From 4352b8aee98005853aa63f57d6377282de17a33f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 23 Aug 2026 13:28:57 -0700 Subject: Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ... --- block/bsg.c | 308 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 308 insertions(+) create mode 100644 block/bsg.c (limited to 'block/bsg.c') diff --git a/block/bsg.c b/block/bsg.c new file mode 100644 index 000000000..82aaf3cee --- /dev/null +++ b/block/bsg.c @@ -0,0 +1,308 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * bsg.c - block layer implementation of the sg v4 interface + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver" +#define BSG_VERSION "0.4" + +struct bsg_device { + struct request_queue *queue; + struct device device; + struct cdev cdev; + int max_queue; + unsigned int timeout; + unsigned int reserved_size; + bsg_sg_io_fn *sg_io_fn; + bsg_uring_cmd_fn *uring_cmd_fn; +}; + +static inline struct bsg_device *to_bsg_device(struct inode *inode) +{ + return container_of(inode->i_cdev, struct bsg_device, cdev); +} + +#define BSG_DEFAULT_CMDS 64 +#define BSG_MAX_DEVS (1 << MINORBITS) + +static DEFINE_IDA(bsg_minor_ida); +static const struct class bsg_class; +static int bsg_major; + +static unsigned int bsg_timeout(struct bsg_device *bd, struct sg_io_v4 *hdr) +{ + unsigned int timeout = BLK_DEFAULT_SG_TIMEOUT; + + if (hdr->timeout) + timeout = msecs_to_jiffies(hdr->timeout); + else if (bd->timeout) + timeout = bd->timeout; + + return max_t(unsigned int, timeout, BLK_MIN_SG_TIMEOUT); +} + +static int bsg_sg_io(struct bsg_device *bd, bool open_for_write, + void __user *uarg) +{ + struct sg_io_v4 hdr; + int ret; + + if (copy_from_user(&hdr, uarg, sizeof(hdr))) + return -EFAULT; + if (hdr.guard != 'Q') + return -EINVAL; + ret = bd->sg_io_fn(bd->queue, &hdr, open_for_write, + bsg_timeout(bd, &hdr)); + if (!ret && copy_to_user(uarg, &hdr, sizeof(hdr))) + return -EFAULT; + return ret; +} + +static int bsg_open(struct inode *inode, struct file *file) +{ + if (!blk_get_queue(to_bsg_device(inode)->queue)) + return -ENXIO; + return 0; +} + +static int bsg_release(struct inode *inode, struct file *file) +{ + blk_put_queue(to_bsg_device(inode)->queue); + return 0; +} + +static int bsg_get_command_q(struct bsg_device *bd, int __user *uarg) +{ + return put_user(READ_ONCE(bd->max_queue), uarg); +} + +static int bsg_set_command_q(struct bsg_device *bd, int __user *uarg) +{ + int max_queue; + + if (get_user(max_queue, uarg)) + return -EFAULT; + if (max_queue < 1) + return -EINVAL; + WRITE_ONCE(bd->max_queue, max_queue); + return 0; +} + +static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct bsg_device *bd = to_bsg_device(file_inode(file)); + struct request_queue *q = bd->queue; + void __user *uarg = (void __user *) arg; + int __user *intp = uarg; + int val; + + switch (cmd) { + /* + * Our own ioctls + */ + case SG_GET_COMMAND_Q: + return bsg_get_command_q(bd, uarg); + case SG_SET_COMMAND_Q: + return bsg_set_command_q(bd, uarg); + + /* + * SCSI/sg ioctls + */ + case SG_GET_VERSION_NUM: + return put_user(30527, intp); + case SCSI_IOCTL_GET_IDLUN: + return put_user(0, intp); + case SCSI_IOCTL_GET_BUS_NUMBER: + return put_user(0, intp); + case SG_SET_TIMEOUT: + if (get_user(val, intp)) + return -EFAULT; + bd->timeout = clock_t_to_jiffies(val); + return 0; + case SG_GET_TIMEOUT: + return jiffies_to_clock_t(bd->timeout); + case SG_GET_RESERVED_SIZE: + return put_user(min(bd->reserved_size, queue_max_bytes(q)), + intp); + case SG_SET_RESERVED_SIZE: + if (get_user(val, intp)) + return -EFAULT; + if (val < 0) + return -EINVAL; + bd->reserved_size = + min_t(unsigned int, val, queue_max_bytes(q)); + return 0; + case SG_EMULATED_HOST: + return put_user(1, intp); + case SG_IO: + return bsg_sg_io(bd, file->f_mode & FMODE_WRITE, uarg); + case