vtd: Make some pci access functions architecture independent.

Signed-off-by: Anthony Xu <anthony.xu@intel.com>
Signed-off-by: Dexuan Cui <dexuan.cui@intel.com>

2 files changed, 65 insertions, 0 deletions

diff --git a/xen/drivers/pci/Makefile b/xen/drivers/pci/Makefile
new file mode 100644
index 0000000000..a98035df4c
--- /dev/null
+++ b/xen/drivers/pci/Makefile
@@ -0,0 +1 @@
+obj-y += pci.o
diff --git a/xen/drivers/pci/pci.c b/xen/drivers/pci/pci.c
new file mode 100644
index 0000000000..278f6b536d
--- /dev/null
+++ b/xen/drivers/pci/pci.c
@@ -0,0 +1,64 @@
+/******************************************************************************
+ * pci.c
+ *
+ * Architecture-independent PCI access functions.
+ */
+
+#include <xen/pci.h>
+#include <xen/pci_regs.h>
+
+int pci_find_cap_offset(u8 bus, u8 dev, u8 func, u8 cap)
+{
+    u8 id;
+    int max_cap = 48;
+    u8 pos = PCI_CAPABILITY_LIST;
+    u16 status;
+
+    status = pci_conf_read16(bus, dev, func, PCI_STATUS);
+    if ( (status & PCI_STATUS_CAP_LIST) == 0 )
+        return 0;
+
+    while ( max_cap-- )
+    {
+        pos = pci_conf_read8(bus, dev, func, pos);
+        if ( pos < 0x40 )
+            break;
+
+        pos &= ~3;
+        id = pci_conf_read8(bus, dev, func, pos + PCI_CAP_LIST_ID);
+
+        if ( id == 0xff )
+            break;
+        else if ( id == cap )
+            return pos;
+
+        pos += PCI_CAP_LIST_NEXT;
+    }
+
+    return 0;
+}
+
+int pci_find_next_cap(u8 bus, unsigned int devfn, u8 pos, int cap)
+{
+    u8 id;
+    int ttl = 48;
+
+    while ( ttl-- )
+    {
+        pos = pci_conf_read8(bus, PCI_SLOT(devfn), PCI_FUNC(devfn), pos);
+        if ( pos < 0x40 )
+            break;
+
+        pos &= ~3;
+        id = pci_conf_read8(bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
+                            pos + PCI_CAP_LIST_ID);
+
+        if ( id == 0xff )
+            break;
+        if ( id == cap )
+            return pos;
+
+        pos += PCI_CAP_LIST_NEXT;
+    }
+    return 0;
+}