Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

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
  ...

1 files changed, 689 insertions, 0 deletions

diff --git a/fs/char_dev.c b/fs/char_dev.c
new file mode 100644
index 000000000..00229e25c
--- /dev/null
+++ b/fs/char_dev.c
@@ -0,0 +1,689 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/char_dev.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/kdev_t.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/cleanup.h>
+
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+
+#include <linux/kobject.h>
+#include <linux/kobj_map.h>
+#include <linux/cdev.h>
+#include <linux/mutex.h>
+#include <linux/backing-dev.h>
+#include <linux/tty.h>
+
+#include "internal.h"
+
+static struct kobj_map *cdev_map __ro_after_init;
+
+static DEFINE_MUTEX(chrdevs_lock);
+
+#define CHRDEV_MAJOR_HASH_SIZE 255
+
+static struct char_device_struct {
+	struct char_device_struct *next;
+	unsigned int major;
+	unsigned int baseminor;
+	int minorct;
+	char name[64];
+	struct cdev *cdev;		/* will die */
+} *chrdevs[CHRDEV_MAJOR_HASH_SIZE];
+
+/* index in the above */
+static inline int major_to_index(unsigned major)
+{
+	return major % CHRDEV_MAJOR_HASH_SIZE;
+}
+
+#ifdef CONFIG_PROC_FS
+
+void chrdev_show(struct seq_file *f, off_t offset)
+{
+	struct char_device_struct *cd;
+
+	mutex_lock(&chrdevs_lock);
+	for (cd = chrdevs[major_to_index(offset)]; cd; cd = cd->next) {
+		if (cd->major == offset)
+			seq_printf(f, "%3d %s\n", cd->major, cd->name);
+	}
+	mutex_unlock(&chrdevs_lock);
+}
+
+#endif /* CONFIG_PROC_FS */
+
+static int find_dynamic_major(void)
+{
+	int i;
+	struct char_device_struct *cd;
+
+	for (i = ARRAY_SIZE(chrdevs)-1; i >= CHRDEV_MAJOR_DYN_END; i--) {
+		if (chrdevs[i] == NULL)
+			return i;
+	}
+
+	for (i = CHRDEV_MAJOR_DYN_EXT_START;
+	     i >= CHRDEV_MAJOR_DYN_EXT_END; i--) {
+		for (cd = chrdevs[major_to_index(i)]; cd; cd = cd->next)
+			if (cd->major == i)
+				break;
+
+		if (cd == NULL)
+			return i;
+	}
+
+	return -EBUSY;
+}
+
+/*
+ * Register a single major with a specified minor range.
+ *
+ * If major == 0 this function will dynamically allocate an unused major.
+ * If major > 0 this function will attempt to reserve the range of minors
+ * with given major.
+ *
+ */
+static struct char_device_struct *
+__register_chrdev_region(unsigned int major, unsigned int baseminor,
+			   int minorct, const char *name)
+{
+	struct char_device_struct *cd __free(kfree) = NULL;
+	struct char_device_struct *curr, *prev = NULL;
+	int ret;
+	int i;
+
+	if (major >= CHRDEV_MAJOR_MAX) {
+		pr_err("CHRDEV \"%s\" major requested (%u) is greater than the maximum (%u)\n",
+		       name, major, CHRDEV_MAJOR_MAX-1);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (minorct > MINORMASK + 1 - baseminor) {
+		pr_err("CHRDEV \"%s\" minor range requested (%u-%u) is out of range of maximum range (%u-%u) for a single major\n",
+			name, baseminor, baseminor + minorct - 1, 0, MINORMASK);
+		return ERR_PTR(-EINVAL);
+	}
+
+	cd = kzalloc_obj(struct char_device_struct);
+	if (cd == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	guard(mutex)(&chrdevs_lock);
+
+	if (major == 0) {
+		ret = find_dynamic_major();
+		if (ret < 0) {
+			pr_err("CHRDEV \"%s\" dynamic allocation region is full\n",
+			       name);
+			return ERR_PTR(ret);
+		}
+		major = ret;
+	}
+
+	ret = -EBUSY;
+	i = major_to_index(major);
+	for (curr = chrdevs[i]; curr; prev = curr, curr = curr->next) {
+		if (curr->major < major)
+			continue;
+
+		if (curr->major > major)
