Re: [PATCH] drm/amdkfd: Remove vla

[Felix Kuehling]

Thanks Christian for catching that. I'm working on a patch series to
upstream Vega10 support, about 95% done. It will add this ASIC info for
Vega10:

static const struct kfd_device_info vega10_device_info = {
	.asic_family = CHIP_VEGA10,
	.max_pasid_bits = 16,
	.max_no_of_hqd  = 24,
	.doorbell_size  = 8,
	.ih_ring_entry_size = 8 * sizeof(uint32_t), /* !!! IH ring entry size is bigger on Vega10 !!! */
	.event_interrupt_class = &event_interrupt_class_v9,
	.num_of_watch_points = 4,
	.mqd_size_aligned = MQD_SIZE_ALIGNED,
	.supports_cwsr = true,
	.needs_iommu_device = false,
	.needs_pci_atomics = false,
};

If you change it to uint32_t ih_ring_entry[8] and update the check, it
should be reasonably future proof.

Regards,
 Felix


On 2018-04-10 02:38 AM, Christian KÃnig wrote:
> Am 09.04.2018 um 23:06 schrieb Laura Abbott:
>> There's an ongoing effort to remove VLAs[1] from the kernel to
>> eventually
>> turn on -Wvla. The single VLA usage in the amdkfd driver is actually
>> constant across all current platforms.
>
> Actually that isn't correct.
>
> Could be that we haven't upstreamed KFD support for them, but Vega10
> have a different interrupt ring entry size and so would cause the
> error message here.
>
>> Switch to a constant size array
>> instead.
>
> I would say to just make make the array bigger.
>
> Regards,
> Christian.
>
>>
>> [1] https://lkml.org/lkml/2018/3/7/621
>>
>> Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx>
>> ---
>> Â drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c | 8 +++++---
>> Â 1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c
>> b/drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c
>> index 035c351f47c5..c9863858f343 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c
>> @@ -139,10 +139,12 @@ static void interrupt_wq(struct work_struct *work)
>> Â {
>> ÂÂÂÂÂ struct kfd_dev *dev = container_of(work, struct kfd_dev,
>> ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ interrupt_work);
>> +ÂÂÂ uint32_t ih_ring_entry[4];
>> Â -ÂÂÂ uint32_t ih_ring_entry[DIV_ROUND_UP(
>> -ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ dev->device_info->ih_ring_entry_size,
>> -ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ sizeof(uint32_t))];
>> +ÂÂÂ if (dev->device_info->ih_ring_entry_size > (4 *
>> sizeof(uint32_t))) {
>> +ÂÂÂÂÂÂÂ dev_err(kfd_chardev(), "Ring entry too small\n");
>> +ÂÂÂÂÂÂÂ return;
>> +ÂÂÂ }
>> Â ÂÂÂÂÂ while (dequeue_ih_ring_entry(dev, ih_ring_entry))
>> ÂÂÂÂÂÂÂÂÂ dev->device_info->event_interrupt_class->interrupt_wq(dev,
>
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx