ALPHA: support graphics on non-zero PCI domains

This code replaces earlier and incomplete handling of graphics on non-zero PCI
domains (aka hoses or peer PCI buses).

An option (CONFIG_VGA_HOSE) is set TRUE if configuring a GENERIC kernel, or a
kernel for MARVEL, TITAN, or TSUNAMI machines, as these are the machines whose
SRM consoles are capable of configuring and handling graphics options on
non-zero hoses.  All other machines have the option set FALSE.

A routine, "find_console_vga_hose()", is used to find the graphics device
which the machine's firmware believes is the console device, and it sets a
global (pci_vga_hose) for later use in managing access to the device.  This is
called in "init_arch" on TITAN and TSUNAMI machines; MARVEL machines use a
custom version of this routine because of extra complexity.

A routine, "locate_and_init_vga()", is used to find the graphics device and
set a global (pci_vga_hose) for later use in managing access to the device, in
the case where "find_console_vga_hose" has failed.

Various adjustments are made to the ioremap and ioportmap routines for
detecting and translating "legacy" VGA register and memory references to the
real PCI domain.

[akpm@linux-foundation.org: don't statically init bss]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Jay Estabrook <jay.estabrook@hp.com>
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/alpha/kernel/proto.h b/arch/alpha/kernel/proto.h
index 95912ecc65e..708d5ca8778 100644
--- a/arch/alpha/kernel/proto.h
+++ b/arch/alpha/kernel/proto.h
@@ -108,6 +108,15 @@ extern int wildfire_cpuid_to_nid(int);
 extern unsigned long wildfire_node_mem_start(int);
 extern unsigned long wildfire_node_mem_size(int);
 
+/* console.c */
+#ifdef CONFIG_VGA_HOSE
+extern void find_console_vga_hose(void);
+extern void locate_and_init_vga(void *(*)(void *, void *));
+#else
+static inline void find_console_vga_hose(void) { }
+static inline void locate_and_init_vga(void *(*sel_func)(void *, void *)) { }
+#endif
+
 /* setup.c */
 extern unsigned long srm_hae;
 extern int boot_cpuid;