![Lennert Buytenhek](/assets/img/avatar_default.png)
Patch from Lennert Buytenhek Assigning the address zero to a PCI device BAR causes some part of the PCI subsystem to believe that resource allocation for that BAR failed due to resource conflicts, which will make attempts to enable the device fail. Work around this by assigning I/O addresses starting from 00010000. While we're at it, make the PCI I/O resource end at 0001ffff, since we only have 64k of outbound I/O window on the IXP2000, and we don't do bank switching. Signed-off-by: Lennert Buytenhek Signed-off-by: Deepak Saxena Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
236 lines
4.9 KiB
C
236 lines
4.9 KiB
C
/*
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* arch/arm/mach-ixp2000/pci.c
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*
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* PCI routines for IXDP2400/IXDP2800 boards
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*
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* Original Author: Naeem Afzal <naeem.m.afzal@intel.com>
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* Maintained by: Deepak Saxena <dsaxena@plexity.net>
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*
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* Copyright 2002 Intel Corp.
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* Copyright (C) 2003-2004 MontaVista Software, Inc.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/pci.h>
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#include <linux/interrupt.h>
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <linux/ioport.h>
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#include <linux/slab.h>
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#include <linux/delay.h>
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#include <asm/io.h>
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#include <asm/irq.h>
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#include <asm/system.h>
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#include <asm/mach-types.h>
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#include <asm/hardware.h>
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#include <asm/mach/pci.h>
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static int pci_master_aborts = 0;
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static int clear_master_aborts(void);
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u32 *
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ixp2000_pci_config_addr(unsigned int bus_nr, unsigned int devfn, int where)
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{
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u32 *paddress;
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if (PCI_SLOT(devfn) > 7)
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return 0;
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/* Must be dword aligned */
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where &= ~3;
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/*
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* For top bus, generate type 0, else type 1
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*/
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if (!bus_nr) {
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/* only bits[23:16] are used for IDSEL */
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paddress = (u32 *) (IXP2000_PCI_CFG0_VIRT_BASE
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| (1 << (PCI_SLOT(devfn) + 16))
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| (PCI_FUNC(devfn) << 8) | where);
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} else {
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paddress = (u32 *) (IXP2000_PCI_CFG1_VIRT_BASE
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| (bus_nr << 16)
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| (PCI_SLOT(devfn) << 11)
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| (PCI_FUNC(devfn) << 8) | where);
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}
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return paddress;
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}
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/*
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* Mask table, bits to mask for quantity of size 1, 2 or 4 bytes.
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* 0 and 3 are not valid indexes...
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*/
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static u32 bytemask[] = {
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/*0*/ 0,
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/*1*/ 0xff,
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/*2*/ 0xffff,
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/*3*/ 0,
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/*4*/ 0xffffffff,
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};
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int ixp2000_pci_read_config(struct pci_bus *bus, unsigned int devfn, int where,
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int size, u32 *value)
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{
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u32 n;
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u32 *addr;
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n = where % 4;
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addr = ixp2000_pci_config_addr(bus->number, devfn, where);
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if (!addr)
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return PCIBIOS_DEVICE_NOT_FOUND;
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pci_master_aborts = 0;
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*value = (*addr >> (8*n)) & bytemask[size];
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if (pci_master_aborts) {
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pci_master_aborts = 0;
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*value = 0xffffffff;
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return PCIBIOS_DEVICE_NOT_FOUND;
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}
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return PCIBIOS_SUCCESSFUL;
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}
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/*
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* We don't do error checks by callling clear_master_aborts() b/c the
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* assumption is that the caller did a read first to make sure a device
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* exists.
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*/
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int ixp2000_pci_write_config(struct pci_bus *bus, unsigned int devfn, int where,
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int size, u32 value)
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{
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u32 mask;
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u32 *addr;
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u32 temp;
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mask = ~(bytemask[size] << ((where % 0x4) * 8));
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addr = ixp2000_pci_config_addr(bus->number, devfn, where);
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if (!addr)
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return PCIBIOS_DEVICE_NOT_FOUND;
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temp = (u32) (value) << ((where % 0x4) * 8);
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*addr = (*addr & mask) | temp;
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clear_master_aborts();
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return PCIBIOS_SUCCESSFUL;
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}
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static struct pci_ops ixp2000_pci_ops = {
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.read = ixp2000_pci_read_config,
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.write = ixp2000_pci_write_config
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};
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struct pci_bus *ixp2000_pci_scan_bus(int nr, struct pci_sys_data *sysdata)
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{
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return pci_scan_bus(sysdata->busnr, &ixp2000_pci_ops, sysdata);
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}
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int ixp2000_pci_abort_handler(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
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{
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volatile u32 temp;
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unsigned long flags;
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pci_master_aborts = 1;
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local_irq_save(flags);
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temp = *(IXP2000_PCI_CONTROL);
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if (temp & ((1 << 8) | (1 << 5))) {
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ixp2000_reg_write(IXP2000_PCI_CONTROL, temp);
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}
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temp = *(IXP2000_PCI_CMDSTAT);
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if (temp & (1 << 29)) {
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while (temp & (1 << 29)) {
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ixp2000_reg_write(IXP2000_PCI_CMDSTAT, temp);
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temp = *(IXP2000_PCI_CMDSTAT);
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}
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}
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local_irq_restore(flags);
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/*
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* If it was an imprecise abort, then we need to correct the
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* return address to be _after_ the instruction.
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*/
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if (fsr & (1 << 10))
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regs->ARM_pc += 4;
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return 0;
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}
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int
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clear_master_aborts(void)
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{
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volatile u32 temp;
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unsigned long flags;
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local_irq_save(flags);
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temp = *(IXP2000_PCI_CONTROL);
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if (temp & ((1 << 8) | (1 << 5))) {
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ixp2000_reg_write(IXP2000_PCI_CONTROL, temp);
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}
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temp = *(IXP2000_PCI_CMDSTAT);
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if (temp & (1 << 29)) {
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while (temp & (1 << 29)) {
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ixp2000_reg_write(IXP2000_PCI_CMDSTAT, temp);
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temp = *(IXP2000_PCI_CMDSTAT);
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}
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}
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local_irq_restore(flags);
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return 0;
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}
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void __init
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ixp2000_pci_preinit(void)
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{
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hook_fault_code(16+6, ixp2000_pci_abort_handler, SIGBUS,
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"PCI config cycle to non-existent device");
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}
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/*
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* IXP2000 systems often have large resource requirements, so we just
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* use our own resource space.
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*/
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static struct resource ixp2000_pci_mem_space = {
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.start = 0xe0000000,
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.end = 0xffffffff,
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.flags = IORESOURCE_MEM,
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.name = "PCI Mem Space"
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};
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static struct resource ixp2000_pci_io_space = {
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.start = 0x00010000,
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.end = 0x0001ffff,
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.flags = IORESOURCE_IO,
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.name = "PCI I/O Space"
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};
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int ixp2000_pci_setup(int nr, struct pci_sys_data *sys)
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{
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if (nr >= 1)
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return 0;
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sys->resource[0] = &ixp2000_pci_io_space;
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sys->resource[1] = &ixp2000_pci_mem_space;
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sys->resource[2] = NULL;
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return 1;
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}
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