Re: [PATCH v3 2/2] acpi, gicv3-its, numa: Adding numa node mapping for gic-its units

[Ganapatrao Kulkarni <gpkulkarni@gmail.com>]

On Wed, Jun 21, 2017 at 2:58 PM, Lorenzo Pieralisi
<lorenzo.pieralisi@arm.com> wrote:
> On Wed, Jun 21, 2017 at 11:45:43AM +0530, Ganapatrao Kulkarni wrote:
>> Add code to parse SRAT ITS Affinity sub table as defined in ACPI 6.2
>> Later in per device probe, ITS devices are mapped to
>> numa node using ITS id to proximity domain mapping.
>>
>> Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
>> ---
>>  drivers/irqchip/irq-gic-v3-its.c | 80 +++++++++++++++++++++++++++++++++++++++-
>>  1 file changed, 79 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
>> index 45ea1933..88cfb32 100644
>> --- a/drivers/irqchip/irq-gic-v3-its.c
>> +++ b/drivers/irqchip/irq-gic-v3-its.c
>> @@ -1833,6 +1833,82 @@ static int __init its_of_probe(struct device_node *node)
>>
>>  #define ACPI_GICV3_ITS_MEM_SIZE (SZ_128K)
>>
>> +#ifdef CONFIG_ACPI_NUMA
>> +struct its_srat_map {
>> +     u32     numa_node;  /* numa node id */
>> +     u32     its_id;  /* GIC ITS ID */
>> +};
>> +
>> +static struct its_srat_map its_srat_maps[MAX_NUMNODES] __initdata = {
>> +     [0 ... MAX_NUMNODES - 1] = {NUMA_NO_NODE, UINT_MAX} };
>
> Nit: UINT_MAX is as valid as 0 as its_id (but the intent here is to make
> it look like an invalid value), given that the its_in_srat counter
> defines what entries are valid I do not necessarily see the point in
> initializing with something that is a valid value != 0.

ok, this array may not need any init,

>
>> +static int its_in_srat __initdata;
>> +
>> +static int __init
>> +acpi_get_its_numa_node(u32 its_id)
>> +{
>> +     int i;
>> +
>> +     for (i = 0; i < its_in_srat; i++) {
>> +             if (its_id == its_srat_maps[i].its_id)
>> +                     return its_srat_maps[i].numa_node;
>> +     }
>> +     return NUMA_NO_NODE;
>> +}
>> +
>> +static int __init
>> +gic_acpi_parse_srat_its(struct acpi_subtable_header *header,
>> +                      const unsigned long end)
>> +{
>> +     int pxm, node;
>> +     struct acpi_srat_its_affinity *its_affinity;
>> +
>> +     its_affinity = (struct acpi_srat_its_affinity *)header;
>> +     if (!its_affinity)
>> +             return -EINVAL;
>> +
>> +     if (its_affinity->header.length <
>> +                     sizeof(struct acpi_srat_its_affinity)) {
>> +             pr_err("SRAT:ITS: Invalid SRAT header length: %d\n",
>> +                     its_affinity->header.length);
>> +             return -EINVAL;
>> +     }
>> +
>> +     if (its_in_srat >= MAX_NUMNODES) {
>> +             pr_err("SRAT:ITS: ITS devices exceeding max count[%d]\n",
>> +                             MAX_NUMNODES);
>> +             return -EINVAL;
>> +     }
>> +
>> +     pxm = its_affinity->proximity_domain;
>> +     node = acpi_map_pxm_to_node(pxm);
>> +
>> +     if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) {
>> +             pr_err("SRAT:ITS: Invalid numa node %d\n", node);
>> +             return -EINVAL;
>
> As Marc mentioned you should bail out here but continue parsing entries,
> aka "return 0";

agreed.
>
> Thanks,
> Lorenzo
>
>> +     }
>> +
>> +     its_srat_maps[its_in_srat].numa_node = node;
>> +     its_srat_maps[its_in_srat].its_id = its_affinity->its_id;
>> +     its_in_srat++;
>> +     pr_info("ACPI: NUMA: SRAT: ITS: PXM %d -> ITS_ID %d -> NODE %d\n",
>> +             pxm, its_affinity->its_id, node);
>> +
>> +     return 0;
>> +}
>> +
>> +static int __init acpi_table_parse_srat_its(void)
>> +{
>> +     return acpi_table_parse_entries(ACPI_SIG_SRAT,
>> +                                     sizeof(struct acpi_table_srat),
>> +                                     ACPI_SRAT_TYPE_GIC_ITS_AFFINITY,
>> +                                     gic_acpi_parse_srat_its, 0);
>> +}
>> +#else
>> +#define acpi_table_parse_srat_its()  do { } while (0)
>> +#define acpi_get_its_numa_node(its_id)       NUMA_NO_NODE
>> +#endif
>> +
>>  static int __init gic_acpi_parse_madt_its(struct acpi_subtable_header *header,
>>                                         const unsigned long end)
>>  {
>> @@ -1861,7 +1937,8 @@ static int __init gic_acpi_parse_madt_its(struct acpi_subtable_header *header,
>>               goto dom_err;
>>       }
>>
>> -     err = its_probe_one(&res, dom_handle, NUMA_NO_NODE);
>> +     err = its_probe_one(&res, dom_handle,
>> +                     acpi_get_its_numa_node(its_entry->translation_id));
>>       if (!err)
>>               return 0;
>>
>> @@ -1873,6 +1950,7 @@ static int __init gic_acpi_parse_madt_its(struct acpi_subtable_header *header,
>>
>>  static void __init its_acpi_probe(void)
>>  {
>> +     acpi_table_parse_srat_its();
>>       acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
>>                             gic_acpi_parse_madt_its, 0);
>>  }
>> --
>> 1.8.1.4
>>

thanks
Ganapat