[pci] Formalise the PCI I/O API

2025-12-23 05:21:49 +03:00 · 2008-10-12 12:50:44 +01:00
parent fd67452807
commit 8a4ccebec9
10 changed files with 220 additions and 81 deletions
--- a/src/arch/i386/interface/pcbios/pcibios.c
+++ b/src/arch/i386/interface/pcbios/pcibios.c
@@ -0,0 +1,113 @@
+/*
+ * 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 <realmode.h>
+
+/** @file
+ *
+ * PCI configuration space access via PCI BIOS
+ *
+ */
+
+/**
+ * Determine maximum PCI bus number within system
+ *
+ * @ret max_bus		Maximum bus number
+ */
+static int pcibios_max_bus ( void ) {
+	int discard_a, discard_D;
+	uint8_t max_bus;
+
+	__asm__ __volatile__ ( REAL_CODE ( "stc\n\t"
+					   "int $0x1a\n\t"
+					   "jnc 1f\n\t"
+					   "xorw %%cx, %%cx\n\t"
+					   "\n1:\n\t" )
+			       : "=c" ( max_bus ), "=a" ( discard_a ),
+				 "=D" ( discard_D )
+			       : "a" ( PCIBIOS_INSTALLATION_CHECK >> 16 ),
+				 "D" ( 0 )
+			       : "ebx", "edx" );
+
+	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;
+
+	__asm__ __volatile__ ( REAL_CODE ( "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" )
+			       : "=a" ( status ), "=b" ( discard_b ),
+				 "=c" ( *value ), "=D" ( discard_D )
+			       : "a" ( command >> 16 ), "D" ( command ),
+			         "b" ( PCI_BUSDEVFN ( pci->bus, pci->devfn ) )
+			       : "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;
+
+	__asm__ __volatile__ ( REAL_CODE ( "stc\n\t"
+					   "int $0x1a\n\t"
+					   "jnc 1f\n\t"
+					   "movb $0xff, %%ah\n\t"
+					   "\n1:\n\t" )
+			       : "=a" ( status ), "=b" ( discard_b ),
+				 "=c" ( discard_c ), "=D" ( discard_D )
+			       : "a" ( command >> 16 ),	"D" ( command ),
+			         "b" ( PCI_BUSDEVFN ( pci->bus, pci->devfn ) ),
+				 "c" ( value )
+			       : "edx" );
+	
+	return ( ( status >> 8 ) & 0xff );
+}
+
+PROVIDE_PCIAPI ( pcbios, pci_max_bus, pcibios_max_bus );
+PROVIDE_PCIAPI_INLINE ( pcbios, pci_read_config_byte );
+PROVIDE_PCIAPI_INLINE ( pcbios, pci_read_config_word );
+PROVIDE_PCIAPI_INLINE ( pcbios, pci_read_config_dword );
+PROVIDE_PCIAPI_INLINE ( pcbios, pci_write_config_byte );
+PROVIDE_PCIAPI_INLINE ( pcbios, pci_write_config_word );
+PROVIDE_PCIAPI_INLINE ( pcbios, pci_write_config_dword );