[PATCH 3/3] nvme: Add support for Apple 2018+ models

[benh@kernel.crashing.org (Benjamin Herrenschmidt)]

Based on reverse engineering and original patch by

Paul Pawlowski <paul at mrarm.io>

This adds support for Apple weird implementation of NVME in their
2018 or later machines. It accounts for the twice-as-big SQ entries
for the IO queues, and the fact that only interrupt vector 0 appears
to function properly.

Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
 drivers/nvme/host/core.c |  5 ++++-
 drivers/nvme/host/nvme.h | 10 ++++++++++
 drivers/nvme/host/pci.c  |  6 ++++++
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 716ebe87a2b8..480ea24d8cf4 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2701,7 +2701,10 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
 		ctrl->hmmaxd = le16_to_cpu(id->hmmaxd);
 
 		/* Grab required IO queue size */
-		ctrl->iosqes = id->sqes & 0xf;
+		if (ctrl->quirks & NVME_QUIRK_128_BYTES_SQES)
+			ctrl->iosqes = 7;
+		else
+			ctrl->iosqes = id->sqes & 0xf;
 		if (ctrl->iosqes < NVME_NVM_IOSQES) {
 			dev_err(ctrl->device,
 				"unsupported required IO queue size %d\n", ctrl->iosqes);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 34ef35fcd8a5..b2a78d08b984 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -92,6 +92,16 @@ enum nvme_quirks {
 	 * Broken Write Zeroes.
 	 */
 	NVME_QUIRK_DISABLE_WRITE_ZEROES		= (1 << 9),
+
+	/*
+	 * Use only one interrupt vector for all queues
+	 */
+	NVME_QUIRK_SINGLE_VECTOR		= (1 << 10),
+
+	/*
+	 * Use non-standard 128 bytes SQEs.
+	 */
+	NVME_QUIRK_128_BYTES_SQES		= (1 << 11),
 };
 
 /*
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 54b35ea4af88..ab2358137419 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2080,6 +2080,9 @@ static int nvme_setup_irqs(struct nvme_dev *dev, unsigned int nr_io_queues)
 	dev->io_queues[HCTX_TYPE_DEFAULT] = 1;
 	dev->io_queues[HCTX_TYPE_READ] = 0;
 
+	if (dev->ctrl.quirks & NVME_QUIRK_SINGLE_VECTOR)
+		irq_queues = 1;
+
 	return pci_alloc_irq_vectors_affinity(pdev, 1, irq_queues,
 			      PCI_IRQ_ALL_TYPES | PCI_IRQ_AFFINITY, &affd);
 }
@@ -3037,6 +3040,9 @@ static const struct pci_device_id nvme_id_table[] = {
 	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2001) },
 	{ 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 },
 	{ 0, }
 };
 MODULE_DEVICE_TABLE(pci, nvme_id_table);
-- 
2.17.1