+			break;
+
+		if (curr->baseminor + curr->minorct <= baseminor)
+			continue;
+
+		if (curr->baseminor >= baseminor + minorct)
+			break;
+
+		return ERR_PTR(ret);
+	}
+
+	cd->major = major;
+	cd->baseminor = baseminor;
+	cd->minorct = minorct;
+	strscpy(cd->name, name, sizeof(cd->name));
+
+	if (!prev) {
+		cd->next = curr;
+		chrdevs[i] = cd;
+	} else {
+		cd->next = prev->next;
+		prev->next = cd;
+	}
+
+	return_ptr(cd);
+}
+
+static struct char_device_struct *
+__unregister_chrdev_region(unsigned major, unsigned baseminor, int minorct)
+{
+	struct char_device_struct *cd = NULL, **cp;
+	int i = major_to_index(major);
+
+	mutex_lock(&chrdevs_lock);
+	for (cp = &chrdevs[i]; *cp; cp = &(*cp)->next)
+		if ((*cp)->major == major &&
+		    (*cp)->baseminor == baseminor &&
+		    (*cp)->minorct == minorct)
+			break;
+	if (*cp) {
+		cd = *cp;
+		*cp = cd->next;
+	}
+	mutex_unlock(&chrdevs_lock);
+	return cd;
+}
+
+/**
+ * register_chrdev_region() - register a range of device numbers
+ * @from: the first in the desired range of device numbers; must include
+ *        the major number.
+ * @count: the number of consecutive device numbers required
+ * @name: the name of the device or driver.
+ *
+ * Return value is zero on success, a negative error code on failure.
+ */
+int register_chrdev_region(dev_t from, unsigned count, const char *name)
+{
+	struct char_device_struct *cd;
+	dev_t to = from + count;
+	dev_t n, next;
+
+	for (n = from; n < to; n = next) {
+		next = MKDEV(MAJOR(n)+1, 0);
+		if (next > to)
+			next = to;
+		cd = __register_chrdev_region(MAJOR(n), MINOR(n),
+			       next - n, name);
+		if (IS_ERR(cd))
+			goto fail;
+	}
+	return 0;
+fail:
+	to = n;
+	for (n = from; n < to; n = next) {
+		next = MKDEV(MAJOR(n)+1, 0);
+		kfree(__unregister_chrdev_region(MAJOR(n), MINOR(n), next - n));
+	}
+	return PTR_ERR(cd);
+}
+
+/**
+ * alloc_chrdev_region() - register a range of char device numbers
+ * @dev: output parameter for first assigned number
+ * @baseminor: first of the requested range of minor numbers
+ * @count: the number of minor numbers required
+ * @name: the name of the associated device or driver
+ *
+ * Allocates a range of char device numbers.  The major number will be
+ * chosen dynamically, and returned (along with the first minor number)
+ * in @dev.  Returns zero or a negative error code.
+ */
+int alloc_chrdev_region(dev_t *dev, unsigned baseminor, unsigned count,
+			const char *name)
+{
+	struct char_device_struct *cd;
+	cd = __register_chrdev_region(0, baseminor, count, name);
+	if (IS_ERR(cd))
+		return PTR_ERR(cd);
+	*dev = MKDEV(cd->major, cd->baseminor);
+	return 0;
+}
+
+/**
+ * __register_chrdev() - create and register a cdev occupying a range of minors
+ * @major: major device number or 0 for dynamic allocation
+ * @baseminor: first of the requested range of minor numbers
+ * @count: the number of minor numbers required
+ * @name: name of this range of devices
+ * @fops: file operations associated with this devices
+ *
+ * If @major == 0 this functions will dynamically allocate a major and return
+ * its number.
+ *
+ * If @major > 0 this function will attempt to reserve a device with the given
+ * major number and will return zero on success.
+ *
+ * Returns a -ve errno on failure.
+ *
+ * The name of this device has nothing to do with the name of the device in
+ * /dev. It only helps to keep track of the different owners of devices. If
+ * your module name has only one type of devices it's ok to use e.g. the name
+ * of the module here.
