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