[PATCH V2 6/8] x86/platform/uv: Decode UVsystab Info

[Mike Travis]

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@xxxxxxx>
Reviewed-by: Steve Wahl <steve.wahl@xxxxxxx>
Reviewed-by: Dimitri Sivanich <dimitri.sivanich@xxxxxxx>
To: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
To: Ingo Molnar <mingo@xxxxxxxxxx>
To: H. Peter Anvin <hpa@xxxxxxxxx>
To: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
To: Borislav Petkov <bp@xxxxxxxxx>
To: Christoph Hellwig <hch@xxxxxxxxxxxxx>
To: Sasha Levin <sashal@xxxxxxxxxx>
Cc: Dimitri Sivanich <dimitri.sivanich@xxxxxxx>
Cc: Russ Anderson <russ.anderson@xxxxxxx>
Cc: Hedi Berriche <hedi.berriche@xxxxxxx>
Cc: Steve Wahl <steve.wahl@xxxxxxx>
Cc: Justin Ernst <justin.ernst@xxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
V2: Removed redundant error message after call to uv_bios_init.
    Removed redundant error message after call to decode_uv_systab.
    Clarify selection of UV4 and higher when checking for extended UVsystab
    in decode_uv_systab().
---
 arch/x86/kernel/apic/x2apic_uv_x.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

--- linux.orig/arch/x86/kernel/apic/x2apic_uv_x.c
+++ linux/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
 
 	/* 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);
 

--