new file mode 100644
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: BSD-2-Clause
+
+/* This file manages homa_sock and homa_socktab objects. */
+
+#include "homa_impl.h"
+#include "homa_peer.h"
+#include "homa_pool.h"
+
+/**
+ * homa_socktab_init() - Constructor for homa_socktabs.
+ * @socktab: The object to initialize; previous contents are discarded.
+ */
+void homa_socktab_init(struct homa_socktab *socktab)
+{
+ int i;
+
+ spin_lock_init(&socktab->write_lock);
+ for (i = 0; i < HOMA_SOCKTAB_BUCKETS; i++)
+ INIT_HLIST_HEAD(&socktab->buckets[i]);
+ INIT_LIST_HEAD(&socktab->active_scans);
+}
+
+/**
+ * homa_socktab_destroy() - Destructor for homa_socktabs.
+ * @socktab: The object to destroy.
+ */
+void homa_socktab_destroy(struct homa_socktab *socktab)
+{
+ struct homa_socktab_scan scan;
+ struct homa_sock *hsk;
+
+ for (hsk = homa_socktab_start_scan(socktab, &scan); hsk;
+ hsk = homa_socktab_next(&scan)) {
+ homa_sock_destroy(hsk);
+ }
+ homa_socktab_end_scan(&scan);
+}
+
+/**
+ * homa_socktab_start_scan() - Begin an iteration over all of the sockets
+ * in a socktab.
+ * @socktab: Socktab to scan.
+ * @scan: Will hold the current state of the scan; any existing
+ * contents are discarded.
+ *
+ * Return: The first socket in the table, or NULL if the table is
+ * empty.
+ *
+ * Each call to homa_socktab_next will return the next socket in the table.
+ * All sockets that are present in the table at the time this function is
+ * invoked will eventually be returned, as long as they are not removed
+ * from the table. It is safe to remove sockets from the table and/or
+ * delete them while the scan is in progress. If a socket is removed from
+ * the table during the scan, it may or may not be returned by
+ * homa_socktab_next. New entries added during the scan may or may not be
+ * returned. The caller must hold an RCU read lock when invoking the
+ * scan-related methods here, as well as when manipulating sockets returned
+ * during the scan. It is safe to release and reacquire the RCU read lock
+ * during a scan, as long as no socket is held when the read lock is
+ * released and homa_socktab_next isn't invoked until the RCU read lock
+ * is reacquired.
+ */
+struct homa_sock *homa_socktab_start_scan(struct homa_socktab *socktab,
+ struct homa_socktab_scan *scan)
+{
+ scan->socktab = socktab;
+ scan->current_bucket = -1;
+ scan->next = NULL;
+
+ spin_lock_bh(&socktab->write_lock);
+ list_add_tail_rcu(&scan->scan_links, &socktab->active_scans);
+ spin_unlock_bh(&socktab->write_lock);
+
+ return homa_socktab_next(scan);
+}
+
+/**
+ * homa_socktab_next() - Return the next socket in an iteration over a socktab.
+ * @scan: State of the scan.
+ *
+ * Return: The next socket in the table, or NULL if the iteration has
+ * returned all of the sockets in the table. Sockets are not
+ * returned in any particular order. It's possible that the
+ * returned socket has been destroyed.
+ */
+struct homa_sock *homa_socktab_next(struct homa_socktab_scan *scan)
+{
+ struct homa_socktab_links *links;
+ struct homa_sock *hsk;
+
+ while (1) {
+ while (!scan->next) {
+ struct hlist_head *bucket;
+
+ scan->current_bucket++;
+ if (scan->current_bucket >= HOMA_SOCKTAB_BUCKETS)
+ return NULL;
+ bucket = &scan->socktab->buckets[scan->current_bucket];
+ scan->next = (struct homa_socktab_links *)
+ rcu_dereference(hlist_first_rcu(bucket));
+ }
+ links = scan->next;
+ hsk = links->sock;
+ scan->next = (struct homa_socktab_links *)
+ rcu_dereference(hlist_next_rcu(&links->hash_links));
+ return hsk;
+ }
+}
+
+/**
+ * homa_socktab_end_scan() - Must be invoked on completion of each scan
+ * to clean up state associated with the scan.
+ * @scan: State of the scan.
+ */
+void homa_socktab_end_scan(struct homa_socktab_scan *scan)
+{
+ spin_lock_bh(&scan->socktab->write_lock);
+ list_del(&scan->scan_links);
+ spin_unlock_bh(&scan->socktab->write_lock);
+}
+
+/**
+ * homa_sock_init() - Constructor for homa_sock objects. This function
+ * initializes only the parts of the socket that are owned by Homa.
+ * @hsk: Object to initialize.
+ * @homa: Homa implementation that will manage the socket.
+ *
+ * Return: 0 for success, otherwise a negative errno.
+ */
+int homa_sock_init(struct homa_sock *hsk, struct homa *homa)
+{
+ struct homa_socktab *socktab = homa->port_map;
+ int result = 0;
+ int i;
+
+ spin_lock_bh(&socktab->write_lock);
+ atomic_set(&hsk->protect_count, 0);
+ spin_lock_init(&hsk->lock);
+ hsk->last_locker = "none";
+ atomic_set(&hsk->protect_count, 0);
+ hsk->homa = homa;
+ hsk->ip_header_length = (hsk->inet.sk.sk_family == AF_INET)
+ ? HOMA_IPV4_HEADER_LENGTH : HOMA_IPV6_HEADER_LENGTH;
+ hsk->shutdown = false;
+ while (1) {
+ if (homa->next_client_port < HOMA_MIN_DEFAULT_PORT)
+ homa->next_client_port = HOMA_MIN_DEFAULT_PORT;
+ if (!homa_sock_find(socktab, homa->next_client_port))
+ break;
+ homa->next_client_port++;
+ }
+ hsk->port = homa->next_client_port;
+ hsk->inet.inet_num = hsk->port;
+ hsk->inet.inet_sport = htons(hsk->port);
+ homa->next_client_port++;
+ hsk->socktab_links.sock = hsk;
+ hlist_add_head_rcu(&hsk->socktab_links.hash_links,
+ &socktab->buckets[homa_port_hash(hsk->port)]);
+ INIT_LIST_HEAD(&hsk->active_rpcs);
+ INIT_LIST_HEAD(&hsk->dead_rpcs);
+ hsk->dead_skbs = 0;
+ INIT_LIST_HEAD(&hsk->waiting_for_bufs);
+ INIT_LIST_HEAD(&hsk->ready_requests);
+ INIT_LIST_HEAD(&hsk->ready_responses);
+ INIT_LIST_HEAD(&hsk->request_interests);
+ INIT_LIST_HEAD(&hsk->response_interests);
+ for (i = 0; i < HOMA_CLIENT_RPC_BUCKETS; i++) {
+ struct homa_rpc_bucket *bucket = &hsk->client_rpc_buckets[i];
+
+ spin_lock_init(&bucket->lock);
+ INIT_HLIST_HEAD(&bucket->rpcs);
+ bucket->id = i;
+ }
+ for (i = 0; i < HOMA_SERVER_RPC_BUCKETS; i++) {
+ struct homa_rpc_bucket *bucket = &hsk->server_rpc_buckets[i];
+
+ spin_lock_init(&bucket->lock);
+ INIT_HLIST_HEAD(&bucket->rpcs);
+ bucket->id = i + 1000000;
+ }
+ hsk->buffer_pool = kzalloc(sizeof(*hsk->buffer_pool), GFP_KERNEL);
+ if (!hsk->buffer_pool)
+ result = -ENOMEM;
+ spin_unlock_bh(&socktab->write_lock);
+ return result;
+}
+
+/*
+ * homa_sock_unlink() - Unlinks a socket from its socktab and does
+ * related cleanups. Once this method returns, the socket will not be
+ * discoverable through the socktab.
+ */
+void homa_sock_unlink(struct homa_sock *hsk)
+{
+ struct homa_socktab *socktab = hsk->homa->port_map;
+ struct homa_socktab_scan *scan;
+
+ /* If any scans refer to this socket, advance them to refer to
+ * the next socket instead.
