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, 442 insertions, 0 deletions

diff --git a/block/blk-ioc.c b/block/blk-ioc.c
new file mode 100644
index 000000000..d15918d7f
--- /dev/null
+++ b/block/blk-ioc.c
@@ -0,0 +1,442 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions related to io context handling
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <linux/sched/task.h>
+
+#include "blk.h"
+#include "blk-mq-sched.h"
+
+/*
+ * For io context allocations
+ */
+static struct kmem_cache *iocontext_cachep;
+
+#ifdef CONFIG_BLK_ICQ
+/**
+ * get_io_context - increment reference count to io_context
+ * @ioc: io_context to get
+ *
+ * Increment reference count to @ioc.
+ */
+static void get_io_context(struct io_context *ioc)
+{
+	BUG_ON(atomic_long_read(&ioc->refcount) <= 0);
+	atomic_long_inc(&ioc->refcount);
+}
+
+/*
+ * Exit an icq. Called with ioc locked for blk-mq, and with both ioc
+ * and queue locked for legacy.
+ */
+static void ioc_exit_icq(struct io_cq *icq)
+{
+	struct elevator_type *et = icq->q->elevator->type;
+
+	if (icq->flags & ICQ_EXITED)
+		return;
+
+	if (et->ops.exit_icq)
+		et->ops.exit_icq(icq);
+
+	icq->flags |= ICQ_EXITED;
+}
+
+static void ioc_exit_icqs(struct io_context *ioc)
+{
+	struct io_cq *icq;
+
+	spin_lock_irq(&ioc->lock);
+	hlist_for_each_entry(icq, &ioc->icq_list, ioc_node)
+		ioc_exit_icq(icq);
+	spin_unlock_irq(&ioc->lock);
+}
+
+/*
+ * Release an icq. Called with ioc locked for blk-mq, and with both ioc
+ * and queue locked for legacy.
+ */
+static void ioc_destroy_icq(struct io_cq *icq)
+{
+	struct io_context *ioc = icq->ioc;
+	struct request_queue *q = icq->q;
+	struct elevator_type *et = q->elevator->type;
+
+	lockdep_assert_held(&ioc->lock);
+	lockdep_assert_held(&q->queue_lock);
+
+	if (icq->flags & ICQ_DESTROYED)
+		return;
+
+	radix_tree_delete(&ioc->icq_tree, icq->q->id);
+	hlist_del_init(&icq->ioc_node);
+	list_del_init(&icq->q_node);
+
+	/*
+	 * Both setting lookup hint to and clearing it from @icq are done
+	 * under queue_lock.  If it's not pointing to @icq now, it never
+	 * will.  Hint assignment itself can race safely.
+	 */
+	if (rcu_access_pointer(ioc->icq_hint) == icq)
+		rcu_assign_pointer(ioc->icq_hint, NULL);
+
+	ioc_exit_icq(icq);
+
+	/*
+	 * @icq->q might have gone away by the time RCU callback runs
+	 * making it impossible to determine icq_cache.  Record it in @icq.
+	 */
+	icq->__rcu_icq_cache = et->icq_cache;
+	icq->flags |= ICQ_DESTROYED;
+	kfree_rcu(icq, __rcu_head);
+}
+
+/*
+ * Slow path for ioc release in put_io_context().  Performs double-lock
+ * dancing to unlink all icq's and then frees ioc.
+ */
+static void ioc_release_fn(struct work_struct *work)
+{
+	struct io_context *ioc = container_of(work, struct io_context,
+					      release_work);
+	spin_lock_irq(&ioc->lock);
+
+	while (!hlist_empty(&ioc->icq_list)) {
+		struct io_cq *icq = hlist_entry(ioc->icq_list.first,
+						struct io_cq, ioc_node);
+		struct request_queue *q = icq->q;
+
+		if (spin_trylock(&q->queue_lock)) {
+			ioc_destroy_icq(icq);
+			spin_unlock(&q->queue_lock);
+		} else {
+			/* Make sure q and icq cannot be freed. */
+			rcu_read_lock();
+
+			/* Re-acquire the locks in the correct order. */
+			spin_unlock(&ioc->lock);
+			spin_lock(&q->queue_lock);
+			spin_lock(&ioc->lock);
+
+			ioc_destroy_icq(icq);
+
+			spin_unlock(&q->queue_lock);
+			rcu_read_unlock();
+		}
+	}
+
+	spin_unlock_irq(&ioc->lock);
+
+	kmem_cache_free(iocontext_cachep, ioc);
+}
+
+/*
+ * Releasing icqs requires reverse order double locking and we may already be
+ * holding a queue_lock.  Do it asynchronously from a workqueue.
