diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-cxl | 26 | ||||
| -rw-r--r-- | Documentation/driver-api/cxl/memory-devices.rst | 5 | ||||
| -rw-r--r-- | drivers/cxl/Makefile | 3 | ||||
| -rw-r--r-- | drivers/cxl/bus.c | 29 | ||||
| -rw-r--r-- | drivers/cxl/cxl.h | 3 | ||||
| -rw-r--r-- | drivers/cxl/mem.c | 285 |
6 files changed, 349 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl new file mode 100644 index 000000000000..2fe7490ad6a8 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -0,0 +1,26 @@ +What: /sys/bus/cxl/devices/memX/firmware_version +Date: December, 2020 +KernelVersion: v5.12 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) "FW Revision" string as reported by the Identify + Memory Device Output Payload in the CXL-2.0 + specification. + +What: /sys/bus/cxl/devices/memX/ram/size +Date: December, 2020 +KernelVersion: v5.12 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) "Volatile 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/memX/pmem/size +Date: December, 2020 +KernelVersion: v5.12 +Contact: linux-cxl@vger.kernel.org +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. diff --git a/Documentation/driver-api/cxl/memory-devices.rst b/Documentation/driver-api/cxl/memory-devices.rst index 43177e700d62..1fef2c0a167d 100644 --- a/Documentation/driver-api/cxl/memory-devices.rst +++ b/Documentation/driver-api/cxl/memory-devices.rst @@ -27,3 +27,8 @@ CXL Memory Device .. kernel-doc:: drivers/cxl/mem.c :internal: + +CXL Bus +------- +.. kernel-doc:: drivers/cxl/bus.c + :doc: cxl bus diff --git a/drivers/cxl/Makefile b/drivers/cxl/Makefile index 4a30f7c3fc4a..a314a1891f4d 100644 --- a/drivers/cxl/Makefile +++ b/drivers/cxl/Makefile @@ -1,4 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_CXL_BUS) += cxl_bus.o obj-$(CONFIG_CXL_MEM) += cxl_mem.o +ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=CXL +cxl_bus-y := bus.o cxl_mem-y := mem.o diff --git a/drivers/cxl/bus.c b/drivers/cxl/bus.c new file mode 100644 index 000000000000..58f74796d525 --- /dev/null +++ b/drivers/cxl/bus.c @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2020 Intel Corporation. All rights reserved. */ +#include <linux/device.h> +#include <linux/module.h> + +/** + * DOC: cxl bus + * + * The CXL bus provides namespace for control devices and a rendezvous + * point for cross-device interleave coordination. + */ +struct bus_type cxl_bus_type = { + .name = "cxl", +}; +EXPORT_SYMBOL_GPL(cxl_bus_type); + +static __init int cxl_bus_init(void) +{ + return bus_register(&cxl_bus_type); +} + +static void cxl_bus_exit(void) +{ + bus_unregister(&cxl_bus_type); +} + +module_init(cxl_bus_init); +module_exit(cxl_bus_exit); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index baac26d9e63b..8fd4a177fe25 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -57,6 +57,7 @@ (FIELD_GET(CXLMDEV_RESET_NEEDED_MASK, status) != \ CXLMDEV_RESET_NEEDED_NOT) +struct cxl_memdev; /** * struct cxl_mem - A CXL memory device * @pdev: The PCI device associated with this CXL device. @@ -74,6 +75,7 @@ struct cxl_mem { struct pci_dev *pdev; void __iomem *regs; + struct cxl_memdev *cxlmd; void __iomem *status_regs; void __iomem *mbox_regs; @@ -87,4 +89,5 @@ struct cxl_mem { struct range ram_range; }; +extern struct bus_type cxl_bus_type; #endif /* __CXL_H__ */ diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index 04e15759bc9b..1c0195b07063 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -1,6 +1,9 @@ // SPDX-License-Identifier: GPL-2.0-only /* Copyright(c) 2020 Intel Corporation. All rights reserved. */ #include <linux/module.h> +#include <linux/mutex.h> +#include <linux/cdev.h> +#include <linux/idr.h> #include <linux/pci.h> #include <linux/io.h> #include <linux/io-64-nonatomic-lo-hi.h> @@ -23,6 +26,12 @@ * - Handle and