_device.c')
-rw-r--r--drivers/target/target_core_device.c44
1 files changed, 44 insertions, 0 deletions
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index cacd97a8cbd0..da457e25717a 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -828,6 +828,50 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name)
return dev;
}
+/*
+ * Check if the underlying struct block_device request_queue supports
+ * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
+ * in ATA and we need to set TPE=1
+ */
+bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib,
+ struct request_queue *q, int block_size)
+{
+ if (!blk_queue_discard(q))
+ return false;
+
+ attrib->max_unmap_lba_count = (q->limits.max_discard_sectors << 9) /
+ block_size;
+ /*
+ * Currently hardcoded to 1 in Linux/SCSI code..
+ */
+ attrib->max_unmap_block_desc_count = 1;
+ attrib->unmap_granularity = q->limits.discard_granularity / block_size;
+ attrib->unmap_granularity_alignment = q->limits.discard_alignment /
+ block_size;
+ attrib->unmap_zeroes_data = q->limits.discard_zeroes_data;
+ return true;
+}
+EXPORT_SYMBOL(target_configure_unmap_from_queue);
+
+/*
+ * Convert from blocksize advertised to the initiator to the 512 byte
+ * units unconditionally used by the Linux block layer.
+ */
+sector_t target_to_linux_sector(struct se_device *dev, sector_t lb)
+{
+ switch (dev->dev_attrib.block_size) {
+ case 4096:
+ return lb << 3;
+ case 2048:
+ return lb << 2;
+ case 1024:
+ return lb << 1;
+ default:
+ return lb;
+ }
+}
+EXPORT_SYMBOL(target_to_linux_sector);
+
int target_configure_device(struct se_device *dev)
{
struct se_hba *hba = dev->se_hba;

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