android_kernel_xiaomi_sm8350/arch/powerpc/kernel/ibmebus.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

392 lines
9.3 KiB
C

/*
* IBM PowerPC IBM eBus Infrastructure Support.
*
* Copyright (c) 2005 IBM Corporation
* Heiko J Schick <schickhj@de.ibm.com>
*
* All rights reserved.
*
* This source code is distributed under a dual license of GPL v2.0 and OpenIB
* BSD.
*
* OpenIB BSD License
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials
* provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <linux/init.h>
#include <linux/console.h>
#include <linux/kobject.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <asm/ibmebus.h>
#include <asm/abs_addr.h>
static struct ibmebus_dev ibmebus_bus_device = { /* fake "parent" device */
.name = ibmebus_bus_device.ofdev.dev.bus_id,
.ofdev.dev.bus_id = "ibmebus",
.ofdev.dev.bus = &ibmebus_bus_type,
};
static void *ibmebus_alloc_coherent(struct device *dev,
size_t size,
dma_addr_t *dma_handle,
gfp_t flag)
{
void *mem;
mem = kmalloc(size, flag);
*dma_handle = (dma_addr_t)mem;
return mem;
}
static void ibmebus_free_coherent(struct device *dev,
size_t size, void *vaddr,
dma_addr_t dma_handle)
{
kfree(vaddr);
}
static dma_addr_t ibmebus_map_single(struct device *dev,
void *ptr,
size_t size,
enum dma_data_direction direction)
{
return (dma_addr_t)(ptr);
}
static void ibmebus_unmap_single(struct device *dev,
dma_addr_t dma_addr,
size_t size,
enum dma_data_direction direction)
{
return;
}
static int ibmebus_map_sg(struct device *dev,
struct scatterlist *sg,
int nents, enum dma_data_direction direction)
{
int i;
for (i = 0; i < nents; i++) {
sg[i].dma_address = (dma_addr_t)page_address(sg[i].page)
+ sg[i].offset;
sg[i].dma_length = sg[i].length;
}
return nents;
}
static void ibmebus_unmap_sg(struct device *dev,
struct scatterlist *sg,
int nents, enum dma_data_direction direction)
{
return;
}
static int ibmebus_dma_supported(struct device *dev, u64 mask)
{
return 1;
}
struct dma_mapping_ops ibmebus_dma_ops = {
.alloc_coherent = ibmebus_alloc_coherent,
.free_coherent = ibmebus_free_coherent,
.map_single = ibmebus_map_single,
.unmap_single = ibmebus_unmap_single,
.map_sg = ibmebus_map_sg,
.unmap_sg = ibmebus_unmap_sg,
.dma_supported = ibmebus_dma_supported,
};
static int ibmebus_bus_probe(struct device *dev)
{
struct ibmebus_dev *ibmebusdev = to_ibmebus_dev(dev);
struct ibmebus_driver *ibmebusdrv = to_ibmebus_driver(dev->driver);
const struct of_device_id *id;
int error = -ENODEV;
if (!ibmebusdrv->probe)
return error;
id = of_match_device(ibmebusdrv->id_table, &ibmebusdev->ofdev);
if (id) {
error = ibmebusdrv->probe(ibmebusdev, id);
}
return error;
}
static int ibmebus_bus_remove(struct device *dev)
{
struct ibmebus_dev *ibmebusdev = to_ibmebus_dev(dev);
struct ibmebus_driver *ibmebusdrv = to_ibmebus_driver(dev->driver);
if (ibmebusdrv->remove) {
return ibmebusdrv->remove(ibmebusdev);
}
return 0;
}
static void __devinit ibmebus_dev_release(struct device *dev)
{
of_node_put(to_ibmebus_dev(dev)->ofdev.node);
kfree(to_ibmebus_dev(dev));
}
static ssize_t ibmebusdev_show_name(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%s\n", to_ibmebus_dev(dev)->name);
}
static DEVICE_ATTR(name, S_IRUSR | S_IRGRP | S_IROTH, ibmebusdev_show_name,
NULL);
static struct ibmebus_dev* __devinit ibmebus_register_device_common(
struct ibmebus_dev *dev, char *name)
{
int err = 0;
dev->name = name;
dev->ofdev.dev.parent = &ibmebus_bus_device.ofdev.dev;
dev->ofdev.dev.bus = &ibmebus_bus_type;
dev->ofdev.dev.release = ibmebus_dev_release;
/* An ibmebusdev is based on a of_device. We have to change the
* bus type to use our own DMA mapping operations.
