Strip down i386 PCI configuration space I/O to the bare minimum. A

typical build will now include 880 bytes of PCI support code, compared to
2327 bytes in Etherboot 5.4.

(There is a slight cost of around 5 extra bytes per access to a
non-constant config space address; this should be an overall win.
Driver-specific accesses will usually be to constant addresses, for
which there is no additional cost.)

src/arch/i386/core/pci_io.c

@@ -1,451 +0,0 @@
-/*
-** Support for NE2000 PCI clones added David Monro June 1997
-** Generalised to other NICs by Ken Yap July 1997
-**
-** Most of this is taken from:
-**
-** /usr/src/linux/drivers/pci/pci.c
-** /usr/src/linux/include/linux/pci.h
-** /usr/src/linux/arch/i386/bios32.c
-** /usr/src/linux/include/linux/bios32.h
-** /usr/src/linux/drivers/net/ne.c
-*/
-#include "etherboot.h"
-#include <gpxe/init.h>
-#include <gpxe/pci.h>
-#include "pci_io.h"
-#ifdef KEEP_IT_REAL
-#include "realmode.h"
-#endif
-
-/* Macros for direct PCI access */
-#define CONFIG_ADDRESS	0xcf8
-#define CONFIG_DATA	0xcfc
-#define CONFIG_CMD( pci, where )					\
-	( 0x80000000 | ( pci->bus << 16 ) | ( pci->devfn << 8 ) |	\
-	  ( where & ~3 ) )
-
-/* Signatures for PCI BIOS */
-#define BIOS_SIG(a,b,c,d)	( ( a<<0 ) + ( b<<8 ) + ( c<<16 ) + ( d<<24 ) )
-#define PRINT_BIOS_SIG(x)	( (x) & 0xff ), ( ( (x)>>8 ) & 0xff ), \
-				( ( (x)>>16 ) & 0xff ),( ( (x)>>24 ) & 0xff )
-#define BIOS32_SIGNATURE	BIOS_SIG ( '_', '3', '2', '_' )
-#define PCI_SIGNATURE		BIOS_SIG ( 'P', 'C', 'I', ' ' )
-#define PCI_SERVICE		BIOS_SIG ( '$', 'P', 'C', 'I' )
-
-/* BIOS32 structure as found in PCI BIOS ROM */
-struct bios32 {
-	unsigned long signature;	/* _32_ */
-	unsigned long entry;		/* 32 bit physical address */
-	unsigned char revision;		/* Revision level, 0 */
-	unsigned char length;		/* Length in paragraphs */
-	unsigned char checksum;		/* Should byte sum to zero */
-	unsigned char reserved[5];	/* Must be zero */
-};
-
-/* Values returned by BIOS32 service directory */
-#define BIOS32_SERVICE_PRESENT		0x00
-#define BIOS32_SERVICE_NOT_PRESENT	0x80
-#define CF ( 1 << 0 )
-
-/* PCI BIOS entry point */
-#ifndef KEEP_IT_REAL
-static unsigned long pcibios32_entry;
-#endif
-static int have_pcibios;
-
-/* Macro for calling a 32-bit entry point with flat physical
- * addresses.  Use in a statement such as
- * __asm__ ( FLAT_FAR_CALL_ESI,
- *	     : "=S" ( discard, or real output ), <other output registers>
- *	     : "S" ( entry_point ), <other input registers> );
- * "=S" *must* be specified as an output, otherwise the compiler will
- * assume that it remains unaltered.
- */
-#define FLAT_FAR_CALL_ESI "call _virt_to_phys\n\t" \
-			  "pushl %%cs\n\t" \
-			  "call *%%esi\n\t" \
-			  "cli\n\t" \
-			  "cld\n\t" \
-			  "call _phys_to_virt\n\t"
-
-/*
- * Functions for accessing PCI configuration space directly with type
- * 1 accesses.
- *
- */
-
-static inline int pcidirect_read_config_byte ( struct pci_device *pci,
-					       unsigned int where,
-					       uint8_t *value ) {
-    outl ( CONFIG_CMD ( pci, where ), CONFIG_ADDRESS );
-    *value = inb ( CONFIG_DATA + ( where & 3 ) );
-    return 0;
-}
-
-static inline int pcidirect_read_config_word ( struct pci_device *pci,
-					       unsigned int where,
-					       uint16_t *value ) {
-    outl ( CONFIG_CMD ( pci, where ), CONFIG_ADDRESS );
-    *value = inw ( CONFIG_DATA + ( where & 2 ) );
