[Skiboot] [PATCH 2/2] npu2: Purge cache when resetting a GPU

[Alexey Kardashevskiy]

On 08/06/2019 02:08, Reza Arbab wrote:
> After putting all a GPU's links in reset, do a cache purge in case we
> have CPU cache lines belonging to the now-unaccessible GPU memory.
> 
> Fixes: 68d11e4460ec ("npu2: Reset NVLinks when resetting a GPU")
> Cc: skiboot-stable at lists.ozlabs.org
> Signed-off-by: Reza Arbab <arbab at linux.ibm.com>
> ---
>  hw/npu2.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/hw/npu2.c b/hw/npu2.c
> index 774592911110..3a2808d7133c 100644
> --- a/hw/npu2.c
> +++ b/hw/npu2.c
> @@ -561,6 +561,8 @@ static int64_t npu2_gpu_bridge_sec_bus_reset(void *dev,
>  
>  	gpu = list_top(&pd->children, struct pci_device, link);
>  	if (gpu && (*data & PCI_CFG_BRCTL_SECONDARY_RESET)) {
> +		int64_t rc;
> +
>  		dt_for_each_compatible(dt_root, np, "ibm,power9-npu-pciex") {
>  			npphb = pci_get_phb(dt_prop_get_cell(np,
>  					"ibm,opal-phbid", 1));
> @@ -574,6 +576,10 @@ static int64_t npu2_gpu_bridge_sec_bus_reset(void *dev,
>  					npu2_dev_procedure_reset(ndev);
>  			}
>  		}
> +
> +		rc = purge_l2_l3_caches();
> +		if (rc)
> +			return rc;


Ah, missed that :( Probably would make more sense to have this in
npu2_dev_procedure_reset() as the other caller also purges caches.

Either way

Reviewed-by: Alexey Kardashevskiy <aik at ozlabs.ru>



>  	}
>  
>  	return OPAL_PARTIAL;
> 

-- 
Alexey