Re: [PATCH v6 05/14] ACPI: platform-msi: retrieve dev id from IORT

Tomasz Nowicki
2017-01-03T11:25:11Z

On 03.01.2017 10:37, Tomasz Nowicki wrote:
> On 03.01.2017 09:43, Tomasz Nowicki wrote:
>> On 02.01.2017 14:31, Hanjun Guo wrote:
>>> For devices connecting to ITS, it needs dev id to identify
>>> itself, and this dev id is represented in the IORT table in
>>> named componant node [1] for platform devices, so in this
>>> patch we will scan the IORT to retrieve device's dev id.
>>>
>>> Introduce iort_pmsi_get_dev_id() with pointer dev passed
>>> in for that purpose.
>>>
>>> [1]:
>>> https://static.docs.arm.com/den0049/b/DEN0049B_IO_Remapping_Table.pdf
>>>
>>> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
>>> Tested-by: Sinan Kaya <okaya@codeaurora.org>
>>> Tested-by: Majun <majun258@huawei.com>
>>> Tested-by: Xinwei Kong <kong.kongxinwei@hisilicon.com>
>>> Cc: Marc Zyngier <marc.zyngier@arm.com>
>>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>>> Cc: Tomasz Nowicki <tn@semihalf.com>
>>> Cc: Thomas Gleixner <tglx@linutronix.de>
>>> ---
>>> drivers/acpi/arm64/iort.c | 26
>>> ++++++++++++++++++++++++++
>>> drivers/irqchip/irq-gic-v3-its-platform-msi.c | 4 +++-
>>> include/linux/acpi_iort.h | 8 ++++++++
>>> 3 files changed, 37 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
>>> index 174e983..ab7bae7 100644
>>> --- a/drivers/acpi/arm64/iort.c
>>> +++ b/drivers/acpi/arm64/iort.c
>>> @@ -444,6 +444,32 @@ u32 iort_msi_map_rid(struct device *dev, u32
>>> req_id)
>>> }
>>>
>>> /**
>>> + * iort_pmsi_get_dev_id() - Get the device id for a device
>>> + * @dev: The device for which the mapping is to be done.
>>> + * @dev_id: The device ID found.
>>> + *
>>> + * Returns: 0 for successful find a dev id, errors otherwise
>>> + */
>>> +int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
>>> +{
>>> + struct acpi_iort_node *node;
>>> +
>>> + if (!iort_table)
>>> + return -ENODEV;
>>> +
>>> + node = iort_find_dev_node(dev);
>>> + if (!node) {
>>> + dev_err(dev, "can't find related IORT node\n");
>>> + return -ENODEV;
>>> + }
>>> +
>>> + if(!iort_node_get_id(node, dev_id, IORT_MSI_TYPE, 0))
>>> + return -ENODEV;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/**
>> Giving that you are extending this to NC->
>> SMMU->ITS case in later patch, we can use existing helpers from iort.c,
>> like that:
>>
>> +/**
>> + * iort_pmsi_get_dev_id() - Get the device id for a device
>> + * @dev: The device for which the mapping is to be done.
>> + * @dev_id: The device ID found.
>> + *
>> + * Returns: 0 for successful find a dev id, errors otherwise
>> + */
>> +int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
>> +{
>> + struct acpi_iort_node *node;
>> +
>> + node = iort_find_dev_node(dev);
>> + if (!node)
>> + return -ENODEV;
>> +
>> + if (!iort_node_map_rid(node, 0, dev_id, IORT_MSI_TYPE))
>> + return -ENODEV;
>> +
>> + return 0;
>> +}
>>
>> Correct me if I am wrong.
>>
>
> "0" as rid_in for iort_node_map_rid() isn't good idea, sorry...
>

I refactored iort_node_map_rid() and added new
iort_node_map_single_rid() which should works for you. Below patch bases
on v4.10-rc2:

