[Cbe-oss-dev] [RFC/PATCH] adding support for direct MBX interrupt on Axon based platform.

[Benjamin Herrenschmidt]

On Fri, 2007-05-18 at 13:36 +0200, Jean-Christophe Dubois wrote:
> This patch allows Linux to support the Mailbox direct interrupt that is left 
> out in the actual SLOF device tree.
> 
> This patch has been tested on the CAB and the Malta blade with 2.6.20 and 
> 2.6.21 kernels.

Are we sure we can't program Axon to generate a different class ?

Cheers,
Ben.

> Signed-Off-by: Jean-Christophe DUBOIS <jdubois at mc.com>
> 
> Index: linux-2.6.20/arch/powerpc/platforms/cell/interrupt.c
> ===================================================================
> --- linux-2.6.20.orig/arch/powerpc/platforms/cell/interrupt.c	2007-02-04 
> 19:44:54.000000000 +0100
> +++ linux-2.6.20/arch/powerpc/platforms/cell/interrupt.c	2007-03-28 
> 16:35:17.000000000 +0200
> @@ -64,6 +64,22 @@
>  	unsigned char node = bits.source >> 4;
>  	unsigned char class = bits.class & 3;
>  
> +	/*
> +	 * This is a special case for the Axon direct interrupt.
> +	 * The direct interrupt is characterized by a priority set to 8
> +	 * But the priority is not used to generate the hwnum
> +	 * So here is a little hack.
> +	 */
> +	if ((unit == 0x0 || unit == 0xb) && (class == 2)
> +	    && ((bits.prio>>4)  == 8)) {
> +		/*
> +		 * in order to discriminate the direct MBX we change the
> +		 * unit for an unused value:
> +		 * 0xc for IOIF0 and 0xd for IOIF1
> +		 */
> +		unit = unit?0xd:0xc;
> +	}
> +
>  	/* Decode IPIs */
>  	if (bits.flags & CBE_IIC_IRQ_IPI)
>  		return IIC_IRQ_TYPE_IPI | (bits.prio >> 4);
> @@ -93,7 +109,6 @@
>  	.eoi = iic_eoi,
>  };
>  
> -
>  static void iic_ioexc_eoi(unsigned int irq)
>  {
>  }
> @@ -130,7 +145,6 @@
>  	desc->chip->eoi(irq);
>  }
>  
> -
>  static struct irq_chip iic_ioexc_chip = {
>  	.typename = " CELL-IOEX",
>  	.mask = iic_mask,
> Index: linux-2.6.20/arch/powerpc/platforms/cell/setup.c
> ===================================================================
> --- linux-2.6.20.orig/arch/powerpc/platforms/cell/setup.c	2007-03-28 
> 16:34:37.000000000 +0200
> +++ linux-2.6.20/arch/powerpc/platforms/cell/setup.c	2007-03-28 
> 16:35:17.000000000 +0200
> @@ -104,6 +104,42 @@
>  	desc->chip->eoi(irq);
>  }
>  
> +static void c3po_mask(unsigned int irq)
> +{
> +}
> +
> +static void c3po_unmask(unsigned int irq)
> +{
> +}
> +
> +static void c3po_eoi(unsigned int irq)
> +{
> +}
> +
> +static void c3po_ack(unsigned int irq)
> +{
> +}
> +
> +static struct irq_chip c3po_chip = {
> +	.typename = " AXON-C3PO",
> +	.mask = c3po_mask,
> +	.unmask = c3po_unmask,
> +	.ack = c3po_ack,
> +	.eoi = c3po_eoi,
> +};
> +
> +static void c3po_irq_cascade(unsigned int irq, struct irq_desc *desc)
> +{
> +	int hw_int = (int)desc->handler_data;
> +	unsigned int virq = irq_find_mapping(NULL, hw_int);
> +
> +	if (virq != NO_IRQ) {
> +		generic_handle_irq(virq);
> +	}
> +
> +	desc->chip->eoi(irq);
> +}
> +
>  static void __init mpic_init_IRQ(void)
>  {
>  	struct device_node *dn;
> @@ -134,12 +170,66 @@
>  	}
>  }
>  
> +static void __init c3po_init_IRQ(void)
> +{
> +	struct device_node *dn;
> +	// We need a way to find out the cell/node to which the c3po is qttqched
> +	int node = 0;
> +
> +	for (dn = NULL;
> +	     (dn = of_find_node_by_name(dn, "c3po"));node++) {
> +		unsigned int virq;
> +		int hw_int;
> +		int iic_int;
> +		u32 *prop;
> +		int len;
> +
> +		int ioif = 0; /* Fallback to 0 if bad prop in dev-tree */
> +		struct device_node *pdn = of_get_parent(dn);
> +
> +		if (pdn) {
> +			prop = (u32*) get_property(pdn, "ioif",&len);
> +			if ( prop && len == 4 )
> +				ioif = *prop;
> +
> +			of_node_put(pdn);
> +		}
> +
> +		hw_int = (node * 256) + 136 + ioif;
> +		iic_int = (node << IIC_IRQ_NODE_SHIFT) |
> +			      (2 << IIC_IRQ_CLASS_SHIFT) |
> +			      (0xc + ioif);
> +
> +		printk(KERN_INFO "c3po: ioif=%d, hw_int=%d, iic_int=%d \n",
> +				ioif, hw_int, iic_int);
> +
> +		// We add the direct MBOX interrupt
> +		virq = irq_create_mapping(NULL, iic_int);
> +		if (virq == NO_IRQ)
> +			continue;
> +
> +		set_irq_data(virq, (void *)hw_int);
> +
> +		set_irq_chained_handler (virq, c3po_irq_cascade);
> +
> +		virq = irq_create_mapping(NULL, hw_int);
> +		if (virq == NO_IRQ)
> +			continue;
> +
> +		set_irq_chip_and_handler(virq, &c3po_chip, handle_edge_irq);
> +
> +		set_irq_type(virq, IRQ_TYPE_EDGE_RISING);
> +
> +	}
> +}
> +
>  
>  static void __init cell_init_irq(void)
>  {
>  	iic_init_IRQ();
>  	spider_init_IRQ();
>  	mpic_init_IRQ();
> +	c3po_init_IRQ();
>  }
>  
>  static void __init cell_setup_arch(void)
> 
> 
> 
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