x86_64 SGI UV: Fix writes to led registers on remote uv hubs.

The wrong address was being used to write the SCIR led regs on remote
hubs.  Also, there was an inconsistency between how BIOS and the kernel
indexed these regs.  Standardize on using the lower 6 bits of the APIC
ID as the index.

This patch fixes the problem of writing to an errant address to a
cpu # >= 64.

Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Jack Steiner <steiner@sgi.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 25 insertions, 7 deletions

diff --git a/arch/x86/include/asm/uv/uv_hub.h b/arch/x86/include/asm/uv/uv_hub.h
index 811bfabc80b7..bcdb708993d2 100644
--- a/arch/x86/include/asm/uv/uv_hub.h
+++ b/arch/x86/include/asm/uv/uv_hub.h
@@ -338,6 +338,18 @@ static inline unsigned long uv_global_gru_mmr_address(int pnode, unsigned long o
 	return UV_GLOBAL_GRU_MMR_BASE | offset | (pnode << uv_hub_info->m_val);
 }
 
+static inline void uv_write_global_mmr8(int pnode, unsigned long offset,
+				unsigned char val)
+{
+	writeb(val, uv_global_mmr64_address(pnode, offset));
+}
+
+static inline unsigned char uv_read_global_mmr8(int pnode,
+						 unsigned long offset)
+{
+	return readb(uv_global_mmr64_address(pnode, offset));
+}
+
 /*
  * Access hub local MMRs. Faster than using global space but only local MMRs
  * are accessible.
@@ -457,11 +469,17 @@ static inline void uv_set_scir_bits(unsigned char value)
 	}
 }
 
+static inline unsigned long uv_scir_offset(int apicid)
+{
+	return SCIR_LOCAL_MMR_BASE | (apicid & 0x3f);
+}
+
 static inline void uv_set_cpu_scir_bits(int cpu, unsigned char value)
 {
 	if (uv_cpu_hub_info(cpu)->scir.state != value) {
+		uv_write_global_mmr8(uv_cpu_to_pnode(cpu),
+				uv_cpu_hub_info(cpu)->scir.offset, value);
 		uv_cpu_hub_info(cpu)->scir.state = value;
-		uv_write_local_mmr8(uv_cpu_hub_info(cpu)->scir.offset, value);
 	}
 }
 
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index d56b0efb2057..5f92494dab61 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -629,8 +629,10 @@ void __init uv_system_init(void)
 	uv_rtc_init();
 
 	for_each_present_cpu(cpu) {
+		int apicid = per_cpu(x86_cpu_to_apicid, cpu);
+
 		nid = cpu_to_node(cpu);
-		pnode = uv_apicid_to_pnode(per_cpu(x86_cpu_to_apicid, cpu));
+		pnode = uv_apicid_to_pnode(apicid);
 		blade = boot_pnode_to_blade(pnode);
 		lcpu = uv_blade_info[blade].nr_possible_cpus;
 		uv_blade_info[blade].nr_possible_cpus++;
@@ -651,15 +653,13 @@ void __init uv_system_init(void)
 		uv_cpu_hub_info(cpu)->gnode_extra = gnode_extra;
 		uv_cpu_hub_info(cpu)->global_mmr_base = mmr_base;
 		uv_cpu_hub_info(cpu)->coherency_domain_number = sn_coherency_id;
-		uv_cpu_hub_info(cpu)->scir.offset = SCIR_LOCAL_MMR_BASE + lcpu;
+		uv_cpu_hub_info(cpu)->scir.offset = uv_scir_offset(apicid);
 		uv_node_to_blade[nid] = blade;
 		uv_cpu_to_blade[cpu] = blade;
 		max_pnode = max(pnode, max_pnode);
 
-		printk(KERN_DEBUG "UV: cpu %d, apicid 0x%x, pnode %d, nid %d, "
-			"lcpu %d, blade %d\n",
-			cpu, per_cpu(x86_cpu_to_apicid, cpu), pnode, nid,
-			lcpu, blade);
+		printk(KERN_DEBUG "UV: cpu %d, apicid 0x%x, pnode %d, nid %d, lcpu %d, blade %d\n",
+			cpu, apicid, pnode, nid, lcpu, blade);
 	}
 
 	/* Add blade/pnode info for nodes without cpus */