Re: MSI messages

[Grant Grundler]

On Sat, Dec 13, 2008 at 01:38:24PM +0400, Manu Abraham wrote:
> Hi,
> 
> I am wondering how to handle this:
> 
> Does the kernel somehow handle MSI message readback from the PCI config space 
> for the MSI message as described in 6.8.1 of the PCI Bus specification 2.3 or 
> does a device specific driver have to read the Message Address and Data ?
> 
> To put it short: i am wondering how i should read the MSI messages.

The "message" is actually mapped to an the interrupt vector by the core
generic interrupt handling code in the kernel.

A "GSI" (Generic Sys Interrupt?) is associated with each entry in
the MSI-X table. Driver then calls request_irq() to bind an interrupt
handler to each GSI. So the driver never directly sees the "message".

hth,
grant
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/