[Linaro-acpi] [PATCH V8 1/8] ACPI: I/O Remapping Table (IORT) initial support

Fu Wei fu.wei at linaro.org
Mon Sep 5 08:31:32 PDT 2016


Hi Tomasz,

On 5 September 2016 at 14:12, Tomasz Nowicki <tn at semihalf.com> wrote:
> On 02.09.2016 13:52, Fu Wei wrote:
>>
>> Hi Tomasz,
>>
>> On 11 August 2016 at 18:06, Tomasz Nowicki <tn at semihalf.com> wrote:
>>>
>>> IORT shows representation of IO topology for ARM based systems.
>>> It describes how various components are connected together on
>>> parent-child basis e.g. PCI RC -> SMMU -> ITS. Also see IORT spec.
>>>
>>> http://infocenter.arm.com/help/topic/com.arm.doc.den0049b/DEN0049B_IO_Remapping_Table.pdf
>>>
>>> Initial support allows to detect IORT table presence and save its
>>> root pointer obtained through acpi_get_table(). The pointer validity
>>> depends on acpi_gbl_permanent_mmap because if acpi_gbl_permanent_mmap
>>> is not set while using IORT nodes we would dereference unmapped pointers.
>>>
>>> For the aforementioned reason call iort_table_detect() from acpi_init()
>>> which guarantees acpi_gbl_permanent_mmap to be set at that point.
>>>
>>> Add generic helpers which are helpful for scanning and retrieving
>>> information from IORT table content. List of the most important helpers:
>>> - iort_find_dev_node() finds IORT node for a given device
>>> - iort_node_map_rid() maps device RID and returns IORT node which
>>> provides
>>>   final translation
>>>
>>> IORT support is placed under drivers/acpi/arm64/ new directory due to its
>>> ARM64 specific nature. The code there is considered only for ARM64.
>>> The long term plan is to keep all ARM64 specific tables support
>>> in this place e.g. GTDT table.
>>>
>>> Signed-off-by: Tomasz Nowicki <tn at semihalf.com>
>>> Reviewed-by: Hanjun Guo <hanjun.guo at linaro.org>
>>> ---
>>>  drivers/acpi/Kconfig        |   5 +
>>>  drivers/acpi/Makefile       |   2 +
>>>  drivers/acpi/arm64/Kconfig  |   6 ++
>>>  drivers/acpi/arm64/Makefile |   1 +
>>>  drivers/acpi/arm64/iort.c   | 218
>>> ++++++++++++++++++++++++++++++++++++++++++++
>>>  drivers/acpi/bus.c          |   2 +
>>>  include/linux/iort.h        |  30 ++++++
>>>  7 files changed, 264 insertions(+)
>>>  create mode 100644 drivers/acpi/arm64/Kconfig
>>>  create mode 100644 drivers/acpi/arm64/Makefile
>>>  create mode 100644 drivers/acpi/arm64/iort.c
>>>  create mode 100644 include/linux/iort.h
>>>
>>> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
>>> index 445ce28..6cef2d1 100644
>>> --- a/drivers/acpi/Kconfig
>>> +++ b/drivers/acpi/Kconfig
>>> @@ -521,4 +521,9 @@ config ACPI_CONFIGFS
>>>           userspace. The configurable ACPI groups will be visible under
>>>           /config/acpi, assuming configfs is mounted under /config.
>>>
>>> +if ARM64
>>> +source "drivers/acpi/arm64/Kconfig"
>>> +
>>> +endif
>>> +
>>>  endif  # ACPI
>>> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
>>> index 5ae9d85..e5ada78 100644
>>> --- a/drivers/acpi/Makefile
>>> +++ b/drivers/acpi/Makefile
>>> @@ -105,3 +105,5 @@ obj-$(CONFIG_ACPI_CONFIGFS) += acpi_configfs.o
>>>
>>>  video-objs                     += acpi_video.o video_detect.o
>>>  obj-y                          += dptf/
>>> +
>>> +obj-$(CONFIG_ARM64)            += arm64/
>>> diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
>>> new file mode 100644
>>> index 0000000..fc818dc
>>> --- /dev/null
>>> +++ b/drivers/acpi/arm64/Kconfig
>>> @@ -0,0 +1,6 @@
>>> +#
>>> +# ACPI Configuration for ARM64
>>> +#
>>> +
>>> +config IORT_TABLE
>>
>>
>> Sorry for nit-picking, but is that better to use ACPI_IORT
>> or maybe ARM64__IORT ??
>
>
> ACPI_IORT sounds good.

Thanks, Tomasz :-)
I have rebaseed my GTDT patchset on your v8 patchset,
But before I post my new patchset, I  hope we can harmonize with each
other on these:

1. ACPI_IORT --  ACPI_GTDT
2. for the file name,  maybe can follow "/drivers/acpi/acpi_*.c" like
acpi_iort.c and acpi_gtdt.c
or  follow "/drivers/acpi/apei/*.c" like iort.c and gtdt.c.

looking forward to you new patchset :-)
Thanks :-)

>
> Tomasz



-- 
Best regards,

Fu Wei
Software Engineer
Red Hat



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