3 files changed, 53 insertions, 7 deletions

diff --git a/drivers/gpu/vga/Kconfig b/drivers/gpu/vga/Kconfig
index 790e675..0920492 100644
--- a/drivers/gpu/vga/Kconfig
+++ b/drivers/gpu/vga/Kconfig
@@ -8,3 +8,11 @@ config VGA_ARB
 	  are accessed at same time they need some kind of coordination. Please
 	  see Documentation/vgaarbiter.txt for more details. Select this to
 	  enable VGA arbiter.
+
+config VGA_ARB_MAX_GPUS
+	int "Maximum number of GPUs"
+	default 16
+	depends on VGA_ARB
+	help
+	  Reserves space in the kernel to maintain resource locking for
+	  multiple GPUS.  The overhead for each GPU is very small.
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
index 2f6cf69..8827814 100644
--- a/drivers/gpu/vga/vgaarb.c
+++ b/drivers/gpu/vga/vgaarb.c
@@ -688,7 +688,7 @@ EXPORT_SYMBOL(vga_client_register);
  * the arbiter.
  */
 
-#define MAX_USER_CARDS         16
+#define MAX_USER_CARDS         CONFIG_VGA_ARB_MAX_GPUS
 #define PCI_INVALID_CARD       ((struct pci_dev *)-1UL)
 
 /*
@@ -954,6 +954,7 @@ static ssize_t vga_arb_write(struct file *file, const char __user * buf,
 		}
 
 	} else if (strncmp(curr_pos, "target ", 7) == 0) {
+		struct pci_bus *pbus;
 		unsigned int domain, bus, devfn;
 		struct vga_device *vgadev;
 
@@ -969,18 +970,31 @@ static ssize_t vga_arb_write(struct file *file, const char __user * buf,
 				ret_val = -EPROTO;
 				goto done;
 			}
-
-			pdev = pci_get_bus_and_slot(bus, devfn);
+			pr_devel("vgaarb: %s ==> %x:%x:%x.%x\n", curr_pos,
+				domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
+
+			pbus = pci_find_bus(domain, bus);
+			pr_devel("vgaarb: pbus %p\n", pbus);
+			if (pbus == NULL) {
+				pr_err("vgaarb: invalid PCI domain and/or bus address %x:%x\n",
+					domain, bus);
+				ret_val = -ENODEV;
+				goto done;
+			}
+			pdev = pci_get_slot(pbus, devfn);
+			pr_devel("vgaarb: pdev %p\n", pdev);
 			if (!pdev) {
-				pr_info("vgaarb: invalid PCI address!\n");
+				pr_err("vgaarb: invalid PCI address %x:%x\n",
+					bus, devfn);
 				ret_val = -ENODEV;
 				goto done;
 			}
 		}
 
 		vgadev = vgadev_find(pdev);
+		pr_devel("vgaarb: vgadev %p\n", vgadev);
 		if (vgadev == NULL) {
-			pr_info("vgaarb: this pci device is not a vga device\n");
+			pr_err("vgaarb: this pci device is not a vga device\n");
 			pci_dev_put(pdev);
 			ret_val = -ENODEV;
 			goto done;
@@ -998,7 +1012,8 @@ static ssize_t vga_arb_write(struct file *file, const char __user * buf,
 			}
 		}
 		if (i == MAX_USER_CARDS) {
-			pr_err("vgaarb: maximum user cards number reached!\n");
+			pr_err("vgaarb: maximum user cards (%d) number reached!\n",
+				MAX_USER_CARDS);
 			pci_dev_put(pdev);
 			/* XXX: which value to return? */
 			ret_val =  -ENOMEM;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 2b9ac9e..5b548ae 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2754,6 +2754,23 @@ 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
@@ -2767,9 +2784,15 @@ 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;
@@ -2984,6 +3007,7 @@ 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);
@@ -3015,4 +3039,3 @@ 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);
-