linux-kernel-test/arch/mips/include/asm/pci.h
Bjorn Helgaas 96a6b9ad05 mips/PCI: get rid of device resource fixups
Tell the PCI core about host bridge address translation so it can take
care of bus-to-resource conversion for us.

Here's the wrinkle on Cobalt: we can't generate normal I/O port addresses
on PCI because the GT-64111 doesn't do any address translation, so we have
this:

  CPU I/O port addresses		[io 0x0000-0xffffff]
  PCI bus I/O port addresses	[io 0x10000000-0x10ffffff]

Legacy-mode IDE controllers start out with the legacy bus addresses, e.g.,
0x1f0, assigned by pci_setup_device().  These are outside the range of
addresses GT-64111 can generate on PCI, but pcibios_fixup_device_resources()
converted them to CPU addresses anyway by adding io_offset.  Therefore, we
had to pre-adjust them in cobalt_legacy_ide_fixup().

With io_offset = 0xf0000000, we had this:

  res->start = 0x1f0	initialized in pci_setup_device()
  res->start = 0x100001f0	-= io_offset in cobalt_legacy_ide_fixup()
  res->start = 0x1f0	+= io_offset in pcibios_fixup_device_resources()

The difference after this patch is that the generic pci_bus_to_resource()
only adds the offset if the bus address is inside a host bridge window.
Since 0x1f0 is not a valid bus address and is not inside any windows, it is
unaffected, so we now have this:

  region->start = 0x1f0	initialized in pci_setup_device()
  res->start = 0x1f0	no offset by pci_bus_to_resource()

That means we can remove both pcibios_fixup_device_resources() and
cobalt_legacy_ide_fixup().

I would *rather* set the host bridge offset to zero (which corresponds
to what the GT-64111 actually does), and have both CPU and PCI addresses
of [io 0x10000000-0x10ffffff].  However, that would require changes to
generic code that assumes legacy I/O addresses, such as pic1_io_resource
([io 0x0020-0x00021]), and we'd have to keep a Cobalt IDE fixup.

Of course, none of this changes the fact that references to I/O port
0x1f0 actually go to port 0x100001f0, not 0x1f0, on the Cobalt PCI bus.
Fortunately the VT82C586 IDE controller only decodes the low 24 address
bits, so it does work.

CC: Ralf Baechle <ralf@linux-mips.org>
CC: Yoichi Yuasa <yuasa@linux-mips.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-02-23 20:19:02 -07:00

148 lines
3.8 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#ifndef _ASM_PCI_H
#define _ASM_PCI_H
#include <linux/mm.h>
#ifdef __KERNEL__
/*
* This file essentially defines the interface between board
* specific PCI code and MIPS common PCI code. Should potentially put
* into include/asm/pci.h file.
*/
#include <linux/ioport.h>
/*
* Each pci channel is a top-level PCI bus seem by CPU. A machine with
* multiple PCI channels may have multiple PCI host controllers or a
* single controller supporting multiple channels.
*/
struct pci_controller {
struct pci_controller *next;
struct pci_bus *bus;
struct pci_ops *pci_ops;
struct resource *mem_resource;
unsigned long mem_offset;
struct resource *io_resource;
unsigned long io_offset;
unsigned long io_map_base;
unsigned int index;
/* For compatibility with current (as of July 2003) pciutils
and XFree86. Eventually will be removed. */
unsigned int need_domain_info;
int iommu;
/* Optional access methods for reading/writing the bus number
of the PCI controller */
int (*get_busno)(void);
void (*set_busno)(int busno);
};
/*
* Used by boards to register their PCI busses before the actual scanning.
*/
extern struct pci_controller * alloc_pci_controller(void);
extern void register_pci_controller(struct pci_controller *hose);
/*
* board supplied pci irq fixup routine
*/
extern int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin);
/* Can be used to override the logic in pci_scan_bus for skipping
already-configured bus numbers - to be used for buggy BIOSes
or architectures with incomplete PCI setup by the loader */
extern unsigned int pcibios_assign_all_busses(void);
extern unsigned long PCIBIOS_MIN_IO;
extern unsigned long PCIBIOS_MIN_MEM;
#define PCIBIOS_MIN_CARDBUS_IO 0x4000
extern void pcibios_set_master(struct pci_dev *dev);
static inline void pcibios_penalize_isa_irq(int irq, int active)
{
/* We don't do dynamic PCI IRQ allocation */
}
#define HAVE_PCI_MMAP
extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
enum pci_mmap_state mmap_state, int write_combine);
/*
* Dynamic DMA mapping stuff.
* MIPS has everything mapped statically.
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <asm/scatterlist.h>
#include <linux/string.h>
#include <asm/io.h>
#include <asm-generic/pci-bridge.h>
struct pci_dev;
/*
* The PCI address space does equal the physical memory address space. The
* networking and block device layers use this boolean for bounce buffer
* decisions. This is set if any hose does not have an IOMMU.
*/
extern unsigned int PCI_DMA_BUS_IS_PHYS;
#ifdef CONFIG_PCI
static inline void pci_dma_burst_advice(struct pci_dev *pdev,
enum pci_dma_burst_strategy *strat,
unsigned long *strategy_parameter)
{
*strat = PCI_DMA_BURST_INFINITY;
*strategy_parameter = ~0UL;
}
#endif
#define ARCH_HAS_GENERIC_PCI_OFFSETS
#define pci_domain_nr(bus) ((struct pci_controller *)(bus)->sysdata)->index
static inline int pci_proc_domain(struct pci_bus *bus)
{
struct pci_controller *hose = bus->sysdata;
return hose->need_domain_info;
}
#endif /* __KERNEL__ */
/* implement the pci_ DMA API in terms of the generic device dma_ one */
#include <asm-generic/pci-dma-compat.h>
/* Do platform specific device initialization at pci_enable_device() time */
extern int pcibios_plat_dev_init(struct pci_dev *dev);
/* Chances are this interrupt is wired PC-style ... */
static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
{
return channel ? 15 : 14;
}
#ifdef CONFIG_CPU_CAVIUM_OCTEON
/* MSI arch hook for OCTEON */
#define arch_setup_msi_irqs arch_setup_msi_irqs
#endif
extern char * (*pcibios_plat_setup)(char *str);
#endif /* _ASM_PCI_H */