[PATCH 4/5] nvme: add the Apple shared tag workaround to nvme_alloc_io_tag_set

[Christoph Hellwig]

Add the apple shared tag workaround to nvme_alloc_io_tag_set to prepare
for using that helper in the PCIe driver.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 drivers/nvme/host/core.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index ed163c53976722..d404a3778b1d28 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4899,8 +4899,14 @@ int nvme_alloc_io_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
 	memset(set, 0, sizeof(*set));
 	set->ops = ops;
 	set->queue_depth = ctrl->sqsize + 1;
+	/*
+	 * Some Apple controllers requires tags to be unique across admin and
+	 * the (only) I/O queue, so reserve the first 32 tags of the I/O queue.
+	 */
 	if (ctrl->ops->flags & NVME_F_FABRICS)
 		set->reserved_tags = NVMF_RESERVED_TAGS;
+	else if (ctrl->quirks & NVME_QUIRK_SHARED_TAGS)
+		set->reserved_tags = NVME_AQ_DEPTH;
 	set->numa_node = ctrl->numa_node;
 	set->flags = BLK_MQ_F_SHOULD_MERGE;
 	if (ctrl->ops->flags & NVME_F_BLOCKING)
-- 
2.30.2