diff options
Diffstat (limited to 'drivers/cxl')
| -rw-r--r-- | drivers/cxl/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/cxl/Makefile | 2 | ||||
| -rw-r--r-- | drivers/cxl/acpi.c | 37 | ||||
| -rw-r--r-- | drivers/cxl/core.c | 121 | ||||
| -rw-r--r-- | drivers/cxl/cxl.h | 24 | ||||
| -rw-r--r-- | drivers/cxl/pmem.c | 140 |
6 files changed, 335 insertions, 2 deletions
diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig index 1a44b173dcbc..e6de221cc568 100644 --- a/drivers/cxl/Kconfig +++ b/drivers/cxl/Kconfig @@ -62,4 +62,17 @@ config CXL_ACPI Memory regions to be managed by LIBNVDIMM. If unsure say 'm'. + +config CXL_PMEM + tristate "CXL PMEM: Persistent Memory Support" + depends on LIBNVDIMM + default CXL_BUS + help + In addition to typical memory resources a platform may also advertise + support for persistent memory attached via CXL. This support is + managed via a bridge driver from CXL to the LIBNVDIMM system + subsystem. Say 'y/m' to enable support for enumerating and + provisioning the persistent memory capacity of CXL memory expanders. + + If unsure say 'm'. endif diff --git a/drivers/cxl/Makefile b/drivers/cxl/Makefile index a29efb3e8ad2..32954059b37b 100644 --- a/drivers/cxl/Makefile +++ b/drivers/cxl/Makefile @@ -2,8 +2,10 @@ obj-$(CONFIG_CXL_BUS) += cxl_core.o obj-$(CONFIG_CXL_MEM) += cxl_pci.o obj-$(CONFIG_CXL_ACPI) += cxl_acpi.o +obj-$(CONFIG_CXL_PMEM) += cxl_pmem.o ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=CXL cxl_core-y := core.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 be357eea552c..8a723f7f3f73 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -145,6 +145,30 @@ static int add_host_bridge_dport(struct device *match, void *arg) return 0; } +static int add_root_nvdimm_bridge(struct device *match, void *data) +{ + struct cxl_decoder *cxld; + struct cxl_port *root_port = data; + struct cxl_nvdimm_bridge *cxl_nvb; + struct device *host = root_port->dev.parent; + + if (!is_root_decoder(match)) + return 0; + + cxld = to_cxl_decoder(match); + if (!(cxld->flags & CXL_DECODER_F_PMEM)) + return 0; + + cxl_nvb = devm_cxl_add_nvdimm_bridge(host, root_port); + if (IS_ERR(cxl_nvb)) { + dev_dbg(host, "failed to register pmem\n"); + return PTR_ERR(cxl_nvb); + } + dev_dbg(host, "%s: add: %s\n", dev_name(&root_port->dev), + dev_name(&cxl_nvb->dev)); + return 1; +} + static int cxl_acpi_probe(struct platform_device *pdev) { int rc; @@ -166,8 +190,17 @@ static int cxl_acpi_probe(struct platform_device *pdev) * Root level scanned with host-bridge as dports, now scan host-bridges * for their role as CXL uports to their CXL-capable PCIe Root Ports. */ - return bus_for_each_dev(adev->dev.bus, NULL, root_port, - add_host_bridge_uport); + rc = bus_for_each_dev(adev->dev.bus, NULL, root_port, + add_host_bridge_uport); + if (rc) + return rc; + + if (IS_ENABLED(CONFIG_CXL_PMEM)) + rc = device_for_each_child(&root_port->dev, root_port, + add_root_nvdimm_bridge); + if (rc < 0) + return rc; + return 0; } static const struct acpi_device_id cxl_acpi_ids[] = { diff --git a/drivers/cxl/core.c