manage error conditions. */ +/* + * An entire PCI topology full of devices should be enough for any + * config + */ +#define CXL_MEM_MAX_DEVS 65536 + #define cxl_doorbell_busy(cxlm) \ (readl((cxlm)->mbox_regs + CXLDEV_MBOX_CTRL_OFFSET) & \ CXLDEV_MBOX_CTRL_DOORBELL) @@ -65,6 +74,27 @@ struct mbox_cmd { #define CXL_MBOX_SUCCESS 0 }; +/** + * struct cxl_memdev - CXL bus object representing a Type-3 Memory Device + * @dev: driver core device object + * @cdev: char dev core object for ioctl operations + * @cxlm: pointer to the parent device driver data + * @ops_active: active user of @cxlm in ops handlers + * @ops_dead: completion when all @cxlm ops users have exited + * @id: id number of this memdev instance. + */ +struct cxl_memdev { + struct device dev; + struct cdev cdev; + struct cxl_mem *cxlm; + struct percpu_ref ops_active; + struct completion ops_dead; + int id; +}; + +static int cxl_mem_major; +static DEFINE_IDA(cxl_memdev_ida); + static int cxl_mem_wait_for_doorbell(struct cxl_mem *cxlm) { const unsigned long start = jiffies; @@ -294,6 +324,33 @@ static void cxl_mem_mbox_put(struct cxl_mem *cxlm) mutex_unlock(&cxlm->mbox_mutex); } +static long cxl_memdev_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct cxl_memdev *cxlmd; + struct inode *inode; + int rc = -ENOTTY; + + inode = file_inode(file); + cxlmd = container_of(inode->i_cdev, typeof(*cxlmd), cdev); + + if (!percpu_ref_tryget_live(&cxlmd->ops_active)) + return -ENXIO; + + /* TODO: ioctl body */ + + percpu_ref_put(&cxlmd->ops_active); + + return rc; +} + +static const struct file_operations cxl_memdev_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = cxl_memdev_ioctl, + .compat_ioctl = compat_ptr_ioctl, + .llseek = noop_llseek, +}; + /** * cxl_mem_mbox_send_cmd() - Send a mailbox command to a memory device. * @cxlm: The CXL memory device to communicate with. @@ -512,6 +569,197 @@ static int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec) return 0; } +static struct cxl_memdev *to_cxl_memdev(struct device *dev) +{ + return container_of(dev, struct cxl_memdev, dev); +} + +static void cxl_memdev_release(struct device *dev) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + + percpu_ref_exit(&cxlmd->ops_active); + ida_free(&cxl_memdev_ida, cxlmd->id); + kfree(cxlmd); +} + +static char *cxl_memdev_devnode(struct device *dev, umode_t *mode, kuid_t *uid, + kgid_t *gid) +{ + return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev)); +} + +static ssize_t firmware_version_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_mem *cxlm = cxlmd->cxlm; + + return sprintf(buf, "%.16s\n", cxlm->firmware_version); +} +static DEVICE_ATTR_RO(firmware_version); + +static ssize_t payload_max_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_mem *cxlm = cxlmd->cxlm; + + return sprintf(buf, "%zu\n", cxlm->payload_size); +} +static DEVICE_ATTR_RO(payload_max); + +static ssize_t ram_size_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_mem *cxlm = cxlmd->cxlm; + unsigned long long len = range_len(&cxlm->ram_range); + + return sprintf(buf, "%#llx\n", len); +} + +static struct device_attribute dev_attr_ram_size = + __ATTR(size, 0444, ram_size_show, NULL); + +static ssize_t pmem_size_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_mem *cxlm = cxlmd->cxlm; + unsigned long long len = range_len(&cxlm->pmem_range); + + return sprintf(buf, "%#llx\n", len); +} + +static struct device_attribute dev_attr_pmem_size = + __ATTR(size, 0444, pmem_size_show, NULL); + +static struct attribute *cxl_memdev_attributes[] = { + &dev_attr_firmware_version.attr, + &dev_attr_payload_max.attr, + NULL, +}; + +static struct attribute *cxl_memdev_pmem_attributes[] = { + &dev_attr_pmem_size.attr, + NULL, +}; + +static struct attribute *cxl_memdev_ram_attributes[] = { + &dev_attr_ram_size.attr, + NULL, +}; + +static struct attribute_group cxl_memdev_attribute_group = { + .attrs = cxl_memdev_attributes, +}; + +static struct attribute_group cxl_memdev_ram_attribute_group = { + .name = "ram", + .attrs = cxl_memdev_ram_attributes, +}; + +static struct attribute_group cxl_memdev_pmem_attribute_group = { + .name = "pmem", + .attrs = cxl_memdev_pmem_attributes, +}; + +static const struct attribute_group *cxl_memdev_attribute_groups[] = { + &cxl_memdev_attribute_group, + &cxl_memdev_ram_attribute_group, + &cxl_memdev_pmem_attribute_group, + NULL, +}; + +static const struct device_type cxl_memdev_type = { + .name = "cxl_memdev", + .release = cxl_memdev_release, + .devnode = cxl_memdev_devnode, + .groups = cxl_memdev_attribute_groups, +}; + +static void cxlmdev_unregister(void *_cxlmd) +{ + struct cxl_memdev *cxlmd = _cxlmd; + struct device *dev = &cxlmd->dev; + + percpu_ref_kill(&cxlmd->ops_active); + cdev_device_del(&cxlmd->cdev, dev); + wait_for_completion(&cxlmd->ops_dead); + cxlmd->cxlm = NULL; + put_device(dev); +} + +static void cxlmdev_ops_active_release(struct percpu_ref *ref) +{ + struct cxl_memdev *cxlmd = + container_of(ref, typeof(*cxlmd), ops_active); + + complete(&cxlmd->ops_dead); +} + +static int cxl_mem_add_memdev(struct cxl_mem *cxlm) +{ + struct pci_dev *pdev = cxlm->pdev; + struct cxl_memdev *cxlmd; + struct device *dev; + struct cdev *cdev; + int rc; + + cxlmd = kzalloc(sizeof(*cxlmd), GFP_KERNEL); + if (!cxlmd) + return -ENOMEM; + init_completion(&cxlmd->ops_dead); + + /* + * @cxlm is deallocated when the driver unbinds so operations + * that are using it need to hold a live reference. + */ + cxlmd->cxlm = cxlm; + rc = percpu_ref_init(&cxlmd->ops_active, cxlmdev_ops_active_release, 0, + GFP_KERNEL); + if (rc) + goto err_ref; + + rc = ida_alloc_range(&cxl_memdev_ida, 0, CXL_MEM_MAX_DEVS, GFP_KERNEL); + if (rc < 0) + goto err_id; + cxlmd->id = rc; + + dev = &cxlmd->dev; + device_initialize(dev); + dev->parent = &pdev->dev; + dev->bus = &cxl_bus_type; + dev->devt = MKDEV(cxl_mem_major, cxlmd->id); + dev->type = &cxl_memdev_type; + dev_set_name(dev, "mem%d", cxlmd->id); + + cdev = &cxlmd->cdev; + cdev_init(cdev, &cxl_memdev_fops); + + rc = cdev_device_add(cdev, dev); + if (rc) + goto err_add; + + return devm_add_action_or_reset(dev->parent, cxlmdev_unregister, cxlmd); + +err_add: + ida_free(&cxl_memdev_ida, cxlmd->id); +err_id: + /* + * Theoretically userspace could have already entered the fops, + * so flush ops_active. + */ + percpu_ref_kill(&cxlmd->ops_active); + wait_for_completion(&cxlmd->ops_dead); + percpu_ref_exit(&cxlmd->ops_active); +err_ref: + kfree(cxlmd); + + return rc; +} + /** * cxl_mem_identify() - Send the IDENTIFY command to the device. * @cxlm: The device to identify. @@ -612,7 +860,11 @@ static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id) if (rc) return rc; - return cxl_mem_identify(cxlm); + rc = cxl_mem_identify(cxlm); + if (rc) + return rc; + + return cxl_mem_add_memdev(cxlm); } static const struct pci_device_id cxl_mem_pci_tbl[] = { @@ -631,5 +883,34 @@ static struct pci_driver cxl_mem_driver = { }, }; +static __init int cxl_mem_init(void) +{ + dev_t devt; + int rc; + + rc = alloc_chrdev_region(&devt, 0, CXL_MEM_MAX_DEVS, "cxl"); + if (rc) + return rc; + + cxl_mem_major = MAJOR(devt); + + rc = pci_register_driver(&cxl_mem_driver); + if (rc) { + unregister_chrdev_region(MKDEV(cxl_mem_major, 0), + CXL_MEM_MAX_DEVS); + return rc; + } + + return 0; +} + +static __exit void cxl_mem_exit(void) +{ + pci_unregister_driver(&cxl_mem_driver); + unregister_chrdev_region(MKDEV(cxl_mem_major, 0), CXL_MEM_MAX_DEVS); +} + MODULE_LICENSE("GPL v2"); -module_pci_driver(cxl_mem_driver); +module_init(cxl_mem_init); +module_exit(cxl_mem_exit); +MODULE_IMPORT_NS(CXL); |