diff options
Diffstat (limited to 'drivers/cxl')
| -rw-r--r-- | drivers/cxl/Kconfig | 16 | ||||
| -rw-r--r-- | drivers/cxl/Makefile | 2 | ||||
| -rw-r--r-- | drivers/cxl/acpi.c | 3 | ||||
| -rw-r--r-- | drivers/cxl/core/memdev.c | 16 | ||||
| -rw-r--r-- | drivers/cxl/core/port.c | 105 | ||||
| -rw-r--r-- | drivers/cxl/cxl.h | 6 | ||||
| -rw-r--r-- | drivers/cxl/cxlmem.h | 8 | ||||
| -rw-r--r-- | drivers/cxl/mem.c | 228 | ||||
| -rw-r--r-- | drivers/cxl/port.c | 12 |
9 files changed, 391 insertions, 5 deletions
diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig index 4f4f7587f6ca..b88ab956bb7c 100644 --- a/drivers/cxl/Kconfig +++ b/drivers/cxl/Kconfig @@ -78,6 +78,22 @@ config CXL_PMEM If unsure say 'm'. +config CXL_MEM + tristate "CXL: Memory Expansion" + depends on CXL_PCI + default CXL_BUS + help + The CXL.mem protocol allows a device to act as a provider of "System + RAM" and/or "Persistent Memory" that is fully coherent as if the + memory were attached to the typical CPU memory controller. This is + known as HDM "Host-managed Device Memory". + + Say 'y/m' to enable a driver that will attach to CXL.mem devices for + memory expansion and control of HDM. See Chapter 9.13 in the CXL 2.0 + specification for a detailed description of HDM. + + If unsure say 'm'. + config CXL_PORT default CXL_BUS tristate diff --git a/drivers/cxl/Makefile b/drivers/cxl/Makefile index 56fcac2323cb..ce267ef11d93 100644 --- a/drivers/cxl/Makefile +++ b/drivers/cxl/Makefile @@ -1,10 +1,12 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_CXL_BUS) += core/ obj-$(CONFIG_CXL_PCI) += cxl_pci.o +obj-$(CONFIG_CXL_MEM) += cxl_mem.o obj-$(CONFIG_CXL_ACPI) += cxl_acpi.o obj-$(CONFIG_CXL_PMEM) += cxl_pmem.o obj-$(CONFIG_CXL_PORT) += cxl_port.o +cxl_mem-y := mem.o cxl_pci-y := pci.o cxl_acpi-y := acpi.o cxl_pmem-y := pmem.o diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index 7bd53dc691ec..d8295572bde9 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -314,7 +314,8 @@ static int cxl_acpi_probe(struct platform_device *pdev) if (rc < 0) return rc; - return 0; + /* In case PCI is scanned before ACPI re-trigger memdev attach */ + return cxl_bus_rescan(); } static const struct acpi_device_id cxl_acpi_ids[] = { diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c index b2773664e407..1f76b28f9826 100644 --- a/drivers/cxl/core/memdev.c +++ b/drivers/cxl/core/memdev.c @@ -162,6 +162,12 @@ static const struct device_type cxl_memdev_type = { .groups = cxl_memdev_attribute_groups, }; +bool is_cxl_memdev(struct device *dev) +{ + return dev->type == &cxl_memdev_type; +} +EXPORT_SYMBOL_NS_GPL(is_cxl_memdev, CXL); + /** * set_exclusive_cxl_commands() - atomically disable user cxl commands * @cxlds: The device state to operate on @@ -213,6 +219,15 @@ static void cxl_memdev_unregister(void *_cxlmd) put_device(dev); } +static void detach_memdev(struct work_struct *work) +{ + struct cxl_memdev *cxlmd; + + cxlmd = container_of(work, typeof(*cxlmd), detach_work); + device_release_driver(&cxlmd->dev); + put_device(&cxlmd->dev); +} + static struct cxl_memdev *cxl_memdev_alloc(struct cxl_dev_state *cxlds, const struct file_operations *fops) { @@ -237,6 +252,7 @@ static struct cxl_memdev *cxl_memdev_alloc(struct cxl_dev_state *cxlds, dev->devt = MKDEV(cxl_mem_major, cxlmd->id); dev->type = &cxl_memdev_type; device_set_pm_not_required(dev); + INIT_WORK(&cxlmd->detach_work, detach_memdev); cdev = &cxlmd->cdev; cdev_init(cdev, fops); diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index