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 "ibmasm.h" 26 #include "lowlevel.h" 27 28 static void exec_next_command(struct service_processor *sp); 29 static void free_command(struct kobject *kobj); 30 31 static struct kobj_type ibmasm_cmd_kobj_type = { 32 .release = free_command, 33 }; 34 35 static atomic_t command_count = ATOMIC_INIT(0); 36 37 struct command *ibmasm_new_command(struct service_processor *sp, size_t buffer_size) 38 { 39 struct command *cmd; 40 41 if (buffer_size > IBMASM_CMD_MAX_BUFFER_SIZE) 42 return NULL; 43 44 cmd = kzalloc(sizeof(struct command), GFP_KERNEL); 45 if (cmd == NULL) 46 return NULL; 47 48 49 cmd->buffer = kzalloc(buffer_size, GFP_KERNEL); 50 if (cmd->buffer == NULL) { 51 kfree(cmd); 52 return NULL; 53 } 54 cmd->buffer_size = buffer_size; 55 56 kobject_init(&cmd->kobj); 57 cmd->kobj.ktype = &ibmasm_cmd_kobj_type; 58 cmd->lock = &sp->lock; 59 60 cmd->status = IBMASM_CMD_PENDING; 61 init_waitqueue_head(&cmd->wait); 62 INIT_LIST_HEAD(&cmd->queue_node); 63 64 atomic_inc(&command_count); 65 dbg("command count: %d\n", atomic_read(&command_count)); 66 67 return cmd; 68 } 69 70 static void free_command(struct kobject *kobj) 71 { 72 struct command *cmd = to_command(kobj); 73 74 list_del(&cmd->queue_node); 75 atomic_dec(&command_count); 76 dbg("command count: %d\n", atomic_read(&command_count)); 77 kfree(cmd->buffer); 78 kfree(cmd); 79 } 80 81 static void enqueue_command(struct service_processor *sp, struct command *cmd) 82 { 83 list_add_tail(&cmd->queue_node, &sp->command_queue); 84 } 85 86 static struct command *dequeue_command(struct service_processor *sp) 87 { 88 struct command *cmd; 89 struct list_head *next; 90 91 if (list_empty(&sp->command_queue)) 92 return NULL; 93 94 next = sp->command_queue.next; 95 list_del_init(next); 96 cmd = list_entry(next, struct command, queue_node); 97 98 return cmd; 99 } 100 101 static inline void do_exec_command(struct service_processor *sp) 102 { 103 char tsbuf[32]; 104 105 dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf)); 106 107 if (ibmasm_send_i2o_message(sp)) { 108 sp->current_command->status = IBMASM_CMD_FAILED; 109 wake_up(&sp->current_command->wait); 110 command_put(sp->current_command); 111 exec_next_command(sp); 112 } 113 } 114 115 /** 116 * exec_command 117 * send a command to a service processor 118 * Commands are executed sequentially. One command (sp->current_command) 119 * is sent to the service processor. Once the interrupt handler gets a 120 * message of type command_response, the message is copied into 121 * the current commands buffer, 122 */ 123 void ibmasm_exec_command(struct service_processor *sp, struct command *cmd) 124 { 125 unsigned long flags; 126 char tsbuf[32]; 127 128 dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf)); 129 130 spin_lock_irqsave(&sp->lock, flags); 131 132 if (!sp->current_command) { 133 sp->current_command = cmd; 134 command_get(sp->current_command); 135 spin_unlock_irqrestore(&sp->lock, flags); 136 do_exec_command(sp); 137 } else { 138 enqueue_command(sp, cmd); 139 spin_unlock_irqrestore(&sp->lock, flags); 140 } 141 } 142 143 static void exec_next_command(struct service_processor *sp) 144 { 145 unsigned long flags; 146 char tsbuf[32]; 147 148 dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf)); 149 150 spin_lock_irqsave(&sp->lock, flags); 151 sp->current_command = dequeue_command(sp); 152 if (sp->current_command) { 153 command_get(sp->current_command); 154 spin_unlock_irqrestore(&sp->lock, flags); 155 do_exec_command(sp); 156 } else { 157 spin_unlock_irqrestore(&sp->lock, flags); 158 } 159 } 160 161 /** 162 * Sleep until a command has failed or a response has been received 163 * and the command status been updated by the interrupt handler. 164 * (see receive_response). 165 */ 166 void ibmasm_wait_for_response(struct command *cmd, int timeout) 167 { 168 wait_event_interruptible_timeout(cmd->wait, 169 cmd->status == IBMASM_CMD_COMPLETE || 170 cmd->status == IBMASM_CMD_FAILED, 171 timeout * HZ); 172 } 173 174 /** 175 * receive_command_response 176 * called by the interrupt handler when a dot command of type command_response 177 * was received. 178 */ 179 void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size) 180 { 181 struct command *cmd = sp->current_command; 182 183 if (!sp->current_command) 184 return; 185 186 memcpy_fromio(cmd->buffer, response, min(size, cmd->buffer_size)); 187 cmd->status = IBMASM_CMD_COMPLETE; 188 wake_up(&sp->current_command->wait); 189 command_put(sp->current_command); 190 exec_next_command(sp); 191 } 192