-    return 0;
-}
-
-static inline int pcidirect_read_config_dword ( struct pci_device *pci,
-						unsigned int where,
-						uint32_t *value ) {
-    outl ( CONFIG_CMD ( pci, where ), CONFIG_ADDRESS );
-    *value = inl ( CONFIG_DATA );
-    return 0;
-}
-
-static inline int pcidirect_write_config_byte ( struct pci_device *pci,
-						unsigned int where,
-						uint8_t value ) {
-    outl ( CONFIG_CMD ( pci, where ), CONFIG_ADDRESS );
-    outb ( value, CONFIG_DATA + ( where & 3 ) );
-    return 0;
-}
-
-static inline int pcidirect_write_config_word ( struct pci_device *pci,
-						unsigned int where,
-						uint16_t value ) {
-    outl ( CONFIG_CMD ( pci, where ), CONFIG_ADDRESS );
-    outw ( value, CONFIG_DATA + ( where & 2 ) );
-    return 0;
-}
-
-static inline int pcidirect_write_config_dword ( struct pci_device *pci,
-						 unsigned int where,
-						 uint32_t value ) {
-    outl ( CONFIG_CMD ( pci, where ), CONFIG_ADDRESS );
-    outl ( value, CONFIG_DATA );
-    return 0;
-}
-
-/*
- * Functions for accessing PCI configuration space directly via the
- * PCI BIOS.
- *
- * Under -DKEEP_IT_REAL, we use INT 1A, otherwise we use the BIOS32
- * interface.
- */
-
-#ifdef KEEP_IT_REAL
-
-static void find_pcibios16 ( void ) {
-	uint16_t present;
-	uint32_t signature;
-	uint16_t flags;
-	uint16_t revision;
-	uint8_t max_bus;
-
-	/* PCI BIOS installation check */
-	REAL_EXEC ( rm_pcibios_check,
-		    "int $0x1a\n\t"
-		    "pushfw\n\t"
-		    "popw %%si\n\t",
-		    5,
-		    OUT_CONSTRAINTS ( "=a" ( present ), "=b" ( revision ),
-				      "=c" ( max_bus ), "=d" ( signature ),
-				      "=S" ( flags ) ),
-		    IN_CONSTRAINTS ( "a" ( ( PCIBIOS_PCI_FUNCTION_ID << 8 ) +
-					   PCIBIOS_PCI_BIOS_PRESENT ) ),
-		    CLOBBER ( "edi", "ebp" ) );
-
-	if ( ( flags & CF ) ||
-	     ( ( present >> 8 ) != 0 ) ||
-	     ( signature != PCI_SIGNATURE ) ) {
-		DBG ( "PCI BIOS installation check failed\n" );
-		return;
-	}
-
-	/* We have a PCI BIOS */
-	DBG ( "Found 16-bit PCI BIOS interface with %d buses\n", max_bus + 1 );
-	have_pcibios = 1;
-	pci_max_bus = max_bus;
-	return;
-}
-
-INIT_FN ( INIT_PCIBIOS, find_pcibios16, NULL, NULL );
-
-#define pcibios16_read_write( command, pci, where, value )		\
-	( {								\
-		uint32_t discard_b, discard_D;				\
-		uint16_t ret;						\
-									\
-		REAL_EXEC ( 999, /* need a local label */		\
-			    "int $0x1a\n\t"				\
-			    "jc 1f\n\t"					\
-			    "xorw %%ax, %%ax\n\t"			\
-			    "\n1:\n\t",					\
-			    5,						\
-			    OUT_CONSTRAINTS ( "=a" ( ret ),		\
-					      "=b" ( discard_b ),	\
-					      "=c" ( value ),		\
-					      "=D" ( discard_D ) ),	\
-			    IN_CONSTRAINTS ( "a" ( command +		\
-				    ( PCIBIOS_PCI_FUNCTION_ID << 8 ) ),	\
-					     "b" ( pci->busdevfn ),	\
-					     "c" ( value ),		\
-			    		     "D" ( where ) ),		\
-			    CLOBBER ( "edx", "esi", "ebp" ) );		\
-									\
-		( ret >> 8 );						\
-	} )
-#define pcibios_read_write pcibios16_read_write
-
-#else /* KEEP_IT_REAL */
-
-/*
- * Locate the BIOS32 service directory by scanning for a valid BIOS32
- * structure
- *
- */
-static struct bios32 * find_bios32 ( void ) {
-	uint32_t address;
-
-	/*
-	 * Follow the standard procedure for locating the BIOS32 Service
-	 * directory by scanning the permissible address range from
-	 * 0xe0000 through 0xfffff for a valid BIOS32 structure.
-	 *
-	 */
