linux/drivers/pci/setup-irq.c
Matthew Minter 47a650f279 PCI: Add pci_assign_irq() function and have pci_fixup_irqs() use it
Here we delete the static pdev_fixup_irq() function which is currently what
pci_fixup_irqs() uses to actually assign the IRQs and replace it with the
pci_assign_irq() function which changes the interface and uses the new
function pointers stored in the host bridge structure.

Eventually this will allow pci_fixup_irqs() to be removed entirely and the
new deferred assignment code path will call pci_assign_irq() directly.
However to ensure current users continue to work, a new implementation of
pci_fixup_irqs() is introduced which simply wraps the functionality of
pci_assign_irq().

Signed-off-by: Matthew Minter <matt@masarand.com>
[lorenzo.pieralisi@arm.com: reworked comments/log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-07-02 16:14:28 -05:00

94 lines
2.4 KiB
C

/*
* drivers/pci/setup-irq.c
*
* Extruded from code written by
* Dave Rusling (david.rusling@reo.mts.dec.com)
* David Mosberger (davidm@cs.arizona.edu)
* David Miller (davem@redhat.com)
*
* Support routines for initializing a PCI subsystem.
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/cache.h>
#include "pci.h"
void __weak pcibios_update_irq(struct pci_dev *dev, int irq)
{
dev_dbg(&dev->dev, "assigning IRQ %02d\n", irq);
pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
}
void pci_assign_irq(struct pci_dev *dev)
{
u8 pin;
u8 slot = -1;
int irq = 0;
struct pci_host_bridge *hbrg = pci_find_host_bridge(dev->bus);
if (!(hbrg->map_irq)) {
dev_dbg(&dev->dev, "runtime IRQ mapping not provided by arch\n");
return;
}
/* If this device is not on the primary bus, we need to figure out
which interrupt pin it will come in on. We know which slot it
will come in on 'cos that slot is where the bridge is. Each
time the interrupt line passes through a PCI-PCI bridge we must
apply the swizzle function. */
pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
/* Cope with illegal. */
if (pin > 4)
pin = 1;
if (pin) {
/* Follow the chain of bridges, swizzling as we go. */
if (hbrg->swizzle_irq)
slot = (*(hbrg->swizzle_irq))(dev, &pin);
/*
* If a swizzling function is not used map_irq must
* ignore slot
*/
irq = (*(hbrg->map_irq))(dev, slot, pin);
if (irq == -1)
irq = 0;
}
dev->irq = irq;
dev_dbg(&dev->dev, "assign IRQ: got %d\n", dev->irq);
/* Always tell the device, so the driver knows what is
the real IRQ to use; the device does not use it. */
pcibios_update_irq(dev, irq);
}
void pci_fixup_irqs(u8 (*swizzle)(struct pci_dev *, u8 *),
int (*map_irq)(const struct pci_dev *, u8, u8))
{
/*
* Implement pci_fixup_irqs() through pci_assign_irq().
* This code should be remove eventually, it is a wrapper
* around pci_assign_irq() interface to keep current
* pci_fixup_irqs() behaviour unchanged on architecture
* code still relying on its interface.
*/
struct pci_dev *dev = NULL;
struct pci_host_bridge *hbrg = NULL;
for_each_pci_dev(dev) {
hbrg = pci_find_host_bridge(dev->bus);
hbrg->swizzle_irq = swizzle;
hbrg->map_irq = map_irq;
pci_assign_irq(dev);
hbrg->swizzle_irq = NULL;
hbrg->map_irq = NULL;
}
}
EXPORT_SYMBOL_GPL(pci_fixup_irqs);