diff options
Diffstat (limited to 'drivers/misc/ibmasm/command.c')
| -rw-r--r-- | drivers/misc/ibmasm/command.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/drivers/misc/ibmasm/command.c b/drivers/misc/ibmasm/command.c new file mode 100644 index 000000000..733dd30fb --- /dev/null +++ b/drivers/misc/ibmasm/command.c @@ -0,0 +1,173 @@ +// 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); +} |