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[v4,11/14] nvme-pci: Add a quirk for a pseudo CMB

Message ID 20180423233046.21476-12-logang@deltatee.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Logan Gunthorpe April 23, 2018, 11:30 p.m. UTC 
Introduce a quirk to use CMB-like memory on older devices that have
an exposed BAR but do not advertise support for using CMBLOC and
CMBSIZE.

We'd like to use some of these older cards to test P2P memory.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
---
 drivers/nvme/host/nvme.h |  7 +++++++
 drivers/nvme/host/pci.c  | 24 ++++++++++++++++++++----
 2 files changed, 27 insertions(+), 4 deletions(-)
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Patch

diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 9a689c13998f..885e9ec9b889 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -84,6 +84,13 @@  enum nvme_quirks {
 	 * Supports the LighNVM command set if indicated in vs[1].
 	 */
 	NVME_QUIRK_LIGHTNVM			= (1 << 6),
+
+	/*
+	 * Pseudo CMB Support on BAR 4. For adapters like the Microsemi
+	 * NVRAM that have CMB-like memory on a BAR but does not set
+	 * CMBLOC or CMBSZ.
+	 */
+	NVME_QUIRK_PSEUDO_CMB_BAR4		= (1 << 7),
 };
 
 /*
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 09b6aba6ed28..e526e969680a 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1685,6 +1685,13 @@  static ssize_t nvme_cmb_show(struct device *dev,
 }
 static DEVICE_ATTR(cmb, S_IRUGO, nvme_cmb_show, NULL);
 
+static u32 nvme_pseudo_cmbsz(struct pci_dev *pdev, int bar)
+{
+	return NVME_CMBSZ_WDS | NVME_CMBSZ_RDS |
+		(((ilog2(SZ_16M) - 12) / 4) << NVME_CMBSZ_SZU_SHIFT) |
+		((pci_resource_len(pdev, bar) / SZ_16M) << NVME_CMBSZ_SZ_SHIFT);
+}
+
 static u64 nvme_cmb_size_unit(struct nvme_dev *dev)
 {
 	u8 szu = (dev->cmbsz >> NVME_CMBSZ_SZU_SHIFT) & NVME_CMBSZ_SZU_MASK;
@@ -1704,10 +1711,15 @@  static void nvme_map_cmb(struct nvme_dev *dev)
 	struct pci_dev *pdev = to_pci_dev(dev->dev);
 	int bar;
 
-	dev->cmbsz = readl(dev->bar + NVME_REG_CMBSZ);
-	if (!dev->cmbsz)
-		return;
-	dev->cmbloc = readl(dev->bar + NVME_REG_CMBLOC);
+	if (dev->ctrl.quirks & NVME_QUIRK_PSEUDO_CMB_BAR4) {
+		dev->cmbsz = nvme_pseudo_cmbsz(pdev, 4);
+		dev->cmbloc = 4;
+	} else {
+		dev->cmbsz = readl(dev->bar + NVME_REG_CMBSZ);
+		if (!dev->cmbsz)
+			return;
+		dev->cmbloc = readl(dev->bar + NVME_REG_CMBLOC);
+	}
 
 	size = nvme_cmb_size_unit(dev) * nvme_cmb_size(dev);
 	offset = nvme_cmb_size_unit(dev) * NVME_CMB_OFST(dev->cmbloc);
@@ -2736,6 +2748,10 @@  static const struct pci_device_id nvme_id_table[] = {
 		.driver_data = NVME_QUIRK_LIGHTNVM, },
 	{ PCI_DEVICE(0x1d1d, 0x2807),	/* CNEX WL */
 		.driver_data = NVME_QUIRK_LIGHTNVM, },
+	{ PCI_DEVICE(0x11f8, 0xf117),	/* Microsemi NVRAM adaptor */
+		.driver_data = NVME_QUIRK_PSEUDO_CMB_BAR4, },
+	{ PCI_DEVICE(0x1db1, 0x0002),	/* Everspin nvNitro adaptor */
+		.driver_data = NVME_QUIRK_PSEUDO_CMB_BAR4,  },
 	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_EXPRESS, 0xffffff) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2001) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_APPLE, 0x2003) },