-	for ( address = 0xe0000 ; address < 0xffff0 ; address += 16 ) {
-		struct bios32 * candidate = phys_to_virt ( address );
-		unsigned int length, i;
-		unsigned char sum;
-
-		if ( candidate->signature != BIOS32_SIGNATURE )
-			continue;
-
-		length = candidate->length * 16;
-		if ( ! length )
-			continue;
-
-		for ( sum = 0, i = 0 ; i < length ; i++ )
-			sum += ( ( char * ) candidate ) [i];
-		if ( sum != 0 )
-			continue;
-
-		if ( candidate->revision != 0 ) {
-			DBG ( "unsupported BIOS32 revision %d at %#x\n",
-			      candidate->revision, address );
-			continue;
-		}
-
-		DBG ( "BIOS32 Service Directory structure at %#x\n", address );
-
-		return candidate;
-	}
-
-	return NULL;
-}
-
-/*
- * Look up a service in the BIOS32 service directory
- *
- */
-static unsigned long find_bios32_service ( struct bios32 * bios32,
-					   unsigned long service ) {
-	uint8_t return_code;
-	uint32_t address;
-	uint32_t length;
-	uint32_t entry;
-	uint32_t discard;
-
-	__asm__ ( FLAT_FAR_CALL_ESI
-		  : "=a" ( return_code ), "=b" ( address ),
-		    "=c" ( length ), "=d" ( entry ), "=S" ( discard )
-		  : "a" ( service ), "b" ( 0 ), "S" ( bios32->entry )
-		  : "edi", "ebp" );
-
-	switch ( return_code ) {
-	case BIOS32_SERVICE_PRESENT:
-		DBG ( "BIOS32 service %c%c%c%c present at %#x\n",
-		      PRINT_BIOS_SIG ( service ), ( address + entry ) );
-		return ( address + entry );
-	case BIOS32_SERVICE_NOT_PRESENT:
-		DBG ( "BIOS32 service %c%c%c%c : not present\n",
-		      PRINT_BIOS_SIG ( service ) );
-		return 0;
-	default: /* Shouldn't happen */
-		DBG ( "BIOS32 returned %#x for service %c%c%c%c!\n",
-		      return_code, PRINT_BIOS_SIG ( service ) );
-		return 0;
-	}
-}
-
-/*
- * Find the 32-bit PCI BIOS interface, if present.
- *
- */
-static void find_pcibios32 ( void ) {
-	struct bios32 *bios32;
-	uint32_t signature;
-	uint16_t present;
-	uint32_t flags;
-	uint16_t revision;
-	uint8_t max_bus;
-
-	/* Locate BIOS32 service directory */
-	bios32 = find_bios32 ();
-	if ( ! bios32 ) {
-		DBG ( "No BIOS32\n" );
-		return;
-	}
-
-	/* Locate PCI BIOS service */
-	pcibios32_entry = find_bios32_service ( bios32, PCI_SERVICE );
-	if ( ! pcibios32_entry ) {
-		DBG ( "No PCI BIOS\n" );
-		return;
-	}
-	
-	/* PCI BIOS installation check */
-	__asm__ ( FLAT_FAR_CALL_ESI
-		  "pushfl\n\t"
-		  "popl %%esi\n\t"
-		  : "=a" ( present ), "=b" ( revision ), "=c" ( max_bus ),
-		    "=d" ( signature ), "=S" ( flags )
-		  : "a" ( ( PCIBIOS_PCI_FUNCTION_ID << 8 )
-			  + PCIBIOS_PCI_BIOS_PRESENT ),
-		    "S" ( pcibios32_entry )
-		  : "edi", "ebp" );
-
-	if ( ( flags & CF ) ||
-	     ( ( present >> 8 ) != 0 ) ||
-	     ( signature != PCI_SIGNATURE ) ) {
-		DBG ( "PCI BIOS installation check failed\n" );
-		return;
-	}
-
-	/* We have a PCI BIOS */
-	DBG ( "Found 32-bit PCI BIOS interface at %#x with %d bus(es)\n",
-	      pcibios32_entry, max_bus + 1 );
-	have_pcibios = 1;
-	pci_max_bus = max_bus;
-	return;
-}
-
-INIT_FN ( INIT_PCIBIOS, find_pcibios32, NULL, NULL );
-
-#define pcibios32_read_write( command, pci, where, value )		\
-	( {								\
-		uint32_t discard_b, discard_D, discard_S;		\
-		uint16_t ret;						\
-									\
-		__asm__ ( FLAT_FAR_CALL_ESI				\
-			  "jc 1f\n\t"					\
-			  "xorl %%eax, %%eax\n\t"			\
-			  "\n1:\n\t"					\
-			  : "=a" ( ret ), "=b" ( discard_b ),		\
-			    "=c" ( value ),				\
-			    "=S" ( discard_S ), "=D" ( discard_D )	\
