android_kernel_motorola_sm6225/arch/arm/mach-ixp23xx/pci.c
Lennert Buytenhek 23759dc643 [ARM] 3439/2: xsc3: add I/O coherency support
Patch from Lennert Buytenhek

This patch adds support for the I/O coherent cache available on the
xsc3.  The approach is to provide a simple API to determine whether the
chipset supports coherency by calling arch_is_coherent() and then
setting the appropriate system memory PTE and PMD bits.  In addition,
we call this API on dma_alloc_coherent() and dma_map_single() calls.
A generic version exists that will compile out all the coherency-related
code that is not needed on the majority of ARM systems.

Note that we do not check for coherency in the dma_alloc_writecombine()
function as that still requires a special PTE setting.  We also don't
touch dma_mmap_coherent() as that is a special ARM-only API that is by
definition only used on non-coherent system.

Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-04-02 00:07:39 +01:00

291 lines
6.2 KiB
C

/*
* arch/arm/mach-ixp23xx/pci.c
*
* PCI routines for IXP23XX based systems
*
* Copyright (c) 2005 MontaVista Software, Inc.
*
* based on original code:
*
* Author: Naeem Afzal <naeem.m.afzal@intel.com>
* Copyright 2002-2005 Intel Corp.
*
* 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.
*/
#include <linux/config.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/sizes.h>
#include <asm/system.h>
#include <asm/mach/pci.h>
#include <asm/mach-types.h>
#include <asm/hardware.h>
extern int (*external_fault) (unsigned long, struct pt_regs *);
static int pci_master_aborts = 0;
#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif
int clear_master_aborts(void);
static u32
*ixp23xx_pci_config_addr(unsigned int bus_nr, unsigned int devfn, int where)
{
u32 *paddress;
/*
* Must be dword aligned
*/
where &= ~3;
/*
* For top bus, generate type 0, else type 1
*/
if (!bus_nr) {
if (PCI_SLOT(devfn) >= 8)
return 0;
paddress = (u32 *) (IXP23XX_PCI_CFG0_VIRT
| (1 << (PCI_SLOT(devfn) + 16))
| (PCI_FUNC(devfn) << 8) | where);
} else {
paddress = (u32 *) (IXP23XX_PCI_CFG1_VIRT
| (bus_nr << 16)
| (PCI_SLOT(devfn) << 11)
| (PCI_FUNC(devfn) << 8) | where);
}
return paddress;
}
/*
* Mask table, bits to mask for quantity of size 1, 2 or 4 bytes.
* 0 and 3 are not valid indexes...
*/
static u32 bytemask[] = {
/*0*/ 0,
/*1*/ 0xff,
/*2*/ 0xffff,
/*3*/ 0,
/*4*/ 0xffffffff,
};
static int ixp23xx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *value)
{
u32 n;
u32 *addr;
n = where % 4;
DBG("In config_read(%d) %d from dev %d:%d:%d\n", size, where,
bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn));
addr = ixp23xx_pci_config_addr(bus->number, devfn, where);
if (!addr)
return PCIBIOS_DEVICE_NOT_FOUND;
pci_master_aborts = 0;
*value = (*addr >> (8*n)) & bytemask[size];
if (pci_master_aborts) {
pci_master_aborts = 0;
*value = 0xffffffff;
return PCIBIOS_DEVICE_NOT_FOUND;
}
return PCIBIOS_SUCCESSFUL;
}
/*
* We don't do error checking on the address for writes.
* It's assumed that the user checked for the device existing first
* by doing a read first.
*/
static int ixp23xx_pci_write_config(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 value)
{
u32 mask;
u32 *addr;
u32 temp;
mask = ~(bytemask[size] << ((where % 0x4) * 8));