c5779c982c80..f460460b12b3 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0-only /* Copyright(c) 2020 Intel Corporation. All rights reserved. */ #include <linux/io-64-nonatomic-lo-hi.h> +#include <linux/workqueue.h> #include <linux/device.h> #include <linux/module.h> #include <linux/pci.h> @@ -46,6 +47,8 @@ static int cxl_device_id(struct device *dev) return CXL_DEVICE_ROOT; return CXL_DEVICE_PORT; } + if (is_cxl_memdev(dev)) + return CXL_DEVICE_MEMORY_EXPANDER; return 0; } @@ -318,8 +321,10 @@ static void unregister_port(void *_port) { struct cxl_port *port = _port; - if (!is_cxl_root(port)) + if (!is_cxl_root(port)) { device_lock_assert(port->dev.parent); + port->uport = NULL; + } device_unregister(&port->dev); } @@ -410,7 +415,9 @@ struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport, if (parent_port) port->depth = parent_port->depth + 1; dev = &port->dev; - if (parent_port) + if (is_cxl_memdev(uport)) + rc = dev_set_name(dev, "endpoint%d", port->id); + else if (parent_port) rc = dev_set_name(dev, "port%d", port->id); else rc = dev_set_name(dev, "root%d", port->id); @@ -790,6 +797,38 @@ static struct device *grandparent(struct device *dev) return NULL; } +static void delete_endpoint(void *data) +{ + struct cxl_memdev *cxlmd = data; + struct cxl_port *endpoint = dev_get_drvdata(&cxlmd->dev); + struct cxl_port *parent_port; + struct device *parent; + + parent_port = cxl_mem_find_port(cxlmd); + if (!parent_port) + return; + parent = &parent_port->dev; + + cxl_device_lock(parent); + if (parent->driver && endpoint->uport) { + devm_release_action(parent, cxl_unlink_uport, endpoint); + devm_release_action(parent, unregister_port, endpoint); + } + cxl_device_unlock(parent); + put_device(parent); + put_device(&endpoint->dev); +} + +int cxl_endpoint_autoremove(struct cxl_memdev *cxlmd, struct cxl_port *endpoint) +{ + struct device *dev = &cxlmd->dev; + + get_device(&endpoint->dev); + dev_set_drvdata(dev, endpoint); + return devm_add_action_or_reset(dev, delete_endpoint, cxlmd); +} +EXPORT_SYMBOL_NS_GPL(cxl_endpoint_autoremove, CXL); + /* * The natural end of life of a non-root 'cxl_port' is when its parent port goes * through a ->remove() event ("top-down" unregistration). The unnatural trigger @@ -1034,6 +1073,12 @@ retry: } EXPORT_SYMBOL_NS_GPL(devm_cxl_enumerate_ports, CXL); +struct cxl_port *cxl_mem_find_port(struct cxl_memdev *cxlmd) +{ + return find_cxl_port(grandparent(&cxlmd->dev)); +} +EXPORT_SYMBOL_NS_GPL(cxl_mem_find_port, CXL); + struct cxl_dport *cxl_find_dport_by_dev(struct cxl_port *port, const struct device *dev) { @@ -1352,12 +1397,54 @@ static void cxl_bus_remove(struct device *dev) cxl_nested_unlock(dev); } +static struct workqueue_struct *cxl_bus_wq; + +int cxl_bus_rescan(void) +{ + return bus_rescan_devices(&cxl_bus_type); +} +EXPORT_SYMBOL_NS_GPL(cxl_bus_rescan, CXL); + +bool schedule_cxl_memdev_detach(struct cxl_memdev *cxlmd) +{ + return queue_work(cxl_bus_wq, &cxlmd->detach_work); +} +EXPORT_SYMBOL_NS_GPL(schedule_cxl_memdev_detach, CXL); + +/* for user tooling to ensure port disable work has completed */ +static ssize_t flush_store(struct bus_type *bus, const char *buf, size_t count) +{ + if (sysfs_streq(buf, "1")) { + flush_workqueue(cxl_bus_wq); + return count; + } + + return -EINVAL; +} + +static BUS_ATTR_WO(flush); + +static struct attribute *cxl_bus_attributes[] = { + &bus_attr_flush.attr, + NULL, +}; + +static struct attribute_group cxl_bus_attribute_group = { + .attrs = cxl_bus_attributes, +}; + +static const struct attribute_group *cxl_bus_attribute_groups[] = { + &cxl_bus_attribute_group, + NULL, +}; + struct bus_type cxl_bus_type = { .name = "cxl", .uevent = cxl_bus_uevent, .match = cxl_bus_match, .probe = cxl_bus_probe, .remove = cxl_bus_remove, + .bus_groups = cxl_bus_attribute_groups, }; EXPORT_SYMBOL_NS_GPL(cxl_bus_type, CXL); @@ -1371,12 +1458,21 @@ static __init int cxl_core_init(void) if (rc) return rc; + cxl_bus_wq = alloc_ordered_workqueue("cxl_port", 0); + if (!cxl_bus_wq) { + rc = -ENOMEM; + goto err_wq; + } + rc = bus_register(&cxl_bus_type); if (rc) - goto err; + goto err_bus; + return 0; -err: +err_bus: + destroy_workqueue(cxl_bus_wq); +err_wq: cxl_memdev_exit(); cxl_mbox_exit(); return rc; @@ -1385,6 +1481,7 @@ err: static void cxl_core_exit(void) { bus_unregister(&cxl_bus_type); + destroy_workqueue(cxl_bus_wq); cxl_memdev_exit(); cxl_mbox_exit(); } diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index de4fbe7cbf42..f5e5b4ac8228 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -328,6 +328,9 @@ struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport, struct cxl_port *parent_port); struct cxl_port *find_cxl_root(struct device *dev); int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd); +int cxl_bus_rescan(void); +struct cxl_port *cxl_mem_find_port(struct cxl_memdev *cxlmd); +bool schedule_cxl_memdev_detach(struct cxl_memdev *cxlmd); struct cxl_dport *devm_cxl_add_dport(struct cxl_port *port, struct device *dport, int port_id, @@ -345,6 +348,8 @@ struct cxl_decoder *cxl_switch_decoder_alloc(struct cxl_port *port, int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map); int cxl_decoder_add_locked(struct cxl_decoder *cxld, int *target_map); int cxl_decoder_autoremove(struct device *host, struct cxl_decoder *cxld); +int cxl_endpoint_autoremove(struct cxl_memdev *cxlmd, struct cxl_port *endpoint); + struct cxl_hdm; struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port); int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm); @@ -377,6 +382,7 @@ void cxl_driver_unregister(struct cxl_driver *cxl_drv); #define CXL_DEVICE_NVDIMM 2 #define CXL_DEVICE_PORT 3 #define CXL_DEVICE_ROOT 4 +#define CXL_DEVICE_MEMORY_EXPANDER 5 #define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*") #define CXL_MODALIAS_FMT "cxl:t%d" diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h index 0ba0cf8dcdbc..5d33ce24fe09 100644 --- a/drivers/cxl/cxlmem.h +++ b/drivers/cxl/cxlmem.h @@ -34,12 +34,14 @@ * @dev: driver core device object * @cdev: char dev core object for ioctl operations * @cxlds: The device state backing this device + * @detach_work: active memdev lost a port in its ancestry * @id: id number of this memdev instance. */ struct cxl_memdev { struct device dev; struct cdev cdev; struct cxl_dev_state *cxlds; + struct work_struct detach_work; int id; }; @@ -48,6 +50,12 @@ static inline struct cxl_memdev *to_cxl_memdev(struct device *dev) return container_of(dev, struct cxl_memdev, dev); } +bool is_cxl_memdev(struct device *dev); +static inline bool is_cxl_endpoint(struct cxl_port *port) +{ + return is_cxl_memdev(port->uport); +} + struct cxl_memdev *devm_cxl_add_memdev(struct cxl_dev_state *cxlds); /** diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c new file mode 100644 index 000000000000..49a4b1c47299 --- /dev/null +++ b/drivers/cxl/mem.c @@ -0,0 +1,228 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2022 Intel Corporation. All