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 = kmalloc(sizeof(struct command), GFP_KERNEL); 45 if (cmd == NULL) 46 return NULL; 47 48 memset(cmd, 0, sizeof(*cmd)); 49 50 cmd->buffer = kmalloc(buffer_size, GFP_KERNEL); 51 if (cmd->buffer == NULL) { 52 kfree(cmd); 53 return NULL; 54 } 55 memset(cmd->buffer, 0, buffer_size); 56 cmd->buffer_size = buffer_size; 57 58 kobject_init(&cmd->kobj); 59 cmd->kobj.ktype = &ibmasm_cmd_kobj_type; 60 cmd->lock = &sp->lock; 61 62 cmd->status = IBMASM_CMD_PENDING; 63 init_waitqueue_head(&cmd->wait); 64 INIT_LIST_HEAD(&cmd->queue_node); 65 66 atomic_inc(&command_count); 67 dbg("command count: %d\n", atomic_read(&command_count)); 68 69 return cmd; 70 } 71 72 static void free_command(struct kobject *kobj) 73 { 74 struct command *cmd = to_command(kobj); 75 76 list_del(&cmd->queue_node); 77 atomic_dec(&command_count); 78 dbg("command count: %d\n", atomic_read(&command_count)); 79 kfree(cmd->buffer); 80 kfree(cmd); 81 } 82 83 static void enqueue_command(struct service_processor *sp, struct command *cmd) 84 { 85 list_add_tail(&cmd->queue_node, &sp->command_queue); 86 } 87 88 static struct command *dequeue_command(struct service_processor *sp) 89 { 90 struct command *cmd; 91 struct list_head *next; 92 93 if (list_empty(&sp->command_queue)) 94 return NULL; 95 96 next = sp->command_queue.next; 97 list_del_init(next); 98 cmd = list_entry(next, struct command, queue_node); 99 100 return cmd; 101 } 102 103 static inline void do_exec_command(struct service_processor *sp) 104 { 105 char tsbuf[32]; 106 107 dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf)); 108 109 if (ibmasm_send_i2o_message(sp)) { 110 sp->current_command->status = IBMASM_CMD_FAILED; 111 wake_up(&sp->current_command->wait); 112 command_put(sp->current_command); 113 exec_next_command(sp); 114 } 115 } 116 117 /** 118 * exec_command 119 * send a command to a service processor 120 * Commands are executed sequentially. One command (sp->current_command) 121 * is sent to the service processor. Once the interrupt handler gets a 122 * message of type command_response, the message is copied into 123 * the current commands buffer, 124 */ 125 void ibmasm_exec_command(struct service_processor *sp, struct command *cmd) 126 { 127 unsigned long flags; 128 char tsbuf[32]; 129 130 dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf)); 131 132 spin_lock_irqsave(&sp->lock, flags); 133 134 if (!sp->current_command) { 135 sp->current_command = cmd; 136 command_get(sp->current_command); 137 spin_unlock_irqrestore(&sp->lock, flags); 138 do_exec_command(sp); 139 } else { 140 enqueue_command(sp, cmd); 141 spin_unlock_irqrestore(&sp->lock, flags); 142 } 143 } 144 145 static void exec_next_command(struct service_processor *sp) 146 { 147 unsigned long flags; 148 char tsbuf[32]; 149 150 dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf)); 151 152 spin_lock_irqsave(&sp->lock, flags); 153 sp->current_command = dequeue_command(sp); 154 if (sp->current_command) { 155 command_get(sp->current_command); 156 spin_unlock_irqrestore(&sp->lock, flags); 157 do_exec_command(sp); 158 } else { 159 spin_unlock_irqrestore(&sp->lock, flags); 160 } 161 } 162 163 /** 164 * Sleep until a command has failed or a response has been received 165 * and the command status been updated by the interrupt handler. 166 * (see receive_response). 167 */ 168 void ibmasm_wait_for_response(struct command *cmd, int timeout) 169 { 170 wait_event_interruptible_timeout(cmd->wait, 171 cmd->status == IBMASM_CMD_COMPLETE || 172 cmd->status == IBMASM_CMD_FAILED, 173 timeout * HZ); 174 } 175 176 /** 177 * receive_command_response 178 * called by the interrupt handler when a dot command of type command_response 179 * was received. 180 */ 181 void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size) 182 { 183 struct command *cmd = sp->current_command; 184 185 if (!sp->current_command) 186 return; 187 188 memcpy_fromio(cmd->buffer, response, min(size, cmd->buffer_size)); 189 cmd->status = IBMASM_CMD_COMPLETE; 190 wake_up(&sp->current_command->wait); 191 command_put(sp->current_command); 192 exec_next_command(sp); 193 } 194