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From: Ben Widawsky <ben.widawsky@intel.com>
To: linux-cxl@vger.kernel.org
Cc: Ben Widawsky <ben.widawsky@intel.com>,
	Alison Schofield <alison.schofield@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Ira Weiny <ira.weiny@intel.com>,
	Jonathan Cameron <Jonathan.Cameron@Huawei.com>,
	Vishal Verma <vishal.l.verma@intel.com>
Subject: [PATCH 21/23] cxl/mem: Check that the device is CXL.mem capable
Date: Fri, 23 Jul 2021 14:06:21 -0700	[thread overview]
Message-ID: <20210723210623.114073-22-ben.widawsky@intel.com> (raw)
In-Reply-To: <20210723210623.114073-1-ben.widawsky@intel.com>

CXL.mem capability is required to participate in an interleave set.

Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
---
 drivers/cxl/core/bus.c  | 24 ++++++++++++++++++++++++
 drivers/cxl/core/core.h |  1 +
 drivers/cxl/mem.c       | 18 ++++++++++++++++++
 drivers/cxl/pci.c       | 23 -----------------------
 drivers/cxl/pci.h       |  7 ++++++-
 5 files changed, 49 insertions(+), 24 deletions(-)

diff --git a/drivers/cxl/core/bus.c b/drivers/cxl/core/bus.c
index c8c51718f3c7..75f49fbb8c00 100644
--- a/drivers/cxl/core/bus.c
+++ b/drivers/cxl/core/bus.c
@@ -716,6 +716,30 @@ struct cxl_decoder *devm_cxl_add_endpoint_decoder(struct device *host,
 }
 EXPORT_SYMBOL_GPL(devm_cxl_add_endpoint_decoder);
 
+int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec)
+{
+	int pos;
+
+	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DVSEC);
+	if (!pos)
+		return 0;
+
+	while (pos) {
+		u16 vendor, id;
+
+		pci_read_config_word(pdev, pos + PCI_DVSEC_HEADER1, &vendor);
+		pci_read_config_word(pdev, pos + PCI_DVSEC_HEADER2, &id);
+		if (vendor == PCI_DVSEC_VENDOR_ID_CXL && dvsec == id)
+			return pos;
+
+		pos = pci_find_next_ext_capability(pdev, pos,
+						   PCI_EXT_CAP_ID_DVSEC);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cxl_mem_dvsec);
+
 /**
  * __cxl_driver_register - register a driver for the cxl bus
  * @cxl_drv: cxl driver structure to attach
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index eb1a17103e5d..eab6e6461549 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -6,6 +6,7 @@
 
 #include <cxl.h>
 #include <mem.h>
+#include <pci.h>
 #include <region.h>
 
 extern const struct device_type cxl_nvdimm_bridge_type;
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index ae2024de7912..40281dcc0f3e 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -4,6 +4,7 @@
 #include <linux/module.h>
 #include <linux/pci.h>
 #include "mem.h"
+#include "pci.h"
 
 /**
  * DOC: cxl mem
@@ -33,13 +34,30 @@ static int cxl_memdev_probe(struct device *dev)
 {
 	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
 	struct cxl_mem *cxlm = cxlmd->cxlm;
+	struct pci_dev *pdev = cxlm->pdev;
 	struct device *pdev_parent = cxlm->pdev->dev.parent;
 	struct device *port_dev;
+	int pcie_dvsec;
+	u16 dvsec_ctrl;
 
 	port_dev = bus_find_device(&cxl_bus_type, NULL, pdev_parent, port_match);
 	if (!port_dev)
 		return -ENODEV;
 
+	pcie_dvsec = cxl_mem_dvsec(pdev, PCI_DVSEC_ID_PCIE_DVSEC_CXL_DVSEC_ID);
+	if (!pcie_dvsec) {
+		dev_err(dev, "Unable to determine CXL protocol support");
+		return -ENODEV;
+	}
+
+	pci_read_config_word(pdev,
+			     pcie_dvsec + PCI_DVSEC_ID_CXL_PCIE_CTRL_OFFSET,
+			     &dvsec_ctrl);
+	if (!(dvsec_ctrl & CXL_PCIE_MEM_ENABLE)) {
+		dev_err(dev, "CXL.cache protocol not supported on device");
+		return -ENODEV;
+	}
+
 	return 0;
 }
 
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index f924a8c5a831..96837412914d 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -971,29 +971,6 @@ static void cxl_mem_unmap_regblock(struct cxl_mem *cxlm, void __iomem *base)
 	pci_iounmap(cxlm->pdev, base);
 }
 
