pci: Update pci_set_vga_state() to call arch functions

Update pci_set_vga_state to call arch dependent functions to enable Legacy
VGA I/O transactions to be redirected to correct target.

[akpm@linux-foundation.org: make pci_register_set_vga_state() __init]
Signed-off-by: Mike Travis <travis@sgi.com>
LKML-Reference: <201002022238.o12McE1J018723@imap1.linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Robin Holt <holt@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: David Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 24 insertions, 1 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 315fea47e784..ac2a576133f9 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2615,6 +2615,23 @@ int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type)
         return 0;
 }
 
+/* Some architectures require additional programming to enable VGA */
+static arch_set_vga_state_t arch_set_vga_state;
+
+void __init pci_register_set_vga_state(arch_set_vga_state_t func)
+{
+        arch_set_vga_state = func;      /* NULL disables */
+}
+
+static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode,
+                      unsigned int command_bits, bool change_bridge)
+{
+        if (arch_set_vga_state)
+                return arch_set_vga_state(dev, decode, command_bits,
+                                                change_bridge);
+        return 0;
+}
+
 /**
  * pci_set_vga_state - set VGA decode state on device and parents if requested
  * @dev: the PCI device
@@ -2628,9 +2645,15 @@ int pci_set_vga_state(struct pci_dev *dev, bool decode,
         struct pci_bus *bus;
         struct pci_dev *bridge;
         u16 cmd;
+        int rc;
 
         WARN_ON(command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY));
 
+        /* ARCH specific VGA enables */
+        rc = pci_set_vga_state_arch(dev, decode, command_bits, change_bridge);
+        if (rc)
+                return rc;
+
         pci_read_config_word(dev, PCI_COMMAND, &cmd);
         if (decode == true)
                 cmd |= command_bits;
@@ -2845,6 +2868,7 @@ EXPORT_SYMBOL(pcim_pin_device);
 EXPORT_SYMBOL(pci_disable_device);
 EXPORT_SYMBOL(pci_find_capability);
 EXPORT_SYMBOL(pci_bus_find_capability);
+EXPORT_SYMBOL(pci_register_set_vga_state);
 EXPORT_SYMBOL(pci_release_regions);
 EXPORT_SYMBOL(pci_request_regions);
 EXPORT_SYMBOL(pci_request_regions_exclusive);
@@ -2877,4 +2901,3 @@ EXPORT_SYMBOL(pci_target_state);
 EXPORT_SYMBOL(pci_prepare_to_sleep);
 EXPORT_SYMBOL(pci_back_from_sleep);
 EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state);
-