+ */
+int __register_chrdev(unsigned int major, unsigned int baseminor,
+		      unsigned int count, const char *name,
+		      const struct file_operations *fops)
+{
+	struct char_device_struct *cd;
+	struct cdev *cdev;
+	int err = -ENOMEM;
+
+	cd = __register_chrdev_region(major, baseminor, count, name);
+	if (IS_ERR(cd))
+		return PTR_ERR(cd);
+
+	cdev = cdev_alloc();
+	if (!cdev)
+		goto out2;
+
+	cdev->owner = fops->owner;
+	cdev->ops = fops;
+	kobject_set_name(&cdev->kobj, "%s", name);
+
+	err = cdev_add(cdev, MKDEV(cd->major, baseminor), count);
+	if (err)
+		goto out;
+
+	cd->cdev = cdev;
+
+	return major ? 0 : cd->major;
+out:
+	kobject_put(&cdev->kobj);
+out2:
+	kfree(__unregister_chrdev_region(cd->major, baseminor, count));
+	return err;
+}
+
+/**
+ * unregister_chrdev_region() - unregister a range of device numbers
+ * @from: the first in the range of numbers to unregister
+ * @count: the number of device numbers to unregister
+ *
+ * This function will unregister a range of @count device numbers,
+ * starting with @from.  The caller should normally be the one who
+ * allocated those numbers in the first place...
+ */
+void unregister_chrdev_region(dev_t from, unsigned count)
+{
+	dev_t to = from + count;
+	dev_t n, next;
+
+	for (n = from; n < to; n = next) {
+		next = MKDEV(MAJOR(n)+1, 0);
+		if (next > to)
+			next = to;
+		kfree(__unregister_chrdev_region(MAJOR(n), MINOR(n), next - n));
+	}
+}
+
+/**
+ * __unregister_chrdev - unregister and destroy a cdev
+ * @major: major device number
+ * @baseminor: first of the range of minor numbers
+ * @count: the number of minor numbers this cdev is occupying
+ * @name: name of this range of devices
+ *
+ * Unregister and destroy the cdev occupying the region described by
+ * @major, @baseminor and @count.  This function undoes what
+ * __register_chrdev() did.
+ */
+void __unregister_chrdev(unsigned int major, unsigned int baseminor,
+			 unsigned int count, const char *name)
+{
+	struct char_device_struct *cd;
+
+	cd = __unregister_chrdev_region(major, baseminor, count);
+	if (cd && cd->cdev)
+		cdev_del(cd->cdev);
+	kfree(cd);
+}
+
+static __cacheline_aligned_in_smp DEFINE_SPINLOCK(cdev_lock);
+
+static struct kobject *cdev_get(struct cdev *p)
+{
+	struct module *owner = p->owner;
+	struct kobject *kobj;
+
+	if (!try_module_get(owner))
+		return NULL;
+	kobj = kobject_get_unless_zero(&p->kobj);
+	if (!kobj)
+		module_put(owner);
+	return kobj;
+}
+
+void cdev_put(struct cdev *p)
+{
+	if (p) {
+		struct module *owner = p->owner;
+		kobject_put(&p->kobj);
+		module_put(owner);
+	}
+}
+
+/*
+ * Called every time a character special file is opened
+ */
+static int chrdev_open(struct inode *inode, struct file *filp)
+{
+	const struct file_operations *fops;
+	struct cdev *p;
+	struct cdev *new = NULL;
+	int ret = 0;
+
+	spin_lock(&cdev_lock);
+	p = inode->i_cdev;
+	if (!p) {
+		struct kobject *kobj;
+		int idx;
+		spin_unlock(&cdev_lock);
+		kobj = kobj_lookup(cdev_map, inode->i_rdev, &idx);
+		if (!kobj)
+			return -ENXIO;
+		new = container_of(kobj, struct cdev, kobj);
+		spin_lock(&cdev_lock);
+		/* Check i_cdev again in case somebody beat us to it while
+		   we dropped the lock. */
+		p = inode->i_cdev;
+		if (!p) {
+			inode->i_cdev = p = new;
+			list_add(&inode->i_devices, &p->list);
+			new = NULL;
+		} else if (!cdev_get(p))
+			ret = -ENXIO;
+	} else if (!cdev_get(p))
+		ret = -ENXIO;
+	spin_unlock(&cdev_lock);
+	cdev_put(new);
+	if (ret)
+		return ret;
+
+	ret = -ENXIO;
+	fops = fops_get(p->ops);
+	if (!fops)
+		goto out_cdev_put;
+
+	replace_fops(filp, fops);
+	if (filp->f_op->open) {
+		ret = filp->f_op->open(inode, filp);
+		if (ret)
+			goto out_cdev_put;
+	}
+
+	return 0;
+
+ out_cdev_put:
+	cdev_put(p);
+	return ret;
+}
+
+void cd_forget(struct inode *inode)
+{
+	spin_lock(&cdev_lock);
+	list_del_init(&inode->i_devices);
+	inode->i_cdev = NULL;
+	inode->i_mapping = &inode->i_data;
+	spin_unlock(&cdev_lock);
+}
+
+static void cdev_purge(struct cdev *cdev)
+{
+	spin_lock(&cdev_lock);
+	while (!list_empty(&cdev->list)) {
+		struct inode *inode;
+		inode = container_of(cdev->list.next, struct inode, i_devices);
+		list_del_init(&inode->i_devices);
+		inode->i_cdev = NULL;
+	}
+	spin_unlock(&cdev_lock);
+}
+
+/*
+ * Dummy default file-operations: the only thing this does
+ * is contain the open that then fills in the correct operations
+ * depending on the special file...
