Tomasz Nowicki d8ed75d593 ARM64: PCI: ACPI support for legacy IRQs parsing and consolidation with DT code
To enable PCI legacy IRQs on platforms booting with ACPI, arch code should
include ACPI-specific callbacks that parse and set-up the device IRQ
number, equivalent to the DT boot path. Owing to the current ACPI core scan
handlers implementation, ACPI PCI legacy IRQs bindings cannot be parsed at
device add time, since that would trigger ACPI scan handlers ordering
issues depending on how the ACPI tables are defined.

To solve this problem and consolidate FW PCI legacy IRQs parsing in one
single pcibios callback (pending final removal), this patch moves DT PCI
IRQ parsing to the pcibios_alloc_irq() callback (called by PCI core code at
driver probe time) and adds ACPI PCI legacy IRQs parsing to the same
callback too, so that FW PCI legacy IRQs parsing is confined in one single
arch callback that can be easily removed when code parsing PCI legacy IRQs
is consolidated and moved to core PCI code.

Suggested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-06-10 18:29:46 -05:00

107 lines
2.2 KiB
C

/*
* Code borrowed from powerpc/kernel/pci-common.c
*
* Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
* Copyright (C) 2014 ARM Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
*/
#include <linux/acpi.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
#include <linux/pci.h>
#include <linux/slab.h>
/*
* Called after each bus is probed, but before its children are examined
*/
void pcibios_fixup_bus(struct pci_bus *bus)
{
/* nothing to do, expected to be removed in the future */
}
/*
* We don't have to worry about legacy ISA devices, so nothing to do here
*/
resource_size_t pcibios_align_resource(void *data, const struct resource *res,
resource_size_t size, resource_size_t align)
{
return res->start;
}
/**
* pcibios_enable_device - Enable I/O and memory.
* @dev: PCI device to be enabled
* @mask: bitmask of BARs to enable
*/
int pcibios_enable_device(struct pci_dev *dev, int mask)
{
if (pci_has_flag(PCI_PROBE_ONLY))
return 0;
return pci_enable_resources(dev, mask);
}
/*
* Try to assign the IRQ number when probing a new device
*/
int pcibios_alloc_irq(struct pci_dev *dev)
{
if (acpi_disabled)
dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
#ifdef CONFIG_ACPI
else
return acpi_pci_irq_enable(dev);
#endif
return 0;
}
/*
* raw_pci_read/write - Platform-specific PCI config space access.
*/
int raw_pci_read(unsigned int domain, unsigned int bus,
unsigned int devfn, int reg, int len, u32 *val)
{
return -ENXIO;
}
int raw_pci_write(unsigned int domain, unsigned int bus,
unsigned int devfn, int reg, int len, u32 val)
{
return -ENXIO;
}
#ifdef CONFIG_NUMA
int pcibus_to_node(struct pci_bus *bus)
{
return dev_to_node(&bus->dev);
}
EXPORT_SYMBOL(pcibus_to_node);
#endif
#ifdef CONFIG_ACPI
int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
{
return 0;
}
/* Root bridge scanning */
struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
{
/* TODO: Should be revisited when implementing PCI on ACPI */
return NULL;
}
#endif