vgaarb: Add user selectability of the number of GPUS in a system

Update the VGA Arbiter to allow the user to select the number
of GPU's supported in a system.

v2: simplify setting of MAX_USER_CARDS, revert back to original default of 16

Signed-off-by: Mike Travis <[email protected]>
LKML-Reference: <4B68D51D.6090401@sgi.com>
Cc: Thomas Gleixner <[email protected]>
Cc: Robin Holt <[email protected]>
Cc: Jack Steiner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jesse Barnes <[email protected]>
Cc: David Airlie <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>

diff --git a/drivers/gpu/vga/Kconfig b/drivers/gpu/vga/Kconfig
index 790e675b13eb8f4b16e9b7040bd656759473ae93..0920492cea0a4af77d9ea6ec13c937a4f6ae60bc 100644 (file)
--- 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 ba7fa9ee54dc00a58e26d74fa79433993271854b..325a53364211abb0154c9860d22cf9dc5c078bc4 100644 (file)
--- 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)
 
 /*