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![Lv Zheng](/assets/img/avatar_default.png)
The FIFO unlocking mechanism in acpi_dbg has been broken by the following commit: Commit:287980e49f
Subject: remove lots of IS_ERR_VALUE abuses It converted !IS_ERR_VALUE(ret) into !ret which was not entirely correct. Fix the regression by taking ret > 0 into account too as appropriate. Fixes:287980e49f
(remove lots of IS_ERR_VALUE abuses) Signed-off-by: Lv Zheng <lv.zheng@intel.com> [ rjw: Simplifications, changelog & subject massage ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
804 lines
18 KiB
C
804 lines
18 KiB
C
/*
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* ACPI AML interfacing support
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*
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* Copyright (C) 2015, Intel Corporation
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* Authors: Lv Zheng <lv.zheng@intel.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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/* #define DEBUG */
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#define pr_fmt(fmt) "ACPI : AML: " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/wait.h>
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#include <linux/poll.h>
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#include <linux/sched.h>
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#include <linux/kthread.h>
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#include <linux/proc_fs.h>
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#include <linux/debugfs.h>
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#include <linux/circ_buf.h>
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#include <linux/acpi.h>
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#include "internal.h"
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#define ACPI_AML_BUF_ALIGN (sizeof (acpi_size))
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#define ACPI_AML_BUF_SIZE PAGE_SIZE
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#define circ_count(circ) \
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(CIRC_CNT((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE))
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#define circ_count_to_end(circ) \
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(CIRC_CNT_TO_END((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE))
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#define circ_space(circ) \
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(CIRC_SPACE((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE))
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#define circ_space_to_end(circ) \
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(CIRC_SPACE_TO_END((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE))
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#define ACPI_AML_OPENED 0x0001
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#define ACPI_AML_CLOSED 0x0002
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#define ACPI_AML_IN_USER 0x0004 /* user space is writing cmd */
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#define ACPI_AML_IN_KERN 0x0008 /* kernel space is reading cmd */
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#define ACPI_AML_OUT_USER 0x0010 /* user space is reading log */
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#define ACPI_AML_OUT_KERN 0x0020 /* kernel space is writing log */
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#define ACPI_AML_USER (ACPI_AML_IN_USER | ACPI_AML_OUT_USER)
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#define ACPI_AML_KERN (ACPI_AML_IN_KERN | ACPI_AML_OUT_KERN)
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#define ACPI_AML_BUSY (ACPI_AML_USER | ACPI_AML_KERN)
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#define ACPI_AML_OPEN (ACPI_AML_OPENED | ACPI_AML_CLOSED)
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struct acpi_aml_io {
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wait_queue_head_t wait;
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unsigned long flags;
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unsigned long users;
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struct mutex lock;
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struct task_struct *thread;
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char out_buf[ACPI_AML_BUF_SIZE] __aligned(ACPI_AML_BUF_ALIGN);
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struct circ_buf out_crc;
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char in_buf[ACPI_AML_BUF_SIZE] __aligned(ACPI_AML_BUF_ALIGN);
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struct circ_buf in_crc;
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acpi_osd_exec_callback function;
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void *context;
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unsigned long usages;
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};
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static struct acpi_aml_io acpi_aml_io;
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static bool acpi_aml_initialized;
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static struct file *acpi_aml_active_reader;
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static struct dentry *acpi_aml_dentry;
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static inline bool __acpi_aml_running(void)
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{
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return acpi_aml_io.thread ? true : false;
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}
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static inline bool __acpi_aml_access_ok(unsigned long flag)
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{
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/*
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* The debugger interface is in opened state (OPENED && !CLOSED),
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* then it is allowed to access the debugger buffers from either
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* user space or the kernel space.
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* In addition, for the kernel space, only the debugger thread
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* (thread ID matched) is allowed to access.
