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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IBM ASM Service Processor Device Driver
*
* Copyright (C) IBM Corporation, 2004
*
* Author: Max Asböck <amax@us.ibm.com>
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include "ibmasm.h"
#include "lowlevel.h"
static void exec_next_command(struct service_processor *sp);
static atomic_t command_count = ATOMIC_INIT(0);
struct command *ibmasm_new_command(struct service_processor *sp, size_t buffer_size)
{
struct command *cmd;
if (buffer_size > IBMASM_CMD_MAX_BUFFER_SIZE)
return NULL;
cmd = kzalloc(sizeof(struct command), GFP_KERNEL);
if (cmd == NULL)
return NULL;
cmd->buffer = kzalloc(buffer_size, GFP_KERNEL);
if (cmd->buffer == NULL) {
kfree(cmd);
return NULL;
}
cmd->buffer_size = buffer_size;
kref_init(&cmd->kref);
cmd->lock = &sp->lock;
cmd->status = IBMASM_CMD_PENDING;
init_waitqueue_head(&cmd->wait);
INIT_LIST_HEAD(&cmd->queue_node);
atomic_inc(&command_count);
dbg("command count: %d\n", atomic_read(&command_count));
return cmd;
}
void ibmasm_free_command(struct kref *kref)
{
struct command *cmd = to_command(kref);
list_del(&cmd->queue_node);
atomic_dec(&command_count);
dbg("command count: %d\n", atomic_read(&command_count));
kfree(cmd->buffer);
kfree(cmd);
}
static void enqueue_command(struct service_processor *sp, struct command *cmd)
{
list_add_tail(&cmd->queue_node, &sp->command_queue);
}
static struct command *dequeue_command(struct service_processor *sp)
{
struct command *cmd;
struct list_head *next;
if (list_empty(&sp->command_queue))
return NULL;
next = sp->command_queue.next;
list_del_init(next);
cmd = list_entry(next, struct command, queue_node);
return cmd;
}
static inline void do_exec_command(struct service_processor *sp)
{
char tsbuf[32];
dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
if (ibmasm_send_i2o_message(sp)) {
sp->current_command->status = IBMASM_CMD_FAILED;
wake_up(&sp->current_command->wait);
command_put(sp->current_command);
exec_next_command(sp);
}
}
/**
* exec_command
* send a command to a service processor
* Commands are executed sequentially. One command (sp->current_command)
* is sent to the service processor. Once the interrupt handler gets a
* message of type command_response, the message is copied into
* the current commands buffer,
*/
void ibmasm_exec_command(struct service_processor *sp, struct command *cmd)
{
unsigned long flags;
char tsbuf[32];
dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
spin_lock_irqsave(&sp->lock, flags);
if (!sp->current_command) {
sp->current_command = cmd;
command_get(sp->current_command);
spin_unlock_irqrestore(&sp->lock, flags);
do_exec_command(sp);
} else {
enqueue_command(sp, cmd);
spin_unlock_irqrestore(&sp->lock, flags);
}
}
static void exec_next_command(struct service_processor *sp)
{
unsigned long flags;
char tsbuf[32];
dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
spin_lock_irqsave(&sp->lock, flags);
sp->current_command = dequeue_command(sp);
if (sp->current_command) {
command_get(sp->current_command);
spin_unlock_irqrestore(&sp->lock, flags);
do_exec_command(sp);
} else {
spin_unlock_irqrestore(&sp->lock, flags);
}
}
/**
* Sleep until a command has failed or a response has been received
* and the command status been updated by the interrupt handler.
* (see receive_response).
*/
void ibmasm_wait_for_response(struct command *cmd, int timeout)
{
wait_event_interruptible_timeout(cmd->wait,
cmd->status == IBMASM_CMD_COMPLETE ||
cmd->status == IBMASM_CMD_FAILED,
timeout * HZ);
}
/**
* receive_command_response
* called by the interrupt handler when a dot command of type command_response
* was received.
*/
void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size)
{
struct command *cmd = sp->current_command;
if (!sp->current_command)
return;
memcpy_fromio(cmd->buffer, response, min(size, cmd->buffer_size));
cmd->status = IBMASM_CMD_COMPLETE;
wake_up(&sp->current_command->wait);
command_put(sp->current_command);
exec_next_command(sp);
}
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