diff mbox

[V7,1/8] ACPI: I/O Remapping Table (IORT) initial support

Message ID 576A6D7F.6010407@arm.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Marc Zyngier June 22, 2016, 10:50 a.m. UTC
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:



assuming that Rafael is OK with the general approach, of course.

Thanks,

	M.

Comments

Tomasz Nowicki June 22, 2016, 11:06 a.m. UTC | #1
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?

Tomasz
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Marc Zyngier June 22, 2016, 12:03 p.m. UTC | #2
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.
diff mbox

Patch

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;
 	}