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*/
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if (!(acpi_aml_io.flags & ACPI_AML_OPENED) ||
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(acpi_aml_io.flags & ACPI_AML_CLOSED) ||
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!__acpi_aml_running())
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return false;
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if ((flag & ACPI_AML_KERN) &&
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current != acpi_aml_io.thread)
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return false;
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return true;
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}
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static inline bool __acpi_aml_readable(struct circ_buf *circ, unsigned long flag)
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{
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/*
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* Another read is not in progress and there is data in buffer
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* available for read.
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*/
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if (!(acpi_aml_io.flags & flag) && circ_count(circ))
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return true;
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return false;
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}
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static inline bool __acpi_aml_writable(struct circ_buf *circ, unsigned long flag)
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{
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/*
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* Another write is not in progress and there is buffer space
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* available for write.
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*/
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if (!(acpi_aml_io.flags & flag) && circ_space(circ))
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return true;
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return false;
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}
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static inline bool __acpi_aml_busy(void)
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{
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if (acpi_aml_io.flags & ACPI_AML_BUSY)
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return true;
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return false;
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}
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static inline bool __acpi_aml_opened(void)
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{
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if (acpi_aml_io.flags & ACPI_AML_OPEN)
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return true;
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return false;
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}
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static inline bool __acpi_aml_used(void)
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{
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return acpi_aml_io.usages ? true : false;
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}
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static inline bool acpi_aml_running(void)
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{
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bool ret;
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mutex_lock(&acpi_aml_io.lock);
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ret = __acpi_aml_running();
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mutex_unlock(&acpi_aml_io.lock);
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return ret;
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}
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static bool acpi_aml_busy(void)
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{
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bool ret;
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mutex_lock(&acpi_aml_io.lock);
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ret = __acpi_aml_busy();
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mutex_unlock(&acpi_aml_io.lock);
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return ret;
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}
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static bool acpi_aml_used(void)
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{
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bool ret;
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/*
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* The usage count is prepared to avoid race conditions between the
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* starts and the stops of the debugger thread.
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*/
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mutex_lock(&acpi_aml_io.lock);
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ret = __acpi_aml_used();
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mutex_unlock(&acpi_aml_io.lock);
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return ret;
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}
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static bool acpi_aml_kern_readable(void)
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{
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bool ret;
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mutex_lock(&acpi_aml_io.lock);
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ret = !__acpi_aml_access_ok(ACPI_AML_IN_KERN) ||
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__acpi_aml_readable(&acpi_aml_io.in_crc, ACPI_AML_IN_KERN);
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mutex_unlock(&acpi_aml_io.lock);
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return ret;
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}
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static bool acpi_aml_kern_writable(void)
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{
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bool ret;
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mutex_lock(&acpi_aml_io.lock);
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ret = !__acpi_aml_access_ok(ACPI_AML_OUT_KERN) ||
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__acpi_aml_writable(&acpi_aml_io.out_crc, ACPI_AML_OUT_KERN);
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mutex_unlock(&acpi_aml_io.lock);
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return ret;
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}
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static bool acpi_aml_user_readable(void)
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{
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bool ret;
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mutex_lock(&acpi_aml_io.lock);
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ret = !__acpi_aml_access_ok(ACPI_AML_OUT_USER) ||
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__acpi_aml_readable(&acpi_aml_io.out_crc, ACPI_AML_OUT_USER);
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mutex_unlock(&acpi_aml_io.lock);
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return ret;
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}
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static bool acpi_aml_user_writable(void)
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{
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bool ret;
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mutex_lock(&acpi_aml_io.lock);
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ret = !__acpi_aml_access_ok(ACPI_AML_IN_USER) ||
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__acpi_aml_writable(&acpi_aml_io.in_crc, ACPI_AML_IN_USER);
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mutex_unlock(&acpi_aml_io.lock);
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return ret;
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}
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static int acpi_aml_lock_write(struct circ_buf *circ, unsigned long flag)
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{
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int ret = 0;
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mutex_lock(&acpi_aml_io.lock);
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if (!__acpi_aml_access_ok(flag)) {
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ret = -EFAULT;
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goto out;
