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/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 */