/**
* @file
*
* PCI Support when Configuration Space is accessed via BIOS
*/
/*
* This software is Copyright (C) 1998 by T.sqware - all rights limited
* It is provided in to the public domain "as is", can be freely modified
* as far as this copyight notice is kept unchanged, but does not imply
* an endorsement by T.sqware of the product in which it is included.
*/
#include <rtems.h>
#include <bsp.h>
#include <rtems/pci.h>
#include <string.h> /* memcpy */
/*
* This is simpliest possible PCI BIOS, it assumes that addressing
* is flat and that stack is big enough
*/
static int pcibInitialized = 0;
static unsigned int pcibEntry;
/*
* Array to pass data between c and __asm__ parts, at the time of
* writing I am not yet that familiar with extended __asm__ feature
* of gcc. This code is not on performance path, so we can care
* relatively little about performance here
*/
static volatile unsigned int pcibExchg[5];
static int pcib_convert_err(int err);
/** @brief
* Make device signature from bus number, device numebr and function
* number
*/
#define PCIB_DEVSIG_MAKE(b,d,f) ((b<<8)|(d<<3)|(f))
/** @brief
* Extract valrous part from device signature
*/
#define PCIB_DEVSIG_BUS(x) (((x)>>8) &0xff)
#define PCIB_DEVSIG_DEV(x) (((x)>>3) & 0x1f)
#define PCIB_DEVSIG_FUNC(x) ((x) & 0x7)
/*
* Forward reference. Initialized at bottom.
*/
static const pci_config_access_functions pci_bios_indirect_functions;
/* prototype before defining */
const pci_config_access_functions *pci_bios_initialize(void);
/*
* Detects presense of PCI BIOS, returns pointer to accessor methods.
*/
const pci_config_access_functions *pci_bios_initialize(void)
{
unsigned char *ucp;
unsigned char sum;
int i;
pcibInitialized = 0;
/* First, we have to look for BIOS-32 */
for (ucp = (unsigned char *)0xE0000;
ucp < (unsigned char *)0xFFFFF;
ucp += 0x10) {
if (memcmp(ucp, "_32_", 4) != 0) {
continue;
}
/* Got signature, check length */
if (*(ucp + 9) != 1) {
continue;
}
/* Verify checksum */
sum = 0;
for (i=0; i<16; i++) {
sum += *(ucp+i);
}
if (sum == 0) {
/* found */
break;
}
}
if (ucp >= (unsigned char *)0xFFFFF) {
/* BIOS-32 not found */
return NULL;
}
/* BIOS-32 found, let us find PCI BIOS */
ucp += 4;
pcibExchg[0] = *(unsigned int *)ucp;
__asm__ (" pusha"); /* Push all registers */
__asm__ (" movl pcibExchg, %edi"); /* Move entry point to esi */
__asm__ (" movl $0x49435024, %eax"); /* Move signature to eax */
__asm__ (" xorl %ebx, %ebx"); /* Zero ebx */
__asm__ (" pushl %cs");
__asm__ (" call *%edi"); /* Call entry */
__asm__ (" movl %eax, pcibExchg");
__asm__ (" movl %ebx, pcibExchg+4");
__asm__ (" movl %ecx, pcibExchg+8");
__asm__ (" movl %edx, pcibExchg+12");
__asm__ (" popa");
if ((pcibExchg[0] & 0xff) != 0) {
/* Not found */
return NULL;
}
/* Found PCI entry point */
pcibEntry = pcibExchg[1] + pcibExchg[3];
/* Let us check whether PCI bios is present */
pcibExchg[0] = pcibEntry;
__asm__ (" pusha");
__asm__ (" movl pcibExchg, %edi");
__asm__ (" movb $0xb1, %ah");
__asm__ (" movb $0x01, %al");
__asm__ (" pushl %cs");
__asm__ (" call *%edi");
__asm__ (" movl %eax, pcibExchg");
__asm__ (" movl %ebx, pcibExchg+4");
__asm__ (" movl %ecx, pcibExchg+8");
__asm__ (" movl %edx, pcibExchg+12");
__asm__ (" popa");
if ((pcibExchg[0] & 0xff00) != 0) {