-			  : "a" ( ( PCIBIOS_PCI_FUNCTION_ID << 8 )	\
-				  + command ),			       	\
-			    "b" ( ( pci->bus << 8 ) | pci->devfn ),	\
-			    "c" ( value ), "D" ( where ),		\
-			    "S" ( pcibios32_entry )			\
-			  : "edx", "ebp" );				\
-									\
-		( ret >> 8 );						\
-	} )
-#define pcibios_read_write pcibios32_read_write
-
-#endif /* KEEP_IT_REAL */
-
-static inline int pcibios_read_config_byte ( struct pci_device *pci,
-					     unsigned int where,
-					     uint8_t *value ) {
-	return pcibios_read_write ( PCIBIOS_READ_CONFIG_BYTE,
-				    pci, where, *value );
-}
-
-static inline int pcibios_read_config_word ( struct pci_device *pci,
-					     unsigned int where,
-					     uint16_t *value ) {
-	return pcibios_read_write ( PCIBIOS_READ_CONFIG_WORD,
-				    pci, where, *value );
-}
-
-static inline int pcibios_read_config_dword ( struct pci_device *pci,
-					      unsigned int where,
-					      uint32_t *value ) {
-	return pcibios_read_write ( PCIBIOS_READ_CONFIG_DWORD,
-				    pci, where, *value );
-}
-
-static inline int pcibios_write_config_byte ( struct pci_device *pci,
-					      unsigned int where,
-					      uint8_t value ) {
-	return pcibios_read_write ( PCIBIOS_WRITE_CONFIG_BYTE,
-				    pci, where, value );
-}
-
-static inline int pcibios_write_config_word ( struct pci_device *pci,
-					      unsigned int where,
-					      uint16_t value ) {
-	return pcibios_read_write ( PCIBIOS_WRITE_CONFIG_WORD,
-				    pci, where, value );
-}
-
-static inline int pcibios_write_config_dword ( struct pci_device *pci,
-					       unsigned int where,
-					       uint32_t value ) {
-	return pcibios_read_write ( PCIBIOS_WRITE_CONFIG_DWORD,
-				    pci, where, value );
-}
-
-/*
- * Functions for accessing PCI configuration space via the PCI BIOS if
- * present, otherwise directly via type 1 accesses.
- *
- */
-
-int pci_read_config_byte ( struct pci_device *pci, unsigned int where,
-			   uint8_t *value ) {
-	return have_pcibios ?
-		pcibios_read_config_byte ( pci, where, value ) :
-		pcidirect_read_config_byte ( pci, where, value );
-}
-		
-int pci_read_config_word ( struct pci_device *pci, unsigned int where,
-			   uint16_t *value ) {
-	return have_pcibios ?
-		pcibios_read_config_word ( pci, where, value ) :
-		pcidirect_read_config_word ( pci, where, value );
-}
-		
-int pci_read_config_dword ( struct pci_device *pci, unsigned int where,
-			    uint32_t *value ) {
-	return have_pcibios ?
-		pcibios_read_config_dword ( pci, where, value ) :
-		pcidirect_read_config_dword ( pci, where, value );
-}
-		
-int pci_write_config_byte ( struct pci_device *pci, unsigned int where,
-			    uint8_t value ) {
-	return have_pcibios ?
-		pcibios_write_config_byte ( pci, where, value ) :
-		pcidirect_write_config_byte ( pci, where, value );
-}
-		
-int pci_write_config_word ( struct pci_device *pci, unsigned int where,
-			    uint16_t value ) {
-	return have_pcibios ?
-		pcibios_write_config_word ( pci, where, value ) :
-		pcidirect_write_config_word ( pci, where, value );
-}
-		
-int pci_write_config_dword ( struct pci_device *pci, unsigned int where,
-			     uint32_t value ) {
-	return have_pcibios ?
-		pcibios_write_config_dword ( pci, where, value ) :
-		pcidirect_write_config_dword ( pci, where, value );
-}
-
-unsigned long pci_bus_base ( struct pci_device *pci __unused ) {
-	/* architecturally this must be 0 */
-	return 0;
-}

