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linux/arch/powerpc/platforms/cell/spider-pic.c
Benjamin Herrenschmidt 6e99e45828 [PATCH] powerpc: fix trigger handling in the new irq code 
This patch slightly reworks the new irq code to fix a small design error.  I
removed the passing of the trigger to the map() calls entirely, it was not a
good idea to have one call do two different things.  It also fixes a couple of
corner cases.

Mapping a linux virtual irq to a physical irq now does only that.  Setting the
trigger is a different action which has a different call.

The main changes are:

- I no longer call host->ops->map() for an already mapped irq, I just return
  the virtual number that was already mapped.  It was called before to give an
  opportunity to change the trigger, but that was causing issues as that could
  happen while the interrupt was in use by a device, and because of the
  trigger change, map would potentially muck around with things in a racy way.
   That was causing much burden on a given's controller implementation of
  map() to get it right.  This is much simpler now.  map() is only called on
  the initial mapping of an irq, meaning that you know that this irq is _not_
  being used.  You can initialize the hardware if you want (though you don't
  have to).

- Controllers that can handle different type of triggers (level/edge/etc...)
  now implement the standard irq_chip->set_type() call as defined by the
  generic code.  That means that you can use the standard set_irq_type() to
  configure an irq line manually if you wish or (though I don't like that
  interface), pass explicit trigger flags to request_irq() as defined by the
  generic kernel interfaces.  Also, using those interfaces guarantees that
  your controller set_type callback is called with the descriptor lock held,
  thus providing locking against activity on the same interrupt (including
  mask/unmask/etc...) automatically.  A result is that, for example, MPIC's
  own map() implementation calls irq_set_type(NONE) to configure the hardware
  to the default triggers.

- To allow the above, the irq_map array entry for the new mapped interrupt
  is now set before map() callback is called for the controller.

- The irq_create_of_mapping() (also used by irq_of_parse_and_map()) function
  for mapping interrupts from the device-tree now also call the separate
  set_irq_type(), and only does so if there is a change in the trigger type.

- While I was at it, I changed pci_read_irq_line() (which is the helper I
  would expect most archs to use in their pcibios_fixup() to get the PCI
  interrupt routing from the device tree) to also handle a fallback when the
  DT mapping fails consisting of reading the PCI_INTERRUPT_PIN to know wether
  the device has an interrupt at all, and the the PCI_INTERRUPT_LINE to get an
  interrupt number from the device.  That number is then mapped using the
  default controller, and the trigger is set to level low.  That default
  behaviour works for several platforms that don't have a proper interrupt
  tree like Pegasos.  If it doesn't work for your platform, then either
  provide a proper interrupt tree from the firmware so that fallback isn't
  needed, or don't call pci_read_irq_line()

- Add back a bit that got dropped by my main rework patch for properly
  clearing pending IPIs on pSeries when using a kexec