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}
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if (!__acpi_aml_writable(circ, flag)) {
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ret = -EAGAIN;
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goto out;
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}
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acpi_aml_io.flags |= flag;
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out:
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mutex_unlock(&acpi_aml_io.lock);
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return ret;
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}
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static int acpi_aml_lock_read(struct circ_buf *circ, unsigned long flag)
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{
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int ret = 0;
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mutex_lock(&acpi_aml_io.lock);
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if (!__acpi_aml_access_ok(flag)) {
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ret = -EFAULT;
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goto out;
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}
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if (!__acpi_aml_readable(circ, flag)) {
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ret = -EAGAIN;
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goto out;
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}
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acpi_aml_io.flags |= flag;
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out:
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mutex_unlock(&acpi_aml_io.lock);
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return ret;
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}
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static void acpi_aml_unlock_fifo(unsigned long flag, bool wakeup)
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{
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mutex_lock(&acpi_aml_io.lock);
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acpi_aml_io.flags &= ~flag;
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if (wakeup)
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wake_up_interruptible(&acpi_aml_io.wait);
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mutex_unlock(&acpi_aml_io.lock);
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}
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static int acpi_aml_write_kern(const char *buf, int len)
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{
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int ret;
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struct circ_buf *crc = &acpi_aml_io.out_crc;
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int n;
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char *p;
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ret = acpi_aml_lock_write(crc, ACPI_AML_OUT_KERN);
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if (ret < 0)
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return ret;
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/* sync tail before inserting logs */
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smp_mb();
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p = &crc->buf[crc->head];
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n = min(len, circ_space_to_end(crc));
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memcpy(p, buf, n);
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/* sync head after inserting logs */
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smp_wmb();
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crc->head = (crc->head + n) & (ACPI_AML_BUF_SIZE - 1);
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acpi_aml_unlock_fifo(ACPI_AML_OUT_KERN, true);
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return n;
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}
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static int acpi_aml_readb_kern(void)
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{
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int ret;
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struct circ_buf *crc = &acpi_aml_io.in_crc;
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char *p;
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ret = acpi_aml_lock_read(crc, ACPI_AML_IN_KERN);
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if (ret < 0)
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return ret;
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/* sync head before removing cmds */
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smp_rmb();
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p = &crc->buf[crc->tail];
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ret = (int)*p;
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/* sync tail before inserting cmds */
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smp_mb();
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crc->tail = (crc->tail + 1) & (ACPI_AML_BUF_SIZE - 1);
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acpi_aml_unlock_fifo(ACPI_AML_IN_KERN, true);
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return ret;
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}
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/*
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* acpi_aml_write_log() - Capture debugger output
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* @msg: the debugger output
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*
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* This function should be used to implement acpi_os_printf() to filter out
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* the debugger output and store the output into the debugger interface
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* buffer. Return the size of stored logs or errno.
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*/
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static ssize_t acpi_aml_write_log(const char *msg)
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{
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int ret = 0;
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int count = 0, size = 0;
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if (!acpi_aml_initialized)
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return -ENODEV;
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if (msg)
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count = strlen(msg);
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while (count > 0) {
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again:
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ret = acpi_aml_write_kern(msg + size, count);
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if (ret == -EAGAIN) {
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ret = wait_event_interruptible(acpi_aml_io.wait,
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acpi_aml_kern_writable());
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/*
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* We need to retry when the condition
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* becomes true.
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*/
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if (ret == 0)
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goto again;
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break;
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}
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if (ret < 0)
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break;
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size += ret;
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count -= ret;
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}
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return size > 0 ? size : ret;
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}
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/*
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* acpi_aml_read_cmd() - Capture debugger input
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* @msg: the debugger input
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* @size: the size of the debugger input
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*
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* This function should be used to implement acpi_os_get_line() to capture
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* the debugger input commands and store the input commands into the
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* debugger interface buffer. Return the size of stored commands or errno.