+ */
+static bool ioc_delay_free(struct io_context *ioc)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ioc->lock, flags);
+	if (!hlist_empty(&ioc->icq_list)) {
+		queue_work(system_power_efficient_wq, &ioc->release_work);
+		spin_unlock_irqrestore(&ioc->lock, flags);
+		return true;
+	}
+	spin_unlock_irqrestore(&ioc->lock, flags);
+	return false;
+}
+
+/**
+ * ioc_clear_queue - break any ioc association with the specified queue
+ * @q: request_queue being cleared
+ *
+ * Walk @q->icq_list and exit all io_cq's.
+ */
+void ioc_clear_queue(struct request_queue *q)
+{
+	spin_lock_irq(&q->queue_lock);
+	while (!list_empty(&q->icq_list)) {
+		struct io_cq *icq =
+			list_first_entry(&q->icq_list, struct io_cq, q_node);
+
+		/*
+		 * Other context won't hold ioc lock to wait for queue_lock, see
+		 * details in ioc_release_fn().
+		 */
+		spin_lock(&icq->ioc->lock);
+		ioc_destroy_icq(icq);
+		spin_unlock(&icq->ioc->lock);
+	}
+	spin_unlock_irq(&q->queue_lock);
+}
+#else /* CONFIG_BLK_ICQ */
+static inline void ioc_exit_icqs(struct io_context *ioc)
+{
+}
+static inline bool ioc_delay_free(struct io_context *ioc)
+{
+	return false;
+}
+#endif /* CONFIG_BLK_ICQ */
+
+/**
+ * put_io_context - put a reference of io_context
+ * @ioc: io_context to put
+ *
+ * Decrement reference count of @ioc and release it if the count reaches
+ * zero.
+ */
+void put_io_context(struct io_context *ioc)
+{
+	BUG_ON(atomic_long_read(&ioc->refcount) <= 0);
+	if (atomic_long_dec_and_test(&ioc->refcount) && !ioc_delay_free(ioc))
+		kmem_cache_free(iocontext_cachep, ioc);
+}
+EXPORT_SYMBOL_GPL(put_io_context);
+
+/* Called by the exiting task */
+void exit_io_context(struct task_struct *task)
+{
+	struct io_context *ioc;
+
+	task_lock(task);
+	ioc = task->io_context;
+	task->io_context = NULL;
+	task_unlock(task);
+
+	if (atomic_dec_and_test(&ioc->active_ref)) {
+		ioc_exit_icqs(ioc);
+		put_io_context(ioc);
+	}
+}
+
+static struct io_context *alloc_io_context(gfp_t gfp_flags, int node)
+{
+	struct io_context *ioc;
+
+	ioc = kmem_cache_alloc_node(iocontext_cachep, gfp_flags | __GFP_ZERO,
+				    node);
+	if (unlikely(!ioc))
+		return NULL;
+
+	atomic_long_set(&ioc->refcount, 1);
+	atomic_set(&ioc->active_ref, 1);
+#ifdef CONFIG_BLK_ICQ
+	spin_lock_init(&ioc->lock);
+	INIT_RADIX_TREE(&ioc->icq_tree, GFP_ATOMIC);
+	INIT_HLIST_HEAD(&ioc->icq_list);
+	INIT_WORK(&ioc->release_work, ioc_release_fn);
+#endif
+	ioc->ioprio = IOPRIO_DEFAULT;
+
+	return ioc;
+}
+
+int set_task_ioprio(struct task_struct *task, int ioprio)
+{
+	int err;
+	const struct cred *cred = current_cred(), *tcred;
+
+	rcu_read_lock();
+	tcred = __task_cred(task);
+	if (!uid_eq(tcred->uid, cred->euid) &&
+	    !uid_eq(tcred->uid, cred->uid) && !capable(CAP_SYS_NICE)) {
+		rcu_read_unlock();
+		return -EPERM;
+	}
+	rcu_read_unlock();
+
+	err = security_task_setioprio(task, ioprio);
+	if (err)
+		return err;
+
+	task_lock(task);
+	if (unlikely(!task->io_context)) {
+		struct io_context *ioc;
+
+		task_unlock(task);
+
+		ioc = alloc_io_context(GFP_ATOMIC, NUMA_NO_NODE);
+		if (!ioc)
+			return -ENOMEM;
+
+		task_lock(task);
+		if (task->flags & PF_EXITING) {
+			kmem_cache_free(iocontext_cachep, ioc);
+			goto out;
+		}
+		if (task->io_context)
+			kmem_cache_free(iocontext_cachep, ioc);
+		else
+			task->io_context = ioc;
+	}
+	task->io_context->ioprio = ioprio;
+out:
+	task_unlock(task);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(set_task_ioprio);
+
+int __copy_io(u64 clone_flags, struct task_struct *tsk)
+{
+	struct io_context *ioc = current->io_context;
+
+	/*
+	 * Share io context with parent, if CLONE_IO is set
+	 */
+	if (clone_flags & CLONE_IO) {
+		atomic_inc(&ioc->active_ref);
+		tsk->io_context = ioc;
+	} else if (ioprio_valid(ioc->ioprio)) {
+		tsk->io_context = alloc_io_context(GFP_KERNEL, NUMA_NO_NODE);
+		if (!tsk->io_context)
+			return -ENOMEM;
+		tsk->io_context->ioprio = ioc->ioprio;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_BLK_ICQ
+/**
+ * ioc_lookup_icq - lookup io_cq from ioc in io issue path
+ * @q: the associated request_queue
+ *
+ * Look up io_cq associated with @ioc - @q pair from @ioc.  Must be called
+ * from io issue path, either return NULL if current issue io to @q for the
+ * first time, or return a valid icq.