src/arch/i386/core/pcibios.c

@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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 any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stdint.h>
+#include <gpxe/pci.h>
+#include <pcibios.h>
+#include <realmode.h>
+
+/** @file
+ *
+ * PCI configuration space access via PCI BIOS
+ *
+ */
+
+/**
+ * Determine maximum PCI bus number within system
+ *
+ * @ret max_bus		Maximum bus number
+ */
+int pcibios_max_bus ( void ) {
+	int discard_a;
+	uint8_t max_bus;
+
+	REAL_EXEC ( rm_pcibios_check,
+		    "stc\n\t"
+		    "int $0x1a\n\t"
+		    "jnc 1f\n\t"
+		    "xorw %%cx, %%cx\n\t"
+		    "\n1:\n\t",
+		    2,
+		    OUT_CONSTRAINTS ( "=a" ( discard_a ), "=c" ( max_bus ) ),
+		    IN_CONSTRAINTS ( "a" ( PCIBIOS_INSTALLATION_CHECK >> 16 )),
+		    CLOBBER ( "ebx", "edx", "edi" ) );
+	
+	return max_bus;
+}
+
+/**
+ * Read configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v command	PCI BIOS command
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+int pcibios_read ( struct pci_device *pci, uint32_t command, uint32_t *value ){
+	int discard_b, discard_D;
+	int status;
+
+	REAL_EXEC ( rm_pcibios_read,
+		    "stc\n\t"
+		    "int $0x1a\n\t"
+		    "jnc 1f\n\t"
+		    "xorl %%eax, %%eax\n\t"
+		    "decl %%eax\n\t"
+		    "movl %%eax, %%ecx\n\t"
+		    "\n1:\n\t",
+		    4,
+		    OUT_CONSTRAINTS ( "=a" ( status ), "=b" ( discard_b ),
+				      "=c" ( *value ), "=D" ( discard_D ) ),
+		    IN_CONSTRAINTS ( "a" ( command >> 16 ),
+				     "b" ( ( pci->bus << 8 ) | pci->devfn ),
+				     "D" ( command ) ),
+		    CLOBBER ( "edx" ) );
+	
+	return ( ( status >> 8 ) & 0xff );
+}
+
+/**
+ * Write configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v command	PCI BIOS command
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+int pcibios_write ( struct pci_device *pci, uint32_t command, uint32_t value ){
+	int discard_b, discard_c, discard_D;
+	int status;
+
+	REAL_EXEC ( rm_pcibios_write,
+		    "stc\n\t"
+		    "int $0x1a\n\t"
+		    "jnc 1f\n\t"
+		    "movb $0xff, %%ah\n\t"
+		    "\n1:\n\t",
+		    4,
+		    OUT_CONSTRAINTS ( "=a" ( status ), "=b" ( discard_b ),
+				      "=c" ( discard_c ), "=D" ( discard_D ) ),
+		    IN_CONSTRAINTS ( "a" ( command >> 16 ),
+				     "b" ( ( pci->bus << 8 ) | pci->devfn ),
+				     "c" ( value ), "D" ( command ) ),
+		    CLOBBER ( "edx" ) );
+	
+	return ( ( status >> 8 ) & 0xff );
+}

