Read number of PCI buses returned by BIOS so that we can scan more

quickly.

diff --git a/src/arch/i386/core/pci_io.c b/src/arch/i386/core/pci_io.c
index ffbf53c..28d9cbd 100644 (file)
--- a/src/arch/i386/core/pci_io.c
+++ b/src/arch/i386/core/pci_io.c
@@ -56,8 +56,10 @@ 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,
- *          : <output registers>
+ *          : "=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" \
@@ -135,18 +137,20 @@ static void find_pcibios16 ( void ) {
        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 %%cx\n\t",
-                   4,
+                   "popw %%si\n\t",
+                   5,
                    OUT_CONSTRAINTS ( "=a" ( present ), "=b" ( revision ),
-                                     "=c" ( flags ), "=d" ( signature ) ),
+                                     "=c" ( max_bus ), "=d" ( signature ),
+                                     "=S" ( flags ) ),
                    IN_CONSTRAINTS ( "a" ( ( PCIBIOS_PCI_FUNCTION_ID << 8 ) +
                                           PCIBIOS_PCI_BIOS_PRESENT ) ),
-                   CLOBBER ( "esi", "edi", "ebp" ) );
+                   CLOBBER ( "edi", "ebp" ) );
 
        if ( ( flags & CF ) ||
             ( ( present >> 8 ) != 0 ) ||
@@ -156,8 +160,9 @@ static void find_pcibios16 ( void ) {
        }
 
        /* We have a PCI BIOS */
-       DBG ( "Found 16-bit PCI BIOS interface\n" );
+       DBG ( "Found 16-bit PCI BIOS interface with %d buses\n", max_bus + 1 );
        have_pcibios = 1;
+       pci_max_bus = max_bus;
        return;
 }
 
@@ -280,7 +285,7 @@ static void find_pcibios32 ( void ) {
        uint16_t present;
        uint32_t flags;
        uint16_t revision;
-       uint32_t discard;
+       uint8_t max_bus;
 
        /* Locate BIOS32 service directory */
        bios32 = find_bios32 ();
@@ -299,9 +304,9 @@ static void find_pcibios32 ( void ) {
        /* PCI BIOS installation check */
        __asm__ ( FLAT_FAR_CALL_ESI
                  "pushfl\n\t"
-                 "popl %%ecx\n\t"
-                 : "=a" ( present ), "=b" ( revision ), "=c" ( flags ),
-                   "=d" ( signature ), "=S" ( discard )
+                 "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 )
@@ -315,8 +320,10 @@ static void find_pcibios32 ( void ) {
        }
 
        /* We have a PCI BIOS */
-       DBG ( "Found 32-bit PCI BIOS interface at %#x\n", pcibios32_entry );
+       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;
 }
 
@@ -435,7 +442,7 @@ int pci_write_config_dword ( struct pci_device *pci, unsigned int where,
                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;

diff --git a/src/drivers/bus/pci.c b/src/drivers/bus/pci.c
index 4b34454..44b3a1b 100644 (file)
--- a/src/drivers/bus/pci.c
+++ b/src/drivers/bus/pci.c
@@ -9,6 +9,13 @@
 DEV_BUS( struct pci_device, pci_dev );
 static char pci_magic[0]; /* guaranteed unique symbol */
 
+/*
+ * pci_io.c may know how many buses we have, in which case it can
+ * overwrite this value.
+ *
+ */
+unsigned int pci_max_bus = 0xff;
+
 /*
  * Fill in parameters (vendor & device ids, class, membase etc.) for a
  * PCI device based on bus & devfn.
@@ -18,6 +25,10 @@ static char pci_magic[0]; /* guaranteed unique symbol */
 static int fill_pci_device ( struct pci_device *pci ) {
        uint32_t l;
        int reg;
+
+       /* Check bus is within range */
+       if ( PCI_BUS ( pci->busdevfn ) > pci_max_bus )
+               return 0;
        
        /* Check to see if there's anything physically present.
         */

diff --git a/src/include/pci.h b/src/include/pci.h
index ee1631d..9b7fcad 100644 (file)
--- a/src/include/pci.h
+++ b/src/include/pci.h
@@ -318,6 +318,13 @@ extern int pci_write_config_dword ( struct pci_device *dev, unsigned int where,
                                    uint32_t value );
 extern unsigned long pci_bus_base ( struct pci_device *dev );
 
+/*
+ * pci_io.c is allowed to overwrite pci_max_bus if it knows what the
+ * highest bus in the system will be.
+ *
+ */
+extern unsigned int pci_max_bus;
+
 /*
  * Functions in pci.c
  *