[PATCH 1/4] x86/platform/UV: Fix problem with UV4 Socket IDs not being contiguous

From: Mike Travis
Date: Mon Aug 01 2016 - 15:07:15 EST


The UV4 Socket IDs are not guaranteed to equate to Node values which
can cause the GAM (Global Addressable Memory) table lookups to fail.
Fix this by using an independent index into the GAM table instead of
the Socket ID to reference the base address.

Reviewed-by: Dimitri Sivanich <sivanich@xxxxxxx>
Reviewed-by: Nathan Zimmer <nzimmer@xxxxxxx>
Tested-by: Frank Ramsay <framsay@xxxxxxx>
Tested-by: John Estabrook <estabrook@xxxxxxx>
Signed-off-by: Mike Travis <travis@xxxxxxx>
---
arch/x86/kernel/apic/x2apic_uv_x.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

--- linux-3.12.orig/arch/x86/kernel/apic/x2apic_uv_x.c
+++ linux-3.12/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -325,7 +325,7 @@ static __init void build_uv_gr_table(voi
struct uv_gam_range_entry *gre = uv_gre_table;
struct uv_gam_range_s *grt;
unsigned long last_limit = 0, ram_limit = 0;
- int bytes, i, sid, lsid = -1;
+ int bytes, i, sid, lsid = -1, indx = 0, lindx = -1;

if (!gre)
return;
@@ -356,11 +356,12 @@ static __init void build_uv_gr_table(voi
}
sid = gre->sockid - _min_socket;
if (lsid < sid) { /* new range */
- grt = &_gr_table[sid];
- grt->base = lsid;
+ grt = &_gr_table[indx];
+ grt->base = lindx;
grt->nasid = gre->nasid;
grt->limit = last_limit = gre->limit;
lsid = sid;
+ lindx = indx++;
continue;
}
if (lsid == sid && !ram_limit) { /* update range */
@@ -371,7 +372,7 @@ static __init void build_uv_gr_table(voi
}
if (!ram_limit) { /* non-contiguous ram range */
grt++;
- grt->base = sid - 1;
+ grt->base = lindx;
grt->nasid = gre->nasid;
grt->limit = last_limit = gre->limit;
continue;

--