linux/include/asm-mips/pci.h
David S. Miller e24c2d963a [PATCH] PCI: DMA bursting advice
After seeing, at best, "guesses" as to the following kind
of information in several drivers, I decided that we really
need a way for platforms to specifically give advice in this
area for what works best with their PCI controller implementation.

Basically, this new interface gives DMA bursting advice on
PCI.  There are three forms of the advice:

1) Burst as much as possible, it is not necessary to end bursts
   on some particular boundary for best performance.

2) Burst on some byte count multiple.  A DMA burst to some multiple of
   number of bytes may be done, but it is important to end the burst
   on an exact multiple for best performance.

   The best example of this I am aware of are the PPC64 PCI
   controllers, where if you end a burst mid-cacheline then
   chip has to refetch the data and the IOMMU translations
   which hurts performance a lot.

3) Burst on a single byte count multiple.  Bursts shall end
   exactly on the next multiple boundary for best performance.

   Sparc64 and Alpha's PCI controllers operate this way.  They
   disconnect any device which tries to burst across a cacheline
   boundary.

   Actually, newer sparc64 PCI controllers do not have this behavior.
   That is why the "pdev" is passed into the interface, so I can
   add code later to check which PCI controller the system is using
   and give advice accordingly.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-27 21:52:45 -07:00

169 lines
4.8 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/config.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 int index;
/* For compatibility with current (as of July 2003) pciutils
and XFree86. Eventually will be removed. */
unsigned int need_domain_info;
int iommu;
};
/*
* 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(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);
#define pcibios_scan_all_fns(a, b) 0
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)
{
/* We don't do dynamic PCI IRQ allocation */
}
/*
* 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>
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_MAPPED_DMA_IO
/* pci_unmap_{single,page} is not a nop, thus... */
#define DECLARE_PCI_UNMAP_ADDR(ADDR_NAME) dma_addr_t ADDR_NAME;
#define DECLARE_PCI_UNMAP_LEN(LEN_NAME) __u32 LEN_NAME;
#define pci_unmap_addr(PTR, ADDR_NAME) ((PTR)->ADDR_NAME)
#define pci_unmap_addr_set(PTR, ADDR_NAME, VAL) (((PTR)->ADDR_NAME) = (VAL))
#define pci_unmap_len(PTR, LEN_NAME) ((PTR)->LEN_NAME)
#define pci_unmap_len_set(PTR, LEN_NAME, VAL) (((PTR)->LEN_NAME) = (VAL))
#else /* CONFIG_MAPPED_DMA_IO */
/* pci_unmap_{page,single} is a nop so... */
#define DECLARE_PCI_UNMAP_ADDR(ADDR_NAME)
#define DECLARE_PCI_UNMAP_LEN(LEN_NAME)
#define pci_unmap_addr(PTR, ADDR_NAME) (0)
#define pci_unmap_addr_set(PTR, ADDR_NAME, VAL) do { } while (0)
#define pci_unmap_len(PTR, LEN_NAME) (0)
#define pci_unmap_len_set(PTR, LEN_NAME, VAL) do { } while (0)
#endif /* CONFIG_MAPPED_DMA_IO */
/* This is always fine. */
#define pci_dac_dma_supported(pci_dev, mask) (1)
extern dma64_addr_t pci_dac_page_to_dma(struct pci_dev *pdev,
struct page *page, unsigned long offset, int direction);
extern struct page *pci_dac_dma_to_page(struct pci_dev *pdev,
dma64_addr_t dma_addr);
extern unsigned long pci_dac_dma_to_offset(struct pci_dev *pdev,
dma64_addr_t dma_addr);
extern void pci_dac_dma_sync_single_for_cpu(struct pci_dev *pdev,
dma64_addr_t dma_addr, size_t len, int direction);
extern void pci_dac_dma_sync_single_for_device(struct pci_dev *pdev,
dma64_addr_t dma_addr, size_t len, int direction);
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;
}
extern void pcibios_resource_to_bus(struct pci_dev *dev,
struct pci_bus_region *region, struct resource *res);
#ifdef CONFIG_PCI_DOMAINS
#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 /* CONFIG_PCI_DOMAINS */
#endif /* __KERNEL__ */
/* implement the pci_ DMA API in terms of the generic device dma_ one */
#include <asm-generic/pci-dma-compat.h>
static inline void pcibios_add_platform_entries(struct pci_dev *dev)
{
}
/* Do platform specific device initialization at pci_enable_device() time */
extern int pcibios_plat_dev_init(struct pci_dev *dev);
#endif /* _ASM_PCI_H */