Re: [PATCH 04/11] powerpc/powernv/ioda: Release opencapi device

["Alastair D'Silva" <alastair@au1.ibm.com>]

On Mon, 2019-09-09 at 17:45 +0200, Frederic Barrat wrote:
> With hotplug, an opencapi device can now go away. It needs to be
> released, mostly to clean up its PE state. We were previously not
> defining any device callback. We can reuse the standard PCI release
> callback, it does a bit too much for an opencapi device, but it's
> harmless, and only needs minor tuning.
> 
> Also separate the undo of the PELT-V code in a separate function, it
> is not needed for NPU devices and it improves a bit the readability
> of
> the code.
> 
> Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
> ---
>  arch/powerpc/platforms/powernv/pci-ioda.c | 59 +++++++++++++++----
> ----
>  1 file changed, 39 insertions(+), 20 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c
> b/arch/powerpc/platforms/powernv/pci-ioda.c
> index 06ce7ddaa0cf..e5895c05efae 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -188,7 +188,7 @@ static void pnv_ioda_free_pe(struct pnv_ioda_pe
> *pe)
>  	unsigned int pe_num = pe->pe_number;
>  
>  	WARN_ON(pe->pdev);
> -	WARN_ON(pe->npucomp); /* NPUs are not supposed to be freed */
> +	WARN_ON(pe->npucomp); /* NPUs for nvlink are not supposed to be
> freed */
>  	kfree(pe->npucomp);
>  	memset(pe, 0, sizeof(struct pnv_ioda_pe));
>  	clear_bit(pe_num, phb->ioda.pe_alloc);
> @@ -777,6 +777,34 @@ static int pnv_ioda_set_peltv(struct pnv_phb
> *phb,
>  	return 0;
>  }
>  
> +static void pnv_ioda_unset_peltv(struct pnv_phb *phb,
> +				 struct pnv_ioda_pe *pe,
> +				 struct pci_dev *parent)
> +{
> +	int64_t rc;
> +
> +	while (parent) {
> +		struct pci_dn *pdn = pci_get_pdn(parent);
> +
> +		if (pdn && pdn->pe_number != IODA_INVALID_PE) {
> +			rc = opal_pci_set_peltv(phb->opal_id, pdn-
> >pe_number,
> +						pe->pe_number,
> +						OPAL_REMOVE_PE_FROM_DOM
> AIN);
> +			/* XXX What to do in case of error ? */

Can we take the opportunity to address this comment?

> +		}
> +		parent = parent->bus->self;
> +	}
> +
> +	opal_pci_eeh_freeze_clear(phb->opal_id, pe->pe_number,
> +				  OPAL_EEH_ACTION_CLEAR_FREEZE_ALL);
> +
> +	/* Disassociate PE in PELT */
> +	rc = opal_pci_set_peltv(phb->opal_id, pe->pe_number,
> +				pe->pe_number,
> OPAL_REMOVE_PE_FROM_DOMAIN);
> +	if (rc)
> +		pe_warn(pe, "OPAL error %lld remove self from PELTV\n",
> rc);
> +}
> +
>  static int pnv_ioda_deconfigure_pe(struct pnv_phb *phb, struct
> pnv_ioda_pe *pe)
>  {
>  	struct pci_dev *parent;
> @@ -827,25 +855,13 @@ static int pnv_ioda_deconfigure_pe(struct
> pnv_phb *phb, struct pnv_ioda_pe *pe)
>  	for (rid = pe->rid; rid < rid_end; rid++)
>  		phb->ioda.pe_rmap[rid] = IODA_INVALID_PE;
>  
> -	/* Release from all parents PELT-V */
> -	while (parent) {
> -		struct pci_dn *pdn = pci_get_pdn(parent);
> -		if (pdn && pdn->pe_number != IODA_INVALID_PE) {
> -			rc = opal_pci_set_peltv(phb->opal_id, pdn-
> >pe_number,
> -						pe->pe_number,
> OPAL_REMOVE_PE_FROM_DOMAIN);
> -			/* XXX What to do in case of error ? */
> -		}
> -		parent = parent->bus->self;
> -	}
> -
> -	opal_pci_eeh_freeze_clear(phb->opal_id, pe->pe_number,
> -				  OPAL_EEH_ACTION_CLEAR_FREEZE_ALL);
> +	/*
> +	 * Release from all parents PELT-V. NPUs don't have a PELTV
> +	 * table
> +	 */
> +	if (phb->type != PNV_PHB_NPU_NVLINK && phb->type !=
> PNV_PHB_NPU_OCAPI)
> +		pnv_ioda_unset_peltv(phb, pe, parent);
>  
> -	/* Disassociate PE in PELT */
> -	rc = opal_pci_set_peltv(phb->opal_id, pe->pe_number,
> -				pe->pe_number,
> OPAL_REMOVE_PE_FROM_DOMAIN);
> -	if (rc)
> -		pe_warn(pe, "OPAL error %lld remove self from PELTV\n",
> rc);
>  	rc = opal_pci_set_pe(phb->opal_id, pe->pe_number, pe->rid,
>  			     bcomp, dcomp, fcomp, OPAL_UNMAP_PE);
>  	if (rc)
> @@ -3540,6 +3556,8 @@ static void pnv_ioda_release_pe(struct
> pnv_ioda_pe *pe)
>  	case PNV_PHB_IODA2:
>  		pnv_pci_ioda2_release_pe_dma(pe);
>  		break;
> +	case PNV_PHB_NPU_OCAPI:
> +		break;
>  	default:
>  		WARN_ON(1);
>  	}
> @@ -3592,7 +3610,7 @@ static void pnv_pci_release_device(struct
> pci_dev *pdev)
>  	pe = &phb->ioda.pe_array[pdn->pe_number];
>  	pdn->pe_number = IODA_INVALID_PE;
>  
> -	WARN_ON(--pe->device_count < 0);
> +	WARN_ON((pe->flags != PNV_IODA_PE_DEV) && (--pe->device_count <
> 0));
>  	if (pe->device_count == 0)
>  		pnv_ioda_release_pe(pe);
>  }
> @@ -3641,6 +3659,7 @@ static const struct pci_controller_ops
> pnv_npu_ioda_controller_ops = {
>  
>  static const struct pci_controller_ops
> pnv_npu_ocapi_ioda_controller_ops = {
>  	.enable_device_hook	= pnv_ocapi_enable_device_hook,
> +	.release_device		= pnv_pci_release_device,
>  	.window_alignment	= pnv_pci_window_alignment,
>  	.reset_secondary_bus	= pnv_pci_reset_secondary_bus,
>  	.shutdown		= pnv_pci_ioda_shutdown,
-- 
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819