Re: [PATCH 2/3] PCI: revise VPD access interface

[Ben Hutchings <bhutchings@solarflare.com>]

Stephen Hemminger wrote:
> Change PCI VPD API which was only used by sysfs to something usable
> in drivers. 
>    * move iteration over multiple words to the low level
>    * cleanup types of arguments
>    * add exportable wrapper
> 
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
> 
> --- a/drivers/pci/access.c	2008-09-04 10:16:52.000000000 -0700
> +++ b/drivers/pci/access.c	2008-09-04 10:19:47.000000000 -0700
[...]
> -static int pci_vpd_pci22_write(struct pci_dev *dev, int pos, int size,
> -			       const char *buf)
> +static int pci_vpd_pci22_write(struct pci_dev *dev, loff_t pos, size_t count,
> +			       const void *buf)
>  {
>  	struct pci_vpd_pci22 *vpd =
>  		container_of(dev->vpd, struct pci_vpd_pci22, base);
> -	u32 val;
> +	loff_t end = pos + count;
>  	int ret;
>  
> -	if (pos < 0 || pos > vpd->base.len || pos & 3 ||
> -	    size > vpd->base.len - pos || size < 4)
> +	if (pos > vpd->base.len || pos & 3)
>  		return -EINVAL;
>  
> -	val = (u8) *buf++;
> -	val |= ((u8) *buf++) << 8;
> -	val |= ((u8) *buf++) << 16;
> -	val |= ((u32)(u8) *buf++) << 24;
> -
>  	ret = mutex_lock_killable(&vpd->lock);
>  	if (ret)
>  		return ret;
> -	ret = pci_vpd_pci22_wait(dev);
> -	if (ret < 0)
> -		goto out;
> -	ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA,
> -					  val);
> -	if (ret < 0)
> -		goto out;
> -	ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
> -					 pos | PCI_VPD_ADDR_F);
> -	if (ret < 0)
> -		goto out;
> -	vpd->busy = true;
> -	vpd->flag = 0;
> -	ret = pci_vpd_pci22_wait(dev);
> -out:
> -	mutex_unlock(&vpd->lock);
> -	if (ret < 0)
> -		return ret;
>  
> -	return 4;
> +	while (pos < end) {
> +		u32 val;
> +
> +		ret = pci_vpd_pci22_wait(dev);
> +		if (ret < 0)
> +			break;
> +		memcpy(&val, buf, sizeof(u32));
[...]

I'm not sure this is correct.  pci_user_write_config_dword() expects a
value in host byte order, but this memcpy() makes val always little-endian.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.