x86, UV: Handle missing blade-local memory correctly

UV blades may not have any blade-local memory. Add a field
(nid) to the UV blade structure to indicates whether the node
has local memory. This is needed by the GRU driver (pushed
separately).

Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: linux-mm@kvack.org
LKML-Reference: <20090727143507.GA7006@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 12 insertions, 0 deletions

diff --git a/arch/x86/include/asm/uv/uv_hub.h b/arch/x86/include/asm/uv/uv_hub.h
index 341070f7ad5c..a6dde059e02e 100644
--- a/arch/x86/include/asm/uv/uv_hub.h
+++ b/arch/x86/include/asm/uv/uv_hub.h
@@ -327,6 +327,7 @@ struct uv_blade_info {
         unsigned short  nr_possible_cpus;
         unsigned short  nr_online_cpus;
         unsigned short  pnode;
+        short           memory_nid;
 };
 extern struct uv_blade_info *uv_blade_info;
 extern short *uv_node_to_blade;
@@ -363,6 +364,12 @@ static inline int uv_blade_to_pnode(int bid)
         return uv_blade_info[bid].pnode;
 }
 
+/* Nid of memory node on blade. -1 if no blade-local memory */
+static inline int uv_blade_to_memory_nid(int bid)
+{
+        return uv_blade_info[bid].memory_nid;
+}
+
 /* Determine the number of possible cpus on a blade */
 static inline int uv_blade_nr_possible_cpus(int bid)
 {
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index 096d19aea2f7..ad3f0a984cab 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -591,6 +591,8 @@ void __init uv_system_init(void)
         bytes = sizeof(struct uv_blade_info) * uv_num_possible_blades();
         uv_blade_info = kmalloc(bytes, GFP_KERNEL);
         BUG_ON(!uv_blade_info);
+        for (blade = 0; blade < uv_num_possible_blades(); blade++)
+                uv_blade_info[blade].memory_nid = -1;
 
         get_lowmem_redirect(&lowmem_redir_base, &lowmem_redir_size);
 
@@ -629,6 +631,9 @@ void __init uv_system_init(void)
                 lcpu = uv_blade_info[blade].nr_possible_cpus;
                 uv_blade_info[blade].nr_possible_cpus++;
 
+                /* Any node on the blade, else will contain -1. */
+                uv_blade_info[blade].memory_nid = nid;
+
                 uv_cpu_hub_info(cpu)->lowmem_remap_base = lowmem_redir_base;
                 uv_cpu_hub_info(cpu)->lowmem_remap_top = lowmem_redir_size;
                 uv_cpu_hub_info(cpu)->m_val = m_val;