b/drivers/cxl/core.c index 68d6afea363b..aaffb390d168 100644 --- a/drivers/cxl/core.c +++ b/drivers/cxl/core.c @@ -187,6 +187,12 @@ static const struct device_type cxl_decoder_root_type = { .groups = cxl_decoder_root_attribute_groups, }; +bool is_root_decoder(struct device *dev) +{ + return dev->type == &cxl_decoder_root_type; +} +EXPORT_SYMBOL_GPL(is_root_decoder); + struct cxl_decoder *to_cxl_decoder(struct device *dev) { if (dev_WARN_ONCE(dev, dev->type->release != cxl_decoder_release, @@ -194,6 +200,7 @@ struct cxl_decoder *to_cxl_decoder(struct device *dev) return NULL; return container_of(dev, struct cxl_decoder, dev); } +EXPORT_SYMBOL_GPL(to_cxl_decoder); static void cxl_dport_release(struct cxl_dport *dport) { @@ -611,6 +618,118 @@ void cxl_probe_component_regs(struct device *dev, void __iomem *base, } EXPORT_SYMBOL_GPL(cxl_probe_component_regs); +static void cxl_nvdimm_bridge_release(struct device *dev) +{ + struct cxl_nvdimm_bridge *cxl_nvb = to_cxl_nvdimm_bridge(dev); + + kfree(cxl_nvb); +} + +static const struct attribute_group *cxl_nvdimm_bridge_attribute_groups[] = { + &cxl_base_attribute_group, + NULL, +}; + +static const struct device_type cxl_nvdimm_bridge_type = { + .name = "cxl_nvdimm_bridge", + .release = cxl_nvdimm_bridge_release, + .groups = cxl_nvdimm_bridge_attribute_groups, +}; + +struct cxl_nvdimm_bridge *to_cxl_nvdimm_bridge(struct device *dev) +{ + if (dev_WARN_ONCE(dev, dev->type != &cxl_nvdimm_bridge_type, + "not a cxl_nvdimm_bridge device\n")) + return NULL; + return container_of(dev, struct cxl_nvdimm_bridge, dev); +} +EXPORT_SYMBOL_GPL(to_cxl_nvdimm_bridge); + +static struct cxl_nvdimm_bridge * +cxl_nvdimm_bridge_alloc(struct cxl_port *port) +{ + struct cxl_nvdimm_bridge *cxl_nvb; + struct device *dev; + + cxl_nvb = kzalloc(sizeof(*cxl_nvb), GFP_KERNEL); + if (!cxl_nvb) + return ERR_PTR(-ENOMEM); + + dev = &cxl_nvb->dev; + cxl_nvb->port = port; + cxl_nvb->state = CXL_NVB_NEW; + device_initialize(dev); + device_set_pm_not_required(dev); + dev->parent = &port->dev; + dev->bus = &cxl_bus_type; + dev->type = &cxl_nvdimm_bridge_type; + + return cxl_nvb; +} + +static void unregister_nvb(void *_cxl_nvb) +{ + struct cxl_nvdimm_bridge *cxl_nvb = _cxl_nvb; + bool flush; + + /* + * If the bridge was ever activated then there might be in-flight state + * work to flush. Once the state has been changed to 'dead' then no new + * work can be queued by user-triggered bind. + */ + device_lock(&cxl_nvb->dev); + flush = cxl_nvb->state != CXL_NVB_NEW; + cxl_nvb->state = CXL_NVB_DEAD; + device_unlock(&cxl_nvb->dev); + + /* + * Even though the device core will trigger device_release_driver() + * before the unregister, it does not know about the fact that + * cxl_nvdimm_bridge_driver defers ->remove() work. So, do the driver + * release not and flush it before tearing down the nvdimm device + * hierarchy. + */ + device_release_driver(&cxl_nvb->dev); + if (flush) + flush_work(&cxl_nvb->state_work); + device_unregister(&cxl_nvb->dev); +} + +struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host, + struct