/* * Shared Memory Communications over RDMA (SMC-R) and RoCE * * Manage RMBE * copy new RMBE data into user space * * Copyright IBM Corp. 2016 * * Author(s): Ursula Braun */ #include #include #include #include "smc.h" #include "smc_core.h" #include "smc_cdc.h" #include "smc_tx.h" /* smc_tx_consumer_update() */ #include "smc_rx.h" /* callback implementation for sk.sk_data_ready() * to wakeup rcvbuf consumers that blocked with smc_rx_wait_data(). * indirectly called by smc_cdc_msg_recv_action(). */ static void smc_rx_data_ready(struct sock *sk) { struct socket_wq *wq; /* derived from sock_def_readable() */ /* called already in smc_listen_work() */ rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); if (skwq_has_sleeper(wq)) wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND); if ((sk->sk_shutdown == SHUTDOWN_MASK) || (sk->sk_state == SMC_CLOSED)) sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); else sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); rcu_read_unlock(); } /* blocks rcvbuf consumer until >=len bytes available or timeout or interrupted * @smc smc socket * @timeo pointer to max seconds to wait, pointer to value 0 for no timeout * Returns: * 1 if at least 1 byte available in rcvbuf or if socket error/shutdown. * 0 otherwise (nothing in rcvbuf nor timeout, e.g. interrupted). */ static int smc_rx_wait_data(struct smc_sock *smc, long *timeo) { DEFINE_WAIT_FUNC(wait, woken_wake_function); struct smc_connection *conn = &smc->conn; struct sock *sk = &smc->sk; int rc; if (atomic_read(&conn->bytes_to_rcv)) return 1; sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); add_wait_queue(sk_sleep(sk), &wait); rc = sk_wait_event(sk, timeo, sk->sk_err || sk->sk_shutdown & RCV_SHUTDOWN || sock_flag(sk, SOCK_DONE) || atomic_read(&conn->bytes_to_rcv) || smc_cdc_rxed_any_close_or_senddone(conn), &wait); remove_wait_queue(sk_sleep(sk), &wait); sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); return rc; } /* rcvbuf consumer: main API called by socket layer. * called under sk lock. */ int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, size_t len, int flags) { size_t copylen, read_done = 0, read_remaining = len; size_t chunk_len, chunk_off, chunk_len_sum; struct smc_connection *conn = &smc->conn; union smc_host_cursor cons; int readable, chunk; char *rcvbuf_base; struct sock *sk; long timeo; int target; /* Read at least these many bytes */ int rc; if (unlikely(flags & MSG_ERRQUEUE)) return -EINVAL; /* future work for sk.sk_family == AF_SMC */ if (flags & MSG_OOB) return -EINVAL; /* future work */ sk = &smc->sk; if (sk->sk_state == SMC_LISTEN) return -ENOTCONN; timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); msg->msg_namelen = 0; /* we currently use 1 RMBE per RMB, so RMBE == RMB base addr */ rcvbuf_base = conn->rmb_desc->cpu_addr; do { /* while (read_remaining) */ if (read_done >= target) break; if (atomic_read(&conn->bytes_to_rcv)) goto copy; if (read_done) { if (sk->sk_err || sk->sk_state == SMC_CLOSED || (sk->sk_shutdown & RCV_SHUTDOWN) || !timeo || signal_pending(current) || smc_cdc_rxed_any_close_or_senddone(conn) || conn->local_tx_ctrl.conn_state_flags. peer_conn_abort) break; } else { if (sock_flag(sk, SOCK_DONE)) break; if (sk->sk_err) { read_done = sock_error(sk); break; } if (sk->sk_shutdown & RCV_SHUTDOWN || smc_cdc_rxed_any_close_or_senddone(conn) || conn->local_tx_ctrl.conn_state_flags. peer_conn_abort) break; if (sk->sk_state == SMC_CLOSED) { if (!sock_flag(sk, SOCK_DONE)) { /* This occurs when user tries to read * from never connected socket. */ read_done = -ENOTCONN; break; } break; } if (signal_pending(current)) { read_done = sock_intr_errno(timeo); break; } } if (!atomic_read(&conn->bytes_to_rcv)) { smc_rx_wait_data(smc, &timeo); continue; } copy: /* initialize variables for 1st iteration of subsequent loop */ /* could be just 1 byte, even after smc_rx_wait_data above */ readable = atomic_read(&conn->bytes_to_rcv); /* not more than what user space asked for */ copylen = min_t(size_t, read_remaining, readable); smc_curs_write(&cons, smc_curs_read(&conn->local_tx_ctrl.cons, conn), conn); /* determine chunks where to read from rcvbuf */ /* either unwrapped case, or 1st chunk of wrapped case */ chunk_len = min_t(size_t, copylen, conn->rmbe_size - cons.count); chunk_len_sum = chunk_len; chunk_off = cons.count; for (chunk = 0; chunk < 2; chunk++) { if (!(flags & MSG_TRUNC)) { rc = memcpy_to_msg(msg, rcvbuf_base + chunk_off, chunk_len); if (rc) { if (!read_done) read_done = -EFAULT; goto out; } } read_remaining -= chunk_len; read_done += chunk_len; if (chunk_len_sum == copylen) break; /* either on 1st or 2nd iteration */ /* prepare next (== 2nd) iteration */ chunk_len = copylen - chunk_len; /* remainder */ chunk_len_sum += chunk_len; chunk_off = 0; /* modulo offset in recv ring buffer */ } /* update cursors */ if (!(flags & MSG_PEEK)) { smc_curs_add(conn->rmbe_size, &cons, copylen); /* increased in recv tasklet smc_cdc_msg_rcv() */ smp_mb__before_atomic(); atomic_sub(copylen, &conn->bytes_to_rcv); /* guarantee 0 <= bytes_to_rcv <= rmbe_size */ smp_mb__after_atomic(); smc_curs_write(&conn->local_tx_ctrl.cons, smc_curs_read(&cons, conn), conn); /* send consumer cursor update if required */ /* similar to advertising new TCP rcv_wnd if required */ smc_tx_consumer_update(conn); } } while (read_remaining); out: return read_done; } /* Initialize receive properties on connection establishment. NB: not __init! */ void smc_rx_init(struct smc_sock *smc) { smc->sk.sk_data_ready = smc_rx_data_ready; } cfc718d13a50fbc746ed9b415c25e92&id2=bf29bddf0417a4783da3b24e8c9e017ac649326f'>diff)
efi/fdt: Avoid FDT manipulation after ExitBootServices()
Some AArch64 UEFI implementations disable the MMU in ExitBootServices(), after which unaligned accesses to RAM are no longer supported. Commit: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") fixed an issue in the memory map handling of the stub FDT code, but inadvertently created an issue with such firmware, by moving some of the FDT manipulation to after the invocation of ExitBootServices(). Given that the stub's libfdt implementation uses the ordinary, accelerated string functions, which rely on hardware handling of unaligned accesses, manipulating the FDT with the MMU off may result in alignment faults. So fix the situation by moving the update_fdt_memmap() call into the callback function invoked by efi_exit_boot_services() right before it calls the ExitBootServices() UEFI service (which is arguably a better place for it anyway) Note that disabling the MMU in ExitBootServices() is not compliant with the UEFI spec, and carries great risk due to the fact that switching from cached to uncached memory accesses halfway through compiler generated code (i.e., involving a stack) can never be done in a way that is architecturally safe. Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Riku Voipio <riku.voipio@linaro.org> Cc: <stable@vger.kernel.org> Cc: mark.rutland@arm.com Cc: linux-efi@vger.kernel.org Cc: matt@codeblueprint.co.uk Cc: leif.lindholm@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'net/ipx/Kconfig')