+ */
+struct io_cq *ioc_lookup_icq(struct request_queue *q)
+{
+	struct io_context *ioc = current->io_context;
+	struct io_cq *icq;
+
+	/*
+	 * icq's are indexed from @ioc using radix tree and hint pointer,
+	 * both of which are protected with RCU, io issue path ensures that
+	 * both request_queue and current task are valid, the found icq
+	 * is guaranteed to be valid until the io is done.
+	 */
+	rcu_read_lock();
+	icq = rcu_dereference(ioc->icq_hint);
+	if (icq && icq->q == q)
+		goto out;
+
+	icq = radix_tree_lookup(&ioc->icq_tree, q->id);
+	if (icq && icq->q == q)
+		rcu_assign_pointer(ioc->icq_hint, icq);	/* allowed to race */
+	else
+		icq = NULL;
+out:
+	rcu_read_unlock();
+	return icq;
+}
+EXPORT_SYMBOL(ioc_lookup_icq);
+
+/**
+ * ioc_create_icq - create and link io_cq
+ * @q: request_queue of interest
+ *
+ * Make sure io_cq linking @ioc and @q exists.  If icq doesn't exist, they
+ * will be created using @gfp_mask.
+ *
+ * The caller is responsible for ensuring @ioc won't go away and @q is
+ * alive and will stay alive until this function returns.
+ */
+static struct io_cq *ioc_create_icq(struct request_queue *q)
+{
+	struct io_context *ioc = current->io_context;
+	struct elevator_type *et = q->elevator->type;
+	struct io_cq *icq;
+
+	/* allocate stuff */
+	icq = kmem_cache_alloc_node(et->icq_cache, GFP_ATOMIC | __GFP_ZERO,
+				    q->node);
+	if (!icq)
+		return NULL;
+
+	if (radix_tree_maybe_preload(GFP_ATOMIC) < 0) {
+		kmem_cache_free(et->icq_cache, icq);
+		return NULL;
+	}
+
+	icq->ioc = ioc;
+	icq->q = q;
+	INIT_LIST_HEAD(&icq->q_node);
+	INIT_HLIST_NODE(&icq->ioc_node);
+
+	/* lock both q and ioc and try to link @icq */
+	spin_lock_irq(&q->queue_lock);
+	spin_lock(&ioc->lock);
+
+	if (likely(!radix_tree_insert(&ioc->icq_tree, q->id, icq))) {
+		hlist_add_head(&icq->ioc_node, &ioc->icq_list);
+		list_add(&icq->q_node, &q->icq_list);
+		if (et->ops.init_icq)
+			et->ops.init_icq(icq);
+	} else {
+		kmem_cache_free(et->icq_cache, icq);
+		icq = ioc_lookup_icq(q);
+		if (!icq)
+			printk(KERN_ERR "cfq: icq link failed!\n");
+	}
+
+	spin_unlock(&ioc->lock);
+	spin_unlock_irq(&q->queue_lock);
+	radix_tree_preload_end();
+	return icq;
+}
+
+struct io_cq *ioc_find_get_icq(struct request_queue *q)
+{
+	struct io_context *ioc = current->io_context;
+	struct io_cq *icq = NULL;
+
+	if (unlikely(!ioc)) {
+		ioc = alloc_io_context(GFP_ATOMIC, q->node);
+		if (!ioc)
+			return NULL;
+
+		task_lock(current);
+		if (current->io_context) {
+			kmem_cache_free(iocontext_cachep, ioc);
+			ioc = current->io_context;
+		} else {
+			current->io_context = ioc;
+		}
+
+		get_io_context(ioc);
+		task_unlock(current);
+	} else {
+		get_io_context(ioc);
+		icq = ioc_lookup_icq(q);
+	}
+
+	if (!icq) {
+		icq = ioc_create_icq(q);
+		if (!icq) {
+			put_io_context(ioc);
+			return NULL;
+		}
+	}
+	return icq;
+}
+EXPORT_SYMBOL_GPL(ioc_find_get_icq);
+#endif /* CONFIG_BLK_ICQ */
+
+static int __init blk_ioc_init(void)
+{
+	iocontext_cachep = kmem_cache_create("blkdev_ioc",
+			sizeof(struct io_context), 0, SLAB_PANIC, NULL);
+	return 0;
+}
+subsys_initcall(blk_ioc_init);