 a238317ce8
			
		
	
	
	a238317ce8
	
	
	
		
			
			ACPICA doesn't include protections around address space checking, Linux
build tests always complain increased sparse warnings around ACPICA
internal acpi_os_map/unmap_memory() invocations.  This patch tries to fix
this issue permanently.
There are 2 choices left for us to solve this issue:
 1. Add __iomem address space awareness into ACPICA.
 2. Remove sparse checker of __iomem from ACPICA source code.
This patch chooses solution 2, because:
 1.  Most of the acpi_os_map/unmap_memory() invocations are used for ACPICA.
     table mappings, which in fact are not IO addresses.
 2.  The only IO addresses usage is for "system memory space" mapping code in:
      drivers/acpi/acpica/exregion.c
      drivers/acpi/acpica/evrgnini.c
      drivers/acpi/acpica/exregion.c
    The mapped address is accessed in the handler of "system memory space"
    - acpi_ex_system_memory_space_handler().  This function in fact can be
    changed to invoke acpi_os_read/write_memory() so that __iomem can
    always be type-casted in the OSL layer.
According to the above investigation, we drew the following conclusion:
It is not a good idea to introduce __iomem address space awareness into
ACPICA mostly in order to protect non-IO addresses.
We can simply remove __iomem for acpi_os_map/unmap_memory() to remove
__iomem checker for ACPICA code. Then we need to enforce external usages
to invoke other APIs that are aware of __iomem address space.
The external usages are:
 drivers/acpi/apei/einj.c
 drivers/acpi/acpi_extlog.c
 drivers/char/tpm/tpm_acpi.c
 drivers/acpi/nvs.c
This patch thus performs cleanups in this way:
 1. Add acpi_os_map/unmap_iomem() to be invoked by non-ACPICA code.
 2. Remove __iomem from acpi_os_map/unmap_memory().
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
		
	
			
		
			
				
	
	
		
			112 lines
		
	
	
	
		
			3.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			112 lines
		
	
	
	
		
			3.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /******************************************************************************
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|  *
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|  * Name: aclinuxex.h - Extra OS specific defines, etc. for Linux
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|  *
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|  *****************************************************************************/
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| 
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| /*
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|  * Copyright (C) 2000 - 2014, Intel Corp.
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|  * All rights reserved.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  * 1. Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions, and the following disclaimer,
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|  *    without modification.
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|  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
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|  *    substantially similar to the "NO WARRANTY" disclaimer below
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|  *    ("Disclaimer") and any redistribution must be conditioned upon
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|  *    including a substantially similar Disclaimer requirement for further
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|  *    binary redistribution.
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|  * 3. Neither the names of the above-listed copyright holders nor the names
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|  *    of any contributors may be used to endorse or promote products derived
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|  *    from this software without specific prior written permission.
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|  *
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|  * Alternatively, this software may be distributed under the terms of the
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|  * GNU General Public License ("GPL") version 2 as published by the Free
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|  * Software Foundation.
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|  *
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|  * NO WARRANTY
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|  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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|  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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|  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
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|  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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|  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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|  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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|  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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|  * POSSIBILITY OF SUCH DAMAGES.
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|  */
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| 
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| #ifndef __ACLINUXEX_H__
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| #define __ACLINUXEX_H__
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| 
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| #ifdef __KERNEL__
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| 
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| /*
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|  * Overrides for in-kernel ACPICA
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|  */
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| acpi_status __init acpi_os_initialize(void);
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| 
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| acpi_status acpi_os_terminate(void);
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| 
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| /*
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|  * The irqs_disabled() check is for resume from RAM.
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|  * Interrupts are off during resume, just like they are for boot.
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|  * However, boot has  (system_state != SYSTEM_RUNNING)
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|  * to quiet __might_sleep() in kmalloc() and resume does not.
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|  */
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| static inline void *acpi_os_allocate(acpi_size size)
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| {
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| 	return kmalloc(size, irqs_disabled()? GFP_ATOMIC : GFP_KERNEL);
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| }
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| 
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| static inline void *acpi_os_allocate_zeroed(acpi_size size)
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| {
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| 	return kzalloc(size, irqs_disabled()? GFP_ATOMIC : GFP_KERNEL);
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| }
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| 
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| static inline void acpi_os_free(void *memory)
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| {
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| 	kfree(memory);
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| }
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| 
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| static inline void *acpi_os_acquire_object(acpi_cache_t * cache)
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| {
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| 	return kmem_cache_zalloc(cache,
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| 				 irqs_disabled()? GFP_ATOMIC : GFP_KERNEL);
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| }
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| 
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| static inline acpi_thread_id acpi_os_get_thread_id(void)
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| {
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| 	return (acpi_thread_id) (unsigned long)current;
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| }
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| 
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| /*
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|  * When lockdep is enabled, the spin_lock_init() macro stringifies it's
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|  * argument and uses that as a name for the lock in debugging.
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|  * By executing spin_lock_init() in a macro the key changes from "lock" for
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|  * all locks to the name of the argument of acpi_os_create_lock(), which
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|  * prevents lockdep from reporting false positives for ACPICA locks.
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|  */
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| #define acpi_os_create_lock(__handle) \
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| 	({ \
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| 		spinlock_t *lock = ACPI_ALLOCATE(sizeof(*lock)); \
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| 		if (lock) { \
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| 			*(__handle) = lock; \
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| 			spin_lock_init(*(__handle)); \
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| 		} \
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| 		lock ? AE_OK : AE_NO_MEMORY; \
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| 	})
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| 
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| /*
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|  * OSL interfaces added by Linux
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|  */
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| void early_acpi_os_unmap_memory(void __iomem * virt, acpi_size size);
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| 
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| #endif				/* __KERNEL__ */
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| 
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| #endif				/* __ACLINUXEX_H__ */
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