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, 340 insertions, 0 deletions

diff --git a/fs/afs/vl_alias.c b/fs/afs/vl_alias.c
new file mode 100644
index 000000000..fc9676abd
--- /dev/null
+++ b/fs/afs/vl_alias.c
@@ -0,0 +1,340 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* AFS cell alias detection
+ *
+ * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/namei.h>
+#include <keys/rxrpc-type.h>
+#include "internal.h"
+
+/*
+ * Sample a volume.
+ */
+static struct afs_volume *afs_sample_volume(struct afs_cell *cell, struct key *key,
+					    const char *name, unsigned int namelen)
+{
+	struct afs_volume *volume;
+	struct afs_fs_context fc = {
+		.type		= 0, /* Explicitly leave it to the VLDB */
+		.volnamesz	= namelen,
+		.volname	= name,
+		.net		= cell->net,
+		.cell		= cell,
+		.key		= key, /* This might need to be something */
+	};
+
+	volume = afs_create_volume(&fc);
+	_leave(" = %p", volume);
+	return volume;
+}
+
+/*
+ * Compare the address lists of a pair of fileservers.
+ */
+static int afs_compare_fs_alists(const struct afs_server *server_a,
+				 const struct afs_server *server_b)
+{
+	const struct afs_addr_list *la, *lb;
+	int a = 0, b = 0, addr_matches = 0;
+
+	la = rcu_dereference(server_a->endpoint_state)->addresses;
+	lb = rcu_dereference(server_b->endpoint_state)->addresses;
+
+	while (a < la->nr_addrs && b < lb->nr_addrs) {
+		unsigned long pa = (unsigned long)la->addrs[a].peer;
+		unsigned long pb = (unsigned long)lb->addrs[b].peer;
+		long diff = pa - pb;
+
+		if (diff < 0) {
+			a++;
+		} else if (diff > 0) {
+			b++;
+		} else {
+			addr_matches++;
+			a++;
+			b++;
+		}
+	}
+
+	return addr_matches;
+}
+
+/*
+ * Compare the fileserver lists of two volumes.  The server lists are sorted in
+ * order of ascending UUID.
+ */
+static int afs_compare_volume_slists(const struct afs_volume *vol_a,
+				     const struct afs_volume *vol_b)
+{
+	const struct afs_server_list *la, *lb;
+	int i, a = 0, b = 0, uuid_matches = 0, addr_matches = 0;
+
+	la = rcu_dereference(vol_a->servers);
+	lb = rcu_dereference(vol_b->servers);
+
+	for (i = 0; i < AFS_MAXTYPES; i++)
+		if (vol_a->vids[i] != vol_b->vids[i])
+			return 0;
+
+	while (a < la->nr_servers && b < lb->nr_servers) {
+		const struct afs_server *server_a = la->servers[a].server;
+		const struct afs_server *server_b = lb->servers[b].server;
+		int diff = memcmp(&server_a->uuid, &server_b->uuid, sizeof(uuid_t));
+
+		if (diff < 0) {
+			a++;
+		} else if (diff > 0) {
+			b++;
+		} else {
+			uuid_matches++;
+			addr_matches += afs_compare_fs_alists(server_a, server_b);
+			a++;
+			b++;
+		}
+	}
+
+	_leave(" = %d [um %d]", addr_matches, uuid_matches);
+	return addr_matches;
+}
+
+/*
+ * Compare root.cell volumes.
+ */
+static int afs_compare_cell_roots(struct afs_cell *cell)
+{
+	struct afs_cell *p;
+
+	_enter("");
+
+	rcu_read_lock();
+
+	hlist_for_each_entry_rcu(p, &cell->net->proc_cells, proc_link) {
+		if (p == cell || p->alias_of)
+			continue;
+		if (!p->root_volume)
+			continue; /* Ignore cells that don't have a root.cell volume. */
+
+		if (afs_compare_volume_slists(cell->root_volume, p->root_volume) != 0)
+			goto is_alias;
+	}
+
+	rcu_read_unlock();
+	_leave(" = 0");
+	return 0;
+
+is_alias:
+	rcu_read_unlock();
+	cell->alias_of = afs_use_cell(p, afs_cell_trace_use_alias);
+	return 1;
+}
+
+/*
+ * Query the new cell for a volume from a cell we're already using.