+ */
+const struct file_operations def_chr_fops = {
+	.open = chrdev_open,
+	.llseek = noop_llseek,
+};
+
+static struct kobject *exact_match(dev_t dev, int *part, void *data)
+{
+	struct cdev *p = data;
+	return &p->kobj;
+}
+
+static int exact_lock(dev_t dev, void *data)
+{
+	struct cdev *p = data;
+	return cdev_get(p) ? 0 : -1;
+}
+
+/**
+ * cdev_add() - add a char device to the system
+ * @p: the cdev structure for the device
+ * @dev: the first device number for which this device is responsible
+ * @count: the number of consecutive minor numbers corresponding to this
+ *         device
+ *
+ * cdev_add() adds the device represented by @p to the system, making it
+ * live immediately.  A negative error code is returned on failure.
+ */
+int cdev_add(struct cdev *p, dev_t dev, unsigned count)
+{
+	int error;
+
+	p->dev = dev;
+	p->count = count;
+
+	if (WARN_ON(dev == WHITEOUT_DEV)) {
+		error = -EBUSY;
+		goto err;
+	}
+
+	error = kobj_map(cdev_map, dev, count, NULL,
+			 exact_match, exact_lock, p);
+	if (error)
+		goto err;
+
+	kobject_get(p->kobj.parent);
+
+	return 0;
+
+err:
+	kfree_const(p->kobj.name);
+	p->kobj.name = NULL;
+	return error;
+}
+
+/**
+ * cdev_set_parent() - set the parent kobject for a char device
+ * @p: the cdev structure
+ * @kobj: the kobject to take a reference to
+ *
+ * cdev_set_parent() sets a parent kobject which will be referenced
+ * appropriately so the parent is not freed before the cdev. This
+ * should be called before cdev_add.
+ */
+void cdev_set_parent(struct cdev *p, struct kobject *kobj)
+{
+	WARN_ON(!kobj->state_initialized);
+	p->kobj.parent = kobj;
+}
+
+/**
+ * cdev_device_add() - add a char device and it's corresponding
+ *	struct device, linkink
+ * @dev: the device structure
+ * @cdev: the cdev structure
+ *
+ * cdev_device_add() adds the char device represented by @cdev to the system,
+ * just as cdev_add does. It then adds @dev to the system using device_add
+ * The dev_t for the char device will be taken from the struct device which
+ * needs to be initialized first. This helper function correctly takes a
+ * reference to the parent device so the parent will not get released until
+ * all references to the cdev are released.
+ *
+ * This helper uses dev->devt for the device number. If it is not set
+ * it will not add the cdev and it will be equivalent to device_add.
+ *
+ * This function should be used whenever the struct cdev and the
+ * struct device are members of the same structure whose lifetime is
+ * managed by the struct device.
+ *
+ * NOTE: Callers must assume that userspace was able to open the cdev and
+ * can call cdev fops callbacks at any time, even if this function fails.
+ */
+int cdev_device_add(struct cdev *cdev, struct device *dev)
+{
+	int rc = 0;
+
+	if (dev->devt) {
+		cdev_set_parent(cdev, &dev->kobj);
+
+		rc = cdev_add(cdev, dev->devt, 1);
+		if (rc)
+			return rc;
+	}
+
+	rc = device_add(dev);
+	if (rc && dev->devt)
+		cdev_del(cdev);
+
+	return rc;
+}
+
+/**
+ * cdev_device_del() - inverse of cdev_device_add
+ * @cdev: the cdev structure
+ * @dev: the device structure
+ *
+ * cdev_device_del() is a helper function to call cdev_del and device_del.
