From: Ben Widawsky <ben.widawsky@intel.com>
To: linux-cxl@vger.kernel.org
Cc: Ben Widawsky <ben.widawsky@intel.com>,
linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
"linux-acpi@vger.kernel.org, Ira Weiny" <ira.weiny@intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Vishal Verma <vishal.l.verma@intel.com>,
"Kelley, Sean V" <sean.v.kelley@intel.com>,
Rafael Wysocki <rafael.j.wysocki@intel.com>,
Bjorn Helgaas <helgaas@kernel.org>,
Jonathan Cameron <Jonathan.Cameron@Huawei.com>,
Jon Masters <jcm@jonmasters.org>,
Chris Browy <cbrowy@avery-design.com>,
Randy Dunlap <rdunlap@infradead.org>,
Christoph Hellwig <hch@infradead.org>,
daniel.lll@alibaba-inc.com
Subject: [RFC PATCH v3 05/16] cxl/mem: Map memory device registers
Date: Mon, 11 Jan 2021 14:51:09 -0800 [thread overview]
Message-ID: <20210111225121.820014-6-ben.widawsky@intel.com> (raw)
In-Reply-To: <20210111225121.820014-1-ben.widawsky@intel.com>
All the necessary bits are initialized in order to find and map the
register space for CXL Memory Devices. This is accomplished by using the
Register Locator DVSEC (CXL 2.0 - 8.1.9.1) to determine which PCI BAR to
use, and how much of an offset from that BAR should be added.
If the memory device registers are found and mapped a new internal data
structure tracking device state is allocated.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
---
drivers/cxl/cxl.h | 17 ++++++++
drivers/cxl/mem.c | 100 +++++++++++++++++++++++++++++++++++++++++++++-
drivers/cxl/pci.h | 14 +++++++
3 files changed, 130 insertions(+), 1 deletion(-)
create mode 100644 drivers/cxl/cxl.h
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
new file mode 100644
index 000000000000..d81d0ba4617c
--- /dev/null
+++ b/drivers/cxl/cxl.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright(c) 2020 Intel Corporation. */
+
+#ifndef __CXL_H__
+#define __CXL_H__
+
+/**
+ * struct cxl_mem - A CXL memory device
+ * @pdev: The PCI device associated with this CXL device.
+ * @regs: IO mappings to the device's MMIO
+ */
+struct cxl_mem {
+ struct pci_dev *pdev;
+ void __iomem *regs;
+};
+
+#endif
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 005404888942..8301db34d2ff 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -5,6 +5,58 @@
#include <linux/io.h>
#include "acpi.h"
#include "pci.h"
+#include "cxl.h"
+
+/**
+ * cxl_mem_create() - Create a new &struct cxl_mem.
+ * @pdev: The pci device associated with the new &struct cxl_mem.
+ * @reg_lo: Lower 32b of the register locator
+ * @reg_hi: Upper 32b of the register locator.
+ *
+ * Return: The new &struct cxl_mem on success, NULL on failure.
+ *
+ * Map the BAR for a CXL memory device. This BAR has the memory device's
+ * registers for the device as specified in CXL specification.
+ */
+static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo,
+ u32 reg_hi)
+{
+ struct device *dev = &pdev->dev;
+ struct cxl_mem *cxlm;
+ void __iomem *regs;
+ u64 offset;
+ u8 bar;
+ int rc;
+
+ offset = ((u64)reg_hi << 32) | (reg_lo & CXL_REGLOC_ADDR_MASK);
+ bar = (reg_lo >> CXL_REGLOC_BIR_SHIFT) & CXL_REGLOC_BIR_MASK;
+
+ /* Basic sanity check that BAR is big enough */
+ if (pci_resource_len(pdev, bar) < offset) {
