linux/arch/xtensa/kernel/pci.c
Dominik Brodowski 3b7a17fcda resource/PCI: mark struct resource as const
Now that we return the new resource start position, there is no
need to update "struct resource" inside the align function.
Therefore, mark the struct resource as const.

Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-02-22 16:16:57 -08:00

395 lines
9.8 KiB
C

/*
* arch/xtensa/kernel/pci.c
*
* PCI bios-type initialisation for PCI machines
*
* 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 of the License, or (at your
* option) any later version.
*
* Copyright (C) 2001-2005 Tensilica Inc.
*
* Based largely on work from Cort (ppc/kernel/pci.c)
* IO functions copied from sparc.
*
* Chris Zankel <chris@zankel.net>
*
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/bootmem.h>
#include <asm/pci-bridge.h>
#include <asm/platform.h>
#undef DEBUG
#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif
/* PCI Controller */
/*
* pcibios_alloc_controller
* pcibios_enable_device
* pcibios_fixups
* pcibios_align_resource
* pcibios_fixup_bus
* pcibios_setup
* pci_bus_add_device
* pci_mmap_page_range
*/
struct pci_controller* pci_ctrl_head;
struct pci_controller** pci_ctrl_tail = &pci_ctrl_head;
static int pci_bus_count;
/*
* 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;
resource_size_t start = res->start;
if (res->flags & IORESOURCE_IO) {
if (size > 0x100) {
printk(KERN_ERR "PCI: I/O Region %s/%d too large"
" (%ld bytes)\n", pci_name(dev),
dev->resource - res, size);
}
if (start & 0x300)
start = (start + 0x3ff) & ~0x3ff;
}
return start;
}
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<6; idx++) {
r = &dev->resource[idx];
if (!r->start && r->end) {
printk (KERN_ERR "PCI: Device %s not available because "
"of resource collisions\n", pci_name(dev));
return -EINVAL;
}
if (r->flags & IORESOURCE_IO)
cmd |= PCI_COMMAND_IO;
if (r->flags & IORESOURCE_MEM)
cmd |= PCI_COMMAND_MEMORY;
}
if (dev->resource[PCI_ROM_RESOURCE].start)
cmd |= PCI_COMMAND_MEMORY;
if (cmd != old_cmd) {
printk("PCI: Enabling device %s (%04x -> %04x)\n",
pci_name(dev), old_cmd, cmd);
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
return 0;
}
struct pci_controller * __init pcibios_alloc_controller(void)
{
struct pci_controller *pci_ctrl;
pci_ctrl = (struct pci_controller *)alloc_bootmem(sizeof(*pci_ctrl));
memset(pci_ctrl, 0, sizeof(struct pci_controller));
*pci_ctrl_tail = pci_ctrl;
pci_ctrl_tail = &pci_ctrl->next;
return pci_ctrl;
}
static int __init pcibios_init(void)
{
struct pci_controller *pci_ctrl;
struct pci_bus *bus;
int next_busno = 0, i;
printk("PCI: Probing PCI hardware\n");
/* Scan all of the recorded PCI controllers. */
for (pci_ctrl = pci_ctrl_head; pci_ctrl; pci_ctrl = pci_ctrl->next) {
pci_ctrl->last_busno = 0xff;
bus = pci_scan_bus(pci_ctrl->first_busno, pci_ctrl->ops,
pci_ctrl);
if (pci_ctrl->io_resource.flags) {
unsigned long offs;
offs = (unsigned long)pci_ctrl->io_space.base;
pci_ctrl->io_resource.start += offs;
pci_ctrl->io_resource.end += offs;
bus->resource[0] = &pci_ctrl->io_resource;
}
for (i = 0; i < 3; ++i)
if (pci_ctrl->mem_resources[i].flags)
bus->resource[i+1] =&pci_ctrl->mem_resources[i];
pci_ctrl->bus = bus;
pci_ctrl->last_busno = bus->subordinate;
if (next_busno <= pci_ctrl->last_busno)
next_busno = pci_ctrl->last_busno+1;
}
pci_bus_count = next_busno;
return platform_pcibios_fixup();
}
subsys_initcall(pcibios_init);
void __init pcibios_fixup_bus(struct pci_bus *bus)
{
struct pci_controller *pci_ctrl = bus->sysdata;
struct resource *res;
unsigned long io_offset;
int i;
io_offset = (unsigned long)pci_ctrl->io_space.base;
if (bus->parent == NULL) {
/* this is a host bridge - fill in its resources */
pci_ctrl->bus = bus;
bus->resource[0] = res = &pci_ctrl->io_resource;
if (!res->flags) {
if (io_offset)
printk (KERN_ERR "I/O resource not set for host"
" bridge %d\n", pci_ctrl->index);
res->start = 0;
res->end = IO_SPACE_LIMIT;
res->flags = IORESOURCE_IO;
}
res->start += io_offset;
res->end += io_offset;
for (i = 0; i < 3; i++) {
res = &pci_ctrl->mem_resources[i];
if (!res->flags) {
if (i > 0)
continue;
printk(KERN_ERR "Memory resource not set for "
"host bridge %d\n", pci_ctrl->index);
res->start = 0;
res->end = ~0U;
res->flags = IORESOURCE_MEM;
}
bus->resource[i+1] = res;
}
} else {
/* This is a subordinate bridge */
pci_read_bridge_bases(bus);
