From patchwork Fri Jul 30 20:07:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 12411819 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2CD2C4338F for ; Fri, 30 Jul 2021 20:07:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C927E604D7 for ; Fri, 30 Jul 2021 20:07:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230381AbhG3UHe (ORCPT ); Fri, 30 Jul 2021 16:07:34 -0400 Received: from mga14.intel.com ([192.55.52.115]:24334 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230429AbhG3UHe (ORCPT ); Fri, 30 Jul 2021 16:07:34 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10061"; a="212887034" X-IronPort-AV: E=Sophos;i="5.84,282,1620716400"; d="scan'208";a="212887034" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jul 2021 13:07:28 -0700 X-IronPort-AV: E=Sophos;i="5.84,282,1620716400"; d="scan'208";a="508344191" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.25]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jul 2021 13:07:28 -0700 Subject: [PATCH v3 6/6] cxl/core: Move memdev management to core From: Dan Williams To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , Jonathan.Cameron@huawei.com, vishal.l.verma@intel.com, alison.schofield@intel.com Date: Fri, 30 Jul 2021 13:07:28 -0700 Message-ID: <162767564819.3322476.13664902689737028403.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <162767561501.3322476.716972045397140827.stgit@dwillia2-desk3.amr.corp.intel.com> References: <162767561501.3322476.716972045397140827.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org From: Ben Widawsky The motivation for moving cxl_memdev allocation to the core (beyond better file organization of sysfs attributes in core/ and drivers in cxl/), is that device lifetime is longer than module lifetime. The cxl_pci module should be free to come and go without needing to coordinate with devices that need the text associated with cxl_memdev_release() to stay resident. The move fixes a use after free bug when looping driver load / unload with CONFIG_DEBUG_KOBJECT_RELEASE=y. Another motivation for disconnecting cxl_memdev creation from cxl_pci is to enable other drivers, like a unit test driver, to registers memdevs. Fixes: b39cb1052a5c ("cxl/mem: Register CXL memX devices") Signed-off-by: Ben Widawsky Signed-off-by: Dan Williams --- drivers/cxl/core/Makefile | 1 drivers/cxl/core/bus.c | 16 +++ drivers/cxl/core/core.h | 3 + drivers/cxl/core/memdev.c | 245 +++++++++++++++++++++++++++++++++++++++++++++ drivers/cxl/mem.h | 15 ++- drivers/cxl/pci.c | 228 ------------------------------------------ 6 files changed, 274 insertions(+), 234 deletions(-) create mode 100644 drivers/cxl/core/memdev.c diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile index a49bd72dfed3..1463d44f6c3b 100644 --- a/drivers/cxl/core/Makefile +++ b/drivers/cxl/core/Makefile @@ -5,3 +5,4 @@ ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=CXL -I./drivers/cxl cxl_core-y := bus.o cxl_core-y += pmem.o cxl_core-y += regs.o +cxl_core-y += memdev.o diff --git a/drivers/cxl/core/bus.c b/drivers/cxl/core/bus.c index 176db3058575..c0bc27caed4d 100644 --- a/drivers/cxl/core/bus.c +++ b/drivers/cxl/core/bus.c @@ -633,12 +633,26 @@ EXPORT_SYMBOL_GPL(cxl_bus_type); static __init int cxl_core_init(void) { - return bus_register(&cxl_bus_type); + 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); diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h index 49045daf8bd7..036a3c8106b4 100644 --- a/drivers/cxl/core/core.h +++ b/drivers/cxl/core/core.h @@ -14,4 +14,7 @@ static inline void unregister_cxl_dev(void *dev) device_unregister(dev); } +int cxl_memdev_init(void); +void cxl_memdev_exit(void); + #endif /* __CXL_CORE_H__ */ diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c new file mode 100644 index 000000000000..e005d5558d4e --- /dev/null +++ b/drivers/cxl/core/memdev.c @@ -0,0 +1,245 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2020 Intel Corporation. */ + +#include +#include +#include +#include +#include + +/* + * An entire PCI topology full of