1 2 /* 3 * IBM ASM Service Processor Device Driver 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 18 * 19 * Copyright (C) IBM Corporation, 2004 20 * 21 * Author: Max Asb�ck <amax@us.ibm.com> 22 * 23 */ 24 25 #include <linux/sched.h> 26 #include "ibmasm.h" 27 #include "lowlevel.h" 28 29 static void exec_next_command(struct service_processor *sp); 30 31 static atomic_t command_count = ATOMIC_INIT(0); 32 33 struct command *ibmasm_new_command(struct service_processor *sp, size_t buffer_size) 34 { 35 struct command *cmd; 36 37 if (buffer_size > IBMASM_CMD_MAX_BUFFER_SIZE) 38 return NULL; 39 40 cmd = kzalloc(sizeof(struct command), GFP_KERNEL); 41 if (cmd == NULL) 42 return NULL; 43 44 45 cmd->buffer = kzalloc(buffer_size, GFP_KERNEL); 46 if (cmd->buffer == NULL) { 47 kfree(cmd); 48 return NULL; 49 } 50 cmd->buffer_size = buffer_size; 51 52 kref_init(&cmd->kref); 53 cmd->lock = &sp->lock; 54 55 cmd->status = IBMASM_CMD_PENDING; 56 init_waitqueue_head(&cmd->wait); 57 INIT_LIST_HEAD(&cmd->queue_node); 58 59 atomic_inc(&command_count); 60 dbg("command count: %d\n", atomic_read(&command_count)); 61 62 return cmd; 63 } 64 65 void ibmasm_free_command(struct kref *kref) 66 { 67 struct command *cmd = to_command(kref); 68 69 list_del(&cmd->queue_node); 70 atomic_dec(&command_count); 71 dbg("command count: %d\n", atomic_read(&command_count)); 72 kfree(cmd->buffer); 73 kfree(cmd); 74 } 75 76 static void enqueue_command(struct service_processor *sp, struct command *cmd) 77 { 78 list_add_tail(&cmd->queue_node, &sp->command_queue); 79 } 80 81 static struct command *dequeue_command(struct service_processor *sp) 82 { 83 struct command *cmd; 84 struct list_head *next; 85 86 if (list_empty(&sp->command_queue)) 87 return NULL; 88 89 next = sp->command_queue.next; 90 list_del_init(next); 91 cmd = list_entry(next, struct command, queue_node); 92 93 return cmd; 94 } 95 96 static inline void do_exec_command(struct service_processor *sp) 97 { 98 char tsbuf[32]; 99 100 dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); 101 102 if (ibmasm_send_i2o_message(sp)) { 103 sp->current_command->status = IBMASM_CMD_FAILED; 104 wake_up(&sp->current_command->wait); 105 command_put(sp->current_command); 106 exec_next_command(sp); 107 } 108 } 109 110 /** 111 * exec_command 112 * send a command to a service processor 113 * Commands are executed sequentially. One command (sp->current_command) 114 * is sent to the service processor. Once the interrupt handler gets a 115 * message of type command_response, the message is copied into 116 * the current commands buffer, 117 */ 118 void ibmasm_exec_command(struct service_processor *sp, struct command *cmd) 119 { 120 unsigned long flags; 121 char tsbuf[32]; 122 123 dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); 124 125 spin_lock_irqsave(&sp->lock, flags); 126 127 if (!sp->current_command) { 128 sp->current_command = cmd; 129 command_get(sp->current_command); 130 spin_unlock_irqrestore(&sp->lock, flags); 131 do_exec_command(sp); 132 } else { 133 enqueue_command(sp, cmd); 134 spin_unlock_irqrestore(&sp->lock, flags); 135 } 136 } 137 138 static void exec_next_command(struct service_processor *sp) 139 { 140 unsigned long flags; 141 char tsbuf[32]; 142 143 dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); 144 145 spin_lock_irqsave(&sp->lock, flags); 146 sp->current_command = dequeue_command(sp); 147 if (sp->current_command) { 148 command_get(sp->current_command); 149 spin_unlock_irqrestore(&sp->lock, flags); 150 do_exec_command(sp); 151 } else { 152 spin_unlock_irqrestore(&sp->lock, flags); 153 } 154 } 155 156 /** 157 * Sleep until a command has failed or a response has been received 158 * and the command status been updated by the interrupt handler. 159 * (see receive_response). 160 */ 161 void ibmasm_wait_for_response(struct command *cmd, int timeout) 162 { 163 wait_event_interruptible_timeout(cmd->wait, 164 cmd->status == IBMASM_CMD_COMPLETE || 165 cmd->status == IBMASM_CMD_FAILED, 166 timeout * HZ); 167 } 168 169 /** 170 * receive_command_response 171 * called by the interrupt handler when a dot command of type command_response 172 * was received. 173 */ 174 void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size) 175 { 176 struct command *cmd = sp->current_command; 177 178 if (!sp->current_command) 179 return; 180 181 memcpy_fromio(cmd->buffer, response, min(size, cmd->buffer_size)); 182 cmd->status = IBMASM_CMD_COMPLETE; 183 wake_up(&sp->current_command->wait); 184 command_put(sp->current_command); 185 exec_next_command(sp); 186 } 187