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, 166 insertions, 0 deletions

diff --git a/fs/btrfs/lru_cache.c b/fs/btrfs/lru_cache.c
new file mode 100644
index 000000000..f5a053b90
--- /dev/null
+++ b/fs/btrfs/lru_cache.c
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/mm.h>
+#include "lru_cache.h"
+#include "messages.h"
+
+/*
+ * Initialize a cache object.
+ *
+ * @cache:      The cache.
+ * @max_size:   Maximum size (number of entries) for the cache.
+ *              Use 0 for unlimited size, it's the user's responsibility to
+ *              trim the cache in that case.
+ */
+void btrfs_lru_cache_init(struct btrfs_lru_cache *cache, unsigned int max_size)
+{
+	INIT_LIST_HEAD(&cache->lru_list);
+	mt_init(&cache->entries);
+	cache->size = 0;
+	cache->max_size = max_size;
+}
+
+static struct btrfs_lru_cache_entry *match_entry(struct list_head *head, u64 key,
+						 u64 gen)
+{
+	struct btrfs_lru_cache_entry *entry;
+
+	list_for_each_entry(entry, head, list) {
+		if (entry->key == key && entry->gen == gen)
+			return entry;
+	}
+
+	return NULL;
+}
+
+/*
+ * Lookup for an entry in the cache.
+ *
+ * @cache:      The cache.
+ * @key:        The key of the entry we are looking for.
+ * @gen:        Generation associated to the key.
+ *
+ * Returns the entry associated with the key or NULL if none found.
+ */
+struct btrfs_lru_cache_entry *btrfs_lru_cache_lookup(struct btrfs_lru_cache *cache,
+						     u64 key, u64 gen)
+{
+	struct list_head *head;
+	struct btrfs_lru_cache_entry *entry;
+
+	head = mtree_load(&cache->entries, key);
+	if (!head)
+		return NULL;
+
+	entry = match_entry(head, key, gen);
+	if (entry)
+		list_move_tail(&entry->lru_list, &cache->lru_list);
+
+	return entry;
+}
+
+/*
+ * Remove an entry from the cache.
+ *
+ * @cache:     The cache to remove from.
+ * @entry:     The entry to remove from the cache.
+ *
+ * Note: this also frees the memory used by the entry.
+ */
+void btrfs_lru_cache_remove(struct btrfs_lru_cache *cache,
+			    struct btrfs_lru_cache_entry *entry)
+{
+	struct list_head *prev = entry->list.prev;
+
+	ASSERT(cache->size > 0);
+	ASSERT(!mtree_empty(&cache->entries));
+
+	list_del(&entry->list);
+	list_del(&entry->lru_list);
+
+	if (list_empty(prev)) {
+		struct list_head *head;
+
+		/*
+		 * If previous element in the list entry->list is now empty, it
+		 * means it's a head entry not pointing to any cached entries,
+		 * so remove it from the maple tree and free it.
+		 */
+		head = mtree_erase(&cache->entries, entry->key);
+		ASSERT(head == prev);
+		kfree(head);
+	}
+
+	kfree(entry);
+	cache->size--;
+}
+
+/*
+ * Store an entry in the cache.
+ *
+ * @cache:      The cache.
+ * @entry:      The entry to store.
+ *
+ * Returns 0 on success and < 0 on error.
+ */
+int btrfs_lru_cache_store(struct btrfs_lru_cache *cache,
+			  struct btrfs_lru_cache_entry *new_entry,
+			  gfp_t gfp)
+{
+	const u64 key = new_entry->key;
+	struct list_head *head;
+	int ret;
+
+	head = kmalloc_obj(*head, gfp);
+	if (!head)
+		return -ENOMEM;
+
+	ret = mtree_insert(&cache->entries, key, head, gfp);
+	if (ret == 0) {
+		INIT_LIST_HEAD(head);
+		list_add_tail(&new_entry->list, head);
+	} else if (ret == -EEXIST) {
+		kfree(head);
+		head = mtree_load(&cache->entries, key);
+		ASSERT(head != NULL);
+		if (match_entry(head, key, new_entry->gen) != NULL)
+			return -EEXIST;
+		list_add_tail(&new_entry->list, head);
+	} else if (ret < 0) {
+		kfree(head);
+		return ret;
+	}
+
+	if (cache->max_size > 0 && cache->size == cache->max_size) {
+		struct btrfs_lru_cache_entry *lru_entry;
+
+		lru_entry = list_first_entry(&cache->lru_list,
+					     struct btrfs_lru_cache_entry,
+					     lru_list);
+		btrfs_lru_cache_remove(cache, lru_entry);
+	}
+
+	list_add_tail(&new_entry->lru_list, &cache->lru_list);
+	cache->size++;
+
+	return 0;
+}
+
+/*
+ * Empty a cache.
+ *
+ * @cache:     The cache to empty.
+ *
+ * Removes all entries from the cache.
+ */
+void btrfs_lru_cache_clear(struct btrfs_lru_cache *cache)
+{
+	struct btrfs_lru_cache_entry *entry;
+	struct btrfs_lru_cache_entry *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &cache->lru_list, lru_list)
+		btrfs_lru_cache_remove(cache, entry);
+
+	ASSERT(cache->size == 0);
+	ASSERT(mtree_empty(&cache->entries));
+}