+ */
+ spin_lock_bh(&socktab->write_lock);
+ list_for_each_entry(scan, &socktab->active_scans, scan_links) {
+ if (!scan->next || scan->next->sock != hsk)
+ continue;
+ scan->next = (struct homa_socktab_links *)
+ rcu_dereference(hlist_next_rcu(&scan->next->hash_links));
+ }
+ hlist_del_rcu(&hsk->socktab_links.hash_links);
+ spin_unlock_bh(&socktab->write_lock);
+}
+
+/**
+ * homa_sock_shutdown() - Disable a socket so that it can no longer
+ * be used for either sending or receiving messages. Any system calls
+ * currently waiting to send or receive messages will be aborted.
+ * @hsk: Socket to shut down.
+ */
+void homa_sock_shutdown(struct homa_sock *hsk)
+ __acquires(&hsk->lock)
+ __releases(&hsk->lock)
+{
+ struct homa_interest *interest;
+ struct homa_rpc *rpc;
+
+ homa_sock_lock(hsk, "homa_socket_shutdown");
+ if (hsk->shutdown) {
+ homa_sock_unlock(hsk);
+ return;
+ }
+
+ /* The order of cleanup is very important, because there could be
+ * active operations that hold RPC locks but not the socket lock.
+ * 1. Set @shutdown; this ensures that no new RPCs will be created for
+ * this socket (though some creations might already be in progress).
+ * 2. Remove the socket from its socktab: this ensures that
+ * incoming packets for the socket will be dropped.
+ * 3. Go through all of the RPCs and delete them; this will
+ * synchronize with any operations in progress.
+ * 4. Perform other socket cleanup: at this point we know that
+ * there will be no concurrent activities on individual RPCs.
+ * 5. Don't delete the buffer pool until after all of the RPCs
+ * have been reaped.
+ * See sync.txt for additional information about locking.
+ */
+ hsk->shutdown = true;
+ homa_sock_unlink(hsk);
+ homa_sock_unlock(hsk);
+
+ list_for_each_entry_rcu(rpc, &hsk->active_rpcs, active_links) {
+ homa_rpc_lock(rpc, "homa_sock_shutdown");
+ homa_rpc_free(rpc);
+ homa_rpc_unlock(rpc);
+ }
+
+ homa_sock_lock(hsk, "homa_socket_shutdown #2");
+ list_for_each_entry(interest, &hsk->request_interests, request_links)
+ wake_up_process(interest->thread);
+ list_for_each_entry(interest, &hsk->response_interests, response_links)
+ wake_up_process(interest->thread);
+ homa_sock_unlock(hsk);
+
+ while (!list_empty(&hsk->dead_rpcs))
+ homa_rpc_reap(hsk, 1000);
+
+ if (hsk->buffer_pool) {
+ homa_pool_destroy(hsk->buffer_pool);
+ kfree(hsk->buffer_pool);
+ hsk->buffer_pool = NULL;
+ }
+}
+
+/**
+ * homa_sock_destroy() - Destructor for homa_sock objects. This function
+ * only cleans up the parts of the object that are owned by Homa.
+ * @hsk: Socket to destroy.
+ */
+void homa_sock_destroy(struct homa_sock *hsk)
+{
+ homa_sock_shutdown(hsk);
+ sock_set_flag(&hsk->inet.sk, SOCK_RCU_FREE);
+}
+
+/**
+ * homa_sock_bind() - Associates a server port with a socket; if there
+ * was a previous server port assignment for @hsk, it is abandoned.
+ * @socktab: Hash table in which the binding will be recorded.
+ * @hsk: Homa socket.
+ * @port: Desired server port for @hsk. If 0, then this call
+ * becomes a no-op: the socket will continue to use
+ * its randomly assigned client port.
+ *
+ * Return: 0 for success, otherwise a negative errno.
+ */
+int homa_sock_bind(struct homa_socktab *socktab, struct homa_sock *hsk,
+ __u16 port)
+{
+ struct homa_sock *owner;
+ int result = 0;
+
+ if (port == 0)
+ return result;
+ if (port >= HOMA_MIN_DEFAULT_PORT)
+ return -EINVAL;
+ homa_sock_lock(hsk, "homa_sock_bind");
+ spin_lock_bh(&socktab->write_lock);
+ if (hsk->shutdown) {
+ result = -ESHUTDOWN;
+ goto done;
+ }
+
+ owner = homa_sock_find(socktab, port);
+ if (owner) {
+ if (owner != hsk)
+ result = -EADDRINUSE;
+ goto done;
+ }
+ hlist_del_rcu(&hsk->socktab_links.hash_links);
+ hsk->port = port;
+ hsk->inet.inet_num = port;
+ hsk->inet.inet_sport = htons(hsk->port);
+ hlist_add_head_rcu(&hsk->socktab_links.hash_links,
+ &socktab->buckets[homa_port_hash(port)]);
+done:
+ spin_unlock_bh(&socktab->write_lock);
+ homa_sock_unlock(hsk);
+ return result;
+}
+
+/**
+ * homa_sock_find() - Returns the socket associated with a given port.
