diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-cxl | 20 | ||||
| -rw-r--r-- | Documentation/driver-api/cxl/memory-devices.rst | 6 | ||||
| -rw-r--r-- | drivers/cxl/Kconfig | 15 | ||||
| -rw-r--r-- | drivers/cxl/Makefile | 2 | ||||
| -rw-r--r-- | drivers/cxl/acpi.c | 39 | ||||
| -rw-r--r-- | drivers/cxl/core.c | 160 | ||||
| -rw-r--r-- | drivers/cxl/cxl.h | 31 |
7 files changed, 273 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 2fe7490ad6a8..bda2cc55cc38 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -24,3 +24,23 @@ Description: (RO) "Persistent Only Capacity" as bytes. Represents the identically named field in the Identify Memory Device Output Payload in the CXL-2.0 specification. + +What: /sys/bus/cxl/devices/*/devtype +Date: June, 2021 +KernelVersion: v5.14 +Contact: linux-cxl@vger.kernel.org +Description: + CXL device objects export the devtype attribute which mirrors + the same value communicated in the DEVTYPE environment variable + for uevents for devices on the "cxl" bus. + +What: /sys/bus/cxl/devices/portX/uport +Date: June, 2021 +KernelVersion: v5.14 +Contact: linux-cxl@vger.kernel.org +Description: + CXL port objects are enumerated from either a platform firmware + device (ACPI0017 and ACPI0016) or PCIe switch upstream port with + CXL component registers. The 'uport' symlink connects the CXL + portX object to the device that published the CXL port + capability. diff --git a/Documentation/driver-api/cxl/memory-devices.rst b/Documentation/driver-api/cxl/memory-devices.rst index 44c8ddbc8415..487ce4f41d77 100644 --- a/Documentation/driver-api/cxl/memory-devices.rst +++ b/Documentation/driver-api/cxl/memory-devices.rst @@ -30,6 +30,12 @@ CXL Memory Device CXL Core -------- +.. kernel-doc:: drivers/cxl/cxl.h + :doc: cxl objects + +.. kernel-doc:: drivers/cxl/cxl.h + :internal: + .. kernel-doc:: drivers/cxl/core.c :doc: cxl core diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig index 5483ba92b6da..d2573f6aef91 100644 --- a/drivers/cxl/Kconfig +++ b/drivers/cxl/Kconfig @@ -45,4 +45,19 @@ config CXL_MEM_RAW_COMMANDS potential impact to memory currently in use by the kernel. If developing CXL hardware or the driver say Y, otherwise say N. + +config CXL_ACPI + tristate "CXL ACPI: Platform Support" + depends on ACPI + help + Enable support for host managed device memory (HDM) resources + published by a platform's ACPI CXL memory layout description. See + Chapter 9.14.1 CXL Early Discovery Table (CEDT) in the CXL 2.0 + specification, and CXL Fixed Memory Window Structures (CEDT.CFMWS) + (https://www.computeexpresslink.org/spec-landing). The CXL core + consumes these resource to publish the root of a cxl_port decode + hierarchy to map regions that represent System RAM, or Persistent + Memory regions to be managed by LIBNVDIMM. + + If unsure say 'm'. endif diff --git a/drivers/cxl/Makefile b/drivers/cxl/Makefile index d9d282dc15be..a29efb3e8ad2 100644 --- a/drivers/cxl/Makefile +++ b/drivers/cxl/Makefile @@ -1,7 +1,9 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_CXL_BUS) += cxl_core.o obj-$(CONFIG_CXL_MEM) += cxl_pci.o +obj-$(CONFIG_CXL_ACPI) += cxl_acpi.o ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=CXL cxl_core-y := core.o cxl_pci-y := pci.o +cxl_acpi-y := acpi.o diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c new file mode 100644 index 000000000000..556d25ab6966 --- /dev/null +++ b/drivers/cxl/acpi.c @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2021 Intel Corporation. All rights reserved. */ +#include <linux/platform_device.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/acpi.h> +#include "cxl.h" + +static int cxl_acpi_probe(struct platform_device *pdev) +{ + struct cxl_port *root_port; + struct device *host = &pdev->dev; + + root_port = devm_cxl_add_port(host, host, CXL_RESOURCE_NONE, NULL); + if (IS_ERR(root_port)) + return PTR_ERR(root_port); + dev_dbg(host, "add: %s\n", dev_name(&root_port->dev)); + + return 0; +} + +static const struct acpi_device_id cxl_acpi_ids[] = { + { "ACPI0017", 0 }, + { "", 0 }, +}; +MODULE_DEVICE_TABLE(acpi, cxl_acpi_ids); + +static struct platform_driver cxl_acpi_driver = { + .probe = cxl_acpi_probe, + .driver = { + .name = KBUILD_MODNAME, + .acpi_match_table = cxl_acpi_ids, + }, +}; + +module_platform_driver(cxl_acpi_driver); +MODULE_LICENSE("GPL v2"); +MODULE_IMPORT_NS(CXL); diff --git a/drivers/cxl/core.c b/drivers/cxl/core.c index 853666d8a9f5..dbbb34618d7d 100644 --- a/drivers/cxl/core.c +++ b/drivers/cxl/core.c @@ -4,6 +4,8 @@ #include <linux/device.h> #include <linux/module.h> #include <linux/pci.h> +#include <linux/slab.h> +#include <linux/idr.h> #include "cxl.h" /** @@ -13,6 +15,164 @@ * point for cross-device interleave coordination through cxl ports. */ +static DEFINE_IDA(cxl_port_ida); + +static ssize_t devtype_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", dev->type->name); +} +static DEVICE_ATTR_RO(devtype); + +static