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, 205 insertions, 0 deletions

diff --git a/drivers/md/dm-vdo/wait-queue.c b/drivers/md/dm-vdo/wait-queue.c
new file mode 100644
index 000000000..f81ed0cee
--- /dev/null
+++ b/drivers/md/dm-vdo/wait-queue.c
@@ -0,0 +1,205 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#include "wait-queue.h"
+
+#include <linux/device-mapper.h>
+
+#include "permassert.h"
+
+#include "status-codes.h"
+
+/**
+ * vdo_waitq_enqueue_waiter() - Add a waiter to the tail end of a waitq.
+ * @waitq: The vdo_wait_queue to which to add the waiter.
+ * @waiter: The waiter to add to the waitq.
+ *
+ * The waiter must not already be waiting in a waitq.
+ */
+void vdo_waitq_enqueue_waiter(struct vdo_wait_queue *waitq, struct vdo_waiter *waiter)
+{
+	BUG_ON(waiter->next_waiter != NULL);
+
+	if (waitq->last_waiter == NULL) {
+		/*
+		 * The waitq is empty, so form the initial circular list by self-linking the
+		 * initial waiter.
+		 */
+		waiter->next_waiter = waiter;
+	} else {
+		/* Splice the new waiter in at the end of the waitq. */
+		waiter->next_waiter = waitq->last_waiter->next_waiter;
+		waitq->last_waiter->next_waiter = waiter;
+	}
+
+	/* In both cases, the waiter we added to the list becomes the last waiter. */
+	waitq->last_waiter = waiter;
+	waitq->length += 1;
+}
+
+/**
+ * vdo_waitq_transfer_all_waiters() - Transfer all waiters from one waitq to
+ *                                    a second waitq, emptying the first waitq.
+ * @from_waitq: The waitq containing the waiters to move.
+ * @to_waitq: The waitq that will receive the waiters from the first waitq.
+ */
+void vdo_waitq_transfer_all_waiters(struct vdo_wait_queue *from_waitq,
+				    struct vdo_wait_queue *to_waitq)
+{
+	/* If the source waitq is empty, there's nothing to do. */
+	if (!vdo_waitq_has_waiters(from_waitq))
+		return;
+
+	if (vdo_waitq_has_waiters(to_waitq)) {
+		/*
+		 * Both are non-empty. Splice the two circular lists together
+		 * by swapping the next (head) pointers in the list tails.
+		 */
+		struct vdo_waiter *from_head = from_waitq->last_waiter->next_waiter;
+		struct vdo_waiter *to_head = to_waitq->last_waiter->next_waiter;
+
+		to_waitq->last_waiter->next_waiter = from_head;
+		from_waitq->last_waiter->next_waiter = to_head;
+	}
+
+	to_waitq->last_waiter = from_waitq->last_waiter;
+	to_waitq->length += from_waitq->length;
+	vdo_waitq_init(from_waitq);
+}
+
+/**
+ * vdo_waitq_notify_all_waiters() - Notify all the entries waiting in a waitq.
+ * @waitq: The vdo_wait_queue containing the waiters to notify.
+ * @callback: The function to call to notify each waiter, or NULL to invoke the callback field
+ *            registered in each waiter.
+ * @context: The context to pass to the callback function.
+ *
+ * Notifies all the entries waiting in a waitq to continue execution by invoking a callback
+ * function on each of them in turn. The waitq is copied and emptied before invoking any callbacks,
+ * and only the waiters that were in the waitq at the start of the call will be notified.
+ */
+void vdo_waitq_notify_all_waiters(struct vdo_wait_queue *waitq,
+				  vdo_waiter_callback_fn callback, void *context)
+{
+	/*
+	 * Copy and empty the waitq first, avoiding the possibility of an infinite
+	 * loop if entries are returned to the waitq by the callback function.
+	 */
+	struct vdo_wait_queue waiters;
+
+	vdo_waitq_init(&waiters);
+	vdo_waitq_transfer_all_waiters(waitq, &waiters);
+
+	/* Drain the copied waitq, invoking the callback on every entry. */
+	while (vdo_waitq_has_waiters(&waiters))
+		vdo_waitq_notify_next_waiter(&waiters, callback, context);
+}
+
+/**
+ * vdo_waitq_get_first_waiter() - Return the waiter that is at the head end of a waitq.