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*/
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static ssize_t acpi_aml_read_cmd(char *msg, size_t count)
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{
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int ret = 0;
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int size = 0;
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/*
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* This is ensured by the running fact of the debugger thread
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* unless a bug is introduced.
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*/
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BUG_ON(!acpi_aml_initialized);
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while (count > 0) {
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again:
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/*
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* Check each input byte to find the end of the command.
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*/
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ret = acpi_aml_readb_kern();
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if (ret == -EAGAIN) {
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ret = wait_event_interruptible(acpi_aml_io.wait,
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acpi_aml_kern_readable());
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/*
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* We need to retry when the condition becomes
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* true.
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*/
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if (ret == 0)
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goto again;
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}
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if (ret < 0)
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break;
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*(msg + size) = (char)ret;
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size++;
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count--;
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if (ret == '\n') {
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/*
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* acpi_os_get_line() requires a zero terminated command
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* string.
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*/
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*(msg + size - 1) = '\0';
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break;
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}
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}
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return size > 0 ? size : ret;
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}
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static int acpi_aml_thread(void *unsed)
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{
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acpi_osd_exec_callback function = NULL;
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void *context;
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mutex_lock(&acpi_aml_io.lock);
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if (acpi_aml_io.function) {
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acpi_aml_io.usages++;
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function = acpi_aml_io.function;
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context = acpi_aml_io.context;
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}
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mutex_unlock(&acpi_aml_io.lock);
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if (function)
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function(context);
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mutex_lock(&acpi_aml_io.lock);
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acpi_aml_io.usages--;
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if (!__acpi_aml_used()) {
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acpi_aml_io.thread = NULL;
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wake_up(&acpi_aml_io.wait);
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}
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mutex_unlock(&acpi_aml_io.lock);
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return 0;
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}
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/*
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* acpi_aml_create_thread() - Create AML debugger thread
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* @function: the debugger thread callback
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* @context: the context to be passed to the debugger thread
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*
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* This function should be used to implement acpi_os_execute() which is
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* used by the ACPICA debugger to create the debugger thread.
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*/
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static int acpi_aml_create_thread(acpi_osd_exec_callback function, void *context)
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{
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struct task_struct *t;
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mutex_lock(&acpi_aml_io.lock);
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acpi_aml_io.function = function;
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acpi_aml_io.context = context;
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mutex_unlock(&acpi_aml_io.lock);
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t = kthread_create(acpi_aml_thread, NULL, "aml");
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if (IS_ERR(t)) {
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pr_err("Failed to create AML debugger thread.\n");
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return PTR_ERR(t);
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}
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mutex_lock(&acpi_aml_io.lock);
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acpi_aml_io.thread = t;
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acpi_set_debugger_thread_id((acpi_thread_id)(unsigned long)t);
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wake_up_process(t);
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mutex_unlock(&acpi_aml_io.lock);
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return 0;
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}
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static int acpi_aml_wait_command_ready(bool single_step,
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char *buffer, size_t length)
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{
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acpi_status status;
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if (single_step)
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acpi_os_printf("\n%1c ", ACPI_DEBUGGER_EXECUTE_PROMPT);
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else
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acpi_os_printf("\n%1c ", ACPI_DEBUGGER_COMMAND_PROMPT);
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status = acpi_os_get_line(buffer, length, NULL);
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if (ACPI_FAILURE(status))
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return -EINVAL;
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return 0;
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}
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static int acpi_aml_notify_command_complete(void)
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{
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return 0;
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}
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static int acpi_aml_open(struct inode *inode, struct file *file)
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{
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int ret = 0;
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acpi_status status;
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mutex_lock(&acpi_aml_io.lock);
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/*
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* The debugger interface is being closed, no new user is allowed
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* during this period.
