1 /*- 2 * Copyright (C) 2019 Justin Hibbits 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 16 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 17 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 18 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 19 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 20 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 21 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 22 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 * 24 * $FreeBSD$ 25 */ 26 27 #include <sys/cdefs.h> 28 #include <sys/param.h> 29 #include <sys/eventhandler.h> 30 #include <sys/malloc.h> 31 #include <sys/proc.h> 32 #include <sys/vmem.h> 33 34 #include <vm/vm.h> 35 #include <vm/pmap.h> 36 #include "opal.h" 37 38 #include <machine/cpufunc.h> 39 40 /* 41 * Manage asynchronous tokens for the OPAL abstraction layer. 42 * 43 * Only a finite number of in-flight tokens are supported by OPAL, so we must be 44 * careful managing this. The basic design uses the vmem subsystem as a general 45 * purpose allocator, with wrappers to manage expected behaviors and 46 * requirements. 47 */ 48 static vmem_t *async_token_pool; 49 50 static void opal_handle_async_completion(void *, struct opal_msg *); 51 52 struct async_completion { 53 volatile uint64_t completed; 54 struct opal_msg msg; 55 }; 56 57 struct async_completion *completions; 58 59 /* Setup the token pool. */ 60 int 61 opal_init_async_tokens(int count) 62 { 63 /* Only allow one initialization */ 64 if (async_token_pool != NULL) 65 return (EINVAL); 66 67 async_token_pool = vmem_create("OPAL Async", 0, count, 1, 1, 68 M_WAITOK | M_FIRSTFIT); 69 completions = malloc(count * sizeof(struct async_completion), 70 M_DEVBUF, M_WAITOK | M_ZERO); 71 72 EVENTHANDLER_REGISTER(OPAL_ASYNC_COMP, opal_handle_async_completion, 73 NULL, EVENTHANDLER_PRI_ANY); 74 75 return (0); 76 } 77 78 int 79 opal_alloc_async_token(void) 80 { 81 vmem_addr_t token; 82 83 vmem_alloc(async_token_pool, 1, M_FIRSTFIT | M_WAITOK, &token); 84 completions[token].completed = false; 85 86 return (token); 87 } 88 89 void 90 opal_free_async_token(int token) 91 { 92 93 vmem_free(async_token_pool, token, 1); 94 } 95 96 /* 97 * Wait for the operation watched by the token to complete. Return the result 98 * of the operation, error if it returns early. 99 */ 100 int 101 opal_wait_completion(void *buf, uint64_t size, int token) 102 { 103 int err; 104 105 do { 106 err = opal_call(OPAL_CHECK_ASYNC_COMPLETION, 107 vtophys(buf), size, token); 108 if (err == OPAL_BUSY) { 109 if (completions[token].completed) { 110 atomic_thread_fence_acq(); 111 memcpy(buf, &completions[token].msg, size); 112 return (OPAL_SUCCESS); 113 } 114 } 115 DELAY(100); 116 } while (err == OPAL_BUSY); 117 118 return (err); 119 } 120 121 static void opal_handle_async_completion(void *arg, struct opal_msg *msg) 122 { 123 int token; 124 125 token = msg->params[0]; 126 memcpy(&completions[token].msg, msg, sizeof(*msg)); 127 atomic_thread_fence_rel(); 128 completions[token].completed = true; 129 } 130