rights reserved. */ +#include <linux/device.h> +#include <linux/module.h> +#include <linux/pci.h> + +#include "cxlmem.h" +#include "cxlpci.h" + +/** + * DOC: cxl mem + * + * CXL memory endpoint devices and switches are CXL capable devices that are + * participating in CXL.mem protocol. Their functionality builds on top of the + * CXL.io protocol that allows enumerating and configuring components via + * standard PCI mechanisms. + * + * The cxl_mem driver owns kicking off the enumeration of this CXL.mem + * capability. With the detection of a CXL capable endpoint, the driver will + * walk up to find the platform specific port it is connected to, and determine + * if there are intervening switches in the path. If there are switches, a + * secondary action is to enumerate those (implemented in cxl_core). Finally the + * cxl_mem driver adds the device it is bound to as a CXL endpoint-port for use + * in higher level operations. + */ + +static int wait_for_media(struct cxl_memdev *cxlmd) +{ + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct cxl_endpoint_dvsec_info *info = &cxlds->info; + int rc; + + if (!info->mem_enabled) + return -EBUSY; + + rc = cxlds->wait_media_ready(cxlds); + if (rc) + return rc; + + /* + * We know the device is active, and enabled, if any ranges are non-zero + * we'll need to check later before adding the port since that owns the + * HDM decoder registers. + */ + return 0; +} + +static int create_endpoint(struct cxl_memdev *cxlmd, + struct cxl_port *parent_port) +{ + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct cxl_port *endpoint; + + endpoint = devm_cxl_add_port(&parent_port->dev, &cxlmd->dev, + cxlds->component_reg_phys, parent_port); + if (IS_ERR(endpoint)) + return PTR_ERR(endpoint); + + dev_dbg(&cxlmd->dev, "add: %s\n", dev_name(&endpoint->dev)); + + if (!endpoint->dev.driver) { + dev_err(&cxlmd->dev, "%s failed probe\n", + dev_name(&endpoint->dev)); + return -ENXIO; + } + + return cxl_endpoint_autoremove(cxlmd, endpoint); +} + +/** + * cxl_dvsec_decode_init() - Setup HDM decoding for the endpoint + * @cxlds: Device state + * + * Additionally, enables global HDM decoding. Warning: don't call this outside + * of probe. Once probe is complete, the port driver owns all access to the HDM + * decoder registers. + * + * Returns: false if DVSEC Ranges are being used instead of HDM + * decoders, or if it can not be determined if DVSEC Ranges are in use. + * Otherwise, returns true. + */ +__mock bool cxl_dvsec_decode_init(struct cxl_dev_state *cxlds) +{ + struct cxl_endpoint_dvsec_info *info = &cxlds->info; + struct cxl_register_map map; + struct cxl_component_reg_map *cmap = &map.component_map; + bool global_enable, do_hdm_init = false; + void __iomem *crb; + u32 global_ctrl; + + /* map hdm decoder */ + crb = ioremap(cxlds->component_reg_phys, CXL_COMPONENT_REG_BLOCK_SIZE); + if (!crb) { + dev_dbg(cxlds->dev, "Failed to map component registers\n"); + return false; + } + + cxl_probe_component_regs(cxlds->dev, crb, cmap); + if (!cmap->hdm_decoder.valid) { + dev_dbg(cxlds->dev, "Invalid HDM decoder registers\n"); + goto out; + } + + global_ctrl = readl(crb + cmap->hdm_decoder.offset + + CXL_HDM_DECODER_CTRL_OFFSET); + global_enable = global_ctrl & CXL_HDM_DECODER_ENABLE; + if (!global_enable && info->ranges) { + dev_dbg(cxlds->dev, + "DVSEC ranges already programmed and HDM decoders not enabled.