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 25 #include <sys/cdefs.h> 26 #include <sys/param.h> 27 #include <sys/eventhandler.h> 28 #include <sys/malloc.h> 29 #include <sys/proc.h> 30 #include <sys/vmem.h> 31 32 #include <vm/vm.h> 33 #include <vm/pmap.h> 34 #include "opal.h" 35 36 #include <machine/cpufunc.h> 37 38 /* 39 * Manage asynchronous tokens for the OPAL abstraction layer. 40 * 41 * Only a finite number of in-flight tokens are supported by OPAL, so we must be 42 * careful managing this. The basic design uses the vmem subsystem as a general 43 * purpose allocator, with wrappers to manage expected behaviors and 44 * requirements. 45 */ 46 static vmem_t *async_token_pool; 47 48 static void opal_handle_async_completion(void *, struct opal_msg *); 49 50 struct async_completion { 51 volatile uint64_t completed; 52 struct opal_msg msg; 53 }; 54 55 struct async_completion *completions; 56 57 /* Setup the token pool. */ 58 int 59 opal_init_async_tokens(int count) 60 { 61 /* Only allow one initialization */ 62 if (async_token_pool != NULL) 63 return (EINVAL); 64 65 async_token_pool = vmem_create("OPAL Async", 0, count, 1, 1, 66 M_WAITOK | M_FIRSTFIT); 67 completions = malloc(count * sizeof(struct async_completion), 68 M_DEVBUF, M_WAITOK | M_ZERO); 69 70 EVENTHANDLER_REGISTER(OPAL_ASYNC_COMP, opal_handle_async_completion, 71 NULL, EVENTHANDLER_PRI_ANY); 72 73 return (0); 74 } 75 76 int 77 opal_alloc_async_token(void) 78 { 79 vmem_addr_t token; 80 81 vmem_alloc(async_token_pool, 1, M_FIRSTFIT | M_WAITOK, &token); 82 completions[token].completed = false; 83 84 return (token); 85 } 86 87 void 88 opal_free_async_token(int token) 89 { 90 91 vmem_free(async_token_pool, token, 1); 92 } 93 94 /* 95 * Wait for the operation watched by the token to complete. Return the result 96 * of the operation, error if it returns early. 97 */ 98 int 99 opal_wait_completion(void *buf, uint64_t size, int token) 100 { 101 int err; 102 103 do { 104 err = opal_call(OPAL_CHECK_ASYNC_COMPLETION, 105 vtophys(buf), size, token); 106 if (err == OPAL_BUSY) { 107 if (completions[token].completed) { 108 atomic_thread_fence_acq(); 109 memcpy(buf, &completions[token].msg, size); 110 return (OPAL_SUCCESS); 111 } 112 } 113 DELAY(100); 114 } while (err == OPAL_BUSY); 115 116 return (err); 117 } 118 119 static void opal_handle_async_completion(void *arg, struct opal_msg *msg) 120 { 121 int token; 122 123 token = msg->params[0]; 124 memcpy(&completions[token].msg, msg, sizeof(*msg)); 125 atomic_thread_fence_rel(); 126 completions[token].completed = true; 127 } 128