src/arch/i386/core/pcidirect.c

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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 any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <gpxe/pci.h>
+#include <pcidirect.h>
+
+/** @file
+ *
+ * PCI configuration space access via Type 1 accesses
+ *
+ */
+
+/**
+ * Prepare for Type 1 PCI configuration space access
+ *
+ * @v pci		PCI device
+ * @v where	Location within PCI configuration space
+ */
+void pcidirect_prepare ( struct pci_device *pci, int where ) {
+	outl ( ( 0x80000000 | ( pci->bus << 16 ) | ( pci->devfn << 8 ) |
+		 ( where & ~3 ) ), PCIDIRECT_CONFIG_ADDRESS );
+}
+

src/arch/i386/include/pci_io.h

@@ -1,20 +1,35 @@
-#ifndef PCI_IO_H
-#define PCI_IO_H
+#ifndef _PCI_IO_H
+#define _PCI_IO_H
 
-/* %ah */
-#define PCIBIOS_PCI_FUNCTION_ID         ( 0xb1 )
-/* %al */
-#define PCIBIOS_PCI_BIOS_PRESENT        ( 0x01 )
-#define PCIBIOS_FIND_PCI_DEVICE         ( 0x02 )
-#define PCIBIOS_FIND_PCI_CLASS_CODE     ( 0x03 )
-#define PCIBIOS_GENERATE_SPECIAL_CYCLE  ( 0x06 )
-#define PCIBIOS_READ_CONFIG_BYTE        ( 0x08 )
-#define PCIBIOS_READ_CONFIG_WORD        ( 0x09 )
-#define PCIBIOS_READ_CONFIG_DWORD       ( 0x0a )
-#define PCIBIOS_WRITE_CONFIG_BYTE       ( 0x0b )
-#define PCIBIOS_WRITE_CONFIG_WORD       ( 0x0c )
-#define PCIBIOS_WRITE_CONFIG_DWORD      ( 0x0d )
-#define PCIBIOS_GET_IRQ_ROUTING_OPTIONS	( 0x0e )
-#define PCIBIOS_SET_PCI_IRQ		( 0x0f )
+#include <pcibios.h>
+#include <pcidirect.h>
 
-#endif /* PCI_IO_H */
+/** @file
+ *
+ * i386 PCI configuration space access
+ *
+ * We have two methods of PCI configuration space access: the PCI BIOS
+ * and direct Type 1 accesses.  Selecting between them is via the
+ * compile-time switch -DCONFIG_PCI_DIRECT.
+ *
+ */
+
+#if CONFIG_PCI_DIRECT
+#define pci_max_bus		pcidirect_max_bus
+#define pci_read_config_byte	pcidirect_read_config_byte
+#define pci_read_config_word	pcidirect_read_config_word
+#define pci_read_config_dword	pcidirect_read_config_dword
+#define pci_write_config_byte	pcidirect_write_config_byte
+#define pci_write_config_word	pcidirect_write_config_word
+#define pci_write_config_dword	pcidirect_write_config_dword
+#else /* CONFIG_PCI_DIRECT */
+#define pci_max_bus		pcibios_max_bus
+#define pci_read_config_byte	pcibios_read_config_byte
+#define pci_read_config_word	pcibios_read_config_word
+#define pci_read_config_dword	pcibios_read_config_dword
+#define pci_write_config_byte	pcibios_write_config_byte
+#define pci_write_config_word	pcibios_write_config_word
+#define pci_write_config_dword	pcibios_write_config_dword
+#endif /* CONFIG_PCI_DIRECT */
+
+#endif /* _PCI_IO_H */

