diff options
Diffstat (limited to 'drivers/cxl/core/bus.c')
| -rw-r--r-- | drivers/cxl/core/bus.c | 660 |
1 files changed, 660 insertions, 0 deletions
diff --git a/drivers/cxl/core/bus.c b/drivers/cxl/core/bus.c new file mode 100644 index 000000000000..267d8042bec2 --- /dev/null +++ b/drivers/cxl/core/bus.c @@ -0,0 +1,660 @@ +// 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/device.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/slab.h> +#include <linux/idr.h> +#include <cxlmem.h> +#include <cxl.h> +#include "core.h" + +/** + * DOC: cxl core + * + * The CXL core provides a set of interfaces that can be consumed by CXL aware + * drivers. The interfaces allow for creation, modification, and destruction of + * regions, memory devices, ports, and decoders. CXL aware drivers must register + * with the CXL core via these interfaces in order to be able to participate in + * cross-device interleave coordination. The CXL core also establishes and + * maintains the bridge to the nvdimm subsystem. + * + * CXL core introduces sysfs hierarchy to control the devices that are + * instantiated by the core. + */ + +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, +}; + +struct attribute_group cxl_base_attribute_group = { + .attrs = cxl_base_attributes, +}; + +static ssize_t start_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct cxl_decoder *cxld = to_cxl_decoder(dev); + + return sysfs_emit(buf, "%#llx\n", cxld->range.start); +} +static DEVICE_ATTR_RO(start); + +static ssize_t size_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct cxl_decoder *cxld = to_cxl_decoder(dev); + + return sysfs_emit(buf, "%#llx\n", range_len(&cxld->range)); +} +static DEVICE_ATTR_RO(size); + +#define CXL_DECODER_FLAG_ATTR(name, flag) \ +static ssize_t name##_show(struct device *dev, \ + struct device_attribute *attr, char *buf) \ +{ \ + struct cxl_decoder *cxld = to_cxl_decoder(dev); \ + \ + return sysfs_emit(buf, "%s\n", \ + (cxld->flags & (flag)) ? "1" : "0"); \ +} \ +static DEVICE_ATTR_RO(name) + +CXL_DECODER_FLAG_ATTR(cap_pmem, CXL_DECODER_F_PMEM); +CXL_DECODER_FLAG_ATTR(cap_ram, CXL_DECODER_F_RAM); +CXL_DECODER_FLAG_ATTR(cap_type2, CXL_DECODER_F_TYPE2); +CXL_DECODER_FLAG_ATTR(cap_type3, CXL_DECODER_F_TYPE3); +CXL_DECODER_FLAG_ATTR(locked, CXL_DECODER_F_LOCK); + +static ssize_t target_type_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct cxl_decoder *cxld = to_cxl_decoder(dev); + + switch (cxld->target_type) { + case CXL_DECODER_ACCELERATOR: + return sysfs_emit(buf, "accelerator\n"); + case CXL_DECODER_EXPANDER: + return sysfs_emit(buf, "expander\n"); + } + return -ENXIO; +} +static DEVICE_ATTR_RO(target_type); + +static ssize_t target_list_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct cxl_decoder *cxld = to_cxl_decoder(dev); + ssize_t offset = 0; + int i, rc = 0; + + device_lock(dev); + for (i = 0; i < cxld->interleave_ways; i++) { + struct cxl_dport *dport = cxld->target[i]; + struct cxl_dport *next = NULL; + + if (!dport) + break; + + if (i + 1 < cxld->interleave_ways) + next = cxld->target[i + 1]; + rc = sysfs_emit_at(buf, offset, "%d%s", dport->port_id, + next ? "," : ""); + if (rc < 0) + break; + offset += rc; + } + device_unlock(dev); + + if (rc < 0) + return rc; + + rc = sysfs_emit_at(buf, offset, "\n"); + if (rc < 0) + return rc; + + return offset + rc; +} +static DEVICE_ATTR_RO(target_list); + +static struct attribute *cxl_decoder_base_attrs[] = { + &dev_attr_start.attr, + &dev_attr_size.attr, + &dev_attr_locked.attr, + &dev_attr_target_list.attr, + NULL, +}; + +static struct attribute_group cxl_decoder_base_attribute_group = { + .attrs = cxl_decoder_base_attrs, +}; + +static struct attribute *cxl_decoder_root_attrs[] = { + &dev_attr_cap_pmem.attr, + &dev_attr_cap_ram.attr, + &dev_attr_cap_type2.attr, + &dev_attr_cap_type3.attr, + NULL, +}; + +static struct attribute_group cxl_decoder_root_attribute_group = { + .attrs = cxl_decoder_root_attrs, +}; + +static const struct attribute_group *cxl_decoder_root_attribute_groups[] = { + &cxl_decoder_root_attribute_group, + &cxl_decoder_base_attribute_group, + &cxl_base_attribute_group, + NULL, +}; + +static struct attribute *cxl_decoder_switch_attrs[] = { + &dev_attr_target_type.attr, + NULL, +}; + +static struct attribute_group cxl_decoder_switch_attribute_group = { + .attrs = cxl_decoder_switch_attrs, +}; + +static const struct attribute_group *cxl_decoder_switch_attribute_groups[] = { + &cxl_decoder_switch_attribute_group, + &cxl_decoder_base_attribute_group, + &cxl_base_attribute_group, + NULL, +}; + +static void cxl_decoder_release(struct device *dev) +{ + struct cxl_decoder *cxld = to_cxl_decoder(dev); + struct cxl_port *port = to_cxl_port(dev->parent); + + ida_free(&port->decoder_ida, cxld->id); + kfree(cxld); +} + +static const struct device_type cxl_decoder_switch_type = { + .name = "cxl_decoder_switch", + .release = cxl_decoder_release, + .groups = cxl_decoder_switch_attribute_groups, +}; + +static const struct device_type cxl_decoder_root_type = { + .name = "cxl_decoder_root", + .release = cxl_decoder_release, + .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, + "not a cxl_decoder device\n")) + 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) +{ + list_del(&dport->list); + put_device(dport->dport); + kfree(dport); +} + +static void cxl_port_release(struct device *dev) +{ + struct cxl_port *port = to_cxl_port(dev); + struct cxl_dport *dport, *_d; + + device_lock(dev); + list_for_each_entry_safe(dport, _d, &port->dports, list) + cxl_dport_release(dport); + device_unlock(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_port(void *_port) +{ + struct cxl_port *port = _port; + struct cxl_dport *dport; + + device_lock(&port->dev); + list_for_each_entry(dport, &port->dports, list) { + char link_name[CXL_TARGET_STRLEN]; + + if (snprintf(link_name, CXL_TARGET_STRLEN, "dport%d", + dport->port_id) >= CXL_TARGET_STRLEN) + continue; + sysfs_remove_link(&port->dev.kobj, link_name); + } + device_unlock(&port->dev); + device_unregister(&port->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; + ida_init(&port->decoder_ida); + INIT_LIST_HEAD(&port->dports); + + 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_port, port); + 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); + +static struct cxl_dport *find_dport(struct cxl_port *port, int id) +{ + struct cxl_dport *dport; + + device_lock_assert(&port->dev); + list_for_each_entry (dport, &port->dports, list) + if (dport->port_id == id) + return dport; + return NULL; +} + +static int add_dport(struct cxl_port *port, struct cxl_dport *new) +{ + struct cxl_dport *dup; + + device_lock(&port->dev); + dup = find_dport(port, new->port_id); + if (dup) + dev_err(&port->dev, + "unable to add dport%d-%s non-unique port id (%s)\n", + new->port_id, dev_name(new->dport), + dev_name(dup->dport)); + else + list_add_tail(&new->list, &port->dports); + device_unlock(&port->dev); + + return dup ? -EEXIST : 0; +} + +/** + * cxl_add_dport - append downstream port data to a cxl_port + * @port: the cxl_port that references this dport + * @dport_dev: firmware or PCI device representing the dport + * @port_id: identifier for this dport in a decoder's target list + * @component_reg_phys: optional location of CXL component registers + * + * Note that all allocations and links are undone by cxl_port deletion + * and release. + */ +int cxl_add_dport(struct cxl_port *port, struct device *dport_dev, int port_id, + resource_size_t component_reg_phys) +{ + char link_name[CXL_TARGET_STRLEN]; + struct cxl_dport *dport; + int rc; + + if (snprintf(link_name, CXL_TARGET_STRLEN, "dport%d", port_id) >= + CXL_TARGET_STRLEN) + return -EINVAL; + + dport = kzalloc(sizeof(*dport), GFP_KERNEL); + if (!dport) + return -ENOMEM; + + INIT_LIST_HEAD(&dport->list); + dport->dport = get_device(dport_dev); + dport->port_id = port_id; + dport->component_reg_phys = component_reg_phys; + dport->port = port; + + rc = add_dport(port, dport); + if (rc) + goto err; + + rc = sysfs_create_link(&port->dev.kobj, &dport_dev->kobj, link_name); + if (rc) + goto err; + + return 0; +err: + cxl_dport_release(dport); + return rc; +} +EXPORT_SYMBOL_GPL(cxl_add_dport); + +static struct cxl_decoder * +cxl_decoder_alloc(struct cxl_port *port, int nr_targets, resource_size_t base, + resource_size_t len, int interleave_ways, + int interleave_granularity, enum cxl_decoder_type