cxl_port *port) +{ + struct cxl_nvdimm_bridge *cxl_nvb; + struct device *dev; + int rc; + + if (!IS_ENABLED(CONFIG_CXL_PMEM)) + return ERR_PTR(-ENXIO); + + cxl_nvb = cxl_nvdimm_bridge_alloc(port); + if (IS_ERR(cxl_nvb)) + return cxl_nvb; + + dev = &cxl_nvb->dev; + rc = dev_set_name(dev, "nvdimm-bridge"); + if (rc) + goto err; + + rc = device_add(dev); + if (rc) + goto err; + + rc = devm_add_action_or_reset(host, unregister_nvb, cxl_nvb); + if (rc) + return ERR_PTR(rc); + + return cxl_nvb; + +err: + put_device(dev); + return ERR_PTR(rc); +} +EXPORT_SYMBOL_GPL(devm_cxl_add_nvdimm_bridge); + /** * cxl_probe_device_regs() - Detect CXL Device register blocks * @dev: Host device of the @base mapping @@ -808,6 +927,8 @@ EXPORT_SYMBOL_GPL(cxl_driver_unregister); static int cxl_device_id(struct device *dev) { + if (dev->type == &cxl_nvdimm_bridge_type) + return CXL_DEVICE_NVDIMM_BRIDGE; return 0; } diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index a6f8e7097ea2..5da2163ca45f 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -4,6 +4,7 @@ #ifndef __CXL_H__ #define __CXL_H__ +#include <linux/libnvdimm.h> #include <linux/bitfield.h> #include <linux/bitops.h> #include <linux/io.h> @@ -202,6 +203,23 @@ struct cxl_decoder { struct cxl_dport *target[]; }; + +enum cxl_nvdimm_brige_state { + CXL_NVB_NEW, + CXL_NVB_DEAD, + CXL_NVB_ONLINE, + CXL_NVB_OFFLINE, +}; + +struct cxl_nvdimm_bridge { + struct device dev; + struct cxl_port *port; + struct nvdimm_bus *nvdimm_bus; + struct nvdimm_bus_descriptor nd_desc; + struct work_struct state_work; + enum cxl_nvdimm_brige_state state; +}; + /** * struct cxl_port - logical collection of upstream port devices and * downstream port devices to construct a CXL memory @@ -247,6 +265,7 @@ int cxl_add_dport(struct cxl_port *port, struct device *dport, int port_id, resource_size_t component_reg_phys); struct cxl_decoder *to_cxl_decoder(struct device *dev); +bool is_root_decoder(struct device *dev); struct cxl_decoder * devm_cxl_add_decoder(struct device *host, struct cxl_port *port, int nr_targets, resource_size_t base, resource_size_t len, @@ -287,7 +306,12 @@ int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner, #define cxl_driver_register(x) __cxl_driver_register(x, THIS_MODULE, KBUILD_MODNAME) void cxl_driver_unregister(struct cxl_driver *cxl_drv); +#define CXL_DEVICE_NVDIMM_BRIDGE 1 + #define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*") #define CXL_MODALIAS_FMT "cxl:t%d" +struct cxl_nvdimm_bridge *to_cxl_nvdimm_bridge(struct device *dev); +struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host, + struct cxl_port *port); #endif /* __CXL_H__ */ diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c new file mode 100644 index 000000000000..8365839856dc --- /dev/null +++ b/drivers/cxl/pmem.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2021 Intel Corporation. All rights reserved. */ +#include <linux/libnvdimm.