Messages in this thread | | | Subject | Re: [PATCH v2] irqchip/gic-v3-its: Allow GIC ITS number more than MAX_NUMNODES | From | Hanjun Guo <> | Date | Wed, 26 Jul 2017 17:55:17 +0800 |
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On 2017/7/26 16:00, Marc Zyngier wrote: > On 26/07/17 08:52, Hanjun Guo wrote: >> On 2017/7/25 18:30, Marc Zyngier wrote: >>> On 22/07/17 04:54, Hanjun Guo wrote: >>>> From: Hanjun Guo <hanjun.guo@linaro.org> >>>> >>>> When running 4.13-rc1 on top of D05, I got the boot log: >>>> >>>> [ 0.000000] SRAT: PXM 0 -> ITS 0 -> Node 0 >>>> [ 0.000000] SRAT: PXM 0 -> ITS 1 -> Node 0 >>>> [ 0.000000] SRAT: PXM 0 -> ITS 2 -> Node 0 >>>> [ 0.000000] SRAT: PXM 1 -> ITS 3 -> Node 1 >>>> [ 0.000000] SRAT: ITS affinity exceeding max count[4] >>>> >>>> This is wrong on D05 as we have 8 ITSes with 4 NUMA nodes. >>>> >>>> So dynamically alloc the memory needed instead of using >>>> its_srat_maps[MAX_NUMNODES], which count the number of >>>> ITS entry(ies) in SRAT and alloc its_srat_maps as needed, >>>> then build the mapping of numa node to ITS ID. Of course, >>>> its_srat_maps will be freed after ITS probing because >>>> we don't need that after boot. >>>> >>>> After doing this, I got what I wanted: >>>> >>>> [ 0.000000] SRAT: PXM 0 -> ITS 0 -> Node 0 >>>> [ 0.000000] SRAT: PXM 0 -> ITS 1 -> Node 0 >>>> [ 0.000000] SRAT: PXM 0 -> ITS 2 -> Node 0 >>>> [ 0.000000] SRAT: PXM 1 -> ITS 3 -> Node 1 >>>> [ 0.000000] SRAT: PXM 2 -> ITS 4 -> Node 2 >>>> [ 0.000000] SRAT: PXM 2 -> ITS 5 -> Node 2 >>>> [ 0.000000] SRAT: PXM 2 -> ITS 6 -> Node 2 >>>> [ 0.000000] SRAT: PXM 3 -> ITS 7 -> Node 3 >>>> >>>> Fixes: dbd2b8267233 ("irqchip/gic-v3-its: Add ACPI NUMA node mapping") >>>> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> >>>> Cc: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com> >>>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> >>>> Cc: Marc Zyngier <marc.zyngier@arm.com> >>>> --- >>>> >>>> v1->v2: >>>> - Add NULL check in acpi_get_its_numa_node() for no ITS affinity case; >>>> - Free the its_srat_maps after ITS probing. >>>> >>>> drivers/irqchip/irq-gic-v3-its.c | 39 ++++++++++++++++++++++++++++++++------- >>>> 1 file changed, 32 insertions(+), 7 deletions(-) >>>> >>>> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c >>>> index 3ccdf76..1d692aa 100644 >>>> --- a/drivers/irqchip/irq-gic-v3-its.c >>>> +++ b/drivers/irqchip/irq-gic-v3-its.c >>>> @@ -1847,13 +1847,16 @@ struct its_srat_map { >>>> u32 its_id; >>>> }; >>>> >>>> -static struct its_srat_map its_srat_maps[MAX_NUMNODES] __initdata; >>>> +static struct its_srat_map *its_srat_maps __initdata; >>>> static int its_in_srat __initdata; >>>> >>>> static int __init acpi_get_its_numa_node(u32 its_id) >>>> { >>>> int i; >>>> >>>> + if (!its_srat_maps) >>>> + return NUMA_NO_NODE; >>>> + >>>> for (i = 0; i < its_in_srat; i++) { >>>> if (its_id == its_srat_maps[i].its_id) >>>> return its_srat_maps[i].numa_node; >>>> @@ -1861,6 +1864,12 @@ static int __init acpi_get_its_numa_node(u32 its_id) >>>> return NUMA_NO_NODE; >>>> } >>>> >>>> +static int __init gic_acpi_match_srat_its(struct acpi_subtable_header *header, >>>> + const unsigned long end) >>>> +{ >>>> + return 0; >>>> +} >>>> + >>>> static int __init gic_acpi_parse_srat_its(struct acpi_subtable_header *header, >>>> const unsigned long end) >>>> { >>>> @@ -1877,12 +1886,6 @@ static int __init gic_acpi_parse_srat_its(struct acpi_subtable_header *header, >>>> return -EINVAL; >>>> } >>>> >>>> - if (its_in_srat >= MAX_NUMNODES) { >>>> - pr_err("SRAT: ITS affinity exceeding max count[%d]\n", >>>> - MAX_NUMNODES); >>>> - return -EINVAL; >>>> - } >>>> - >>> >>> So you're getting rid of that message when overflowing the array... >> >> This overflowing will not happen, because I scan the SRAT >> to count the entry(ies) of ITS affinity first to alloc the >> array, and then parse the same SRAT again to setup the mapping >> of NUMA node to ITS, so is it fine for us to just remove the >> check here? > > Removing that check is fine, as long as you make sure the allocation > hasn't failed.
Sorry, just want to make sure I understand correctly. This function will not be called if allocation failure, so do you mean we can keep the code as it is?
Thanks Hanjun
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