src/arch/i386/include/pcibios.h

@@ -0,0 +1,122 @@
+#ifndef _PCIBIOS_H
+#define _PCIBIOS_H
+
+#include <stdint.h>
+
+/** @file
+ *
+ * PCI configuration space access via PCI BIOS
+ *
+ */
+
+struct pci_device;
+
+#define PCIBIOS_INSTALLATION_CHECK	0xb1010000
+#define PCIBIOS_READ_CONFIG_BYTE	0xb1080000
+#define PCIBIOS_READ_CONFIG_WORD	0xb1090000
+#define PCIBIOS_READ_CONFIG_DWORD	0xb10a0000
+#define PCIBIOS_WRITE_CONFIG_BYTE	0xb10b0000
+#define PCIBIOS_WRITE_CONFIG_WORD	0xb10c0000
+#define PCIBIOS_WRITE_CONFIG_DWORD	0xb10d0000
+
+extern int pcibios_max_bus ( void );
+extern int pcibios_read ( struct pci_device *pci, uint32_t command,
+			  uint32_t *value );
+extern int pcibios_write ( struct pci_device *pci, uint32_t command,
+			   uint32_t value );
+
+/**
+ * Read byte from PCI configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+static inline __attribute__ (( always_inline )) int
+pcibios_read_config_byte ( struct pci_device *pci, unsigned int where,
+			   uint8_t *value ) {
+	uint32_t tmp;
+	int rc;
+
+	rc = pcibios_read ( pci, PCIBIOS_READ_CONFIG_BYTE | where, &tmp );
+	*value = tmp;
+	return rc;
+}
+
+/**
+ * Read word from PCI configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+static inline __attribute__ (( always_inline )) int
+pcibios_read_config_word ( struct pci_device *pci, unsigned int where,
+			   uint16_t *value ) {
+	uint32_t tmp;
+	int rc;
+
+	rc = pcibios_read ( pci, PCIBIOS_READ_CONFIG_WORD | where, &tmp );
+	*value = tmp;
+	return rc;
+}
+
+/**
+ * Read dword from PCI configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+static inline __attribute__ (( always_inline )) int
+pcibios_read_config_dword ( struct pci_device *pci, unsigned int where,
+			    uint32_t *value ) {
+	return pcibios_read ( pci, PCIBIOS_READ_CONFIG_DWORD | where, value );
+}
+
+/**
+ * Write byte to PCI configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+static inline __attribute__ (( always_inline )) int
+pcibios_write_config_byte ( struct pci_device *pci, unsigned int where,
+			    uint8_t value ) {
+	return pcibios_write ( pci, PCIBIOS_WRITE_CONFIG_BYTE | where, value );
+}
+
+/**
+ * Write word to PCI configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+static inline __attribute__ (( always_inline )) int
+pcibios_write_config_word ( struct pci_device *pci, unsigned int where,
+			    uint16_t value ) {
+	return pcibios_write ( pci, PCIBIOS_WRITE_CONFIG_BYTE | where, value );
+}
+
+/**
+ * Write dword to PCI configuration space via PCI BIOS
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+static inline __attribute__ (( always_inline )) int
+pcibios_write_config_dword ( struct pci_device *pci, unsigned int where,
+			     uint32_t value ) {
+	return pcibios_write ( pci, PCIBIOS_WRITE_CONFIG_BYTE | where, value );
+}
+
+#endif /* _PCIBIOS_H */

