PERFORCE change 171561 for review

[John Baldwin]

On Wednesday 09 December 2009 6:21:00 am Alexander Motin wrote:
> http://p4web.freebsd.org/chv.cgi?CH=171561
> 
> Change 171561 by mav at mav_mavtest on 2009/12/09 11:20:05
> 
> 	Increase Max Read Request Size for PCIe chips to 1024 bytes.
> 	It gives those slow beasts additional 10% of write bandwidth.

We should probably add a method in pci.c to do this ala 
pci_enable_busmaster().  Several drivers have cut and pasted similar versions 
of this code that I think it warrants having a common function now.

> Affected files ...
> 
> .. //depot/projects/scottl-camlock/src/sys/dev/siis/siis.c#30 edit
> 
> Differences ...
> 
> ==== //depot/projects/scottl-camlock/src/sys/dev/siis/siis.c#30 (text+ko) 
====
> 
> @@ -231,7 +231,20 @@
>  siis_resume(device_t dev)
>  {
>  	struct siis_controller *ctlr = device_get_softc(dev);
> +	int cap;
> +	uint16_t val;
>  
> +	/* Set PCIe max read request size to at least 1024 bytes */
> +	if (pci_find_extcap(dev, PCIY_EXPRESS, &cap) == 0) {
> +		val = pci_read_config(dev,
> +		    cap + PCIR_EXPRESS_DEVICE_CTL, 2);
> +		if ((val & PCIM_EXP_CTL_MAX_READ_REQUEST) < 0x3000) {
> +			val &= ~PCIM_EXP_CTL_MAX_READ_REQUEST;
> +			val |= 0x3000;
> +			pci_write_config(dev,
> +			    cap + PCIR_EXPRESS_DEVICE_CTL, val, 2);
> +		}
> +	}
>  	/* Put controller into reset state. */
>  	ctlr->gctl |= SIIS_GCTL_GRESET;
>  	ATA_OUTL(ctlr->r_gmem, SIIS_GCTL, ctlr->gctl);
> 

-- 
John Baldwin