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*/
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if (acpi_aml_io.flags & ACPI_AML_CLOSED) {
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ret = -EBUSY;
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goto err_lock;
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}
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if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
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/*
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* Only one reader is allowed to initiate the debugger
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* thread.
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*/
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if (acpi_aml_active_reader) {
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ret = -EBUSY;
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goto err_lock;
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} else {
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pr_debug("Opening debugger reader.\n");
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acpi_aml_active_reader = file;
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}
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} else {
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/*
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* No writer is allowed unless the debugger thread is
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* ready.
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*/
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if (!(acpi_aml_io.flags & ACPI_AML_OPENED)) {
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ret = -ENODEV;
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goto err_lock;
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}
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}
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if (acpi_aml_active_reader == file) {
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pr_debug("Opening debugger interface.\n");
|
|
mutex_unlock(&acpi_aml_io.lock);
|
|
|
|
pr_debug("Initializing debugger thread.\n");
|
|
status = acpi_initialize_debugger();
|
|
if (ACPI_FAILURE(status)) {
|
|
pr_err("Failed to initialize debugger.\n");
|
|
ret = -EINVAL;
|
|
goto err_exit;
|
|
}
|
|
pr_debug("Debugger thread initialized.\n");
|
|
|
|
mutex_lock(&acpi_aml_io.lock);
|
|
acpi_aml_io.flags |= ACPI_AML_OPENED;
|
|
acpi_aml_io.out_crc.head = acpi_aml_io.out_crc.tail = 0;
|
|
acpi_aml_io.in_crc.head = acpi_aml_io.in_crc.tail = 0;
|
|
pr_debug("Debugger interface opened.\n");
|
|
}
|
|
acpi_aml_io.users++;
|
|
err_lock:
|
|
if (ret < 0) {
|
|
if (acpi_aml_active_reader == file)
|
|
acpi_aml_active_reader = NULL;
|
|
}
|
|
mutex_unlock(&acpi_aml_io.lock);
|
|
err_exit:
|
|
return ret;
|
|
}
|
|
|
|
static int acpi_aml_release(struct inode *inode, struct file *file)
|
|
{
|
|
mutex_lock(&acpi_aml_io.lock);
|
|
acpi_aml_io.users--;
|
|
if (file == acpi_aml_active_reader) {
|
|
pr_debug("Closing debugger reader.\n");
|
|
acpi_aml_active_reader = NULL;
|
|
|
|
pr_debug("Closing debugger interface.\n");
|
|
acpi_aml_io.flags |= ACPI_AML_CLOSED;
|
|
|
|
/*
|
|
* Wake up all user space/kernel space blocked
|
|
* readers/writers.
|
|
*/
|
|
wake_up_interruptible(&acpi_aml_io.wait);
|
|
mutex_unlock(&acpi_aml_io.lock);
|
|
/*
|
|
* Wait all user space/kernel space readers/writers to
|
|
* stop so that ACPICA command loop of the debugger thread
|
|
* should fail all its command line reads after this point.
|
|
*/
|
|
wait_event(acpi_aml_io.wait, !acpi_aml_busy());
|
|
|
|
/*
|
|
* Then we try to terminate the debugger thread if it is
|
|
* not terminated.