type, + unsigned long flags) +{ + struct cxl_decoder *cxld; + struct device *dev; + int rc = 0; + + if (interleave_ways < 1) + return ERR_PTR(-EINVAL); + + device_lock(&port->dev); + if (list_empty(&port->dports)) + rc = -EINVAL; + device_unlock(&port->dev); + if (rc) + return ERR_PTR(rc); + + cxld = kzalloc(struct_size(cxld, target, nr_targets), GFP_KERNEL); + if (!cxld) + return ERR_PTR(-ENOMEM); + + rc = ida_alloc(&port->decoder_ida, GFP_KERNEL); + if (rc < 0) + goto err; + + *cxld = (struct cxl_decoder) { + .id = rc, + .range = { + .start = base, + .end = base + len - 1, + }, + .flags = flags, + .interleave_ways = interleave_ways, + .interleave_granularity = interleave_granularity, + .target_type = type, + }; + + /* handle implied target_list */ + if (interleave_ways == 1) + cxld->target[0] = + list_first_entry(&port->dports, struct cxl_dport, list); + dev = &cxld->dev; + device_initialize(dev); + device_set_pm_not_required(dev); + dev->parent = &port->dev; + dev->bus = &cxl_bus_type; + + /* root ports do not have a cxl_port_type parent */ + if (port->dev.parent->type == &cxl_port_type) + dev->type = &cxl_decoder_switch_type; + else + dev->type = &cxl_decoder_root_type; + + return cxld; +err: + kfree(cxld); + return ERR_PTR(rc); +} + +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, + int interleave_ways, int interleave_granularity, + enum cxl_decoder_type type, unsigned long flags) +{ + struct cxl_decoder *cxld; + struct device *dev; + int rc; + + cxld = cxl_decoder_alloc(port, nr_targets, base, len, interleave_ways, + interleave_granularity, type, flags); + if (IS_ERR(cxld)) + return cxld; + + dev = &cxld->dev; + rc = dev_set_name(dev, "decoder%d.%d", port->id, cxld->id); + if (rc) + goto err; + + rc = device_add(dev); + if (rc) + goto err; + + rc = devm_add_action_or_reset(host, unregister_cxl_dev, dev); + if (rc) + return ERR_PTR(rc); + return cxld; + +err: + put_device(dev); + return ERR_PTR(rc); +} +EXPORT_SYMBOL_GPL(devm_cxl_add_decoder); + +/** + * __cxl_driver_register - register a driver for the cxl bus + * @cxl_drv: cxl driver structure to attach + * @owner: owning module/driver + * @modname: KBUILD_MODNAME for parent driver + */ +int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner, + const char *modname) +{ + if (!cxl_drv->probe) { + pr_debug("%s ->probe() must be specified\n", modname); + return -EINVAL; + } + + if (!cxl_drv->name) { + pr_debug("%s ->name must be specified\n", modname); + return -EINVAL; + } + + if (!cxl_drv->id) { + pr_debug("%s ->id must be specified\n", modname); + return -EINVAL; + } + + cxl_drv->drv.bus = &cxl_bus_type; + cxl_drv->drv.owner = owner; + cxl_drv->drv.mod_name = modname; + cxl_drv->drv.name = cxl_drv->name; + + return driver_register(&cxl_drv->drv); +} +EXPORT_SYMBOL_GPL(__cxl_driver_register); + +void cxl_driver_unregister(struct cxl_driver *cxl_drv) +{ + driver_unregister(&cxl_drv->drv); +} +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; + if (dev->type == &cxl_nvdimm_type) + return CXL_DEVICE_NVDIMM; + return 0; +} + +static int cxl_bus_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + return add_uevent_var(env, "MODALIAS=" CXL_MODALIAS_FMT, + cxl_device_id(dev)); +} + +static int cxl_bus_match(struct device *dev, struct device_driver *drv) +{ + return cxl_device_id(dev) == to_cxl_drv(drv)->id; +} + +static int cxl_bus_probe(struct device *dev) +{ + return to_cxl_drv(dev->driver)->probe(dev); +} + +static void cxl_bus_remove(struct device *dev) +{ + struct cxl_driver *cxl_drv = to_cxl_drv(dev->driver); + + if (cxl_drv->remove) + cxl_drv->remove(dev); +} + +struct bus_type cxl_bus_type = { + .name = "cxl", + .uevent = cxl_bus_uevent, + .match = cxl_bus_match, + .probe = cxl_bus_probe, + .remove = cxl_bus_remove, +}; +EXPORT_SYMBOL_GPL(cxl_bus_type); + +static __init int cxl_core_init(void) +{ + int rc; + + rc = cxl_memdev_init(); + if (rc) + return rc; + + rc = bus_register(&cxl_bus_type); + if (rc) + goto err; + return 0; + +err: + cxl_memdev_exit(); + return rc; +} + +static void cxl_core_exit(void) +{ + bus_unregister(&cxl_bus_type); + cxl_memdev_exit(); +} + +module_init(cxl_core_init); +module_exit(cxl_core_exit); +MODULE_LICENSE("GPL v2"); |