[Very RFC 19/46] powernv/eeh: Use standard PCI capability lookup functions

[Alexey Kardashevskiy]

On 20/11/2019 12:28, Oliver O'Halloran wrote:
> We have a pci_dev so we can use the functions provided by the PCI core for
> looking up capabilities. This should be safe since these are only called
> when initialising the eeh_dev when the device is first probed and not in
> the EEH recovery path where config accesses are blocked.
> 
> This might cause a problem if an EEH event occured while probing the device,
> but I'm pretty sure that's going to be broken anyway.
> 
> Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
> ---
>  arch/powerpc/platforms/powernv/eeh-powernv.c | 67 ++------------------

I like this diffstat :)

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



>  1 file changed, 4 insertions(+), 63 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
> index a974822c5097..b79aca8368c6 100644
> --- a/arch/powerpc/platforms/powernv/eeh-powernv.c
> +++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
> @@ -358,65 +358,6 @@ static int pnv_eeh_write_config(struct eeh_dev *edev,
>  	return pnv_pci_cfg_write(pdn, where, size, val);
>  }
>  
> -static int pnv_eeh_find_cap(struct eeh_dev *edev, int cap)
> -{
> -	int pos = PCI_CAPABILITY_LIST;
> -	int cnt = 48;   /* Maximal number of capabilities */
> -	u32 status, id;
> -
> -	/* Check if the device supports capabilities */
> -	pnv_eeh_read_config(edev, PCI_STATUS, 2, &status);
> -	if (!(status & PCI_STATUS_CAP_LIST))
> -		return 0;
> -
> -	while (cnt--) {
> -		pnv_eeh_read_config(edev, pos, 1, &pos);
> -		if (pos < 0x40)
> -			break;
> -
> -		pos &= ~3;
> -		pnv_eeh_read_config(edev, pos + PCI_CAP_LIST_ID, 1, &id);
> -		if (id == 0xff)
> -			break;
> -
> -		/* Found */
> -		if (id == cap)
> -			return pos;
> -
> -		/* Next one */
> -		pos += PCI_CAP_LIST_NEXT;
> -	}
> -
> -	return 0;
> -}
> -
> -static int pnv_eeh_find_ecap(struct eeh_dev *edev, int cap)
> -{
> -	u32 header;
> -	int pos = 256, ttl = (4096 - 256) / 8;
> -
> -	if (!edev || !edev->pcie_cap)
> -		return 0;
> -	if (pnv_eeh_read_config(edev, pos, 4, &header) != PCIBIOS_SUCCESSFUL)
> -		return 0;
> -	else if (!header)
> -		return 0;
> -
> -	while (ttl-- > 0) {
> -		if (PCI_EXT_CAP_ID(header) == cap && pos)
> -			return pos;
> -
> -		pos = PCI_EXT_CAP_NEXT(header);
> -		if (pos < 256)
> -			break;
> -
> -		if (pnv_eeh_read_config(edev, pos, 4, &header) != PCIBIOS_SUCCESSFUL)
> -			break;
> -	}
> -
> -	return 0;
> -}
> -
>  /**
>   * pnv_eeh_probe - Do probe on PCI device
>   * @pdev: pci_dev to probe
> @@ -458,10 +399,10 @@ static struct eeh_dev *pnv_eeh_probe_pdev(struct pci_dev *pdev)
>  
>  	/* Initialize eeh device */
>  	edev->class_code = pdn->class_code;
> -	edev->pcix_cap = pnv_eeh_find_cap(edev, PCI_CAP_ID_PCIX);
> -	edev->pcie_cap = pnv_eeh_find_cap(edev, PCI_CAP_ID_EXP);
> -	edev->af_cap   = pnv_eeh_find_cap(edev, PCI_CAP_ID_AF);
> -	edev->aer_cap  = pnv_eeh_find_ecap(edev, PCI_EXT_CAP_ID_ERR);
> +	edev->pcix_cap = pci_find_capability(pdev, PCI_CAP_ID_PCIX);
> +	edev->pcie_cap = pci_find_capability(pdev, PCI_CAP_ID_EXP);
> +	edev->af_cap   = pci_find_capability(pdev, PCI_CAP_ID_AF);
> +	edev->aer_cap  = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR);
>  	if ((edev->class_code >> 8) == PCI_CLASS_BRIDGE_PCI) {
>  		edev->mode |= EEH_DEV_BRIDGE;
>  		if (edev->pcie_cap) {
> 

-- 
Alexey