x86/platform/uv: Decode UVsystab Info

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 <mike.travis@hpe.com>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hedi Berriche <hedi.berriche@hpe.com>
Cc: Justin Ernst <justin.ernst@hpe.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190910145840.135325066@stormcage.eag.rdlabs.hpecorp.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/apic/x2apic_uv_x.c

@@ -1303,7 +1303,8 @@ 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;
@@ -1554,8 +1555,15 @@ 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);