linux/include/acpi/acpi_io.h
Lorenzo Pieralisi 437b38c511 ACPI: Add memory semantics to acpi_os_map_memory()
The memory attributes attached to memory regions depend on architecture
specific mappings.

For some memory regions, the attributes specified by firmware (eg
uncached) are not sufficient to determine how a memory region should be
mapped by an OS (for instance a region that is define as uncached in
firmware can be mapped as Normal or Device memory on arm64) and
therefore the OS must be given control on how to map the region to match
the expected mapping behaviour (eg if a mapping is requested with memory
semantics, it must allow unaligned accesses).

Rework acpi_os_map_memory() and acpi_os_ioremap() back-end to split
them into two separate code paths:

acpi_os_memmap() -> memory semantics
acpi_os_ioremap() -> MMIO semantics

The split allows the architectural implementation back-ends to detect
the default memory attributes required by the mapping in question
(ie the mapping API defines the semantics memory vs MMIO) and map the
memory accordingly.

Link: https://lore.kernel.org/linux-arm-kernel/31ffe8fc-f5ee-2858-26c5-0fd8bdd68702@arm.com
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-08-25 19:44:57 +02:00

36 lines
889 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ACPI_IO_H_
#define _ACPI_IO_H_
#include <linux/io.h>
#include <asm/acpi.h>
#ifndef acpi_os_ioremap
static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys,
acpi_size size)
{
return ioremap_cache(phys, size);
}
#endif
#ifndef acpi_os_memmap
static inline void __iomem *acpi_os_memmap(acpi_physical_address phys,
acpi_size size)
{
return ioremap_cache(phys, size);
}
#endif
extern bool acpi_permanent_mmap;
void __iomem __ref
*acpi_os_map_iomem(acpi_physical_address phys, acpi_size size);
void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size);
void __iomem *acpi_os_get_iomem(acpi_physical_address phys, unsigned int size);
void __iomem *acpi_os_map_generic_address(struct acpi_generic_address *addr);
void acpi_os_unmap_generic_address(struct acpi_generic_address *addr);
#endif