*/
if ((err = of_device_register(&dev->ofdev)) != 0) {
printk(KERN_ERR "%s: failed to register device (%d).\n",
__FUNCTION__, err);
return NULL;
}
device_create_file(&dev->ofdev.dev, &dev_attr_name);
return dev;
}
static struct ibmebus_dev* __devinit ibmebus_register_device_node(
struct device_node *dn)
{
struct ibmebus_dev *dev;
char *loc_code;
int length;
loc_code = (char *)get_property(dn, "ibm,loc-code", NULL);
if (!loc_code) {
printk(KERN_WARNING "%s: node %s missing 'ibm,loc-code'\n",
__FUNCTION__, dn->name ? dn->name : "<unknown>");
return NULL;
}
if (strlen(loc_code) == 0) {
printk(KERN_WARNING "%s: 'ibm,loc-code' is invalid\n",
__FUNCTION__);
return NULL;
}
dev = kmalloc(sizeof(struct ibmebus_dev), GFP_KERNEL);
if (!dev) {
return NULL;
}
memset(dev, 0, sizeof(struct ibmebus_dev));
dev->ofdev.node = of_node_get(dn);
length = strlen(loc_code);
memcpy(dev->ofdev.dev.bus_id, loc_code
+ (length - min(length, BUS_ID_SIZE - 1)),
min(length, BUS_ID_SIZE - 1));
/* Register with generic device framework. */
if (ibmebus_register_device_common(dev, dn->name) == NULL) {
kfree(dev);
return NULL;
}
return dev;
}
static void ibmebus_probe_of_nodes(char* name)
{
struct device_node *dn = NULL;
while ((dn = of_find_node_by_name(dn, name))) {
if (ibmebus_register_device_node(dn) == NULL) {
of_node_put(dn);
return;
}
}
of_node_put(dn);
return;
}
static void ibmebus_add_devices_by_id(struct of_device_id *idt)
{
while (strlen(idt->name) > 0) {
ibmebus_probe_of_nodes(idt->name);
idt++;
}
return;
}
static int ibmebus_match_helper(struct device *dev, void *data)
{
if (strcmp((char*)data, to_ibmebus_dev(dev)->name) == 0)
return 1;
return 0;
}
static int ibmebus_unregister_device(struct device *dev)
{
device_remove_file(dev, &dev_attr_name);
of_device_unregister(to_of_device(dev));
return 0;
}
static void ibmebus_remove_devices_by_id(struct of_device_id *idt)
{
struct device *dev;
while (strlen(idt->name) > 0) {
while ((dev = bus_find_device(&ibmebus_bus_type, NULL,
(void*)idt->name,
ibmebus_match_helper))) {
ibmebus_unregister_device(dev);
}
idt++;
}
return;
}
int ibmebus_register_driver(struct ibmebus_driver *drv)
{
int err = 0;
drv->driver.name = drv->name;
drv->driver.bus = &ibmebus_bus_type;
drv->driver.probe = ibmebus_bus_probe;
drv->driver.remove = ibmebus_bus_remove;
if ((err = driver_register(&drv->driver) != 0))
return err;
ibmebus_add_devices_by_id(drv->id_table);
return 0;
}
EXPORT_SYMBOL(ibmebus_register_driver);
void ibmebus_unregister_driver(struct ibmebus_driver *drv)
{
driver_unregister(&drv->driver);
ibmebus_remove_devices_by_id(drv->id_table);
}
EXPORT_SYMBOL(ibmebus_unregister_driver);
int ibmebus_request_irq(struct ibmebus_dev *dev,
u32 ist,
irqreturn_t (*handler)(int, void*, struct pt_regs *),
unsigned long irq_flags, const char * devname,
void *dev_id)
{
unsigned int irq = irq_create_mapping(NULL, ist);
if (irq == NO_IRQ)
return -EINVAL;
return request_irq(irq, handler,
irq_flags, devname, dev_id);
}
EXPORT_SYMBOL(ibmebus_request_irq);
void ibmebus_free_irq(struct ibmebus_dev *dev, u32 ist, void *dev_id)
{
unsigned int irq = irq_find_mapping(NULL, ist);
free_irq(irq, dev_id);
}
EXPORT_SYMBOL(ibmebus_free_irq);
static int ibmebus_bus_match(struct device *dev, struct device_driver *drv)
{
const struct ibmebus_dev *ebus_dev = to_ibmebus_dev(dev);
struct ibmebus_driver *ebus_drv = to_ibmebus_driver(drv);
const struct of_device_id *ids = ebus_drv->id_table;
const struct of_device_id *found_id;
if (!ids)
return 0;
found_id = of_match_device(ids, &ebus_dev->ofdev);
if (found_id)
return 1;
return 0;
}
struct bus_type ibmebus_bus_type = {
.name = "ibmebus",
.match = ibmebus_bus_match,
};
EXPORT_SYMBOL(ibmebus_bus_type);
static int __init ibmebus_bus_init(void)
{
int err;
printk(KERN_INFO "IBM eBus Device Driver\n");
err = bus_register(&ibmebus_bus_type);
if (err) {
printk(KERN_ERR ":%s: failed to register IBM eBus.\n",
__FUNCTION__);
return err;
}
err = device_register(&ibmebus_bus_device.ofdev.dev);
if (err) {
printk(KERN_WARNING "%s: device_register returned %i\n",
__FUNCTION__, err);
bus_unregister(&ibmebus_bus_type);
return err;
}
return 0;
}
__initcall(ibmebus_bus_init);