+ * @waitq: The vdo_wait_queue from which to get the first waiter.
+ *
+ * Return: The first (oldest) waiter in the waitq, or NULL if the waitq is empty.
+ */
+struct vdo_waiter *vdo_waitq_get_first_waiter(const struct vdo_wait_queue *waitq)
+{
+	struct vdo_waiter *last_waiter = waitq->last_waiter;
+
+	if (last_waiter == NULL) {
+		/* There are no waiters, so we're done. */
+		return NULL;
+	}
+
+	/* The waitq is circular, so the last entry links to the head of the waitq. */
+	return last_waiter->next_waiter;
+}
+
+/**
+ * vdo_waitq_dequeue_matching_waiters() - Remove all waiters that match based on the specified
+ *                                        matching method and append them to a vdo_wait_queue.
+ * @waitq: The vdo_wait_queue to process.
+ * @waiter_match: The method to determine matching.
+ * @match_context: Contextual info for the match method.
+ * @matched_waitq: A wait_waitq to store matches.
+ */
+void vdo_waitq_dequeue_matching_waiters(struct vdo_wait_queue *waitq,
+					vdo_waiter_match_fn waiter_match,
+					void *match_context,
+					struct vdo_wait_queue *matched_waitq)
+{
+	struct vdo_wait_queue iteration_waitq;
+
+	vdo_waitq_init(&iteration_waitq);
+	vdo_waitq_transfer_all_waiters(waitq, &iteration_waitq);
+
+	while (vdo_waitq_has_waiters(&iteration_waitq)) {
+		struct vdo_waiter *waiter = vdo_waitq_dequeue_waiter(&iteration_waitq);
+
+		vdo_waitq_enqueue_waiter((waiter_match(waiter, match_context) ?
+					  matched_waitq : waitq), waiter);
+	}
+}
+
+/**
+ * vdo_waitq_dequeue_waiter() - Remove the first (oldest) waiter from a waitq.
+ * @waitq: The vdo_wait_queue from which to remove the first entry.
+ *
+ * The caller will be responsible for waking the waiter by continuing its
+ * execution appropriately.
+ *
+ * Return: The first (oldest) waiter in the waitq, or NULL if the waitq is empty.
+ */
+struct vdo_waiter *vdo_waitq_dequeue_waiter(struct vdo_wait_queue *waitq)
+{
+	struct vdo_waiter *first_waiter = vdo_waitq_get_first_waiter(waitq);
+	struct vdo_waiter *last_waiter = waitq->last_waiter;
+
+	if (first_waiter == NULL)
+		return NULL;
+
+	if (first_waiter == last_waiter) {
+		/* The waitq has a single entry, so empty it by nulling the tail. */
+		waitq->last_waiter = NULL;
+	} else {
+		/*
+		 * The waitq has multiple waiters, so splice the first waiter out
+		 * of the circular waitq.
+		 */
+		last_waiter->next_waiter = first_waiter->next_waiter;
+	}
+
+	/* The waiter is no longer in a waitq. */
+	first_waiter->next_waiter = NULL;
+	waitq->length -= 1;
+
+	return first_waiter;
+}
+
+/**
+ * vdo_waitq_notify_next_waiter() - Notify the next entry waiting in a waitq.
+ * @waitq: The vdo_wait_queue containing the waiter to notify.
+ * @callback: The function to call to notify the waiter, or NULL to invoke the callback field
+ *            registered in the waiter.
+ * @context: The context to pass to the callback function.
+ *
+ * Notifies the next entry waiting in a waitq to continue execution by invoking a callback function
+ * on it after removing it from the waitq.
+ *
+ * Return: true if there was a waiter in the waitq.
+ */
+bool vdo_waitq_notify_next_waiter(struct vdo_wait_queue *waitq,
+				  vdo_waiter_callback_fn callback, void *context)
+{
+	struct vdo_waiter *waiter = vdo_waitq_dequeue_waiter(waitq);
+
+	if (waiter == NULL)
+		return false;
+
+	if (callback == NULL)
+		callback = waiter->callback;
+	callback(waiter, context);
+
+	return true;
+}