\n"); + goto out; + } + + do_hdm_init = true; + + /* + * Permanently (for this boot at least) opt the device into HDM + * operation. Individual HDM decoders still need to be enabled after + * this point. + */ + if (!global_enable) { + dev_dbg(cxlds->dev, "Enabling HDM decode\n"); + writel(global_ctrl | CXL_HDM_DECODER_ENABLE, + crb + cmap->hdm_decoder.offset + + CXL_HDM_DECODER_CTRL_OFFSET); + } + +out: + iounmap(crb); + return do_hdm_init; +} + +static int cxl_mem_probe(struct device *dev) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct cxl_port *parent_port; + int rc; + + /* + * Someone is trying to reattach this device after it lost its port + * connection (an endpoint port previously registered by this memdev was + * disabled). This racy check is ok because if the port is still gone, + * no harm done, and if the port hierarchy comes back it will re-trigger + * this probe. Port rescan and memdev detach work share the same + * single-threaded workqueue. + */ + if (work_pending(&cxlmd->detach_work)) + return -EBUSY; + + rc = wait_for_media(cxlmd); + if (rc) { + dev_err(dev, "Media not active (%d)\n", rc); + return rc; + } + + /* + * If DVSEC ranges are being used instead of HDM decoder registers there + * is no use in trying to manage those. + */ + if (!cxl_dvsec_decode_init(cxlds)) { + struct cxl_endpoint_dvsec_info *info = &cxlds->info; + int i; + + /* */ + for (i = 0; i < 2; i++) { + u64 base, size; + + /* + * Give a nice warning to the user that BIOS has really + * botched things for them if it didn't place DVSEC + * ranges in the memory map. + */ + base = info->dvsec_range[i].start; + size = range_len(&info->dvsec_range[i]); + if (size && !region_intersects(base, size, + IORESOURCE_SYSTEM_RAM, + IORES_DESC_NONE)) { + dev_err(dev, + "DVSEC range %#llx-%#llx must be reserved by BIOS, but isn't\n", + base, base + size - 1); + } + } + dev_err(dev, + "Active DVSEC range registers in use. Will not bind.\n"); + return -EBUSY; + } + + rc = devm_cxl_enumerate_ports(cxlmd); + if (rc) + return rc; + + parent_port = cxl_mem_find_port(cxlmd); + if (!parent_port) { + dev_err(dev, "CXL port topology not found\n"); + return -ENXIO; + } + + cxl_device_lock(&parent_port->dev); + if (!parent_port->dev.driver) { + dev_err(dev, "CXL port topology %s not enabled\n", + dev_name(&parent_port->dev)); + rc = -ENXIO; + goto out; + } + + rc = create_endpoint(cxlmd, parent_port); +out: + cxl_device_unlock(&parent_port->dev); + put_device(&parent_port->dev); + return rc; +} + +static struct cxl_driver cxl_mem_driver = { + .name = "cxl_mem", + .probe = cxl_mem_probe, + .id = CXL_DEVICE_MEMORY_EXPANDER, +}; + +module_cxl_driver(cxl_mem_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_IMPORT_NS(CXL); +MODULE_ALIAS_CXL(CXL_DEVICE_MEMORY_EXPANDER); +/* + * create_endpoint() wants to validate port driver attach immediately after + * endpoint registration. + */ +MODULE_SOFTDEP("pre: cxl_port"); diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c index 5a1aec28dc46..4d4e23b9adff 100644 --- a/drivers/cxl/port.c +++ b/drivers/cxl/port.c @@ -25,12 +25,24 @@ * PCIe topology. */ +static void schedule_detach(void *cxlmd) +{ + schedule_cxl_memdev_detach(cxlmd); +} + static int cxl_port_probe(struct device *dev) { struct cxl_port *port = to_cxl_port(dev); struct cxl_hdm *cxlhdm; int rc; + if (is_cxl_endpoint(port)) { + struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport); + + get_device(&cxlmd->dev); + return devm_add_action_or_reset(dev, schedule_detach, cxlmd); + } + rc = devm_cxl_port_enumerate_dports(port); if (rc < 0) return rc; |