+ * It should be used whenever cdev_device_add is used.
+ *
+ * If dev->devt is not set it will not remove the cdev and will be equivalent
+ * to device_del.
+ *
+ * NOTE: This guarantees that associated sysfs callbacks are not running
+ * or runnable, however any cdevs already open will remain and their fops
+ * will still be callable even after this function returns.
+ */
+void cdev_device_del(struct cdev *cdev, struct device *dev)
+{
+	device_del(dev);
+	if (dev->devt)
+		cdev_del(cdev);
+}
+
+static void cdev_unmap(dev_t dev, unsigned count)
+{
+	kobj_unmap(cdev_map, dev, count);
+}
+
+/**
+ * cdev_del() - remove a cdev from the system
+ * @p: the cdev structure to be removed
+ *
+ * cdev_del() removes @p from the system, possibly freeing the structure
+ * itself.
+ *
+ * NOTE: This guarantees that cdev device will no longer be able to be
+ * opened, however any cdevs already open will remain and their fops will
+ * still be callable even after cdev_del returns.
+ */
+void cdev_del(struct cdev *p)
+{
+	cdev_unmap(p->dev, p->count);
+	kobject_put(&p->kobj);
+}
+
+
+static void cdev_default_release(struct kobject *kobj)
+{
+	struct cdev *p = container_of(kobj, struct cdev, kobj);
+	struct kobject *parent = kobj->parent;
+
+	cdev_purge(p);
+	kobject_put(parent);
+}
+
+static void cdev_dynamic_release(struct kobject *kobj)
+{
+	struct cdev *p = container_of(kobj, struct cdev, kobj);
+	struct kobject *parent = kobj->parent;
+
+	cdev_purge(p);
+	kfree(p);
+	kobject_put(parent);
+}
+
+static struct kobj_type ktype_cdev_default = {
+	.release	= cdev_default_release,
+};
+
+static struct kobj_type ktype_cdev_dynamic = {
+	.release	= cdev_dynamic_release,
+};
+
+/**
+ * cdev_alloc() - allocate a cdev structure
+ *
+ * Allocates and returns a cdev structure, or NULL on failure.
+ */
+struct cdev *cdev_alloc(void)
+{
+	struct cdev *p = kzalloc_obj(struct cdev);
+	if (p) {
+		INIT_LIST_HEAD(&p->list);
+		kobject_init(&p->kobj, &ktype_cdev_dynamic);
+	}
+	return p;
+}
+
+/**
+ * cdev_init() - initialize a cdev structure
+ * @cdev: the structure to initialize
+ * @fops: the file_operations for this device
+ *
+ * Initializes @cdev, remembering @fops, making it ready to add to the
+ * system with cdev_add().
+ */
+void cdev_init(struct cdev *cdev, const struct file_operations *fops)
+{
+	memset(cdev, 0, sizeof *cdev);
+	INIT_LIST_HEAD(&cdev->list);
+	kobject_init(&cdev->kobj, &ktype_cdev_default);
+	cdev->ops = fops;
+}
+
+static struct kobject *base_probe(dev_t dev, int *part, void *data)
+{
+	if (request_module("char-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0)
+		/* Make old-style 2.4 aliases work */
+		request_module("char-major-%d", MAJOR(dev));
+	return NULL;
+}
+
+void __init chrdev_init(void)
+{
+	cdev_map = kobj_map_init(base_probe, &chrdevs_lock);
+}
+
+
+/* Let modules do char dev stuff */
+EXPORT_SYMBOL(register_chrdev_region);
+EXPORT_SYMBOL(unregister_chrdev_region);
+EXPORT_SYMBOL(alloc_chrdev_region);
+EXPORT_SYMBOL(cdev_init);
+EXPORT_SYMBOL(cdev_alloc);
+EXPORT_SYMBOL(cdev_del);
+EXPORT_SYMBOL(cdev_add);
+EXPORT_SYMBOL(cdev_set_parent);
+EXPORT_SYMBOL(cdev_device_add);
+EXPORT_SYMBOL(cdev_device_del);
+EXPORT_SYMBOL(__register_chrdev);
+EXPORT_SYMBOL(__unregister_chrdev);