devices should be enough for any + * config + */ +#define CXL_MEM_MAX_DEVS 65536 + +static int cxl_mem_major; +static DEFINE_IDA(cxl_memdev_ida); + +static void cxl_memdev_release(struct device *dev) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + + 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 sysfs_emit(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 sysfs_emit(buf, "%zu\n", cxlm->payload_size); +} +static DEVICE_ATTR_RO(payload_max); + +static ssize_t label_storage_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; + + return sysfs_emit(buf, "%zu\n", cxlm->lsa_size); +} +static DEVICE_ATTR_RO(label_storage_size); + +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 sysfs_emit(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 sysfs_emit(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, + &dev_attr_label_storage_size.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 cxl_memdev_unregister(void *_cxlmd) +{ + struct cxl_memdev *cxlmd = _cxlmd; + struct device *dev = &cxlmd->dev; + struct cdev *cdev = &cxlmd->cdev; + const struct cdevm_file_operations *cdevm_fops; + + cdevm_fops = container_of(cdev->ops, typeof(*cdevm_fops), fops); + cdevm_fops->shutdown(dev); + + cdev_device_del(&cxlmd->cdev, dev); + put_device(dev); +} + +static struct cxl_memdev *cxl_memdev_alloc(struct cxl_mem *cxlm, + const struct file_operations *fops) +{ + 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 ERR_PTR(-ENOMEM); + + rc = ida_alloc_range(&cxl_memdev_ida, 0, CXL_MEM_MAX_DEVS, GFP_KERNEL); + if (rc < 0) + goto err; + 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; + device_set_pm_not_required(dev); + + cdev = &cxlmd->cdev; + cdev_init(cdev, fops); + return cxlmd; + +err: + kfree(cxlmd); + return ERR_PTR(rc); +} + +struct cxl_memdev * +devm_cxl_add_memdev(struct device *host, struct cxl_mem *cxlm, + const struct cdevm_file_operations *cdevm_fops) +{ + struct cxl_memdev *cxlmd; + struct device *dev; + struct cdev *cdev; + int rc; + + cxlmd = cxl_memdev_alloc(cxlm, &cdevm_fops->fops); + if (IS_ERR(cxlmd)) + return cxlmd; + + dev = &cxlmd->dev; + rc = dev_set_name(dev, "mem%d", cxlmd->id); + if (rc) + goto err; + + /* + * Activate ioctl operations, no cxl_memdev_rwsem manipulation + * needed as this is ordered with cdev_add() publishing the device. + */ + cxlmd->cxlm = cxlm; + + cdev = &cxlmd->cdev; + rc = cdev_device_add(cdev, dev); + if (rc) + goto err; + + rc = devm_add_action_or_reset(host, cxl_memdev_unregister, cxlmd); + if (rc) + return ERR_PTR(rc); + return cxlmd; + +err: + /* + * The cdev was briefly live, shutdown any ioctl operations that + * saw that state. + */ + cdevm_fops->shutdown(dev); + put_device(dev); + return ERR_PTR(rc); +} +EXPORT_SYMBOL_GPL(devm_cxl_add_memdev); + +__init int cxl_memdev_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); + + return 0; +} + +void cxl_memdev_exit(void) +{ + unregister_chrdev_region(MKDEV(cxl_mem_major, 0), CXL_MEM_MAX_DEVS); +} diff --git a/drivers/cxl/mem.h b/drivers/cxl/mem.h index 77f4411c7c6a..cd957a661ead 100644 --- a/drivers/cxl/mem.h +++ b/drivers/cxl/mem.h @@ -28,12 +28,6 @@ (FIELD_GET(CXLMDEV_RESET_NEEDED_MASK, status) != \ CXLMDEV_RESET_NEEDED_NOT) -/* - * An entire PCI topology full of devices should be enough for any - * config - */ -#define CXL_MEM_MAX_DEVS 65536 - /** * struct cdevm_file_operations - devm coordinated cdev file operations * @fops: typical file operations @@ -63,6 +57,15 @@ struct cxl_memdev { int id; }; +static inline struct cxl_memdev *to_cxl_memdev(struct device *dev) +{ + return container_of(dev, struct cxl_memdev, dev); +} + +struct cxl_memdev * +devm_cxl_add_memdev(struct device *host, struct cxl_mem *cxlm, + const struct cdevm_file_operations *cdevm_fops); + /** * struct cxl_mem - A CXL memory device * @pdev: The PCI device associated with this CXL device. diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c index e20a643ee0c0..b54bcfab57c9 100644 --- a/drivers/cxl/pci.c +++ b/drivers/cxl/pci.c @@ -94,8 +94,6 @@ struct mbox_cmd { #define