struct attribute *cxl_base_attributes[] = { + &dev_attr_devtype.attr, + NULL, +}; + +static struct attribute_group cxl_base_attribute_group = { + .attrs = cxl_base_attributes, +}; + +static void cxl_port_release(struct device *dev) +{ + struct cxl_port *port = to_cxl_port(dev); + + ida_free(&cxl_port_ida, port->id); + kfree(port); +} + +static const struct attribute_group *cxl_port_attribute_groups[] = { + &cxl_base_attribute_group, + NULL, +}; + +static const struct device_type cxl_port_type = { + .name = "cxl_port", + .release = cxl_port_release, + .groups = cxl_port_attribute_groups, +}; + +struct cxl_port *to_cxl_port(struct device *dev) +{ + if (dev_WARN_ONCE(dev, dev->type != &cxl_port_type, + "not a cxl_port device\n")) + return NULL; + return container_of(dev, struct cxl_port, dev); +} + +static void unregister_dev(void *dev) +{ + device_unregister(dev); +} + +static void cxl_unlink_uport(void *_port) +{ + struct cxl_port *port = _port; + + sysfs_remove_link(&port->dev.kobj, "uport"); +} + +static int devm_cxl_link_uport(struct device *host, struct cxl_port *port) +{ + int rc; + + rc = sysfs_create_link(&port->dev.kobj, &port->uport->kobj, "uport"); + if (rc) + return rc; + return devm_add_action_or_reset(host, cxl_unlink_uport, port); +} + +static struct cxl_port *cxl_port_alloc(struct device *uport, + resource_size_t component_reg_phys, + struct cxl_port *parent_port) +{ + struct cxl_port *port; + struct device *dev; + int rc; + + port = kzalloc(sizeof(*port), GFP_KERNEL); + if (!port) + return ERR_PTR(-ENOMEM); + + rc = ida_alloc(&cxl_port_ida, GFP_KERNEL); + if (rc < 0) + goto err; + port->id = rc; + + /* + * The top-level cxl_port "cxl_root" does not have a cxl_port as + * its parent and it does not have any corresponding component + * registers as its decode is described by a fixed platform + * description. + */ + dev = &port->dev; + if (parent_port) + dev->parent = &parent_port->dev; + else + dev->parent = uport; + + port->uport = uport; + port->component_reg_phys = component_reg_phys; + + device_initialize(dev); + device_set_pm_not_required(dev); + dev->bus = &cxl_bus_type; + dev->type = &cxl_port_type; + + return port; + +err: + kfree(port); + return ERR_PTR(rc); +} + +/** + * devm_cxl_add_port - register a cxl_port in CXL memory decode hierarchy + * @host: host device for devm operations + * @uport: "physical" device implementing this upstream port + * @component_reg_phys: (optional) for configurable cxl_port instances + * @parent_port: next hop up in the CXL memory decode hierarchy + */ +struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport, + resource_size_t component_reg_phys, + struct cxl_port *parent_port) +{ + struct cxl_port *port; + struct device *dev; + int rc; + + port = cxl_port_alloc(uport, component_reg_phys, parent_port); + if (IS_ERR(port)) + return port; + + dev = &port->dev; + if (parent_port) + rc = dev_set_name(dev, "port%d", port->id); + else + rc = dev_set_name(dev, "root%d", port->id); + if (rc) + goto err; + + rc = device_add(dev); + if (rc) + goto err; + + rc = devm_add_action_or_reset(host, unregister_dev, dev); + if (rc) + return ERR_PTR(rc); + + rc = devm_cxl_link_uport(host, port); + if (rc) + return ERR_PTR(rc); + + return port; + +err: + put_device(dev); + return ERR_PTR(rc); +} +EXPORT_SYMBOL_GPL(devm_cxl_add_port); + /** * cxl_probe_component_regs() - Detect CXL Component register blocks * @dev: Host device of the @base mapping diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 2c47e9cffd44..5651e5bb8274 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -8,6 +8,14 @@ #include <linux/bitops.h> #include <linux/io.h> +/** + * DOC: cxl objects + * + * The CXL core objects like ports, decoders, and regions are shared + * between the subsystem drivers cxl_acpi, cxl_pci, and core drivers + * (port-driver, region-driver, nvdimm object-drivers... etc). + */ + /* CXL 2.0 8.2.5 CXL.cache and CXL.mem Registers*/ #define CXL_CM_OFFSET 0x1000 #define CXL_CM_CAP_HDR_OFFSET 0x0 @@ -145,5 +153,28 @@ int cxl_map_device_regs(struct pci_dev *pdev, struct cxl_device_regs *regs, struct cxl_register_map *map); +#define CXL_RESOURCE_NONE ((resource_size_t) -1) + +/** + * struct cxl_port - logical collection of upstream port devices and + * downstream port devices to construct a CXL memory + * decode hierarchy. + * @dev: this port's device + * @uport: PCI or platform device implementing the upstream port capability + * @id: id for port device-name + * @component_reg_phys: component register capability base address (optional) + */ +struct cxl_port { + struct device dev; + struct device *uport; + int id; + resource_size_t component_reg_phys; +}; + +struct cxl_port *to_cxl_port(struct device *dev); +struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport, + resource_size_t component_reg_phys, + struct cxl_port *parent_port); + extern struct bus_type cxl_bus_type; #endif /* __CXL_H__ */ |