[PATCH] drm/amdkfd: report atomics support in io_links over xgmi

[Felix Kuehling]

Am 2021-04-29 um 9:12 p.m. schrieb Zeng, Oak:
> I think part of this can be done more clean in amdgpu_device_init:
>
> 	r = 0;
> 	If (!adev->gmc.xgmi.connected_to_cpu)
> 		/* enable PCIE atomic ops */
> 		r = pci_enable_atomic_ops_to_root(adev->pdev,
> 					  PCI_EXP_DEVCAP2_ATOMIC_COMP32 |
> 					  PCI_EXP_DEVCAP2_ATOMIC_COMP64);
> 	if (r) {
> 		adev->have_atomics_support = false;
> 		DRM_INFO("PCIE atomic ops is not supported\n");
> 	} else {
> 		adev->have_atomics_support = true;
> 	}

This code is already in amdgpu_device_init. I'm not sure what's your
point. Are you suggesting that the topology flags should be updated in
amdgpu_device_init? That's not really possible because the KFD topology
data structures don't exist at that time (they do only after the call to
amdgpu_device_ip_init) and the data structures are not known in
amdgpu_device.c. It's cleaner to keep this compartmentalized in
kfd_topology.c.

Regards,
  Felix


> Regards,
> Oak 
>
>  
>
> On 2021-04-29, 5:36 AM, "Kim, Jonathan" <Jonathan.Kim at amd.com> wrote:
>
>     Link atomics support over xGMI should be reported independently of PCIe.
>
>     Signed-off-by: Jonathan Kim <jonathan.kim at amd.com>
>     Tested-by: Ramesh Errabolu <ramesh.errabolu at amd.com>
>     ---
>      drivers/gpu/drm/amd/amdkfd/kfd_topology.c | 29 ++++++++++++++---------
>      1 file changed, 18 insertions(+), 11 deletions(-)
>
>     diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
>     index 083ac9babfa8..30430aefcfc7 100644
>     --- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
>     +++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
>     @@ -1196,6 +1196,7 @@ static void kfd_fill_iolink_non_crat_info(struct kfd_topology_device *dev)
>      {
>      	struct kfd_iolink_properties *link, *cpu_link;
>      	struct kfd_topology_device *cpu_dev;
>     +	struct amdgpu_device *adev;
>      	uint32_t cap;
>      	uint32_t cpu_flag = CRAT_IOLINK_FLAGS_ENABLED;
>      	uint32_t flag = CRAT_IOLINK_FLAGS_ENABLED;
>     @@ -1203,18 +1204,24 @@ static void kfd_fill_iolink_non_crat_info(struct kfd_topology_device *dev)
>      	if (!dev || !dev->gpu)
>      		return;
>
>     -	pcie_capability_read_dword(dev->gpu->pdev,
>     -			PCI_EXP_DEVCAP2, &cap);
>     -
>     -	if (!(cap & (PCI_EXP_DEVCAP2_ATOMIC_COMP32 |
>     -		     PCI_EXP_DEVCAP2_ATOMIC_COMP64)))
>     -		cpu_flag |= CRAT_IOLINK_FLAGS_NO_ATOMICS_32_BIT |
>     -			CRAT_IOLINK_FLAGS_NO_ATOMICS_64_BIT;
>     +	adev = (struct amdgpu_device *)(dev->gpu->kgd);
>     +	if (!adev->gmc.xgmi.connected_to_cpu) {
>     +		pcie_capability_read_dword(dev->gpu->pdev,
>     +				PCI_EXP_DEVCAP2, &cap);
>     +
>     +		if (!(cap & (PCI_EXP_DEVCAP2_ATOMIC_COMP32 |
>     +			     PCI_EXP_DEVCAP2_ATOMIC_COMP64)))
>     +			cpu_flag |= CRAT_IOLINK_FLAGS_NO_ATOMICS_32_BIT |
>     +				CRAT_IOLINK_FLAGS_NO_ATOMICS_64_BIT;
>     +	}
>
>     -	if (!dev->gpu->pci_atomic_requested ||
>     -	    dev->gpu->device_info->asic_family == CHIP_HAWAII)
>     -		flag |= CRAT_IOLINK_FLAGS_NO_ATOMICS_32_BIT |
>     -			CRAT_IOLINK_FLAGS_NO_ATOMICS_64_BIT;
>     +	if (!adev->gmc.xgmi.num_physical_nodes) {
>     +		if (!dev->gpu->pci_atomic_requested ||
>     +				dev->gpu->device_info->asic_family ==
>     +							CHIP_HAWAII)
>     +			flag |= CRAT_IOLINK_FLAGS_NO_ATOMICS_32_BIT |
>     +				CRAT_IOLINK_FLAGS_NO_ATOMICS_64_BIT;
>     +	}
>
>      	/* GPU only creates direct links so apply flags setting to all */
>      	list_for_each_entry(link, &dev->io_link_props, list) {
>     -- 
>     2.17.1
>
>