+ */
+static int afs_query_for_alias_one(struct afs_cell *cell, struct key *key,
+				   struct afs_cell *p)
+{
+	struct afs_volume *volume, *pvol = NULL;
+	int ret;
+
+	/* Arbitrarily pick a volume from the list. */
+	read_seqlock_excl(&p->volume_lock);
+	if (!RB_EMPTY_ROOT(&p->volumes))
+		pvol = afs_get_volume(rb_entry(p->volumes.rb_node,
+					       struct afs_volume, cell_node),
+				      afs_volume_trace_get_query_alias);
+	read_sequnlock_excl(&p->volume_lock);
+	if (!pvol)
+		return 0;
+
+	_enter("%s:%s", cell->name, pvol->name);
+
+	/* And see if it's in the new cell. */
+	volume = afs_sample_volume(cell, key, pvol->name, pvol->name_len);
+	if (IS_ERR(volume)) {
+		afs_put_volume(pvol, afs_volume_trace_put_query_alias);
+		if (PTR_ERR(volume) != -ENOMEDIUM)
+			return PTR_ERR(volume);
+		/* That volume is not in the new cell, so not an alias */
+		return 0;
+	}
+
+	/* The new cell has a like-named volume also - compare volume ID,
+	 * server and address lists.
+	 */
+	ret = 0;
+	if (pvol->vid == volume->vid) {
+		rcu_read_lock();
+		if (afs_compare_volume_slists(volume, pvol))
+			ret = 1;
+		rcu_read_unlock();
+	}
+
+	afs_put_volume(volume, afs_volume_trace_put_query_alias);
+	afs_put_volume(pvol, afs_volume_trace_put_query_alias);
+	return ret;
+}
+
+/*
+ * Query the new cell for volumes we know exist in cells we're already using.
+ */
+static int afs_query_for_alias(struct afs_cell *cell, struct key *key)
+{
+	struct afs_cell *p;
+
+	_enter("%s", cell->name);
+
+	if (mutex_lock_interruptible(&cell->net->proc_cells_lock) < 0)
+		return -ERESTARTSYS;
+
+	hlist_for_each_entry(p, &cell->net->proc_cells, proc_link) {
+		if (p == cell || p->alias_of)
+			continue;
+		if (RB_EMPTY_ROOT(&p->volumes))
+			continue;
+		if (p->root_volume)
+			continue; /* Ignore cells that have a root.cell volume. */
+		afs_use_cell(p, afs_cell_trace_use_check_alias);
+		mutex_unlock(&cell->net->proc_cells_lock);
+
+		if (afs_query_for_alias_one(cell, key, p) != 0)
+			goto is_alias;
+
+		if (mutex_lock_interruptible(&cell->net->proc_cells_lock) < 0) {
+			afs_unuse_cell(p, afs_cell_trace_unuse_check_alias);
+			return -ERESTARTSYS;
+		}
+
+		afs_unuse_cell(p, afs_cell_trace_unuse_check_alias);
+	}
+
+	mutex_unlock(&cell->net->proc_cells_lock);
+	_leave(" = 0");
+	return 0;
+
+is_alias:
+	cell->alias_of = p; /* Transfer our ref */
+	return 1;
+}
+
+/*
+ * Look up a VLDB record for a volume.
+ */
+static char *afs_vl_get_cell_name(struct afs_cell *cell, struct key *key)
+{
+	struct afs_vl_cursor vc;
+	char *cell_name = ERR_PTR(-EDESTADDRREQ);
+	bool skipped = false, not_skipped = false;
+	int ret;
+
+	if (!afs_begin_vlserver_operation(&vc, cell, key))
+		return ERR_PTR(-ERESTARTSYS);
+
+	while (afs_select_vlserver(&vc)) {
+		if (!test_bit(AFS_VLSERVER_FL_IS_YFS, &vc.server->flags)) {
+			vc.call_error = -EOPNOTSUPP;
+			skipped = true;
+			continue;
+		}
+		not_skipped = true;
+		cell_name = afs_yfsvl_get_cell_name(&vc);
+	}
+
+	ret = afs_end_vlserver_operation(&vc);
+	if (skipped && !not_skipped)
+		ret = -EOPNOTSUPP;
+	return ret < 0 ? ERR_PTR(ret) : cell_name;
+}
+
+static int yfs_check_canonical_cell_name(struct afs_cell *cell, struct key *key)
+{
+	struct afs_cell *master;
+	size_t name_len;
+	char *cell_name;
+
+	cell_name = afs_vl_get_cell_name(cell, key);
+	if (IS_ERR(cell_name))
+		return PTR_ERR(cell_name);
+
+	if (strcmp(cell_name, cell->name) == 0) {
+		kfree(cell_name);
+		return 0;
+	}
+
+	name_len = strlen(cell_name);
+	if (!name_len || name_len > AFS_MAXCELLNAME)
+		master = ERR_PTR(-EOPNOTSUPP);
+	else
+		master = afs_lookup_cell(cell->net, cell_name, name_len, NULL,
+					 AFS_LOOKUP_CELL_ALIAS_CHECK,
+					 afs_cell_trace_use_lookup_canonical);
+	kfree(cell_name);
+	if (IS_ERR(master))
+		return PTR_ERR(master);
+
+	cell->alias_of = master; /* Transfer our ref */
+	return 1;
+}
+
+static int afs_do_cell_detect_alias(struct afs_cell *cell, struct key *key)
+{
+	struct afs_volume *root_volume;
+	int ret;
+
+	_enter("%s", cell->name);
+
+	ret = yfs_check_canonical_cell_name(cell, key);
+	if (ret != -EOPNOTSUPP)
+		return ret;
+
+	/* Try and get the root.cell volume for comparison with other cells */
+	root_volume = afs_sample_volume(cell, key, "root.cell", 9);
+	if (!IS_ERR(root_volume)) {
+		cell->root_volume = root_volume;
+		return afs_compare_cell_roots(cell);
+	}
+
+	if (PTR_ERR(root_volume) != -ENOMEDIUM)
+		return PTR_ERR(root_volume);
+
+	/* Okay, this cell doesn't have an root.cell volume.  We need to
+	 * locate some other random volume and use that to check.
+	 */
+	return afs_query_for_alias(cell, key);
+}
+
+/*
+ * Check to see if a new cell is an alias of a cell we already have.  At this
+ * point we have the cell's volume server list.
+ *
+ * Returns 0 if we didn't detect an alias, 1 if we found an alias and an error
+ * if we had problems gathering the data required.  In the case the we did
+ * detect an alias, cell->alias_of is set to point to the assumed master.
+ */
+int afs_cell_detect_alias(struct afs_cell *cell, struct key *key)
+{
+	struct afs_net *net = cell->net;
+	int ret;
+
+	if (mutex_lock_interruptible(&net->cells_alias_lock) < 0)
+		return -ERESTARTSYS;
+
+	if (test_bit(AFS_CELL_FL_CHECK_ALIAS, &cell->flags)) {
+		ret = afs_do_cell_detect_alias(cell, key);
+		if (ret >= 0)
+			clear_bit_unlock(AFS_CELL_FL_CHECK_ALIAS, &cell->flags);
+	} else {
+		ret = cell->alias_of ? 1 : 0;
+	}
+
+	mutex_unlock(&net->cells_alias_lock);
+
+	if (ret == 1)
+		pr_notice("kAFS: Cell %s is an alias of %s\n",
+			  cell->name, cell->alias_of->name);
+	return ret;
+}