swh:1:snp:77163734605b0ec556b01d897b7bb4a7e30d46b6
Tip revision: 4fe89d07dcc2804c8b562f6c7896a45643d34b2f authored by Linus Torvalds on 02 October 2022, 21:09:07 UTC
Linux 6.0
Linux 6.0
Tip revision: 4fe89d0
pci-legacy.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* Copyright (C) 2003, 04, 11 Ralf Baechle (ralf@linux-mips.org)
* Copyright (C) 2011 Wind River Systems,
* written by Ralf Baechle (ralf@linux-mips.org)
*/
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/memblock.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/of_address.h>
#include <asm/cpu-info.h>
/*
* If PCI_PROBE_ONLY in pci_flags is set, we don't change any PCI resource
* assignments.
*/
/*
* The PCI controller list.
*/
static LIST_HEAD(controllers);
static int pci_initialized;
/*
* We need to avoid collisions with `mirrored' VGA ports
* and other strange ISA hardware, so we always want the
* addresses to be allocated in the 0x000-0x0ff region
* modulo 0x400.
*
* Why? Because some silly external IO cards only decode
* the low 10 bits of the IO address. The 0x00-0xff region
* is reserved for motherboard devices that decode all 16
* bits, so it's ok to allocate at, say, 0x2800-0x28ff,
* but we want to try to avoid allocating at 0x2900-0x2bff
* which might have be mirrored at 0x0100-0x03ff..
*/
resource_size_t
pcibios_align_resource(void *data, const struct resource *res,
resource_size_t size, resource_size_t align)
{
struct pci_dev *dev = data;
struct pci_controller *hose = dev->sysdata;
resource_size_t start = res->start;
if (res->flags & IORESOURCE_IO) {
/* Make sure we start at our min on all hoses */
if (start < PCIBIOS_MIN_IO + hose->io_resource->start)
start = PCIBIOS_MIN_IO + hose->io_resource->start;
/*
* Put everything into 0x00-0xff region modulo 0x400
*/
if (start & 0x300)
start = (start + 0x3ff) & ~0x3ff;
} else if (res->flags & IORESOURCE_MEM) {
/* Make sure we start at our min on all hoses */
if (start < PCIBIOS_MIN_MEM + hose->mem_resource->start)
start = PCIBIOS_MIN_MEM + hose->mem_resource->start;
}
return start;
}
static void pcibios_scanbus(struct pci_controller *hose)
{
static int next_busno;
static int need_domain_info;
LIST_HEAD(resources);
struct pci_bus *bus;
struct pci_host_bridge *bridge;
int ret;
bridge = pci_alloc_host_bridge(0);
if (!bridge)
return;
if (hose->get_busno && pci_has_flag(PCI_PROBE_ONLY))
next_busno = (*hose->get_busno)();
pci_add_resource_offset(&resources,
hose->mem_resource, hose->mem_offset);
pci_add_resource_offset(&resources,
hose->io_resource, hose->io_offset);
list_splice_init(&resources, &bridge->windows);
bridge->dev.parent = NULL;
bridge->sysdata = hose;
bridge->busnr = next_busno;
bridge->ops = hose->pci_ops;
bridge->swizzle_irq = pci_common_swizzle;
bridge->map_irq = pcibios_map_irq;
ret = pci_scan_root_bus_bridge(bridge);
if (ret) {
pci_free_host_bridge(bridge);
return;
}
hose->bus = bus = bridge->bus;
need_domain_info = need_domain_info || pci_domain_nr(bus);
set_pci_need_domain_info(hose, need_domain_info);
next_busno = bus->busn_res.end + 1;
/* Don't allow 8-bit bus number overflow inside the hose -
reserve some space for bridges. */
if (next_busno > 224) {
next_busno = 0;
need_domain_info = 1;
}
/*
* We insert PCI resources into the iomem_resource and
* ioport_resource trees in either pci_bus_claim_resources()
* or pci_bus_assign_resources().