|
|
*/
|
|
pr_debug("Terminating debugger thread.\n");
|
|
acpi_terminate_debugger();
|
|
wait_event(acpi_aml_io.wait, !acpi_aml_used());
|
|
pr_debug("Debugger thread terminated.\n");
|
|
|
|
mutex_lock(&acpi_aml_io.lock);
|
|
acpi_aml_io.flags &= ~ACPI_AML_OPENED;
|
|
}
|
|
if (acpi_aml_io.users == 0) {
|
|
pr_debug("Debugger interface closed.\n");
|
|
acpi_aml_io.flags &= ~ACPI_AML_CLOSED;
|
|
}
|
|
mutex_unlock(&acpi_aml_io.lock);
|
|
return 0;
|
|
}
|
|
|
|
static int acpi_aml_read_user(char __user *buf, int len)
|
|
{
|
|
int ret;
|
|
struct circ_buf *crc = &acpi_aml_io.out_crc;
|
|
int n;
|
|
char *p;
|
|
|
|
ret = acpi_aml_lock_read(crc, ACPI_AML_OUT_USER);
|
|
if (ret < 0)
|
|
return ret;
|
|
/* sync head before removing logs */
|
|
smp_rmb();
|
|
p = &crc->buf[crc->tail];
|
|
n = min(len, circ_count_to_end(crc));
|
|
if (copy_to_user(buf, p, n)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
/* sync tail after removing logs */
|
|
smp_mb();
|
|
crc->tail = (crc->tail + n) & (ACPI_AML_BUF_SIZE - 1);
|
|
ret = n;
|
|
out:
|
|
acpi_aml_unlock_fifo(ACPI_AML_OUT_USER, ret >= 0);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t acpi_aml_read(struct file *file, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
int ret = 0;
|
|
int size = 0;
|
|
|
|
if (!count)
|
|
return 0;
|
|
if (!access_ok(VERIFY_WRITE, buf, count))
|
|
return -EFAULT;
|
|
|
|
while (count > 0) {
|
|
again:
|
|
ret = acpi_aml_read_user(buf + size, count);
|
|
if (ret == -EAGAIN) {
|
|
if (file->f_flags & O_NONBLOCK)
|
|
break;
|
|
else {
|
|
ret = wait_event_interruptible(acpi_aml_io.wait,
|
|
acpi_aml_user_readable());
|
|
/*
|
|
* We need to retry when the condition
|
|
* becomes true.
|
|
*/
|
|
if (ret == 0)
|
|
goto again;
|
|
}
|
|
}
|
|
if (ret < 0) {
|
|
if (!acpi_aml_running())
|
|
ret = 0;
|
|
break;
|
|
}
|
|
if (ret) {
|
|
size += ret;
|
|
count -= ret;
|
|
*ppos += ret;
|
|
break;
|
|
}
|
|
}
|
|
return size > 0 ? size : ret;
|
|
}
|
|
|
|
static int acpi_aml_write_user(const char __user *buf, int len)
|
|
{
|
|
int ret;
|
|
struct circ_buf *crc = &acpi_aml_io.in_crc;
|
|
int n;
|
|
char *p;
|
|
|
|
ret = acpi_aml_lock_write(crc, ACPI_AML_IN_USER);
|
|
if (ret < 0)
|
|
return ret;
|
|
/* sync tail before inserting cmds */
|
|
smp_mb();
|
|
p = &crc->buf[crc->head];
|
|
n = min(len, circ_space_to_end(crc));
|
|
if (copy_from_user(p, buf, n)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
/* sync head after inserting cmds */
|
|
smp_wmb();
|
|
crc->head = (crc->head + n) & (ACPI_AML_BUF_SIZE - 1);
|
|
ret = n;
|
|
out:
|
|
acpi_aml_unlock_fifo(ACPI_AML_IN_USER, ret >= 0);
|
|
return n;
|
|
}
|
|
|
|
static ssize_t acpi_aml_write(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
int ret = 0;
|
|
int size = 0;
|
|
|
|
if (!count)
|
|
return 0;
|
|
if (!access_ok(VERIFY_READ, buf, count))
|
|
return -EFAULT;
|
|
|
|
while (count > 0) {
|
|
again:
|
|
ret = acpi_aml_write_user(buf + size, count);
|
|
if (ret == -EAGAIN) {
|
|
if (file->f_flags & O_NONBLOCK)
|
|
break;
|
|
else {
|
|
ret = wait_event_interruptible(acpi_aml_io.wait,
|
|
acpi_aml_user_writable());
|
|
/*
|
|
* We need to retry when the condition
|
|
* becomes true.
