linux/include/acpi/platform/aclinuxex.h
Lv Zheng a238317ce8 ACPI: Clean up acpi_os_map/unmap_memory() to eliminate __iomem.
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>
2014-05-27 18:13:08 +02:00

113 lines
3.8 KiB
C

/******************************************************************************
*
* Name: aclinuxex.h - Extra OS specific defines, etc. for Linux
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2014, Intel Corp.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*/
#ifndef __ACLINUXEX_H__
#define __ACLINUXEX_H__
#ifdef __KERNEL__
/*
* Overrides for in-kernel ACPICA
*/
acpi_status __init acpi_os_initialize(void);
acpi_status acpi_os_terminate(void);
/*
* The irqs_disabled() check is for resume from RAM.
* Interrupts are off during resume, just like they are for boot.
* However, boot has (system_state != SYSTEM_RUNNING)
* to quiet __might_sleep() in kmalloc() and resume does not.
*/
static inline void *acpi_os_allocate(acpi_size size)
{
return kmalloc(size, irqs_disabled()? GFP_ATOMIC : GFP_KERNEL);
}
static inline void *acpi_os_allocate_zeroed(acpi_size size)
{
return kzalloc(size, irqs_disabled()? GFP_ATOMIC : GFP_KERNEL);
}
static inline void acpi_os_free(void *memory)
{
kfree(memory);
}
static inline void *acpi_os_acquire_object(acpi_cache_t * cache)
{
return kmem_cache_zalloc(cache,
irqs_disabled()? GFP_ATOMIC : GFP_KERNEL);
}
static inline acpi_thread_id acpi_os_get_thread_id(void)
{
return (acpi_thread_id) (unsigned long)current;
}
/*
* When lockdep is enabled, the spin_lock_init() macro stringifies it's
* argument and uses that as a name for the lock in debugging.
* By executing spin_lock_init() in a macro the key changes from "lock" for
* all locks to the name of the argument of acpi_os_create_lock(), which
* prevents lockdep from reporting false positives for ACPICA locks.
*/
#define acpi_os_create_lock(__handle) \
({ \
spinlock_t *lock = ACPI_ALLOCATE(sizeof(*lock)); \
if (lock) { \
*(__handle) = lock; \
spin_lock_init(*(__handle)); \
} \
lock ? AE_OK : AE_NO_MEMORY; \
})
/*
* OSL interfaces added by Linux
*/
void early_acpi_os_unmap_memory(void __iomem * virt, acpi_size size);
#endif /* __KERNEL__ */
#endif /* __ACLINUXEX_H__ */