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SubjectRe: [PATCH V7 1/8] ACPI: I/O Remapping Table (IORT) initial support
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On 22/06/16 12:06, Tomasz Nowicki wrote:
> On 22.06.2016 12:50, Marc Zyngier wrote:
>> On 21/06/16 08:12, Hanjun Guo wrote:
>>> Hi Tomasz,
>>>
>>> Sorry for jumping out late, just one comment below.
>>>
>>> On 2016/6/20 19:02, Tomasz Nowicki 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.
>>>>
>>>> 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
>>>>
>>>> Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
>>>> ---
>>>> drivers/acpi/Kconfig | 3 +
>>>> drivers/acpi/Makefile | 1 +
>>>> drivers/acpi/bus.c | 2 +
>>>> drivers/acpi/iort.c | 220 ++++++++++++++++++++++++++++++++++++++++++++++++++
>>>> include/linux/iort.h | 30 +++++++
>>>
>>> [...]
>>>
>>>> +static acpi_status
>>>> +iort_match_node_callback(struct acpi_iort_node *node, void *context)
>>>> +{
>>>> + struct device *dev = context;
>>>> +
>>>> + switch (node->type) {
>>>> + case ACPI_IORT_NODE_NAMED_COMPONENT: {
>>>> + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
>>>
>>> ACPI_ALLOCATE_BUFFER is used here, so ...
>>>
>>>> + struct acpi_device *adev = to_acpi_device_node(dev->fwnode);
>>>> + struct acpi_iort_named_component *ncomp;
>>>> +
>>>> + if (!adev)
>>>> + break;
>>>> +
>>>> + ncomp = (struct acpi_iort_named_component *)node->node_data;
>>>> +
>>>> + if (ACPI_FAILURE(acpi_get_name(adev->handle,
>>>> + ACPI_FULL_PATHNAME, &buffer))) {
>>>> + dev_warn(dev, "Can't get device full path name\n");
>>>> + break;
>>>> + }
>>>> +
>>>> + if (!strcmp(ncomp->device_name, (char *)buffer.pointer))
>>>> + return AE_OK;
>>>
>>> ... we need to kfree(buffer.pointer) before we return or break.
>>
>> For the record, I've queued this patch on top:
>>
>> diff --git a/drivers/acpi/iort.c b/drivers/acpi/iort.c
>> index 496dcf6..3b9e55b 100644
>> --- a/drivers/acpi/iort.c
>> +++ b/drivers/acpi/iort.c
>> @@ -158,11 +158,15 @@ iort_match_node_callback(struct acpi_iort_node *node, void *context)
>> if (ACPI_FAILURE(acpi_get_name(adev->handle,
>> ACPI_FULL_PATHNAME, &buffer))) {
>> dev_warn(dev, "Can't get device full path name\n");
>> - break;
>> - }
>> + } else {
>> + int match;
>>
>> - if (!strcmp(ncomp->device_name, (char *)buffer.pointer))
>> - return AE_OK;
>> + match = !strcmp(ncomp->device_name, buffer.pointer);
>> + acpi_os_free(&buffer);
>> +
>> + if (match)
>> + return AE_OK;
>> + }
>>
>> break;
>> }
>>
>>
>> assuming that Rafael is OK with the general approach, of course.
>>
>
> Thanks Marc. As Lorenzo pointed out, we need another fix for
> iort_node_map_rid(). Do you want me to refresh the whole series or this
> patch only?

If the changes are localized enough, just this patch.

Thanks,

M.
--
Jazz is not dead. It just smells funny...

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