+ * @socktab: Hash table in which to perform lookup.
+ * @port: The port of interest.
+ * Return: The socket that owns @port, or NULL if none.
+ *
+ * Note: this function uses RCU list-searching facilities, but it doesn't
+ * call rcu_read_lock. The caller should do that, if the caller cares (this
+ * way, the caller's use of the socket will also be protected).
+ */
+struct homa_sock *homa_sock_find(struct homa_socktab *socktab, __u16 port)
+{
+ struct homa_socktab_links *link;
+ struct homa_sock *result = NULL;
+
+ hlist_for_each_entry_rcu(link, &socktab->buckets[homa_port_hash(port)],
+ hash_links) {
+ struct homa_sock *hsk = link->sock;
+
+ if (hsk->port == port) {
+ result = hsk;
+ break;
+ }
+ }
+ return result;
+}
+
+/**
+ * homa_sock_lock_slow() - This function implements the slow path for
+ * acquiring a socketC lock. It is invoked when a socket lock isn't immediately
+ * available. It waits for the lock, but also records statistics about
+ * the waiting time.
+ * @hsk: socket to lock.
+ */
+void homa_sock_lock_slow(struct homa_sock *hsk)
+ __acquires(&hsk->lock)
+{
+ spin_lock_bh(&hsk->lock);
+}
+
+/**
+ * homa_bucket_lock_slow() - This function implements the slow path for
+ * locking a bucket in one of the hash tables of RPCs. It is invoked when a
+ * lock isn't immediately available. It waits for the lock, but also records
+ * statistics about the waiting time.
+ * @bucket: The hash table bucket to lock.
+ * @id: ID of the particular RPC being locked (multiple RPCs may
+ * share a single bucket lock).
+ */
+void homa_bucket_lock_slow(struct homa_rpc_bucket *bucket, __u64 id)
+ __acquires(&bucket->lock)
+{
+ spin_lock_bh(&bucket->lock);
+}
new file mode 100644
@@ -0,0 +1,406 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/* This file defines structs and other things related to Homa sockets. */
+
+#ifndef _HOMA_SOCK_H
+#define _HOMA_SOCK_H
+
+/* Forward declarations. */
+struct homa;
+struct homa_pool;
+
+void homa_sock_lock_slow(struct homa_sock *hsk);
+
+/**
+ * define HOMA_SOCKTAB_BUCKETS - Number of hash buckets in a homa_socktab.
+ * Must be a power of 2.
+ */
+#define HOMA_SOCKTAB_BUCKETS 1024
+
+/**
+ * struct homa_socktab - A hash table that maps from port numbers (either
+ * client or server) to homa_sock objects.
+ *
+ * This table is managed exclusively by homa_socktab.c, using RCU to
+ * minimize synchronization during lookups.
+ */
+struct homa_socktab {
+ /**
+ * @write_lock: Controls all modifications to this object; not needed
+ * for socket lookups (RCU is used instead). Also used to
+ * synchronize port allocation.
+ */
+ spinlock_t write_lock;
+
+ /**
+ * @buckets: Heads of chains for hash table buckets. Chains
+ * consist of homa_socktab_link objects.
+ */
+ struct hlist_head buckets[HOMA_SOCKTAB_BUCKETS];
+
+ /**
+ * @active_scans: List of homa_socktab_scan structs for all scans
+ * currently underway on this homa_socktab.
+ */
+ struct list_head active_scans;
+};
+
+/**
+ * struct homa_socktab_links - Used to link homa_socks into the hash chains
+ * of a homa_socktab.