src/arch/i386/include/pcidirect.h

@@ -0,0 +1,126 @@
+#ifndef _PCIDIRECT_H
+#define _PCIDIRECT_H
+
+#include <stdint.h>
+#include <io.h>
+
+/** @file
+ *
+ * PCI configuration space access via Type 1 accesses
+ *
+ */
+
+#define PCIDIRECT_CONFIG_ADDRESS	0xcf8
+#define PCIDIRECT_CONFIG_DATA		0xcfc
+
+struct pci_device;
+
+extern void pcidirect_prepare ( struct pci_device *pci, int where );
+
+/**
+ * Determine maximum PCI bus number within system
+ *
+ * @ret max_bus		Maximum bus number
+ */
+static inline int pcidirect_max_bus ( void ) {
+	/* No way to work this out via Type 1 accesses */
+	return 0xff;
+}
+
+/**
+ * Read byte from PCI configuration space via Type 1 access
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+static inline __attribute__ (( always_inline )) int
+pcidirect_read_config_byte ( struct pci_device *pci, unsigned int where,
+			     uint8_t *value ) {
+	pcidirect_prepare ( pci, where );
+	*value = inb ( PCIDIRECT_CONFIG_DATA + ( where & 3 ) );
+	return 0;
+}
+
+/**
+ * Read word from PCI configuration space via Type 1 access
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+static inline __attribute__ (( always_inline )) int
+pcidirect_read_config_word ( struct pci_device *pci, unsigned int where,
+			     uint16_t *value ) {
+	pcidirect_prepare ( pci, where );
+	*value = inw ( PCIDIRECT_CONFIG_DATA + ( where & 2 ) );
+	return 0;
+}
+
+/**
+ * Read dword from PCI configuration space via Type 1 access
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value read
+ * @ret rc	Return status code
+ */
+static inline __attribute__ (( always_inline )) int
+pcidirect_read_config_dword ( struct pci_device *pci, unsigned int where,
+			      uint32_t *value ) {
+	pcidirect_prepare ( pci, where );
+	*value = inl ( PCIDIRECT_CONFIG_DATA + where );
+	return 0;
+}
+
+/**
+ * Write byte to PCI configuration space via Type 1 access
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+static inline __attribute__ (( always_inline )) int
+pcidirect_write_config_byte ( struct pci_device *pci, unsigned int where,
+			      uint8_t value ) {
+	pcidirect_prepare ( pci, where );
+	outb ( value, PCIDIRECT_CONFIG_DATA + ( where & 3 ) );
+	return 0;
+}
+
+/**
+ * Write word to PCI configuration space via Type 1 access
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+static inline __attribute__ (( always_inline )) int
+pcidirect_write_config_word ( struct pci_device *pci, unsigned int where,
+			      uint16_t value ) {
+	pcidirect_prepare ( pci, where );
+	outb ( value, PCIDIRECT_CONFIG_DATA + ( where & 2 ) );
+	return 0;
+}
+
+/**
+ * Write dword to PCI configuration space via Type 1 access
+ *
+ * @v pci	PCI device
+ * @v where	Location within PCI configuration space
+ * @v value	Value to be written
+ * @ret rc	Return status code
+ */
+static inline __attribute__ (( always_inline )) int
+pcidirect_write_config_dword ( struct pci_device *pci, unsigned int where,
+			       uint32_t value ) {
+	pcidirect_prepare ( pci, where );
+	outb ( value, PCIDIRECT_CONFIG_DATA + where );
+	return 0;
+}
+
+#endif /* _PCIDIRECT_H */

src/drivers/bus/pci.c

@@ -38,15 +38,6 @@ static struct pci_driver pci_drivers_end[0] __table_end ( pci_drivers );
 
 static void pcibus_remove ( struct root_device *rootdev );
 
-/**
- * Maximum PCI bus number
- *
- * Architecture-specific code may know how many buses we have, in
- * which case it can overwrite this value.
- *
- */
-unsigned int pci_max_bus = 0xff;
-
 /**
  * Read PCI BAR
  *
@@ -242,13 +233,15 @@ static void unregister_pcidev ( struct pci_device *pci ) {
  */
 static int pcibus_probe ( struct root_device *rootdev ) {
 	struct pci_device *pci = NULL;
+	unsigned int max_bus;
 	unsigned int bus;
 	unsigned int devfn;
-	uint8_t hdrtype;
+	uint8_t hdrtype = 0;
 	uint32_t tmp;
 	int rc;
 
-	for ( bus = 0 ; bus <= pci_max_bus ; bus++ ) {
+	max_bus = pci_max_bus();
+	for ( bus = 0 ; bus <= max_bus ; bus++ ) {
 		for ( devfn = 0 ; devfn <= 0xff ; devfn++ ) {
 
 			/* Allocate struct pci_device */

src/include/gpxe/pci.h

@@ -19,6 +19,7 @@
 #include <stdint.h>
 #include <gpxe/device.h>
 #include <gpxe/tables.h>
+#include <pci_io.h>
 #include "pci_ids.h"
 
 /*
@@ -318,19 +319,6 @@ struct pci_driver {
 	.name = _name,						\
 }
 
-extern unsigned int pci_max_bus;
-extern int pci_read_config_byte	( struct pci_device *pci, unsigned int where,
-				  uint8_t *value );
-extern int pci_write_config_byte ( struct pci_device *pci, unsigned int where,
-				   uint8_t value );
-extern int pci_read_config_word ( struct pci_device *pci, unsigned int where,
-				  uint16_t *value );
-extern int pci_write_config_word ( struct pci_device *pci, unsigned int where,
-				   uint16_t value );
-extern int pci_read_config_dword ( struct pci_device *pci, unsigned int where,
-				   uint32_t *value );
-extern int pci_write_config_dword ( struct pci_device *pci, unsigned int where,
-				    uint32_t value );
 extern void adjust_pci_device ( struct pci_device *pci );
 extern unsigned long pci_bar_start ( struct pci_device *pci,
 				     unsigned int reg );