x86/platform/uv: Decode UVsystab Info

Upstream commit f5a8f0e

Decode the hubless UVsystab passed from BIOS to the kernel saving
pertinent info in a similar manner that hubbed UVsystabs are decoded.

Signed-off-by: Mike Travis <[email protected]>
Reviewed-by: Steve Wahl <[email protected]>
Reviewed-by: Dimitri Sivanich <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Hedi Berriche <[email protected]>
Cc: Justin Ernst <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Russ Anderson <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Orabug: 30518602
Signed-off-by: Somasundaram Krishnasamy <[email protected]>
Reviewed-by: John Donnelly <[email protected]>

Author: mike-travis

arch/x86/kernel/apic/x2apic_uv_x.c

@@ -1330,7 +1330,8 @@ static int __init decode_uv_systab(void)
 	struct uv_systab *st;
 	int i;
 
-	if (uv_hub_info->hub_revision < UV4_HUB_REVISION_BASE)
+	/* If system is uv3 or lower, there is no extended UVsystab */
+	if (is_uv_hubbed(0xfffffe) < uv(4) && is_uv_hubless(0xfffffe) < uv(4))
 		return 0;	/* No extended UVsystab required */
 
 	st = uv_systab;
@@ -1581,8 +1582,15 @@ static __init int uv_system_init_hubless(void)
 
 	/* Init kernel/BIOS interface */
 	rc = uv_bios_init();
+	if (rc < 0)
+		return rc;
 
-	/* Create user access node if UVsystab available */
+	/* Process UVsystab */
+	rc = decode_uv_systab();
+	if (rc < 0)
+		return rc;
+
+	/* Create user access node */
 	if (rc >= 0)
 		uv_setup_proc_files(1);