+ */
+struct homa_socktab_links {
+ /** @hash_links: links this element into the hash chain. */
+ struct hlist_node hash_links;
+
+ /** @sock: Homa socket structure. */
+ struct homa_sock *sock;
+};
+
+/**
+ * struct homa_socktab_scan - Records the state of an iteration over all
+ * the entries in a homa_socktab, in a way that permits RCU-safe deletion
+ * of entries.
+ */
+struct homa_socktab_scan {
+ /** @socktab: The table that is being scanned. */
+ struct homa_socktab *socktab;
+
+ /**
+ * @current_bucket: the index of the bucket in socktab->buckets
+ * currently being scanned. If >= HOMA_SOCKTAB_BUCKETS, the scan
+ * is complete.
+ */
+ int current_bucket;
+
+ /**
+ * @next: the next socket to return from homa_socktab_next (this
+ * socket has not yet been returned). NULL means there are no
+ * more sockets in the current bucket.
+ */
+ struct homa_socktab_links *next;
+
+ /**
+ * @scan_links: Used to link this scan into @socktab->scans.
+ */
+ struct list_head scan_links;
+};
+
+/**
+ * struct homa_rpc_bucket - One bucket in a hash table of RPCs.
+ */
+
+struct homa_rpc_bucket {
+ /**
+ * @lock: serves as a lock both for this bucket (e.g., when
+ * adding and removing RPCs) and also for all of the RPCs in
+ * the bucket. Must be held whenever manipulating an RPC in
+ * this bucket. This dual purpose permits clean and safe
+ * deletion and garbage collection of RPCs.
+ */
+ spinlock_t lock;
+
+ /** @rpcs: list of RPCs that hash to this bucket. */
+ struct hlist_head rpcs;
+
+ /**
+ * @id: identifier for this bucket, used in error messages etc.
+ * It's the index of the bucket within its hash table bucket
+ * array, with an additional offset to separate server and
+ * client RPCs.
+ */
+ int id;
+};
+
+/**
+ * define HOMA_CLIENT_RPC_BUCKETS - Number of buckets in hash tables for
+ * client RPCs. Must be a power of 2.
+ */
+#define HOMA_CLIENT_RPC_BUCKETS 1024
+
+/**
+ * define HOMA_SERVER_RPC_BUCKETS - Number of buckets in hash tables for
+ * server RPCs. Must be a power of 2.
+ */
+#define HOMA_SERVER_RPC_BUCKETS 1024
+
+/**
+ * struct homa_sock - Information about an open socket.
+ */
+struct homa_sock {
+ /* Info for other network layers. Note: IPv6 info (struct ipv6_pinfo
+ * comes at the very end of the struct, *after* Homa's data, if this
+ * socket uses IPv6).
+ */
+ union {
+ /** @sock: generic socket data; must be the first field. */
+ struct sock sock;
+
+ /**
+ * @inet: generic Internet socket data; must also be the
+ first field (contains sock as its first member).
+ */
+ struct inet_sock inet;
+ };
+
+ /**
+ * @lock: Must be held when modifying fields such as interests
+ * and lists of RPCs. This lock is used in place of sk->sk_lock
+ * because it's used differently (it's always used as a simple
+ * spin lock). See sync.txt for more on Homa's synchronization
+ * strategy.
+ */
+ spinlock_t lock;
+
+ /**
+ * @last_locker: identifies the code that most recently acquired
+ * @lock successfully. Occasionally used for debugging.
+ */
+ char *last_locker;
+
+ /**
+ * @protect_count: counts the number of calls to homa_protect_rpcs
+ * for which there have not yet been calls to homa_unprotect_rpcs.
+ * See sync.txt for more info.
+ */
+ atomic_t protect_count;
+
+ /**
+ * @homa: Overall state about the Homa implementation. NULL
+ * means this socket has been deleted.
+ */
+ struct homa *homa;
+
+ /** @shutdown: True means the socket is no longer usable. */
+ bool shutdown;
+
+ /**
+ * @port: Port number: identifies this socket uniquely among all
+ * those on this node.
+ */
+ __u16 port;
+
+ /**
+ * @ip_header_length: Length of IP headers for this socket (depends
+ * on IPv4 vs. IPv6).
+ */
+ int ip_header_length;
+
+ /**
+ * @socktab_links: Links this socket into the homa_socktab
+ * based on @port.