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index e0d2e6e..2526b89 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -297,8 +297,17 @@ static acpi_status iort_match_node_callback(struct
acpi_iort_node *node,
}

static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32
rid_in,
- u32 *rid_out)
+ u32 *rid_out, bool single)
{
+ if (!single) {
+ if (rid_in < map->input_base ||
+ (rid_in >= map->input_base + map->id_count))
+ return -ENXIO;
+
+ *rid_out = map->output_base + (rid_in - map->input_base);
+ return 0;
+ }
+
/* Single mapping does not care for input id */
if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
if (type == ACPI_IORT_NODE_NAMED_COMPONENT ||
@@ -309,15 +318,9 @@ static int iort_id_map(struct acpi_iort_id_mapping
*map, u8 type, u32 rid_in,

pr_warn(FW_BUG "[map %p] SINGLE MAPPING flag not allowed for node
type %d, skipping ID map\n",
map, type);
- return -ENXIO;
}

- if (rid_in < map->input_base ||
- (rid_in >= map->input_base + map->id_count))
- return -ENXIO;
-
- *rid_out = map->output_base + (rid_in - map->input_base);
- return 0;
+ return -ENXIO;
}

static
@@ -359,6 +362,38 @@ struct acpi_iort_node *iort_node_get_id(struct
acpi_iort_node *node,
return NULL;
}

+static struct acpi_iort_node *iort_node_map_rid_one(struct
acpi_iort_node *node,
+ u32 *rid, bool single)
+{
+ struct acpi_iort_id_mapping *map;
+ struct acpi_iort_node *next;
+ int i;
+
+ if (!node->mapping_offset || !node->mapping_count)
+ return NULL;
+
+ map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
+ node->mapping_offset);
+
+ /* Firmware bug! */
+ if (!map->output_reference) {
+ pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
+ node, node->type);
+ return NULL;
+ }
+
+ next = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
+ map->output_reference);
+
+ /* Do the RID translation */
+ for (i = 0; i < node->mapping_count; i++, map++) {
+ if (!iort_id_map(map, node->type, *rid, rid, single))
+ return next;
+ }
+
+ return NULL;
+}
+
static struct acpi_iort_node *iort_node_map_rid(struct acpi_iort_node
*node,
u32 rid_in, u32 *rid_out,
u8 type_mask)
@@ -367,42 +402,15 @@ static struct acpi_iort_node
*iort_node_map_rid(struct acpi_iort_node *node,

/* Parse the ID mapping tree to find specified node type */
while (node) {
- struct acpi_iort_id_mapping *map;
- int i;
-
if (IORT_TYPE_MASK(node->type) & type_mask) {
if (rid_out)
*rid_out = rid;
return node;
}

- if (!node->mapping_offset || !node->mapping_count)
- goto fail_map;
-
- map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
- node->mapping_offset);
-
- /* Firmware bug! */
- if (!map->output_reference) {
- pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
- node, node->type);
- goto fail_map;
- }
-
- /* Do the RID translation */
- for (i = 0; i < node->mapping_count; i++, map++) {
- if (!iort_id_map(map, node->type, rid, &rid))
- break;
- }
-
- if (i == node->mapping_count)
- goto fail_map;
-
- node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
- map->output_reference);
+ node = iort_node_map_rid_one(node, &rid, false);
}

-fail_map:
/* Map input RID to output RID unchanged on mapping failure*/
if (rid_out)
*rid_out = rid_in;
@@ -410,6 +418,20 @@ static struct acpi_iort_node
*iort_node_map_rid(struct acpi_iort_node *node,
return NULL;
}

+static struct acpi_iort_node *iort_node_map_single_rid(
+ struct acpi_iort_node *node,
+ u32 *rid_out, u8 type_mask)
+{
+ u32 rid;
+
+ /* Get the initial rid */
+ node = iort_node_map_rid_one(node, &rid, true);
+ if (!node)
+ return NULL;
+
+ return iort_node_map_rid(node, rid, rid_out, type_mask);
+}
+
static struct acpi_iort_node *iort_find_dev_node(struct device *dev)
{
struct pci_bus *pbus;