Add shared PCI support and enhance pc386 to support non-legacy PCI configuration space

This patch fundamentally results from enhancements to the pc386 BSP
to support systems which do **NOT** have the legacy PCI BIOS. The
patch adds support for detecting when legacy PCI BIOS is not
present and then using IO space to access to PCI Configuration Space.
This resulted in dynamically selected between two implementations
of PCI and refactoring out the shared methods.

This patch adds shared implementations of pci_bus_count() and
pci_find_device(). Subsequent patches will remove implementations
of these methods in other BSPs where possible.

1 files changed, 19 insertions, 130 deletions

diff --git a/c/src/lib/libbsp/i386/shared/pci/pcibios.c b/c/src/lib/libbsp/i386/shared/pci/pcibios.c
index 7dc53a125e..e74649413b 100644
--- a/c/src/lib/libbsp/i386/shared/pci/pcibios.c
+++ b/c/src/lib/libbsp/i386/shared/pci/pcibios.c
@@ -40,16 +40,23 @@ static int pcib_convert_err(int err);
 #define PCIB_DEVSIG_BUS(x) (((x)>>8) &0xff)
 #define PCIB_DEVSIG_DEV(x) (((x)>>3) & 0x1f)
 #define PCIB_DEVSIG_FUNC(x) ((x) & 0x7)
+
 /*
- * Detects presense of PCI BIOS, returns
- * error code
+ * Forward reference. Initialized at bottom.
  */
-int
-pci_initialize(void)
+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;
+  unsigned char  sum;
+  int            i;
 
   pcibInitialized = 0;
 
@@ -80,7 +87,7 @@ pci_initialize(void)
 
   if (ucp >= (unsigned char *)0xFFFFF) {
     /* BIOS-32 not found */
-    return PCIB_ERR_NOTPRESENT;
+    return NULL;
   }
 
   /* BIOS-32 found, let us find PCI BIOS */
@@ -102,7 +109,7 @@ pci_initialize(void)
 
   if ((pcibExchg[0] & 0xff) != 0) {
     /* Not found */
-    return PCIB_ERR_NOTPRESENT;
+    return NULL;
   }
 
   /* Found PCI entry point */
@@ -125,130 +132,18 @@ pci_initialize(void)
 
   if ((pcibExchg[0] & 0xff00) != 0) {
     /* Not found */
-    return PCIB_ERR_NOTPRESENT;
+    return NULL;
   }
 
   if (pcibExchg[3] != 0x20494350) {
     /* Signature does not match */
-    return PCIB_ERR_NOTPRESENT;
+    return NULL;
   }
 
   /* Success */
-
   pcibInitialized = 1;
-  return PCIB_ERR_SUCCESS;
-}
-
-/*
- * Find specified device and return its signature: combination
- * of bus number, device number and function number
- */
-static int
-pcib_find_by_devid(int vendorId, int devId, int idx, int *sig)
-{
-  if (!pcibInitialized) {
-    return PCIB_ERR_UNINITIALIZED;
-  }
-
-  pcibExchg[0] = pcibEntry;
-  pcibExchg[1] = vendorId;
-  pcibExchg[2] = devId;
-  pcibExchg[3] = idx;
-
-  __asm__ ("    pusha");
-  __asm__ ("    movl pcibExchg, %edi");
-  __asm__ ("    movb $0xb1, %ah");
-  __asm__ ("    movb $0x02, %al");
-  __asm__ ("    movl pcibExchg+4, %edx");
-  __asm__ ("    movl pcibExchg+8, %ecx");
-  __asm__ ("    movl pcibExchg+12, %esi");
-  __asm__ ("    pushl %cs");
-  __asm__ ("    call *%edi");
-  __asm__ ("    movl %eax, pcibExchg");
-  __asm__ ("    movl %ebx, pcibExchg+4");
-  __asm__ ("    popa");
-
-  *sig = pcibExchg[1] & 0xffff;
 
-  return pcib_convert_err((pcibExchg[0] >> 8) & 0xff);
-}
-
-int
-pci_find_device(
-  unsigned short vendorid,
-  unsigned short deviceid,
-  int instance,
-  int *pbus,
-  int *pdev,
-  int *pfun
-)
-{
-  int status;
-  int sig = 0;
-
-  status = pcib_find_by_devid( vendorid, deviceid, instance, &sig );
-
-  *pbus = PCIB_DEVSIG_BUS(sig);
-  *pdev = PCIB_DEVSIG_DEV(sig);
-  *pfun = PCIB_DEVSIG_FUNC(sig);
-  return status ? -1 : 0;
-}
-
-static uint8_t ucBusCount = 0xff;
-
-unsigned char
-pci_bus_count(void)
-{
-  if ( ucBusCount == 0xff ) {
-    unsigned char bus;
-    unsigned char dev;
-    unsigned char fun;
-    unsigned char nfn;
-    unsigned char hd = 0;
-    uint32_t d = 0;
-
-    ucBusCount = 0;
-
-    for (bus=0; bus< 0xff; bus++) {
-      for (dev=0; dev<PCI_MAX_DEVICES; dev++) {
-        pci_read_config_dword(bus, dev, fun, PCI_VENDOR_ID, &d);
-
-        if ( -1 == d ) {
-          continue;
-        }
-
-        pci_read_config_byte(bus, dev, fun, PCI_HEADER_TYPE, &hd);
-        nfn = (hd & 0x80) ? PCI_MAX_FUNCTIONS : 1;
-
-        for ( fun=0; fun<nfn; fun++ ) {
-
-          pci_read_config_dword(bus, dev, fun, PCI_VENDOR_ID, &d);
-          if ( -1 == d )
-            continue;
-
-          pci_read_config_dword(bus, dev, fun, PCI_CLASS_REVISION, &d);
-
-          if ( (d >> 16) == PCI_CLASS_BRIDGE_PCI ) {
-            pci_read_config_byte(bus, dev, fun, PCI_SUBORDINATE_BUS, &hd);
-
-            if ( hd > ucBusCount )
-              ucBusCount = hd;
-          }
-
-        }
-      }
-    }
-
-    if ( ucBusCount == 0 ) {
-      printk("pci_bus_count() found 0 busses, assuming 1\n");
-      ucBusCount = 1;
-    } else if ( ucBusCount == 0xff ) {
-      printk("pci_bus_count() found 0xff busses, assuming 1\n");
-      ucBusCount = 1;
-    }
-  }
-
-  return ucBusCount;
+  return &pci_bios_indirect_functions;
 }
 
 /*
@@ -568,7 +463,7 @@ BSP_pci_write_config_dword(
   return PCIBIOS_SUCCESSFUL;
 }
 
-const pci_config_access_functions pci_indirect_functions = {
+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,
@@ -576,9 +471,3 @@ const pci_config_access_functions pci_indirect_functions = {
   BSP_pci_write_config_word,
   BSP_pci_write_config_dword
 };
-
-rtems_pci_config_t BSP_pci_configuration = {
-  (volatile unsigned char*)0,
-  (volatile unsigned char*)0,
-  &pci_indirect_functions
-};