PCI: Add support for AGP in cur/max bus speed

Take advantage of some gaps in the table to fit in support for AGP speeds.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

3 files changed, 55 insertions, 5 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 188ee9cf0605..2803ab96a98c 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -437,11 +437,56 @@ void pcie_update_link_speed(struct pci_bus *bus, u16 linksta)
 }
 EXPORT_SYMBOL_GPL(pcie_update_link_speed);
 
+static unsigned char agp_speeds[] = {
+        AGP_UNKNOWN,
+        AGP_1X,
+        AGP_2X,
+        AGP_4X,
+        AGP_8X
+};
+
+static enum pci_bus_speed agp_speed(int agp3, int agpstat)
+{
+        int index = 0;
+
+        if (agpstat & 4)
+                index = 3;
+        else if (agpstat & 2)
+                index = 2;
+        else if (agpstat & 1)
+                index = 1;
+        else
+                goto out;
+        
+        if (agp3) {
+                index += 2;
+                if (index == 5)
+                        index = 0;
+        }
+
+ out:
+        return agp_speeds[index];
+}
+
+
 static void pci_set_bus_speed(struct pci_bus *bus)
 {
         struct pci_dev *bridge = bus->self;
         int pos;
 
+        pos = pci_find_capability(bridge, PCI_CAP_ID_AGP);
+        if (!pos)
+                pos = pci_find_capability(bridge, PCI_CAP_ID_AGP3);
+        if (pos) {
+                u32 agpstat, agpcmd;
+
+                pci_read_config_dword(bridge, pos + PCI_AGP_STATUS, &agpstat);
+                bus->max_bus_speed = agp_speed(agpstat & 8, agpstat & 7);
+
+                pci_read_config_dword(bridge, pos + PCI_AGP_COMMAND, &agpcmd);
+                bus->cur_bus_speed = agp_speed(agpstat & 8, agpcmd & 7);
+        }
+
         pos = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
         if (pos) {
                 u16 status;
diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c
index 6f6b8d24786a..c7260d4e339b 100644
--- a/drivers/pci/slot.c
+++ b/drivers/pci/slot.c
@@ -61,11 +61,11 @@ static char *pci_bus_speed_strings[] = {
         "66 MHz PCI-X 266",     /* 0x09 */
         "100 MHz PCI-X 266",    /* 0x0a */
         "133 MHz PCI-X 266",    /* 0x0b */
-        NULL,                   /* 0x0c */
-        NULL,                   /* 0x0d */
-        NULL,                   /* 0x0e */
-        NULL,                   /* 0x0f */
-        NULL,                   /* 0x10 */
+        "Unknown AGP",          /* 0x0c */
+        "1x AGP",               /* 0x0d */
+        "2x AGP",               /* 0x0e */
+        "4x AGP",               /* 0x0f */
+        "8x AGP",               /* 0x10 */
         "66 MHz PCI-X 533",     /* 0x11 */
         "100 MHz PCI-X 533",    /* 0x12 */
         "133 MHz PCI-X 533",    /* 0x13 */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index a446097a9f68..842adaad312e 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -200,6 +200,11 @@ enum pci_bus_speed {
         PCI_SPEED_66MHz_PCIX_266        = 0x09,
         PCI_SPEED_100MHz_PCIX_266       = 0x0a,
         PCI_SPEED_133MHz_PCIX_266       = 0x0b,
+        AGP_UNKNOWN                     = 0x0c,
+        AGP_1X                          = 0x0d,
+        AGP_2X                          = 0x0e,
+        AGP_4X                          = 0x0f,
+        AGP_8X                          = 0x10,
         PCI_SPEED_66MHz_PCIX_533        = 0x11,
         PCI_SPEED_100MHz_PCIX_533       = 0x12,
         PCI_SPEED_133MHz_PCIX_533       = 0x13,