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/slab.h> +#include "cxl.h" + +/* + * Ordered workqueue for cxl nvdimm device arrival and departure + * to coordinate bus rescans when a bridge arrives and trigger remove + * operations when the bridge is removed. + */ +static struct workqueue_struct *cxl_pmem_wq; + +static int cxl_pmem_ctl(struct nvdimm_bus_descriptor *nd_desc, + struct nvdimm *nvdimm, unsigned int cmd, void *buf, + unsigned int buf_len, int *cmd_rc) +{ + return -ENOTTY; +} + +static bool online_nvdimm_bus(struct cxl_nvdimm_bridge *cxl_nvb) +{ + if (cxl_nvb->nvdimm_bus) + return true; + cxl_nvb->nvdimm_bus = + nvdimm_bus_register(&cxl_nvb->dev, &cxl_nvb->nd_desc); + return cxl_nvb->nvdimm_bus != NULL; +} + +static void offline_nvdimm_bus(struct cxl_nvdimm_bridge *cxl_nvb) +{ + if (!cxl_nvb->nvdimm_bus) + return; + nvdimm_bus_unregister(cxl_nvb->nvdimm_bus); + cxl_nvb->nvdimm_bus = NULL; +} + +static void cxl_nvb_update_state(struct work_struct *work) +{ + struct cxl_nvdimm_bridge *cxl_nvb = + container_of(work, typeof(*cxl_nvb), state_work); + bool release = false; + + device_lock(&cxl_nvb->dev); + switch (cxl_nvb->state) { + case CXL_NVB_ONLINE: + if (!online_nvdimm_bus(cxl_nvb)) { + dev_err(&cxl_nvb->dev, + "failed to establish nvdimm bus\n"); + release = true; + } + break; + case CXL_NVB_OFFLINE: + case CXL_NVB_DEAD: + offline_nvdimm_bus(cxl_nvb); + break; + default: + break; + } + device_unlock(&cxl_nvb->dev); + + if (release) + device_release_driver(&cxl_nvb->dev); + + put_device(&cxl_nvb->dev); +} + +static void cxl_nvdimm_bridge_remove(struct device *dev) +{ + struct cxl_nvdimm_bridge *cxl_nvb = to_cxl_nvdimm_bridge(dev); + + if (cxl_nvb->state == CXL_NVB_ONLINE) + cxl_nvb->state = CXL_NVB_OFFLINE; + if (queue_work(cxl_pmem_wq, &cxl_nvb->state_work)) + get_device(&cxl_nvb->dev); +} + +static int cxl_nvdimm_bridge_probe(struct device *dev) +{ + struct cxl_nvdimm_bridge *cxl_nvb = to_cxl_nvdimm_bridge(dev); + + if (cxl_nvb->state == CXL_NVB_DEAD) + return -ENXIO; + + if (cxl_nvb->state == CXL_NVB_NEW) { + cxl_nvb->nd_desc = (struct nvdimm_bus_descriptor) { + .provider_name = "CXL", + .module = THIS_MODULE, + .ndctl = cxl_pmem_ctl, + }; + + INIT_WORK(&cxl_nvb->state_work, cxl_nvb_update_state); + } + + cxl_nvb->state = CXL_NVB_ONLINE; + if (queue_work(cxl_pmem_wq, &cxl_nvb->state_work)) + get_device(&cxl_nvb->dev); + + return 0; +} + +static struct cxl_driver cxl_nvdimm_bridge_driver = { + .name = "cxl_nvdimm_bridge", + .probe = cxl_nvdimm_bridge_probe, + .remove = cxl_nvdimm_bridge_remove, + .id = CXL_DEVICE_NVDIMM_BRIDGE, +}; + +static __init int cxl_pmem_init(void) +{ + int rc; + + cxl_pmem_wq = alloc_ordered_workqueue("cxl_pmem", 0); + if (!cxl_pmem_wq) + return -ENXIO; + + rc = cxl_driver_register(&cxl_nvdimm_bridge_driver); + if (rc) + goto err; + + return 0; + +err: + destroy_workqueue(cxl_pmem_wq); + return rc; +} + +static __exit void cxl_pmem_exit(void) +{ + cxl_driver_unregister(&cxl_nvdimm_bridge_driver); + destroy_workqueue(cxl_pmem_wq); +} + +MODULE_LICENSE("GPL v2"); +module_init(cxl_pmem_init); +module_exit(cxl_pmem_exit); +MODULE_IMPORT_NS(CXL); +MODULE_ALIAS_CXL(CXL_DEVICE_NVDIMM_BRIDGE); |