diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-cxl | 13 | ||||
| -rw-r--r-- | drivers/cxl/acpi.c | 43 | ||||
| -rw-r--r-- | drivers/cxl/core.c | 107 | ||||
| -rw-r--r-- | drivers/cxl/cxl.h | 21 |
4 files changed, 180 insertions, 4 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index bda2cc55cc38..f680da85fd44 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -44,3 +44,16 @@ Description: CXL component registers. The 'uport' symlink connects the CXL portX object to the device that published the CXL port capability. + +What: /sys/bus/cxl/devices/portX/dportY +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 'dportY' symlink identifies one or + more downstream ports that the upstream port may target in its + decode of CXL memory resources. The 'Y' integer reflects the + hardware port unique-id used in the hardware decoder target + list. diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index 556d25ab6966..5eb9543c587a 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -7,17 +7,58 @@ #include <linux/acpi.h> #include "cxl.h" +static struct acpi_device *to_cxl_host_bridge(struct device *dev) +{ + struct acpi_device *adev = to_acpi_device(dev); + + if (strcmp(acpi_device_hid(adev), "ACPI0016") == 0) + return adev; + return NULL; +} + +static int add_host_bridge_dport(struct device *match, void *arg) +{ + int rc; + acpi_status status; + unsigned long long uid; + struct cxl_port *root_port = arg; + struct device *host = root_port->dev.parent; + struct acpi_device *bridge = to_cxl_host_bridge(match); + + if (!bridge) + return 0; + + status = acpi_evaluate_integer(bridge->handle, METHOD_NAME__UID, NULL, + &uid); + if (status != AE_OK) { + dev_err(host, "unable to retrieve _UID of %s\n", + dev_name(match)); + return -ENODEV; + } + + rc = cxl_add_dport(root_port, match, uid, CXL_RESOURCE_NONE); + if (rc) { + dev_err(host, "failed to add downstream port: %s\n", + dev_name(match)); + return rc; + } + dev_dbg(host, "add dport%llu: %s\n", uid, dev_name(match)); + return 0; +} + static int cxl_acpi_probe(struct platform_device *pdev) { struct cxl_port *root_port; struct device *host = &pdev->dev; + struct acpi_device *adev = ACPI_COMPANION(host); 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; + return bus_for_each_dev(adev->dev.bus, NULL, root_port, + add_host_bridge_dport); } static const struct acpi_device_id cxl_acpi_ids[] = { diff --git a/drivers/cxl/core.c b/drivers/cxl/core.c index dbbb34618d7d..8a3f3804f252 100644 --- a/drivers/cxl/core.c +++ b/drivers/cxl/core.c @@ -33,10 +33,22 @@ static struct attribute_group cxl_base_attribute_group = { .attrs = cxl_base_attributes, }; +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); } @@ -60,9 +72,22 @@ struct cxl_port *to_cxl_port(struct device *dev) return container_of(dev, struct cxl_port, dev); } -static void unregister_dev(void *dev) +static void unregister_port(void *_port) { - device_unregister(dev); + 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) @@ -113,6 +138,7 @@ static struct cxl_port *cxl_port_alloc(struct device *uport, port->uport = uport; port->component_reg_phys = component_reg_phys; + INIT_LIST_HEAD(&port->dports); device_initialize(dev); device_set_pm_not_required(dev); @@ -157,7 +183,7 @@ struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport, if (rc) goto err; - rc = devm_add_action_or_reset(host, unregister_dev, dev); + rc = devm_add_action_or_reset(host, unregister_port, port); if (rc) return ERR_PTR(rc); @@ -173,6 +199,81 @@ err: } 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); + /** * 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 5651e5bb8274..dd159fd6d692 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -154,6 +154,7 @@ int cxl_map_device_regs(struct pci_dev *pdev, struct cxl_register_map *map); #define CXL_RESOURCE_NONE ((resource_size_t) -1) +#define CXL_TARGET_STRLEN 20 /** * struct cxl_port - logical collection of upstream port devices and @@ -162,19 +163,39 @@ int cxl_map_device_regs(struct pci_dev *pdev, * @dev: this port's device * @uport: PCI or platform device implementing the upstream port capability * @id: id for port device-name + * @dports: cxl_dport instances referenced by decoders * @component_reg_phys: component register capability base address (optional) */ struct cxl_port { struct device dev; struct device *uport; int id; + struct list_head dports; resource_size_t component_reg_phys; }; +/** + * struct cxl_dport - CXL downstream port + * @dport: PCI bridge or firmware device representing the downstream link + * @port_id: unique hardware identifier for dport in decoder target list + * @component_reg_phys: downstream port component registers + * @port: reference to cxl_port that contains this downstream port + * @list: node for a cxl_port's list of cxl_dport instances + */ +struct cxl_dport { + struct device *dport; + int port_id; + resource_size_t component_reg_phys; + struct cxl_port *port; + struct list_head list; +}; + 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); +int cxl_add_dport(struct cxl_port *port, struct device *dport, int port_id, + resource_size_t component_reg_phys); extern struct bus_type cxl_bus_type; #endif /* __CXL_H__ */ |