From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Wed, 7 Aug 2019 17:51:22 +1000
Subject: [PATCH] nvme-pci: Support shared tags across queues for Apple 2018
controllers
References: bsc#1156419,jsc#SLE-8281
Git-commit: d38e9f04ebf667d9cb8185b45bff747485f1d3e9
Patch-mainline: v5.4-rc1
Another issue with the Apple T2 based 2018 controllers seem to be
that they blow up (and shut the machine down) if there's a tag
collision between the IO queue and the Admin queue.
My suspicion is that they use our tags for their internal tracking
and don't mix them with the queue id. They also seem to not like
when tags go beyond the IO queue depth, ie 128 tags.
This adds a quirk that marks tags 0..31 of the IO queue reserved
[hare: fixup merge issue]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
drivers/nvme/host/nvme.h | 5 +++++
drivers/nvme/host/pci.c | 31 ++++++++++++++++++++++++++++++-
2 files changed, 35 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 9880f68afa99..b5013c101b35 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -109,6 +109,11 @@ enum nvme_quirks {
* Use non-standard 128 bytes SQEs.
*/
NVME_QUIRK_128_BYTES_SQES = (1 << 12),
+
+ /*
+ * Prevent tag overlap between queues
+ */
+ NVME_QUIRK_SHARED_TAGS = (1 << 13),
};
/*
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 040b97d51d9c..44c8526d9bc6 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2109,6 +2109,14 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
unsigned long size;
nr_io_queues = max_io_queues();
+
+ /*
+ * If tags are shared with admin queue (Apple bug), then
+ * make sure we only use one IO queue.
+ */
+ if (dev->ctrl.quirks & NVME_QUIRK_SHARED_TAGS)
+ nr_io_queues = 1;
+
result = nvme_set_queue_count(&dev->ctrl, &nr_io_queues);
if (result < 0)
return result;
@@ -2279,6 +2287,14 @@ static int nvme_dev_add(struct nvme_dev *dev)
dev->tagset.flags = BLK_MQ_F_SHOULD_MERGE;
dev->tagset.driver_data = dev;
+ /*
+ * Some Apple controllers requires tags to be unique
+ * across admin and IO queue, so reserve the first 32
+ * tags of the IO queue.
+ */
+ if (dev->ctrl.quirks & NVME_QUIRK_SHARED_TAGS)
+ dev->tagset.reserved_tags = NVME_AQ_DEPTH;
+
ret = blk_mq_alloc_tag_set(&dev->tagset);
if (ret) {
dev_warn(dev->ctrl.device,
@@ -2359,6 +2375,18 @@ static int nvme_pci_enable(struct nvme_dev *dev)
"set queue depth=%u\n", dev->q_depth);
}
+ /*
+ * Controllers with the shared tags quirk need the IO queue to be
+ * big enough so that we get 32 tags for the admin queue
+ */
+ if ((dev->ctrl.quirks & NVME_QUIRK_SHARED_TAGS) &&
+ (dev->q_depth < (NVME_AQ_DEPTH + 2))) {
+ dev->q_depth = NVME_AQ_DEPTH + 2;
+ dev_warn(dev->ctrl.device, "IO queue depth clamped to %d\n",
+ dev->q_depth);
+ }
+
+
nvme_map_cmb(dev);
pci_enable_pcie_error_reporting(pdev);
@@ -3076,7 +3104,8 @@ static const struct pci_device_id nvme_id_table[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2003) },
{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2005),
.driver_data = NVME_QUIRK_SINGLE_VECTOR |
- NVME_QUIRK_128_BYTES_SQES },
+ NVME_QUIRK_128_BYTES_SQES |
+ NVME_QUIRK_SHARED_TAGS },
{ 0, }
};
MODULE_DEVICE_TABLE(pci, nvme_id_table);
--
2.16.4