for (i = 0; i < 4; i++) {
if ((res = bus->resource[i]) == NULL || !res->flags)
continue;
if (io_offset && (res->flags & IORESOURCE_IO)) {
res->start += io_offset;
res->end += io_offset;
}
}
}
}
char __init *pcibios_setup(char *str)
{
return str;
}
/* the next one is stolen from the alpha port... */
void __init
pcibios_update_irq(struct pci_dev *dev, int irq)
{
pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
}
int pcibios_enable_device(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<6; idx++) {
r = &dev->resource[idx];
if (!r->start && r->end) {
printk(KERN_ERR "PCI: Device %s not available because "
"of resource collisions\n", pci_name(dev));
return -EINVAL;
}
if (r->flags & IORESOURCE_IO)
cmd |= PCI_COMMAND_IO;
if (r->flags & IORESOURCE_MEM)
cmd |= PCI_COMMAND_MEMORY;
}
if (cmd != old_cmd) {
printk("PCI: Enabling device %s (%04x -> %04x)\n",
pci_name(dev), old_cmd, cmd);
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
return 0;
}
#ifdef CONFIG_PROC_FS
/*
* Return the index of the PCI controller for device pdev.
*/
int
pci_controller_num(struct pci_dev *dev)
{
struct pci_controller *pci_ctrl = (struct pci_controller*) dev->sysdata;
return pci_ctrl->index;
}
#endif /* CONFIG_PROC_FS */
/*
* Platform support for /proc/bus/pci/X/Y mmap()s,
* modelled on the sparc64 implementation by Dave Miller.
* -- paulus.
*/
/*
* Adjust vm_pgoff of VMA such that it is the physical page offset
* corresponding to the 32-bit pci bus offset for DEV requested by the user.
*
* Basically, the user finds the base address for his device which he wishes
* to mmap. They read the 32-bit value from the config space base register,
* add whatever PAGE_SIZE multiple offset they wish, and feed this into the
* offset parameter of mmap on /proc/bus/pci/XXX for that device.
*
* Returns negative error code on failure, zero on success.
*/
static __inline__ int
__pci_mmap_make_offset(struct pci_dev *dev, struct vm_area_struct *vma,
enum pci_mmap_state mmap_state)
{
struct pci_controller *pci_ctrl = (struct pci_controller*) dev->sysdata;
unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
unsigned long io_offset = 0;
int i, res_bit;
if (pci_ctrl == 0)
return -EINVAL; /* should never happen */
/* If memory, add on the PCI bridge address offset */
if (mmap_state == pci_mmap_mem) {
res_bit = IORESOURCE_MEM;
} else {
io_offset = (unsigned long)pci_ctrl->io_space.base;
offset += io_offset;
res_bit = IORESOURCE_IO;
}
/*
* Check that the offset requested corresponds to one of the
* resources of the device.
*/
for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
struct resource *rp = &dev->resource[i];
int flags = rp->flags;
/* treat ROM as memory (should be already) */
if (i == PCI_ROM_RESOURCE)
flags |= IORESOURCE_MEM;
/* Active and same type? */
if ((flags & res_bit) == 0)
continue;
/* In the range of this resource? */
if (offset < (rp->start & PAGE_MASK) || offset > rp->end)
continue;
/* found it! construct the final physical address */
if (mmap_state == pci_mmap_io)
offset += pci_ctrl->io_space.start - io_offset;
vma->vm_pgoff = offset >> PAGE_SHIFT;
return 0;
}
return -EINVAL;
}
/*
* Set vm_page_prot of VMA, as appropriate for this architecture, for a pci
* device mapping.
*/
static __inline__ void
__pci_mmap_set_pgprot(struct pci_dev *dev, struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine)
{
int prot = pgprot_val(vma->vm_page_prot);
/* Set to write-through */
prot &= ~_PAGE_NO_CACHE;
#if 0
if (!write_combine)
prot |= _PAGE_WRITETHRU;
#endif
vma->vm_page_prot = __pgprot(prot);
}
/*
* Perform the actual remap of the pages for a PCI device mapping, as
* appropriate for this architecture. The region in the process to map
* is described by vm_start and vm_end members of VMA, the base physical
* address is found in vm_pgoff.
* The pci device structure is provided so that architectures may make mapping
* decisions on a per-device or per-bus basis.
*
* Returns a negative error code on failure, zero on success.
*/
int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
enum pci_mmap_state mmap_state,
int write_combine)
{
int ret;
ret = __pci_mmap_make_offset(dev, vma, mmap_state);
if (ret < 0)
return ret;
__pci_mmap_set_pgprot(dev, vma, mmap_state, write_combine);
ret = io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
vma->vm_end - vma->vm_start,vma->vm_page_prot);
return ret;
}