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1// SPDX-License-Identifier: GPL-2.0-or-later2 3/*4 * IBM ASM Service Processor Device Driver5 *6 * Copyright (C) IBM Corporation, 20047 *8 * Author: Max Asböck <amax@us.ibm.com>9 */10 11#include <linux/sched.h>12#include <linux/slab.h>13#include "ibmasm.h"14#include "lowlevel.h"15 16static void exec_next_command(struct service_processor *sp);17 18static atomic_t command_count = ATOMIC_INIT(0);19 20struct command *ibmasm_new_command(struct service_processor *sp, size_t buffer_size)21{22 struct command *cmd;23 24 if (buffer_size > IBMASM_CMD_MAX_BUFFER_SIZE)25 return NULL;26 27 cmd = kzalloc(sizeof(struct command), GFP_KERNEL);28 if (cmd == NULL)29 return NULL;30 31 32 cmd->buffer = kzalloc(buffer_size, GFP_KERNEL);33 if (cmd->buffer == NULL) {34 kfree(cmd);35 return NULL;36 }37 cmd->buffer_size = buffer_size;38 39 kref_init(&cmd->kref);40 cmd->lock = &sp->lock;41 42 cmd->status = IBMASM_CMD_PENDING;43 init_waitqueue_head(&cmd->wait);44 INIT_LIST_HEAD(&cmd->queue_node);45 46 atomic_inc(&command_count);47 dbg("command count: %d\n", atomic_read(&command_count));48 49 return cmd;50}51 52void ibmasm_free_command(struct kref *kref)53{54 struct command *cmd = to_command(kref);55 56 list_del(&cmd->queue_node);57 atomic_dec(&command_count);58 dbg("command count: %d\n", atomic_read(&command_count));59 kfree(cmd->buffer);60 kfree(cmd);61}62 63static void enqueue_command(struct service_processor *sp, struct command *cmd)64{65 list_add_tail(&cmd->queue_node, &sp->command_queue);66}67 68static struct command *dequeue_command(struct service_processor *sp)69{70 struct command *cmd;71 struct list_head *next;72 73 if (list_empty(&sp->command_queue))74 return NULL;75 76 next = sp->command_queue.next;77 list_del_init(next);78 cmd = list_entry(next, struct command, queue_node);79 80 return cmd;81}82 83static inline void do_exec_command(struct service_processor *sp)84{85 char tsbuf[32];86 87 dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));88 89 if (ibmasm_send_i2o_message(sp)) {90 sp->current_command->status = IBMASM_CMD_FAILED;91 wake_up(&sp->current_command->wait);92 command_put(sp->current_command);93 exec_next_command(sp);94 }95}96 97/*98 * exec_command99 * send a command to a service processor100 * Commands are executed sequentially. One command (sp->current_command)101 * is sent to the service processor. Once the interrupt handler gets a102 * message of type command_response, the message is copied into103 * the current commands buffer,104 */105void ibmasm_exec_command(struct service_processor *sp, struct command *cmd)106{107 unsigned long flags;108 char tsbuf[32];109 110 dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));111 112 spin_lock_irqsave(&sp->lock, flags);113 114 if (!sp->current_command) {115 sp->current_command = cmd;116 command_get(sp->current_command);117 spin_unlock_irqrestore(&sp->lock, flags);118 do_exec_command(sp);119 } else {120 enqueue_command(sp, cmd);121 spin_unlock_irqrestore(&sp->lock, flags);122 }123}124 125static void exec_next_command(struct service_processor *sp)126{127 unsigned long flags;128 char tsbuf[32];129 130 dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));131 132 spin_lock_irqsave(&sp->lock, flags);133 sp->current_command = dequeue_command(sp);134 if (sp->current_command) {135 command_get(sp->current_command);136 spin_unlock_irqrestore(&sp->lock, flags);137 do_exec_command(sp);138 } else {139 spin_unlock_irqrestore(&sp->lock, flags);140 }141}142 143/*144 * Sleep until a command has failed or a response has been received145 * and the command status been updated by the interrupt handler.146 * (see receive_response).147 */148void ibmasm_wait_for_response(struct command *cmd, int timeout)149{150 wait_event_interruptible_timeout(cmd->wait,151 cmd->status == IBMASM_CMD_COMPLETE ||152 cmd->status == IBMASM_CMD_FAILED,153 timeout * HZ);154}155 156/*157 * receive_command_response158 * called by the interrupt handler when a dot command of type command_response159 * was received.160 */161void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size)162{163 struct command *cmd = sp->current_command;164 165 if (!sp->current_command)166 return;167 168 memcpy_fromio(cmd->buffer, response, min(size, cmd->buffer_size));169 cmd->status = IBMASM_CMD_COMPLETE;170 wake_up(&sp->current_command->wait);171 command_put(sp->current_command);172 exec_next_command(sp);173}174