+ dev_err(dev, "BAR%d: %pr: too small (offset: %#llx)\n", bar,
+ &pdev->resource[bar], (unsigned long long)offset);
+ return NULL;
+ }
+
+ rc = pcim_iomap_regions(pdev, BIT(bar), pci_name(pdev));
+ if (rc != 0) {
+ dev_err(dev, "failed to map registers\n");
+ return NULL;
+ }
+
+ cxlm = devm_kzalloc(&pdev->dev, sizeof(*cxlm), GFP_KERNEL);
+ if (!cxlm) {
+ dev_err(dev, "No memory available\n");
+ return NULL;
+ }
+
+ regs = pcim_iomap_table(pdev)[bar];
+ cxlm->pdev = pdev;
+ cxlm->regs = regs + offset;
+
+ dev_dbg(dev, "Mapped CXL Memory Device resource\n");
+ return cxlm;
+}
static int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec)
{
@@ -33,7 +85,8 @@ static int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec)
static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
struct device *dev = &pdev->dev;
- int rc, regloc;
+ struct cxl_mem *cxlm;
+ int rc, regloc, i;
rc = cxl_bus_acquire(pdev);
if (rc != 0) {
@@ -41,15 +94,59 @@ static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id)
return rc;
}
+ rc = pcim_enable_device(pdev);
+ if (rc)
+ return rc;
+
regloc = cxl_mem_dvsec(pdev, PCI_DVSEC_ID_CXL_REGLOC);
if (!regloc) {
dev_err(dev, "register location dvsec not found\n");
return -ENXIO;
}
+ regloc += 0xc; /* Skip DVSEC + reserved fields */
+
+ rc = -ENXIO;
+ for (i = regloc; i < regloc + 0x24; i += 8) {
+ u32 reg_lo, reg_hi;
+ u8 reg_type;
+
+ /* "register low and high" contain other bits */
+ pci_read_config_dword(pdev, i, ®_lo);
+ pci_read_config_dword(pdev, i + 4, ®_hi);
+
+ reg_type =
+ (reg_lo >> CXL_REGLOC_RBI_SHIFT) & CXL_REGLOC_RBI_MASK;
+
+ if (reg_type == CXL_REGLOC_RBI_MEMDEV) {
+ rc = 0;
+ cxlm = cxl_mem_create(pdev, reg_lo, reg_hi);
+ if (!cxlm)
+ rc = -ENODEV;
+ break;
+ }
+ }
+
+ if (rc)
+ return rc;
+ pci_set_drvdata(pdev, cxlm);
return 0;
}
+static void cxl_mem_remove(struct pci_dev *pdev)
+{
+ struct cxl_mem *cxlm;
+
+ cxlm = pci_get_drvdata(pdev);
+ if (!cxlm)
+ return;
+
+ kfree(cxlm);
+
+ pcim_iounmap_regions(pdev, ~0);
+ pci_set_drvdata(pdev, NULL);
+}
+
static const struct pci_device_id cxl_mem_pci_tbl[] = {
/* PCI class code for CXL.mem Type-3 Devices */
{ PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
@@ -62,6 +159,7 @@ static struct pci_driver cxl_mem_driver = {
.name = KBUILD_MODNAME,
.id_table = cxl_mem_pci_tbl,
.probe = cxl_mem_probe,
+ .remove = cxl_mem_remove,
};
MODULE_LICENSE("GPL v2");
diff --git a/drivers/cxl/pci.h b/drivers/cxl/pci.h
index a8a9935fa90b..df222edb6ac3 100644
--- a/drivers/cxl/pci.h
+++ b/drivers/cxl/pci.h
@@ -17,4 +17,18 @@
#define PCI_DVSEC_ID_CXL_REGLOC 0x8
+/* BAR Indicator Register (BIR) */
+#define CXL_REGLOC_BIR_SHIFT 0
+#define CXL_REGLOC_BIR_MASK 0x7
+
+/* Register Block Identifier (RBI) */
+#define CXL_REGLOC_RBI_SHIFT 8
+#define CXL_REGLOC_RBI_MASK 0xff
+#define CXL_REGLOC_RBI_EMPTY 0
+#define CXL_REGLOC_RBI_COMPONENT 1
+#define CXL_REGLOC_RBI_VIRT 2
+#define CXL_REGLOC_RBI_MEMDEV 3
+
+#define CXL_REGLOC_ADDR_MASK 0xffff0000
+
#endif /* __CXL_PCI_H__ */
--
2.30.0
next prev parent reply other threads:[~2021-01-12 0:30 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-11 22:51 [RFC PATCH v3 00/16] CXL 2.0 Support Ben Widawsky