CXL_MBOX_SUCCESS 0 }; -static int cxl_mem_major; -static DEFINE_IDA(cxl_memdev_ida); static DECLARE_RWSEM(cxl_memdev_rwsem); static struct dentry *cxl_debugfs; static bool cxl_raw_allow_all; @@ -806,11 +804,6 @@ static int cxl_memdev_release_file(struct inode *inode, struct file *file) return 0; } -static struct cxl_memdev *to_cxl_memdev(struct device *dev) -{ - return container_of(dev, struct cxl_memdev, dev); -} - static void cxl_memdev_shutdown(struct device *dev) { struct cxl_memdev *cxlmd = to_cxl_memdev(dev); @@ -1178,214 +1171,6 @@ static int cxl_mem_setup_regs(struct cxl_mem *cxlm) return ret; } -static void cxl_memdev_release(struct device *dev) -{ - struct cxl_memdev *cxlmd = to_cxl_memdev(dev); - - 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 sysfs_emit(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 sysfs_emit(buf, "%zu\n", cxlm->payload_size); -} -static DEVICE_ATTR_RO(payload_max); - -static ssize_t label_storage_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; - - return sysfs_emit(buf, "%zu\n", cxlm->lsa_size); -} -static DEVICE_ATTR_RO(label_storage_size); - -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 sysfs_emit(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 sysfs_emit(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, - &dev_attr_label_storage_size.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 cxl_memdev_unregister(void *_cxlmd) -{ - struct cxl_memdev *cxlmd = _cxlmd; - struct device *dev = &cxlmd->dev; - struct cdev *cdev = &cxlmd->cdev; - const struct cdevm_file_operations *cdevm_fops; - - cdevm_fops = container_of(cdev->ops, typeof(*cdevm_fops), fops); - cdevm_fops->shutdown(dev); - - cdev_device_del(&cxlmd->cdev, dev); - put_device(dev); -} - -static struct cxl_memdev *cxl_memdev_alloc(struct cxl_mem *cxlm, - const struct file_operations *fops) -{ - 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 ERR_PTR(-ENOMEM); - - rc = ida_alloc_range(&cxl_memdev_ida, 0, CXL_MEM_MAX_DEVS, GFP_KERNEL); - if (rc < 0) - goto err; - 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; - device_set_pm_not_required(dev); - - cdev = &cxlmd->cdev; - cdev_init(cdev, fops); - return cxlmd; - -err: - kfree(cxlmd); - return ERR_PTR(rc); -} - -static struct cxl_memdev * -devm_cxl_add_memdev(struct device *host, struct cxl_mem *cxlm, - const struct cdevm_file_operations *cdevm_fops) -{ - struct cxl_memdev *cxlmd; - struct device *dev; - struct cdev *cdev; - int rc; - - cxlmd = cxl_memdev_alloc(cxlm, &cdevm_fops->fops); - if (IS_ERR(cxlmd)) - return cxlmd; - - dev = &cxlmd->dev; - rc = dev_set_name(dev, "mem%d", cxlmd->id); - if (rc) - goto err; - - /* - * Activate ioctl operations, no cxl_memdev_rwsem manipulation - * needed as this is ordered with cdev_add() publishing the device. - */ - cxlmd->cxlm = cxlm; - - cdev = &cxlmd->cdev; - rc = cdev_device_add(cdev, dev); - if (rc) - goto err; - - rc = devm_add_action_or_reset(host, cxl_memdev_unregister, cxlmd); - if (rc) - return ERR_PTR(rc); - return cxlmd; - -err: - /* - * The cdev was briefly live, shutdown any ioctl operations that - * saw that state. - */ - cdevm_fops->shutdown(dev); - put_device(dev); - return ERR_PTR(rc); -} - static int cxl_xfer_log(struct cxl_mem *cxlm, uuid_t *uuid, u32 size, u8 *out) { u32 remaining = size; @@ -1651,25 +1436,15 @@ static struct pci_driver cxl_mem_driver = { static __init int cxl_mem_init(void) { struct dentry *mbox_debugfs; - dev_t devt; int rc; /* Double check the anonymous union trickery in struct cxl_regs */ BUILD_BUG_ON(offsetof(struct cxl_regs, memdev) != offsetof(struct cxl_regs, device_regs.memdev)); - 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); + if (rc) return rc; - } cxl_debugfs = debugfs_create_dir("cxl", NULL); mbox_debugfs = debugfs_create_dir("mbox", cxl_debugfs); @@ -1683,7 +1458,6 @@ static __exit void cxl_mem_exit(void) { debugfs_remove_recursive(cxl_debugfs); pci_unregister_driver(&cxl_mem_driver); - unregister_chrdev_region(MKDEV(cxl_mem_major, 0), CXL_MEM_MAX_DEVS); } MODULE_LICENSE("GPL v2");