/* Not found */
return NULL;
}
if (pcibExchg[3] != 0x20494350) {
/* Signature does not match */
return NULL;
}
/* Success */
pcibInitialized = 1;
return &pci_bios_indirect_functions;
}
/*
* Read byte from config space
*/
static int
pcib_conf_read8(int sig, int off, uint8_t *data)
{
if (!pcibInitialized) {
return PCIB_ERR_UNINITIALIZED;
}
pcibExchg[0] = pcibEntry;
pcibExchg[1] = sig;
pcibExchg[2] = off;
__asm__ (" pusha");
__asm__ (" movl pcibExchg, %esi");
__asm__ (" movb $0xb1, %ah");
__asm__ (" movb $0x08, %al");
__asm__ (" movl pcibExchg+4, %ebx");
__asm__ (" movl pcibExchg+8, %edi");
__asm__ (" pushl %cs");
__asm__ (" call *%esi");
__asm__ (" movl %eax, pcibExchg");
__asm__ (" movl %ecx, pcibExchg+4");
__asm__ (" popa");
if ((pcibExchg[0] & 0xff00) != 0) {
return pcib_convert_err((pcibExchg[0] >> 8) & 0xff);
}
*data = (unsigned char)pcibExchg[1] & 0xff;
return PCIB_ERR_SUCCESS;
}
/*
* Read word from config space
*/
static int
pcib_conf_read16(int sig, int off, uint16_t *data)
{
if (!pcibInitialized) {
return PCIB_ERR_UNINITIALIZED;
}
pcibExchg[0] = pcibEntry;
pcibExchg[1] = sig;
pcibExchg[2] = off;
__asm__ (" pusha");
__asm__ (" movl pcibExchg, %esi");
__asm__ (" movb $0xb1, %ah");
__asm__ (" movb $0x09, %al");
__asm__ (" movl pcibExchg+4, %ebx");
__asm__ (" movl pcibExchg+8, %edi");
__asm__ (" pushl %cs");
__asm__ (" call *%esi");
__asm__ (" movl %eax, pcibExchg");
__asm__ (" movl %ecx, pcibExchg+4");
__asm__ (" popa");
if ((pcibExchg[0] & 0xff00) != 0) {
return pcib_convert_err((pcibExchg[0] >> 8) & 0xff);
}
*data = (unsigned short)pcibExchg[1] & 0xffff;
return PCIB_ERR_SUCCESS;
}
/*
* Read dword from config space
*/
static int
pcib_conf_read32(int sig, int off, uint32_t *data)
{
if (!pcibInitialized) {
return PCIB_ERR_UNINITIALIZED;
}
pcibExchg[0] = pcibEntry;
pcibExchg[1] = sig;
pcibExchg[2] = off;
__asm__ (" pusha");
__asm__ (" movl pcibExchg, %esi");
__asm__ (" movb $0xb1, %ah");
__asm__ (" movb $0x0a, %al");
__asm__ (" movl pcibExchg+4, %ebx");
__asm__ (" movl pcibExchg+8, %edi");
__asm__ (" pushl %cs");
__asm__ (" call *%esi");
__asm__ (" movl %eax, pcibExchg");
__asm__ (" movl %ecx, pcibExchg+4");
__asm__ (" popa");
if ((pcibExchg[0] & 0xff00) != 0) {
return pcib_convert_err((pcibExchg[0] >> 8) & 0xff);
}
*data = (unsigned int)pcibExchg[1];
return PCIB_ERR_SUCCESS;
}
/*
* Write byte into config space
*/
static int
pcib_conf_write8(int sig, int off, uint8_t data)
{
if (!pcibInitialized) {
return PCIB_ERR_UNINITIALIZED;
}
pcibExchg[0] = pcibEntry;
pcibExchg[1] = sig;
pcibExchg[2] = off;
pcibExchg[3] = data & 0xff;
__asm__ (" pusha");
__asm__ (" movl pcibExchg, %esi");
__asm__ (" movb $0xb1, %ah");
__asm__ (" movb $0x0b, %al");
__asm__ (" movl pcibExchg+4, %ebx");
__asm__ (" movl pcibExchg+8, %edi");
__asm__ (" movl pcibExchg+12, %ecx");
__asm__ (" pushl %cs");
__asm__ (" call *%esi");
__asm__ (" movl %eax, pcibExchg");
__asm__ (" popa");
return pcib_convert_err((pcibExchg[0] >> 8) & 0xff);
}
/*
* Write word into config space
*/
static int
pcib_conf_write16(int sig, int off, uint16_t data)
{
if (!pcibInitialized) {
