Re: yosemite interrupt setup

[Manish Lachwani <mlachwani@xxxxxxxxxx>]

Manish Lachwani wrote:

> Thomas Koeller wrote:
>
> > Hi Manish,
> >
> > may I ask you to help me with this:
> >
> > I am currently analyzing the yosemite interrupt handling
> > code. So far I have not been able to find the point
> > where the association between a particular external or
> > message interrupt and its vector is established. It seems
> > that the corresponding OCD address definitions from
> > asm-mips/titan_dep.h, such as RM9000x2_OCD_INTPIN0, are
> > not used anywhere in the code. I guess the kernel does
> > not rely on PMON having set up this before, or does it?
> >
> > thanks,
> > Thomas
> >
> >  
> Hi Thomas
>
> As far as I remember, the message interrupts can be invoked by writing 
> to the INTMSG register. Are you referring to the Hypertransport 
> section or the ethernet section? No, PMON does not do any interrupt 
> related setup. All that is done in Linux.
>
> For example, if you look at the titan ge driver, there is a section:
>
>     /*
>      * Enable the Interrupts for Tx and Rx
>      */
>     reg_data1 = TITAN_GE_READ(TITAN_GE_INTR_XDMA_IE);
>
>     if (port_num == 0) {
>         reg_data1 |= 0x3;
> #ifdef CONFIG_SMP
>         TITAN_GE_WRITE(0x0038, 0x003);
> #else
>         TITAN_GE_WRITE(0x0038, 0x303);
> #endif
>     }
>
>     if (port_num == 1) {
>         reg_data1 |= 0x300;
>     }
>
>     TITAN_GE_WRITE(TITAN_GE_INTR_XDMA_IE, reg_data1);
>     TITAN_GE_WRITE(0x003c, 0x300);
>
>     if (config_done == 0) {
>         TITAN_GE_WRITE(0x0024, 0x04000024);    /* IRQ vector */
>         TITAN_GE_WRITE(0x0020, 0x000fb000);    /* INTMSG base */
>     }
>
>
> Here, 0xfb000020 is the INTMSG register. And 0xfb000024 is the 
> Interrupt Vector register.
> AFAIK, the IRQ vector is 8 bits with the top three bits signifying the 
> interrupt number and the bottom three bits indicates the 32 interrupt 
> status bits. So, essentially there are 256 message
> interrupts.
>
> Let me know if this helps or if there is something specific ...
>
> Thanks
> Manish Lachwani
Hi Thomas

Let me correct myself: 0xfe000020 is the INTMSG base register and 
0xfe000024 is the Interrupt Vector register (for the ethernet block). 
The actual INTMSG register resides in 0xfb000a00. Another example is 
arch/mips/pmc-sierra/yosemite/smp.c where an interrupt is generated by 
writing a vector to the INTMSG register:

*(volatile uint32_t *)(0xfb000a00) = 0x00610002;

Thanks
Manish Lachwani