+ */
+ struct homa_socktab_links socktab_links;
+
+ /**
+ * @active_rpcs: List of all existing RPCs related to this socket,
+ * including both client and server RPCs. This list isn't strictly
+ * needed, since RPCs are already in one of the hash tables below,
+ * but it's more efficient for homa_timer to have this list
+ * (so it doesn't have to scan large numbers of hash buckets).
+ * The list is sorted, with the oldest RPC first. Manipulate with
+ * RCU so timer can access without locking.
+ */
+ struct list_head active_rpcs;
+
+ /**
+ * @dead_rpcs: Contains RPCs for which homa_rpc_free has been
+ * called, but their packet buffers haven't yet been freed.
+ */
+ struct list_head dead_rpcs;
+
+ /** @dead_skbs: Total number of socket buffers in RPCs on dead_rpcs. */
+ int dead_skbs;
+
+ /**
+ * @waiting_for_bufs: Contains RPCs that are blocked because there
+ * wasn't enough space in the buffer pool region for their incoming
+ * messages. Sorted in increasing order of message length.
+ */
+ struct list_head waiting_for_bufs;
+
+ /**
+ * @ready_requests: Contains server RPCs whose request message is
+ * in a state requiring attention from a user process. The head is
+ * oldest, i.e. next to return.
+ */
+ struct list_head ready_requests;
+
+ /**
+ * @ready_responses: Contains client RPCs whose response message is
+ * in a state requiring attention from a user process. The head is
+ * oldest, i.e. next to return.
+ */
+ struct list_head ready_responses;
+
+ /**
+ * @request_interests: List of threads that want to receive incoming
+ * request messages.
+ */
+ struct list_head request_interests;
+
+ /**
+ * @response_interests: List of threads that want to receive incoming
+ * response messages.
+ */
+ struct list_head response_interests;
+
+ /**
+ * @client_rpc_buckets: Hash table for fast lookup of client RPCs.
+ * Modifications are synchronized with bucket locks, not
+ * the socket lock.
+ */
+ struct homa_rpc_bucket client_rpc_buckets[HOMA_CLIENT_RPC_BUCKETS];
+
+ /**
+ * @server_rpc_buckets: Hash table for fast lookup of server RPCs.
+ * Modifications are synchronized with bucket locks, not
+ * the socket lock.
+ */
+ struct homa_rpc_bucket server_rpc_buckets[HOMA_SERVER_RPC_BUCKETS];
+
+ /**
+ * @buffer_pool: used to allocate buffer space for incoming messages.
+ * Storage is dynamically allocated.
+ */
+ struct homa_pool *buffer_pool;
+};
+
+/**
+ * struct homa_v6_sock - For IPv6, additional IPv6-specific information
+ * is present in the socket struct after Homa-specific information.
+ */
+struct homa_v6_sock {
+ /** @homa: All socket info except for IPv6-specific stuff. */
+ struct homa_sock homa;
+
+ /** @inet6: Socket info specific to IPv6. */
+ struct ipv6_pinfo inet6;
+};
+
+void homa_bucket_lock_slow(struct homa_rpc_bucket *bucket,
+ __u64 id);
+int homa_sock_bind(struct homa_socktab *socktab,
+ struct homa_sock *hsk, __u16 port);
+void homa_sock_destroy(struct homa_sock *hsk);
+struct homa_sock *homa_sock_find(struct homa_socktab *socktab, __u16 port);
+int homa_sock_init(struct homa_sock *hsk, struct homa *homa);
+void homa_sock_shutdown(struct homa_sock *hsk);
+void homa_sock_unlink(struct homa_sock *hsk);
+int homa_socket(struct sock *sk);
+void homa_socktab_destroy(struct homa_socktab *socktab);
+void homa_socktab_end_scan(struct homa_socktab_scan *scan);
+void homa_socktab_init(struct homa_socktab *socktab);
+struct homa_sock *homa_socktab_next(struct homa_socktab_scan *scan);
+struct homa_sock *homa_socktab_start_scan(struct homa_socktab *socktab,
+ struct homa_socktab_scan *scan);
+
+/**
+ * homa_sock_lock() - Acquire the lock for a socket. If the socket
+ * isn't immediately available, record stats on the waiting time.