return PCIB_ERR_UNINITIALIZED;
}
pcibExchg[0] = pcibEntry;
pcibExchg[1] = sig;
pcibExchg[2] = off;
pcibExchg[3] = data & 0xffff;
__asm__ (" pusha");
__asm__ (" movl pcibExchg, %esi");
__asm__ (" movb $0xb1, %ah");
__asm__ (" movb $0x0c, %al");
__asm__ (" movl pcibExchg+4, %ebx");
__asm__ (" movl pcibExchg+8, %edi");
__asm__ (" movl pcibExchg+12, %ecx");
__asm__ (" pushl %cs");
__asm__ (" call *%esi");
__asm__ (" movl %eax, pcibExchg");
__asm__ (" popa");
return pcib_convert_err((pcibExchg[0] >> 8) & 0xff);
}
/*
* Write dword into config space
*/
static int
pcib_conf_write32(int sig, int off, uint32_t data)
{
if (!pcibInitialized){
return PCIB_ERR_UNINITIALIZED;
}
pcibExchg[0] = pcibEntry;
pcibExchg[1] = sig;
pcibExchg[2] = off;
pcibExchg[3] = data;
__asm__ (" pusha");
__asm__ (" movl pcibExchg, %esi");
__asm__ (" movb $0xb1, %ah");
__asm__ (" movb $0x0d, %al");
__asm__ (" movl pcibExchg+4, %ebx");
__asm__ (" movl pcibExchg+8, %edi");
__asm__ (" movl pcibExchg+12, %ecx");
__asm__ (" pushl %cs");
__asm__ (" call *%esi");
__asm__ (" movl %eax, pcibExchg");
__asm__ (" popa");
return pcib_convert_err((pcibExchg[0] >> 8) & 0xff);
}
static int
pcib_convert_err(int err)
{
switch(err & 0xff){
case 0:
return PCIB_ERR_SUCCESS;
case 0x81:
return PCIB_ERR_NOFUNC;
case 0x83:
return PCIB_ERR_BADVENDOR;
case 0x86:
return PCIB_ERR_DEVNOTFOUND;
case 0x87:
return PCIB_ERR_BADREG;
default:
break;
}
return PCIB_ERR_NOFUNC;
}
static int
BSP_pci_read_config_byte(
unsigned char bus,
unsigned char slot,
unsigned char fun,
unsigned char offset,
unsigned char *val
)
{
int sig;
sig = PCIB_DEVSIG_MAKE(bus,slot,fun);
pcib_conf_read8(sig, offset, val);
return PCIBIOS_SUCCESSFUL;
}
static int
BSP_pci_read_config_word(
unsigned char bus,
unsigned char slot,
unsigned char fun,
unsigned char offset,
unsigned short *val
)
{
int sig;
sig = PCIB_DEVSIG_MAKE(bus,slot,fun);
pcib_conf_read16(sig, offset, val);
return PCIBIOS_SUCCESSFUL;
}
static int
BSP_pci_read_config_dword(
unsigned char bus,
unsigned char slot,
unsigned char fun,
unsigned char offset,
uint32_t *val
)
{
int sig;
sig = PCIB_DEVSIG_MAKE(bus,slot,fun);
pcib_conf_read32(sig, offset, val);
return PCIBIOS_SUCCESSFUL;
}
static int
BSP_pci_write_config_byte(
unsigned char bus,
unsigned char slot,
unsigned char fun,
unsigned char offset,
unsigned char val
)
{
int sig;
sig = PCIB_DEVSIG_MAKE(bus,slot,fun);
pcib_conf_write8(sig, offset, val);
return PCIBIOS_SUCCESSFUL;
}
static int
BSP_pci_write_config_word(
unsigned char bus,
unsigned char slot,
unsigned char fun,
unsigned char offset,
unsigned short val
)
{
int sig;
sig = PCIB_DEVSIG_MAKE(bus,slot,fun);
pcib_conf_write16(sig, offset, val);
return PCIBIOS_SUCCESSFUL;
}
static int
BSP_pci_write_config_dword(
unsigned char bus,
unsigned char slot,
unsigned char fun,
unsigned char offset,
uint32_t val
)
{
int sig;
sig = PCIB_DEVSIG_MAKE(bus,slot,fun);
pcib_conf_write32(sig, offset, val);
return PCIBIOS_SUCCESSFUL;
}
static const pci_config_access_functions pci_bios_indirect_functions = {
BSP_pci_read_config_byte,
BSP_pci_read_config_word,
BSP_pci_read_config_dword,
BSP_pci_write_config_byte,
BSP_pci_write_config_word,
BSP_pci_write_config_dword
};