|
|
*/
|
|
if (ret == 0)
|
|
goto again;
|
|
}
|
|
}
|
|
if (ret < 0) {
|
|
if (!acpi_aml_running())
|
|
ret = 0;
|
|
break;
|
|
}
|
|
if (ret) {
|
|
size += ret;
|
|
count -= ret;
|
|
*ppos += ret;
|
|
}
|
|
}
|
|
return size > 0 ? size : ret;
|
|
}
|
|
|
|
static unsigned int acpi_aml_poll(struct file *file, poll_table *wait)
|
|
{
|
|
int masks = 0;
|
|
|
|
poll_wait(file, &acpi_aml_io.wait, wait);
|
|
if (acpi_aml_user_readable())
|
|
masks |= POLLIN | POLLRDNORM;
|
|
if (acpi_aml_user_writable())
|
|
masks |= POLLOUT | POLLWRNORM;
|
|
|
|
return masks;
|
|
}
|
|
|
|
static const struct file_operations acpi_aml_operations = {
|
|
.read = acpi_aml_read,
|
|
.write = acpi_aml_write,
|
|
.poll = acpi_aml_poll,
|
|
.open = acpi_aml_open,
|
|
.release = acpi_aml_release,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
|
|
static const struct acpi_debugger_ops acpi_aml_debugger = {
|
|
.create_thread = acpi_aml_create_thread,
|
|
.read_cmd = acpi_aml_read_cmd,
|
|
.write_log = acpi_aml_write_log,
|
|
.wait_command_ready = acpi_aml_wait_command_ready,
|
|
.notify_command_complete = acpi_aml_notify_command_complete,
|
|
};
|
|
|
|
int __init acpi_aml_init(void)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!acpi_debugfs_dir) {
|
|
ret = -ENOENT;
|
|
goto err_exit;
|
|
}
|
|
|
|
/* Initialize AML IO interface */
|
|
mutex_init(&acpi_aml_io.lock);
|
|
init_waitqueue_head(&acpi_aml_io.wait);
|
|
acpi_aml_io.out_crc.buf = acpi_aml_io.out_buf;
|
|
acpi_aml_io.in_crc.buf = acpi_aml_io.in_buf;
|
|
acpi_aml_dentry = debugfs_create_file("acpidbg",
|
|
S_IFREG | S_IRUGO | S_IWUSR,
|
|
acpi_debugfs_dir, NULL,
|
|
&acpi_aml_operations);
|
|
if (acpi_aml_dentry == NULL) {
|
|
ret = -ENODEV;
|
|
goto err_exit;
|
|
}
|
|
ret = acpi_register_debugger(THIS_MODULE, &acpi_aml_debugger);
|
|
if (ret)
|
|
goto err_fs;
|
|
acpi_aml_initialized = true;
|
|
|
|
err_fs:
|
|
if (ret) {
|
|
debugfs_remove(acpi_aml_dentry);
|
|
acpi_aml_dentry = NULL;
|
|
}
|
|
err_exit:
|
|
return ret;
|
|
}
|
|
|
|
void __exit acpi_aml_exit(void)
|
|
{
|
|
if (acpi_aml_initialized) {
|
|
acpi_unregister_debugger(&acpi_aml_debugger);
|
|
if (acpi_aml_dentry) {
|
|
debugfs_remove(acpi_aml_dentry);
|
|
acpi_aml_dentry = NULL;
|
|
}
|
|
acpi_aml_initialized = false;
|
|
}
|
|
}
|
|
|
|
module_init(acpi_aml_init);
|
|
module_exit(acpi_aml_exit);
|
|
|
|
MODULE_AUTHOR("Lv Zheng");
|
|
MODULE_DESCRIPTION("ACPI debugger userspace IO driver");
|
|
MODULE_LICENSE("GPL");
|