x86: SGI UV: Map MMIO-High memory range

UV depends on the MMRHI space being identity mapped. The patch:

	x86: Make 64-bit efi_ioremap use ioremap on MMIO regions

changed this to make efi regions at a different address using
ioremap. Add the identity mapping to uv_system_init.

( Note this code was previously present but was deleted when BIOS
  added the ranges to the EFI map - previous efi code identify
  mapped the ranges. )
Signed-off-by: Jack Steiner <steiner@sgi.com>
LKML-Reference: <20090909154339.GA7946@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/apic/x2apic_uv_x.c

@@ -389,6 +389,16 @@ static __init void map_gru_high(int max_pnode)
 		map_high("GRU", gru.s.base, shift, max_pnode, map_wb);
 }
 
+static __init void map_mmr_high(int max_pnode)
+{
+	union uvh_rh_gam_mmr_overlay_config_mmr_u mmr;
+	int shift = UVH_RH_GAM_MMR_OVERLAY_CONFIG_MMR_BASE_SHFT;
+
+	mmr.v = uv_read_local_mmr(UVH_RH_GAM_MMR_OVERLAY_CONFIG_MMR);
+	if (mmr.s.enable)
+		map_high("MMR", mmr.s.base, shift, max_pnode, map_uc);
+}
+
 static __init void map_mmioh_high(int max_pnode)
 {
 	union uvh_rh_gam_mmioh_overlay_config_mmr_u mmioh;
@@ -643,6 +653,7 @@ void __init uv_system_init(void)
 	}
 
 	map_gru_high(max_pnode);
+	map_mmr_high(max_pnode);
 	map_mmioh_high(max_pnode);
 
 	uv_cpu_init();