SCSI_IOCTL_SEND_COMMAND: + pr_warn_ratelimited("%s: calling unsupported SCSI_IOCTL_SEND_COMMAND\n", + current->comm); + return -EINVAL; + default: + return -ENOTTY; + } +} + +static int bsg_check_uring_features(unsigned int issue_flags) +{ + /* BSG passthrough requires big SQE/CQE support */ + if ((issue_flags & (IO_URING_F_SQE128|IO_URING_F_CQE32)) != + (IO_URING_F_SQE128|IO_URING_F_CQE32)) + return -EOPNOTSUPP; + return 0; +} + +static int bsg_uring_cmd(struct io_uring_cmd *ioucmd, unsigned int issue_flags) +{ + struct bsg_device *bd = to_bsg_device(file_inode(ioucmd->file)); + bool open_for_write = ioucmd->file->f_mode & FMODE_WRITE; + struct request_queue *q = bd->queue; + int ret; + + ret = bsg_check_uring_features(issue_flags); + if (ret) + return ret; + + if (!bd->uring_cmd_fn) + return -EOPNOTSUPP; + + return bd->uring_cmd_fn(q, ioucmd, issue_flags, open_for_write); +} + +static const struct file_operations bsg_fops = { + .open = bsg_open, + .release = bsg_release, + .unlocked_ioctl = bsg_ioctl, + .compat_ioctl = compat_ptr_ioctl, + .uring_cmd = bsg_uring_cmd, + .owner = THIS_MODULE, + .llseek = default_llseek, +}; + +static void bsg_device_release(struct device *dev) +{ + struct bsg_device *bd = container_of(dev, struct bsg_device, device); + + ida_free(&bsg_minor_ida, MINOR(bd->device.devt)); + kfree(bd); +} + +void bsg_unregister_queue(struct bsg_device *bd) +{ + struct gendisk *disk = bd->queue->disk; + + if (disk && disk->queue_kobj.sd) + sysfs_remove_link(&disk->queue_kobj, "bsg"); + cdev_device_del(&bd->cdev, &bd->device); + put_device(&bd->device); +} +EXPORT_SYMBOL_GPL(bsg_unregister_queue); + +struct bsg_device *bsg_register_queue(struct request_queue *q, + struct device *parent, const char *name, bsg_sg_io_fn *sg_io_fn, + bsg_uring_cmd_fn *uring_cmd_fn) +{ + struct bsg_device *bd; + int ret; + + bd = kzalloc_obj(*bd); + if (!bd) + return ERR_PTR(-ENOMEM); + bd->max_queue = BSG_DEFAULT_CMDS; + bd->reserved_size = INT_MAX; + bd->queue = q; + bd->sg_io_fn = sg_io_fn; + bd->uring_cmd_fn = uring_cmd_fn; + + ret = ida_alloc_max(&bsg_minor_ida, BSG_MAX_DEVS - 1, GFP_KERNEL); + if (ret < 0) { + if (ret == -ENOSPC) + dev_err(parent, "bsg: too many bsg devices\n"); + kfree(bd); + return ERR_PTR(ret); + } + bd->device.devt = MKDEV(bsg_major, ret); + bd->device.class = &bsg_class; + bd->device.parent = parent; + bd->device.release = bsg_device_release; + dev_set_name(&bd->device, "%s", name); + device_initialize(&bd->device); + + cdev_init(&bd->cdev, &bsg_fops); + bd->cdev.owner = THIS_MODULE; + ret = cdev_device_add(&bd->cdev, &bd->device); + if (ret) + goto out_put_device; + + if (q->disk && q->disk->queue_kobj.sd) { + ret = sysfs_create_link(&q->disk->queue_kobj, &bd->device.kobj, + "bsg"); + if (ret) + goto out_device_del; + } + + return bd; + +out_device_del: + cdev_device_del(&bd->cdev, &bd->device); +out_put_device: + put_device(&bd->device); + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(bsg_register_queue); + +static char *bsg_devnode(const struct device *dev, umode_t *mode) +{ + return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev)); +} + +static const struct class bsg_class = { + .name = "bsg", + .devnode = bsg_devnode, +}; + +static int __init bsg_init(void) +{ + dev_t devid; + int ret; + + ret = class_register(&bsg_class); + if (ret) + return ret; + + ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg"); + if (ret) + goto destroy_bsg_class; + bsg_major = MAJOR(devid); + + printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION + " loaded (major %d)\n", bsg_major); + return 0; + +destroy_bsg_class: + class_unregister(&bsg_class); + return ret; +} + +MODULE_AUTHOR("Jens Axboe"); +MODULE_DESCRIPTION(BSG_DESCRIPTION); +MODULE_LICENSE("GPL"); + +device_initcall(bsg_init); -- cgit v1.3.1