-static int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec)
-{
-	int pos;
-
-	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DVSEC);
-	if (!pos)
-		return 0;
-
-	while (pos) {
-		u16 vendor, id;
-
-		pci_read_config_word(pdev, pos + PCI_DVSEC_HEADER1, &vendor);
-		pci_read_config_word(pdev, pos + PCI_DVSEC_HEADER2, &id);
-		if (vendor == PCI_DVSEC_VENDOR_ID_CXL && dvsec == id)
-			return pos;
-
-		pos = pci_find_next_ext_capability(pdev, pos,
-						   PCI_EXT_CAP_ID_DVSEC);
-	}
-
-	return 0;
-}
-
 static int cxl_probe_regs(struct cxl_mem *cxlm, void __iomem *base,
 			  struct cxl_register_map *map)
 {
diff --git a/drivers/cxl/pci.h b/drivers/cxl/pci.h
index 8c1a58813816..c5a4d51b7561 100644
--- a/drivers/cxl/pci.h
+++ b/drivers/cxl/pci.h
@@ -11,7 +11,10 @@
  */
 #define PCI_DVSEC_HEADER1_LENGTH_MASK	GENMASK(31, 20)
 #define PCI_DVSEC_VENDOR_ID_CXL		0x1E98
-#define PCI_DVSEC_ID_CXL		0x0
+
+#define PCI_DVSEC_ID_PCIE_DVSEC_CXL_DVSEC_ID	0x0
+#define PCI_DVSEC_ID_CXL_PCIE_CTRL_OFFSET	0xC
+#define   CXL_PCIE_MEM_ENABLE			BIT(2)
 
 #define PCI_DVSEC_ID_CXL_REGLOC_DVSEC_ID	0x8
 #define PCI_DVSEC_ID_CXL_REGLOC_BLOCK1_OFFSET	0xC
@@ -29,4 +32,6 @@
 
 #define CXL_REGLOC_ADDR_MASK GENMASK(31, 16)
 
+int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec);
+
 #endif /* __CXL_PCI_H__ */
-- 
2.32.0


  parent reply	other threads:[~2021-07-23 21:06 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-23 21:06 [PATCH RFCish 00/23] cxl_region and cxl_memdev drivers Ben Widawsky
2021-07-23 21:06 ` [PATCH 01/23] cxl: Move cxl_core to new directory Ben Widawsky
2021-07-23 21:06 ` [PATCH 02/23] cxl/core: Improve CXL core kernel docs Ben Widawsky
2021-07-23 21:06 ` [PATCH 03/23] cxl/core: Extract register and pmem functionality Ben Widawsky
2021-07-23 21:06 ` [PATCH 04/23] cxl/mem: Move character device region creation Ben Widawsky
2021-07-23 21:06 ` [PATCH 05/23] cxl: Pass fops and shutdown to memdev creation Ben Widawsky
2021-07-23 21:06 ` [PATCH 06/23] cxl/core: Move memdev management to core Ben Widawsky
2021-07-23 21:06 ` [PATCH 07/23] cxl/pci: Ignore unknown register block types Ben Widawsky
2021-07-23 21:06 ` [PATCH 08/23] cxl/pci: Simplify register setup Ben Widawsky
2021-07-23 21:06 ` [PATCH 09/23] cxl/pci: Retain map information in cxl_mem_probe Ben Widawsky
2021-07-23 21:06 ` [PATCH 10/23] cxl/decoder: Support parentless decoders Ben Widawsky
2021-07-30 21:03   ` Dan Williams
2021-07-23 21:06 ` [PATCH 11/23] cxl: Enable an endpoint decoder type Ben Widawsky
2021-07-23 21:06 ` [PATCH 12/23] cxl/region: Add region creation ABI Ben Widawsky
2021-08-14  2:19   ` Dan Williams
2021-08-26 21:01     ` Ben Widawsky
2021-08-26 21:44       ` Dan Williams
2021-07-23 21:06 ` [PATCH 13/23] cxl/region: Introduce concept of region configuration Ben Widawsky
2021-07-23 21:06 ` [PATCH 14/23] cxl: Convert driver id to an enum Ben Widawsky
2021-07-23 21:06 ` [PATCH 15/23] cxl/region: Introduce a cxl_region driver Ben Widawsky
2021-07-23 21:06 ` [PATCH 16/23] cxl/core: Convert decoder range to resource Ben Widawsky
2021-07-23 21:06 ` [PATCH 17/23] cxl/region: Handle region's address space allocation Ben Widawsky
2021-07-23 21:06 ` [PATCH 18/23] cxl/region: Only allow CXL capable targets Ben Widawsky
2021-07-23 21:06 ` [PATCH 19/23] cxl/mem: Introduce CXL mem driver Ben Widawsky
2021-07-23 21:06 ` [PATCH 20/23] cxl/memdev: Determine CXL.mem capability Ben Widawsky
2021-07-23 21:06 ` Ben Widawsky [this message]
2021-07-23 21:06 ` [PATCH 22/23] cxl/mem: Add device as a port Ben Widawsky
2021-07-23 21:06 ` [PATCH 23/23] cxl/core: Map component registers for ports Ben Widawsky

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