2021-01-11 22:51 ` [RFC PATCH v3 01/16] docs: cxl: Add basic documentation Ben Widawsky
2021-01-11 22:51 ` [RFC PATCH v3 02/16] cxl/acpi: Add an acpi_cxl module for the CXL interconnect Ben Widawsky
2021-01-12 7:08 ` Randy Dunlap
2021-01-12 18:43 ` Jonathan Cameron
2021-01-12 19:43 ` Dan Williams
2021-01-12 22:06 ` Jonathan Cameron
2021-01-13 17:55 ` Kaneda, Erik
2021-01-20 19:27 ` Dan Williams
2021-01-20 19:18 ` Verma, Vishal L
2021-01-13 12:40 ` Rafael J. Wysocki
2021-01-20 19:21 ` Verma, Vishal L
2021-01-11 22:51 ` [RFC PATCH v3 03/16] cxl/acpi: add OSC support Ben Widawsky
2021-01-12 15:09 ` Rafael J. Wysocki
2021-01-12 18:48 ` Jonathan Cameron
2021-01-11 22:51 ` [RFC PATCH v3 04/16] cxl/mem: Introduce a driver for CXL-2.0-Type-3 endpoints Ben Widawsky
2021-01-12 7:08 ` Randy Dunlap
2021-01-12 19:01 ` Jonathan Cameron
2021-01-12 20:06 ` Dan Williams
2021-01-11 22:51 ` Ben Widawsky [this message]
2021-01-12 19:13 ` [RFC PATCH v3 05/16] cxl/mem: Map memory device registers Jonathan Cameron
2021-01-12 19:21 ` Ben Widawsky
2021-01-12 20:40 ` Dan Williams
2021-01-11 22:51 ` [RFC PATCH v3 06/16] cxl/mem: Find device capabilities Ben Widawsky
2021-01-12 19:17 ` Jonathan Cameron
2021-01-12 19:22 ` Ben Widawsky
2021-01-11 22:51 ` [RFC PATCH v3 07/16] cxl/mem: Implement polled mode mailbox Ben Widawsky
2021-01-13 18:26 ` Jonathan Cameron
2021-01-14 17:40 ` Jonathan Cameron
2021-01-14 17:50 ` Ben Widawsky
2021-01-14 18:13 ` Jonathan Cameron
2021-01-11 22:51 ` [RFC PATCH v3 08/16] cxl/mem: Register CXL memX devices Ben Widawsky
2021-01-14 16:28 ` Jonathan Cameron
2021-01-11 22:51 ` [RFC PATCH v3 09/16] cxl/mem: Add basic IOCTL interface Ben Widawsky
2021-01-14 16:19 ` Jonathan Cameron
2021-01-11 22:51 ` [RFC PATCH v3 10/16] cxl/mem: Add send command Ben Widawsky
2021-01-14 17:10 ` Jonathan Cameron
2021-01-21 18:15 ` Ben Widawsky
2021-01-22 11:43 ` Jonathan Cameron
2021-01-22 17:08 ` Ben Widawsky
2021-01-11 22:51 ` [RFC PATCH v3 11/16] taint: add taint for direct hardware access Ben Widawsky
2021-01-11 22:51 ` [RFC PATCH v3 11/16] taint: add taint for unfettered " Ben Widawsky
2021-01-12 3:31 ` Ben Widawsky
2021-01-11 22:51 ` [RFC PATCH v3 12/16] cxl/mem: Add a "RAW" send command Ben Widawsky
2021-01-11 22:51 ` [RFC PATCH v3 13/16] cxl/mem: Create concept of enabled commands Ben Widawsky
2021-01-14 17:25 ` Jonathan Cameron
2021-01-21 18:40 ` Ben Widawsky
2021-01-22 11:28 ` Jonathan Cameron
2021-01-11 22:51 ` [RFC PATCH v3 14/16] cxl/mem: Use CEL for enabling commands Ben Widawsky
2021-01-14 18:02 ` Jonathan Cameron
2021-01-14 18:13 ` Ben Widawsky
2021-01-14 18:32 ` Jonathan Cameron
2021-01-14 19:04 ` Ben Widawsky
2021-01-14 19:24 ` Jonathan Cameron
2021-01-11 22:51 ` [RFC PATCH v3 15/16] cxl/mem: Add limited Get Log command (0401h) Ben Widawsky
2021-01-14 18:08 ` Jonathan Cameron
2021-01-23 0:14 ` Ben Widawsky
2021-01-11 22:51 ` [RFC PATCH v3 16/16] MAINTAINERS: Add maintainers of the CXL driver Ben Widawsky
2021-01-12 1:12 ` Joe Perches
[not found] ` <0f2a6d62-09d8-416f-e972-3e9869c3e1a6@alibaba-inc.com>
2021-01-12 15:17 ` [RFC PATCH v3 00/16] CXL 2.0 Support Ben Widawsky
2021-01-12 16:19 ` Bjorn Helgaas
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