Re: [PATCH v3 1/2] PCI: Add tango MSI controller support

From: Mason
Date: Wed Mar 29 2017 - 11:51:35 EST


On 29/03/2017 15:16, Mason wrote:

> But I don't understand how to get my pcie pointer back in irq_ack
> or irq_unmask, or the relevant msi. Can you throw me a clue?

Let's see... the irq_chip call-backs receive an irq_data pointer.

struct irq_data - per irq chip data passed down to chip functions
struct irq_chip - hardware interrupt chip descriptor

irq_data contains a void *chip_data member.
Can I use chip_data to stash a struct tango_pcie pointer?

/**
* irq_set_chip_data - set irq chip data for an irq
* @irq: Interrupt number
* @data: Pointer to chip specific data
*
* Set the hardware irq chip data for an irq
*/
int irq_set_chip_data(unsigned int irq, void *data)

But where would I call it? And for which irq?


Otherwise, I found by trial-and-error that I can reach pcie through

data->domain->parent->host_data

data->domain == msi_dom
msi_dom->parent == irq_dom
irq_dom->host_data == pcie

But data->irq and data->hwirq don't hold the MSI index :-(

I suppose I have to ask for some mapping?

Regards.