c78c43fe7d
Use _DMA defined in ACPI spec for translation between
DMA address and CPU address, and implement acpi_arch_dma_setup
for initializing dev->dma_range_map, where acpi_dma_get_range
is called for parsing _DMA.
e.g.
If we have two dma ranges:
cpu address dma address size offset
0x200080000000 0x2080000000 0x400000000 0x1fe000000000
0x400080000000 0x4080000000 0x400000000 0x3fc000000000
_DMA for pci devices should be declared in host bridge as
flowing:
Name (_DMA, ResourceTemplate() {
QWordMemory (ResourceProducer,
PosDecode,
MinFixed,
MaxFixed,
NonCacheable,
ReadWrite,
0x0,
0x4080000000,
0x447fffffff,
0x3fc000000000,
0x400000000,
,
,
)
QWordMemory (ResourceProducer,
PosDecode,
MinFixed,
MaxFixed,
NonCacheable,
ReadWrite,
0x0,
0x2080000000,
0x247fffffff,
0x1fe000000000,
0x400000000,
,
,
)
})
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.