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 13:24:20 -07:00

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/*
* External Interrupt Controller on Spider South Bridge
*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
*
* Author: Arnd Bergmann <arndb@de.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/ioport.h>
#include <asm/pgtable.h>
#include <asm/prom.h>
#include <asm/io.h>
#include "interrupt.h"
/* register layout taken from Spider spec, table 7.4-4 */
enum {
TIR_DEN = 0x004, /* Detection Enable Register */
TIR_MSK = 0x084, /* Mask Level Register */
TIR_EDC = 0x0c0, /* Edge Detection Clear Register */
TIR_PNDA = 0x100, /* Pending Register A */
TIR_PNDB = 0x104, /* Pending Register B */
TIR_CS = 0x144, /* Current Status Register */
TIR_LCSA = 0x150, /* Level Current Status Register A */
TIR_LCSB = 0x154, /* Level Current Status Register B */
TIR_LCSC = 0x158, /* Level Current Status Register C */
TIR_LCSD = 0x15c, /* Level Current Status Register D */
TIR_CFGA = 0x200, /* Setting Register A0 */
TIR_CFGB = 0x204, /* Setting Register B0 */
/* 0x208 ... 0x3ff Setting Register An/Bn */
TIR_PPNDA = 0x400, /* Packet Pending Register A */
TIR_PPNDB = 0x404, /* Packet Pending Register B */
TIR_PIERA = 0x408, /* Packet Output Error Register A */
TIR_PIERB = 0x40c, /* Packet Output Error Register B */
TIR_PIEN = 0x444, /* Packet Output Enable Register */
TIR_PIPND = 0x454, /* Packet Output Pending Register */
TIRDID = 0x484, /* Spider Device ID Register */
REISTIM = 0x500, /* Reissue Command Timeout Time Setting */
REISTIMEN = 0x504, /* Reissue Command Timeout Setting */
REISWAITEN = 0x508, /* Reissue Wait Control*/
};
#define SPIDER_CHIP_COUNT 4
#define SPIDER_SRC_COUNT 64
#define SPIDER_IRQ_INVALID 63
struct spider_pic {
struct irq_host *host;
struct device_node *of_node;
void __iomem *regs;
unsigned int node_id;
};
static struct spider_pic spider_pics[SPIDER_CHIP_COUNT];
static struct spider_pic *spider_virq_to_pic(unsigned int virq)
{
return irq_map[virq].host->host_data;
}
static void __iomem *spider_get_irq_config(struct spider_pic *pic,
unsigned int src)
{
return pic->regs + TIR_CFGA + 8 * src;
}
static void spider_unmask_irq(unsigned int virq)
{
struct spider_pic *pic = spider_virq_to_pic(virq);
void __iomem *cfg = spider_get_irq_config(pic, irq_map[virq].hwirq);
out_be32(cfg, in_be32(cfg) | 0x30000000u);
}
static void spider_mask_irq(unsigned int virq)
{
struct spider_pic *pic = spider_virq_to_pic(virq);
void __iomem *cfg = spider_get_irq_config(pic, irq_map[virq].hwirq);
out_be32(cfg, in_be32(cfg) & ~0x30000000u);
}
static void spider_ack_irq(unsigned int virq)
{
struct spider_pic *pic = spider_virq_to_pic(virq);
unsigned int src = irq_map[virq].hwirq;
/* Reset edge detection logic if necessary
*/
if (get_irq_desc(virq)->status & IRQ_LEVEL)
return;
/* Only interrupts 47 to 50 can be set to edge */
if (src < 47 || src > 50)
return;
/* Perform the clear of the edge logic */
out_be32(pic->regs + TIR_EDC, 0x100 | (src & 0xf));
}
static int spider_set_irq_type(unsigned int virq, unsigned int type)
{
unsigned int sense = type & IRQ_TYPE_SENSE_MASK;
struct spider_pic *pic = spider_virq_to_pic(virq);
unsigned int hw = irq_map[virq].hwirq;
void __iomem *cfg = spider_get_irq_config(pic, hw);
struct irq_desc *desc = get_irq_desc(virq);
u32 old_mask;
u32 ic;
/* Note that only level high is supported for most interrupts */
if (sense != IRQ_TYPE_NONE && sense != IRQ_TYPE_LEVEL_HIGH &&
(hw < 47 || hw > 50))
return -EINVAL;
/* Decode sense type */
switch(sense) {