*/
if (pci_has_flag(PCI_PROBE_ONLY)) {
pci_bus_claim_resources(bus);
} else {
struct pci_bus *child;
pci_bus_size_bridges(bus);
pci_bus_assign_resources(bus);
list_for_each_entry(child, &bus->children, node)
pcie_bus_configure_settings(child);
}
pci_bus_add_devices(bus);
}
#ifdef CONFIG_OF
void pci_load_of_ranges(struct pci_controller *hose, struct device_node *node)
{
struct of_pci_range range;
struct of_pci_range_parser parser;
hose->of_node = node;
if (of_pci_range_parser_init(&parser, node))
return;
for_each_of_pci_range(&parser, &range) {
struct resource *res = NULL;
switch (range.flags & IORESOURCE_TYPE_BITS) {
case IORESOURCE_IO:
hose->io_map_base =
(unsigned long)ioremap(range.cpu_addr,
range.size);
res = hose->io_resource;
break;
case IORESOURCE_MEM:
res = hose->mem_resource;
break;
}
if (res != NULL) {
res->name = node->full_name;
res->flags = range.flags;
res->start = range.cpu_addr;
res->end = range.cpu_addr + range.size - 1;
res->parent = res->child = res->sibling = NULL;
}
}
}
struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus)
{
struct pci_controller *hose = bus->sysdata;
return of_node_get(hose->of_node);
}
#endif
static DEFINE_MUTEX(pci_scan_mutex);
void register_pci_controller(struct pci_controller *hose)
{
struct resource *parent;
parent = hose->mem_resource->parent;
if (!parent)
parent = &iomem_resource;
if (request_resource(parent, hose->mem_resource) < 0)
goto out;
parent = hose->io_resource->parent;
if (!parent)
parent = &ioport_resource;
if (request_resource(parent, hose->io_resource) < 0) {
release_resource(hose->mem_resource);
goto out;
}
INIT_LIST_HEAD(&hose->list);
list_add_tail(&hose->list, &controllers);
/*
* Do not panic here but later - this might happen before console init.
*/
if (!hose->io_map_base) {
printk(KERN_WARNING
"registering PCI controller with io_map_base unset\n");
}
/*
* Scan the bus if it is register after the PCI subsystem
* initialization.
*/
if (pci_initialized) {
mutex_lock(&pci_scan_mutex);
pcibios_scanbus(hose);
mutex_unlock(&pci_scan_mutex);
}
return;
out:
printk(KERN_WARNING
"Skipping PCI bus scan due to resource conflict\n");
}
static int __init pcibios_init(void)
{
struct pci_controller *hose;
/* Scan all of the recorded PCI controllers. */
list_for_each_entry(hose, &controllers, list)
pcibios_scanbus(hose);
pci_initialized = 1;
return 0;
}
subsys_initcall(pcibios_init);
static int pcibios_enable_resources(struct pci_dev *dev, int mask)
{
u16 cmd, old_cmd;
int idx;
struct resource *r;
pci_read_config_word(dev, PCI_COMMAND, &cmd);
old_cmd = cmd;
for (idx = 0; idx < PCI_NUM_RESOURCES; idx++) {
/* Only set up the requested stuff */
if (!(mask & (1<<idx)))
continue;
r = &dev->resource[idx];
if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
continue;
if ((idx == PCI_ROM_RESOURCE) &&
(!(r->flags & IORESOURCE_ROM_ENABLE)))
continue;
if (!r->start && r->end) {
pci_err(dev,
"can't enable device: resource collisions\n");
return -EINVAL;
}
if (r->flags & IORESOURCE_IO)
cmd |= PCI_COMMAND_IO;
if (r->flags & IORESOURCE_MEM)
cmd |= PCI_COMMAND_MEMORY;
}
if (cmd != old_cmd) {
pci_info(dev, "enabling device (%04x -> %04x)\n", old_cmd, cmd);
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
return 0;
}
int pcibios_enable_device(struct pci_dev *dev, int mask)
{
int err = pcibios_enable_resources(dev, mask);
if (err < 0)
return err;
return pcibios_plat_dev_init(dev);
}
void pcibios_fixup_bus(struct pci_bus *bus)
{
struct pci_dev *dev = bus->self;
if (pci_has_flag(PCI_PROBE_ONLY) && dev &&
(dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
pci_read_bridge_bases(bus);
}
}
char * (*pcibios_plat_setup)(char *str) __initdata;
char *__init pcibios_setup(char *str)
{
if (pcibios_plat_setup)
return pcibios_plat_setup(str);
return str;
}