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