case IRQ_TYPE_EDGE_RISING:
ic = 0x3;
break;
case IRQ_TYPE_EDGE_FALLING:
ic = 0x2;
break;
case IRQ_TYPE_LEVEL_LOW:
ic = 0x0;
break;
case IRQ_TYPE_LEVEL_HIGH:
case IRQ_TYPE_NONE:
ic = 0x1;
break;
default:
return -EINVAL;
}
/* Update irq_desc */
desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
desc->status |= type & IRQ_TYPE_SENSE_MASK;
if (type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
desc->status |= IRQ_LEVEL;
/* Configure the source. One gross hack that was there before and
* that I've kept around is the priority to the BE which I set to
* be the same as the interrupt source number. I don't know wether
* that's supposed to make any kind of sense however, we'll have to
* decide that, but for now, I'm not changing the behaviour.
*/
old_mask = in_be32(cfg) & 0x30000000u;
out_be32(cfg, old_mask | (ic << 24) | (0x7 << 16) |
(pic->node_id << 4) | 0xe);
out_be32(cfg + 4, (0x2 << 16) | (hw & 0xff));
return 0;
}
static struct irq_chip spider_pic = {
.typename = " SPIDER ",
.unmask = spider_unmask_irq,
.mask = spider_mask_irq,
.ack = spider_ack_irq,
.set_type = spider_set_irq_type,
};
static int spider_host_match(struct irq_host *h, struct device_node *node)
{
struct spider_pic *pic = h->host_data;
return node == pic->of_node;
}
static int spider_host_map(struct irq_host *h, unsigned int virq,
irq_hw_number_t hw)
{
set_irq_chip_and_handler(virq, &spider_pic, handle_level_irq);
/* Set default irq type */
set_irq_type(virq, IRQ_TYPE_NONE);
return 0;
}
static int spider_host_xlate(struct irq_host *h, struct device_node *ct,
u32 *intspec, unsigned int intsize,
irq_hw_number_t *out_hwirq, unsigned int *out_flags)
{
/* Spider interrupts have 2 cells, first is the interrupt source,
* second, well, I don't know for sure yet ... We mask the top bits
* because old device-trees encode a node number in there
*/
*out_hwirq = intspec[0] & 0x3f;
*out_flags = IRQ_TYPE_LEVEL_HIGH;
return 0;
}
static struct irq_host_ops spider_host_ops = {
.match = spider_host_match,
.map = spider_host_map,
.xlate = spider_host_xlate,
};
static void spider_irq_cascade(unsigned int irq, struct irq_desc *desc,
struct pt_regs *regs)
{
struct spider_pic *pic = desc->handler_data;
unsigned int cs, virq;
cs = in_be32(pic->regs + TIR_CS) >> 24;
if (cs == SPIDER_IRQ_INVALID)
virq = NO_IRQ;
else
virq = irq_linear_revmap(pic->host, cs);
if (virq != NO_IRQ)
generic_handle_irq(virq, regs);
desc->chip->eoi(irq);
}
/* For hooking up the cascace we have a problem. Our device-tree is
* crap and we don't know on which BE iic interrupt we are hooked on at
* least not the "standard" way. We can reconstitute it based on two
* informations though: which BE node we are connected to and wether
* we are connected to IOIF0 or IOIF1. Right now, we really only care
* about the IBM cell blade and we know that its firmware gives us an
* interrupt-map property which is pretty strange.
*/
static unsigned int __init spider_find_cascade_and_node(struct spider_pic *pic)
{
unsigned int virq;
u32 *imap, *tmp;
int imaplen, intsize, unit;
struct device_node *iic;
struct irq_host *iic_host;
#if 0 /* Enable that when we have a way to retreive the node as well */
/* First, we check wether we have a real "interrupts" in the device
* tree in case the device-tree is ever fixed
*/
struct of_irq oirq;
if (of_irq_map_one(pic->of_node, 0, &oirq) == 0) {
virq = irq_create_of_mapping(oirq.controller, oirq.specifier,
oirq.size);
goto bail;
}
#endif
/* Now do the horrible hacks */
tmp = (u32 *)get_property(pic->of_node, "#interrupt-cells", NULL);
if (tmp == NULL)
return NO_IRQ;