addr = ixp23xx_pci_config_addr(bus->number, devfn, where);
if (!addr)
return PCIBIOS_DEVICE_NOT_FOUND;
temp = (u32) (value) << ((where % 0x4) * 8);
*addr = (*addr & mask) | temp;
clear_master_aborts();
return PCIBIOS_SUCCESSFUL;
}
struct pci_ops ixp23xx_pci_ops = {
.read = ixp23xx_pci_read_config,
.write = ixp23xx_pci_write_config,
};
struct pci_bus *ixp23xx_pci_scan_bus(int nr, struct pci_sys_data *sysdata)
{
return pci_scan_bus(sysdata->busnr, &ixp23xx_pci_ops, sysdata);
}
int ixp23xx_pci_abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
{
volatile unsigned long temp;
unsigned long flags;
pci_master_aborts = 1;
local_irq_save(flags);
temp = *IXP23XX_PCI_CONTROL;
/*
* master abort and cmd tgt err
*/
if (temp & ((1 << 8) | (1 << 5)))
*IXP23XX_PCI_CONTROL = temp;
temp = *IXP23XX_PCI_CMDSTAT;
if (temp & (1 << 29))
*IXP23XX_PCI_CMDSTAT = temp;
local_irq_restore(flags);
/*
* If it was an imprecise abort, then we need to correct the
* return address to be _after_ the instruction.
*/
if (fsr & (1 << 10))
regs->ARM_pc += 4;
return 0;
}
int clear_master_aborts(void)
{
volatile u32 temp;
temp = *IXP23XX_PCI_CONTROL;
/*
* master abort and cmd tgt err
*/
if (temp & ((1 << 8) | (1 << 5)))
*IXP23XX_PCI_CONTROL = temp;
temp = *IXP23XX_PCI_CMDSTAT;
if (temp & (1 << 29))
*IXP23XX_PCI_CMDSTAT = temp;
return 0;
}
static void __init ixp23xx_pci_common_init(void)
{
#ifdef __ARMEB__
*IXP23XX_PCI_CONTROL |= 0x20000; /* set I/O swapping */
#endif
/*
* ADDR_31 needs to be clear for PCI memory access to CPP memory
*/
*IXP23XX_CPP2XSI_CURR_XFER_REG3 &= ~IXP23XX_CPP2XSI_ADDR_31;
*IXP23XX_CPP2XSI_CURR_XFER_REG3 |= IXP23XX_CPP2XSI_PSH_OFF;
/*
* Select correct memory for PCI inbound transactions
*/
if (ixp23xx_cpp_boot()) {
*IXP23XX_PCI_CPP_ADDR_BITS &= ~(1 << 1);
} else {
*IXP23XX_PCI_CPP_ADDR_BITS |= (1 << 1);
/*
* Enable coherency on A2 silicon.
*/
if (arch_is_coherent())
*IXP23XX_CPP2XSI_CURR_XFER_REG3 &= ~IXP23XX_CPP2XSI_COH_OFF;
}
}
void __init ixp23xx_pci_preinit(void)
{
ixp23xx_pci_common_init();
hook_fault_code(16+6, ixp23xx_pci_abort_handler, SIGBUS,
"PCI config cycle to non-existent device");
*IXP23XX_PCI_ADDR_EXT = 0x0000e000;
}
/*
* Prevent PCI layer from seeing the inbound host-bridge resources
*/
static void __devinit pci_fixup_ixp23xx(struct pci_dev *dev)
{
int i;
dev->class &= 0xff;
dev->class |= PCI_CLASS_BRIDGE_HOST << 8;
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
dev->resource[i].start = 0;
dev->resource[i].end = 0;
dev->resource[i].flags = 0;
}
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9002, pci_fixup_ixp23xx);
/*
* IXP2300 systems often have large resource requirements, so we just
* use our own resource space.
*/
static struct resource ixp23xx_pci_mem_space = {
.start = IXP23XX_PCI_MEM_START,
.end = IXP23XX_PCI_MEM_START + IXP23XX_PCI_MEM_SIZE - 1,
.flags = IORESOURCE_MEM,
.name = "PCI Mem Space"
};
static struct resource ixp23xx_pci_io_space = {
.start = 0x00000100,
.end = 0x01ffffff,
.flags = IORESOURCE_IO,
.name = "PCI I/O Space"
};
int ixp23xx_pci_setup(int nr, struct pci_sys_data *sys)
{
if (nr >= 1)
return 0;
sys->resource[0] = &ixp23xx_pci_io_space;
sys->resource[1] = &ixp23xx_pci_mem_space;
sys->resource[2] = NULL;
return 1;
}
void ixp23xx_pci_slave_init(void)
{
ixp23xx_pci_common_init();
}