Re: [PATCH v2 08/30] s390/pci: stash associated GISA designation

[Pierre Morel]

On 1/14/22 21:31, Matthew Rosato wrote:
> For passthrough devices, we will need to know the GISA designation of the
> guest if interpretation facilities are to be used.  Setup to stash this in
> the zdev and set a default of 0 (no GISA designation) for now; a subsequent
> patch will set a valid GISA designation for passthrough devices.
> Also, extend mpcific routines to specify this stashed designation as part
> of the mpcific command.
>
> Reviewed-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
> Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> Reviewed-by: Eric Farman <farman@xxxxxxxxxxxxx>
> Reviewed-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
> Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
> ---
>   arch/s390/include/asm/pci.h     | 1 +
>   arch/s390/include/asm/pci_clp.h | 3 ++-
>   arch/s390/pci/pci.c             | 6 ++++++
>   arch/s390/pci/pci_clp.c         | 1 +
>   arch/s390/pci/pci_irq.c         | 5 +++++
>   5 files changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
> index 90824be5ce9a..2474b8d30f2a 100644
> --- a/arch/s390/include/asm/pci.h
> +++ b/arch/s390/include/asm/pci.h
> @@ -123,6 +123,7 @@ struct zpci_dev {
>   	enum zpci_state state;
>   	u32		fid;		/* function ID, used by sclp */
>   	u32		fh;		/* function handle, used by insn's */
> +	u32		gd;		/* GISA designation for passthrough */

I already gave my R-B, and do not want to remove it, but wouldn't it be 
possible to use more explicit names like gisa_designation instead of 
just gd.
It would not change anything to the functionality but would facilitate 
the maintenance?

>   	u16		vfn;		/* virtual function number */
>   	u16		pchid;		/* physical channel ID */
>   	u8		pfgid;		/* function group ID */
> diff --git a/arch/s390/include/asm/pci_clp.h b/arch/s390/include/asm/pci_clp.h
> index 1f4b666e85ee..3af8d196da74 100644
> --- a/arch/s390/include/asm/pci_clp.h
> +++ b/arch/s390/include/asm/pci_clp.h
> @@ -173,7 +173,8 @@ struct clp_req_set_pci {
>   	u16 reserved2;
>   	u8 oc;				/* operation controls */
>   	u8 ndas;			/* number of dma spaces */
> -	u64 reserved3;
> +	u32 reserved3;
> +	u32 gd;				/* GISA designation */

here too.


>   } __packed;
>   
>   /* Set PCI function response */
> diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
> index 792f8e0f2178..0c9879dae752 100644
> --- a/arch/s390/pci/pci.c
> +++ b/arch/s390/pci/pci.c
> @@ -119,6 +119,7 @@ int zpci_register_ioat(struct zpci_dev *zdev, u8 dmaas,
>   	fib.pba = base;
>   	fib.pal = limit;
>   	fib.iota = iota | ZPCI_IOTA_RTTO_FLAG;
> +	fib.gd = zdev->gd;
>   	cc = zpci_mod_fc(req, &fib, &status);
>   	if (cc)
>   		zpci_dbg(3, "reg ioat fid:%x, cc:%d, status:%d\n", zdev->fid, cc, status);
> @@ -132,6 +133,8 @@ int zpci_unregister_ioat(struct zpci_dev *zdev, u8 dmaas)
>   	struct zpci_fib fib = {0};
>   	u8 cc, status;
>   
> +	fib.gd = zdev->gd;
> +
>   	cc = zpci_mod_fc(req, &fib, &status);
>   	if (cc)
>   		zpci_dbg(3, "unreg ioat fid:%x, cc:%d, status:%d\n", zdev->fid, cc, status);
> @@ -159,6 +162,7 @@ int zpci_fmb_enable_device(struct zpci_dev *zdev)
>   	atomic64_set(&zdev->unmapped_pages, 0);
>   
>   	fib.fmb_addr = virt_to_phys(zdev->fmb);
> +	fib.gd = zdev->gd;
>   	cc = zpci_mod_fc(req, &fib, &status);
>   	if (cc) {
>   		kmem_cache_free(zdev_fmb_cache, zdev->fmb);
> @@ -177,6 +181,8 @@ int zpci_fmb_disable_device(struct zpci_dev *zdev)
>   	if (!zdev->fmb)
>   		return -EINVAL;
>   
> +	fib.gd = zdev->gd;
> +
>   	/* Function measurement is disabled if fmb address is zero */
>   	cc = zpci_mod_fc(req, &fib, &status);
>   	if (cc == 3) /* Function already gone. */
> diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
> index be077b39da33..e9ed0e4a5cf0 100644
> --- a/arch/s390/pci/pci_clp.c
> +++ b/arch/s390/pci/pci_clp.c
> @@ -240,6 +240,7 @@ static int clp_set_pci_fn(struct zpci_dev *zdev, u32 *fh, u8 nr_dma_as, u8 comma
>   		rrb->request.fh = zdev->fh;
>   		rrb->request.oc = command;
>   		rrb->request.ndas = nr_dma_as;
> +		rrb->request.gd = zdev->gd;
>   
>   		rc = clp_req(rrb, CLP_LPS_PCI);
>   		if (rrb->response.hdr.rsp == CLP_RC_SETPCIFN_BUSY) {
> diff --git a/arch/s390/pci/pci_irq.c b/arch/s390/pci/pci_irq.c
> index 2f675355fd0c..17e5adfe1273 100644
> --- a/arch/s390/pci/pci_irq.c
> +++ b/arch/s390/pci/pci_irq.c
> @@ -43,6 +43,7 @@ static int zpci_set_airq(struct zpci_dev *zdev)
>   	fib.fmt0.aibvo = 0;	/* each zdev has its own interrupt vector */
>   	fib.fmt0.aisb = virt_to_phys(zpci_sbv->vector) + (zdev->aisb / 64) * 8;
>   	fib.fmt0.aisbo = zdev->aisb & 63;
> +	fib.gd = zdev->gd;
>   
>   	return zpci_mod_fc(req, &fib, &status) ? -EIO : 0;
>   }
> @@ -54,6 +55,8 @@ static int zpci_clear_airq(struct zpci_dev *zdev)
>   	struct zpci_fib fib = {0};
>   	u8 cc, status;
>   
> +	fib.gd = zdev->gd;
> +
>   	cc = zpci_mod_fc(req, &fib, &status);
>   	if (cc == 3 || (cc == 1 && status == 24))
>   		/* Function already gone or IRQs already deregistered. */
> @@ -72,6 +75,7 @@ static int zpci_set_directed_irq(struct zpci_dev *zdev)
>   	fib.fmt = 1;
>   	fib.fmt1.noi = zdev->msi_nr_irqs;
>   	fib.fmt1.dibvo = zdev->msi_first_bit;
> +	fib.gd = zdev->gd;
>   
>   	return zpci_mod_fc(req, &fib, &status) ? -EIO : 0;
>   }
> @@ -84,6 +88,7 @@ static int zpci_clear_directed_irq(struct zpci_dev *zdev)
>   	u8 cc, status;
>   
>   	fib.fmt = 1;
> +	fib.gd = zdev->gd;
>   	cc = zpci_mod_fc(req, &fib, &status);
>   	if (cc == 3 || (cc == 1 && status == 24))
>   		/* Function already gone or IRQs already deregistered. */

--
Pierre Morel
IBM Lab Boeblingen