+ * @hsk: Socket to lock.
+ * @locker: Static string identifying where the socket was locked;
+ * used to track down deadlocks.
+ */
+static inline void homa_sock_lock(struct homa_sock *hsk, const char *locker)
+ __acquires(&hsk->lock)
+{
+ if (!spin_trylock_bh(&hsk->lock))
+ homa_sock_lock_slow(hsk);
+}
+
+/**
+ * homa_sock_unlock() - Release the lock for a socket.
+ * @hsk: Socket to lock.
+ */
+static inline void homa_sock_unlock(struct homa_sock *hsk)
+ __releases(&hsk->lock)
+{
+ spin_unlock_bh(&hsk->lock);
+}
+
+/**
+ * homa_port_hash() - Hash function for port numbers.
+ * @port: Port number being looked up.
+ *
+ * Return: The index of the bucket in which this port will be found (if
+ * it exists.
+ */
+static inline int homa_port_hash(__u16 port)
+{
+ /* We can use a really simple hash function here because client
+ * port numbers are allocated sequentially and server port numbers
+ * are unpredictable.
+ */
+ return port & (HOMA_SOCKTAB_BUCKETS - 1);
+}
+
+/**
+ * homa_client_rpc_bucket() - Find the bucket containing a given
+ * client RPC.
+ * @hsk: Socket associated with the RPC.
+ * @id: Id of the desired RPC.
+ *
+ * Return: The bucket in which this RPC will appear, if the RPC exists.
+ */
+static inline struct homa_rpc_bucket *homa_client_rpc_bucket(struct homa_sock *hsk,
+ __u64 id)
+{
+ /* We can use a really simple hash function here because RPC ids
+ * are allocated sequentially.
+ */
+ return &hsk->client_rpc_buckets[(id >> 1)
+ & (HOMA_CLIENT_RPC_BUCKETS - 1)];
+}
+
+/**
+ * homa_server_rpc_bucket() - Find the bucket containing a given
+ * server RPC.
+ * @hsk: Socket associated with the RPC.
+ * @id: Id of the desired RPC.
+ *
+ * Return: The bucket in which this RPC will appear, if the RPC exists.
+ */
+static inline struct homa_rpc_bucket *homa_server_rpc_bucket(struct homa_sock *hsk,
+ __u64 id)
+{
+ /* Each client allocates RPC ids sequentially, so they will
+ * naturally distribute themselves across the hash space.
+ * Thus we can use the id directly as hash.
+ */
+ return &hsk->server_rpc_buckets[(id >> 1)
+ & (HOMA_SERVER_RPC_BUCKETS - 1)];
+}
+
+/**
+ * homa_bucket_lock() - Acquire the lock for an RPC hash table bucket.
+ * @bucket: Bucket to lock
+ * @id: ID of the RPC that is requesting the lock. Normally ignored,
+ * but used occasionally for diagnostics and debugging.
+ * @locker: Static string identifying the locking code. Normally ignored,
+ * but used occasionally for diagnostics and debugging.
+ */
+static inline void homa_bucket_lock(struct homa_rpc_bucket *bucket,
+ __u64 id, const char *locker)
+{
+ if (!spin_trylock_bh(&bucket->lock))
+ homa_bucket_lock_slow(bucket, id);
+}
+
+/**
+ * homa_bucket_unlock() - Release the lock for an RPC hash table bucket.
+ * @bucket: Bucket to unlock.
+ * @id: ID of the RPC that was using the lock.
+ */
+static inline void homa_bucket_unlock(struct homa_rpc_bucket *bucket, __u64 id)
+ __releases(&bucket->lock)
+{
+ spin_unlock_bh(&bucket->lock);
+}
+
+static inline struct homa_sock *homa_sk(const struct sock *sk)
+{
+ return (struct homa_sock *)sk;
+}
+
+#endif /* _HOMA_SOCK_H */
These files provide functions for managing the state that Homa keeps for each open Homa socket. Signed-off-by: John Ousterhout <ouster@cs.stanford.edu> --- net/homa/homa_sock.c | 382 ++++++++++++++++++++++++++++++++++++++++ net/homa/homa_sock.h | 406 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 788 insertions(+) create mode 100644 net/homa/homa_sock.c create mode 100644 net/homa/homa_sock.h