intsize = *tmp;
imap = (u32 *)get_property(pic->of_node, "interrupt-map", &imaplen);
if (imap == NULL || imaplen < (intsize + 1))
return NO_IRQ;
iic = of_find_node_by_phandle(imap[intsize]);
if (iic == NULL)
return NO_IRQ;
imap += intsize + 1;
tmp = (u32 *)get_property(iic, "#interrupt-cells", NULL);
if (tmp == NULL)
return NO_IRQ;
intsize = *tmp;
/* Assume unit is last entry of interrupt specifier */
unit = imap[intsize - 1];
/* Ok, we have a unit, now let's try to get the node */
tmp = (u32 *)get_property(iic, "ibm,interrupt-server-ranges", NULL);
if (tmp == NULL) {
of_node_put(iic);
return NO_IRQ;
}
/* ugly as hell but works for now */
pic->node_id = (*tmp) >> 1;
of_node_put(iic);
/* Ok, now let's get cracking. You may ask me why I just didn't match
* the iic host from the iic OF node, but that way I'm still compatible
* with really really old old firmwares for which we don't have a node
*/
iic_host = iic_get_irq_host(pic->node_id);
if (iic_host == NULL)
return NO_IRQ;
/* Manufacture an IIC interrupt number of class 2 */
virq = irq_create_mapping(iic_host, 0x20 | unit);
if (virq == NO_IRQ)
printk(KERN_ERR "spider_pic: failed to map cascade !");
return virq;
}
static void __init spider_init_one(struct device_node *of_node, int chip,
unsigned long addr)
{
struct spider_pic *pic = &spider_pics[chip];
int i, virq;
/* Map registers */
pic->regs = ioremap(addr, 0x1000);
if (pic->regs == NULL)
panic("spider_pic: can't map registers !");
/* Allocate a host */
pic->host = irq_alloc_host(IRQ_HOST_MAP_LINEAR, SPIDER_SRC_COUNT,
&spider_host_ops, SPIDER_IRQ_INVALID);
if (pic->host == NULL)
panic("spider_pic: can't allocate irq host !");
pic->host->host_data = pic;
/* Fill out other bits */
pic->of_node = of_node_get(of_node);
/* Go through all sources and disable them */
for (i = 0; i < SPIDER_SRC_COUNT; i++) {
void __iomem *cfg = pic->regs + TIR_CFGA + 8 * i;
out_be32(cfg, in_be32(cfg) & ~0x30000000u);
}
/* do not mask any interrupts because of level */
out_be32(pic->regs + TIR_MSK, 0x0);
/* enable interrupt packets to be output */
out_be32(pic->regs + TIR_PIEN, in_be32(pic->regs + TIR_PIEN) | 0x1);
/* Hook up the cascade interrupt to the iic and nodeid */
virq = spider_find_cascade_and_node(pic);
if (virq == NO_IRQ)
return;
set_irq_data(virq, pic);
set_irq_chained_handler(virq, spider_irq_cascade);
printk(KERN_INFO "spider_pic: node %d, addr: 0x%lx %s\n",
pic->node_id, addr, of_node->full_name);
/* Enable the interrupt detection enable bit. Do this last! */
out_be32(pic->regs + TIR_DEN, in_be32(pic->regs + TIR_DEN) | 0x1);
}
void __init spider_init_IRQ(void)
{
struct resource r;
struct device_node *dn;
int chip = 0;
/* XXX node numbers are totally bogus. We _hope_ we get the device
* nodes in the right order here but that's definitely not guaranteed,
* we need to get the node from the device tree instead.
* There is currently no proper property for it (but our whole
* device-tree is bogus anyway) so all we can do is pray or maybe test
* the address and deduce the node-id
*/
for (dn = NULL;
(dn = of_find_node_by_name(dn, "interrupt-controller"));) {
if (device_is_compatible(dn, "CBEA,platform-spider-pic")) {
if (of_address_to_resource(dn, 0, &r)) {
printk(KERN_WARNING "spider-pic: Failed\n");
continue;
}
} else if (device_is_compatible(dn, "sti,platform-spider-pic")
&& (chip < 2)) {
static long hard_coded_pics[] =
{ 0x24000008000, 0x34000008000 };
r.start = hard_coded_pics[chip];
} else
continue;
spider_init_one(dn, chip++, r.start);
}
}
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