[PATCH] nvme: add command id quirk for apple controllers

[Keith Busch]

Some apple controllers use the command id as an index to implementation
specific data structures and will fail if the value is out of bounds.
The nvme driver's recently introduced command sequence number breaks
this controller.

Provide a quirk so these spec incompliant controllers can function as
before. The driver will not have the ability to detect bad completions
when this quirk is used, but we weren't previously checking this anyway.

The quirk bit was selected so that it can readily apply to stable.

Fixes: e7006de6c2380 ("nvme: code command_id with a genctr for use-after-free validation")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=214509
Cc: Sven Peter <sven at svenpeter.dev>
Reported-by: Orlando Chamberlain <redecorating at protonmail.com>
Reported-by: Aditya Garg <gargaditya08 at live.com>
Signed-off-by: Keith Busch <kbusch at kernel.org>
---
 drivers/nvme/host/core.c | 4 +++-
 drivers/nvme/host/nvme.h | 6 ++++++
 drivers/nvme/host/pci.c  | 3 ++-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index e486845d2c7e..afbd47e16293 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -978,6 +978,7 @@ EXPORT_SYMBOL_GPL(nvme_cleanup_cmd);
 blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req)
 {
 	struct nvme_command *cmd = nvme_req(req)->cmd;
+	struct nvme_ctrl *ctrl = nvme_req(req)->ctrl;
 	blk_status_t ret = BLK_STS_OK;
 
 	if (!(req->rq_flags & RQF_DONTPREP)) {
@@ -1026,7 +1027,8 @@ blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req)
 		return BLK_STS_IOERR;
 	}
 
-	nvme_req(req)->genctr++;
+	if (!ctrl->quirks & NVME_QUIRK_SKIP_CID_GEN)
+		nvme_req(req)->genctr++;
 	cmd->common.command_id = nvme_cid(req);
 	trace_nvme_setup_cmd(req, cmd);
 	return ret;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 9871c0c9374c..ed79a6c7e804 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -138,6 +138,12 @@ enum nvme_quirks {
 	 * 48 bits.
 	 */
 	NVME_QUIRK_DMA_ADDRESS_BITS_48		= (1 << 16),
+
+	/*
+	 * The controller requires the command_id value be be limited, so skip
+	 * encoding the generation sequence number.
+	 */
+	NVME_QUIRK_SKIP_CID_GEN			= (1 << 17),
 };
 
 /*
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index b82492cd7503..456a0e8a5718 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -3369,7 +3369,8 @@ static const struct pci_device_id nvme_id_table[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2005),
 		.driver_data = NVME_QUIRK_SINGLE_VECTOR |
 				NVME_QUIRK_128_BYTES_SQES |
-				NVME_QUIRK_SHARED_TAGS },
+				NVME_QUIRK_SHARED_TAGS |
+				NVME_QUIRK_SKIP_CID_GEN },
 
 	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
 	{ 0, }
-- 
2.25.4