x86: UV SGI: Don't track GRU space in PAT

GRU space is always mapped as WB in the page table. There is
no need to track the mappings in the PAT. This also eliminates
the "freeing invalid memtype" messages when the GRU space is
unmapped.

Signed-off-by: Jack Steiner <steiner@sgi.com>
LKML-Reference: <20091119202341.GA4420@sgi.com>
[ v2: fix build failure ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/pat.h

@@ -24,4 +24,6 @@ int io_reserve_memtype(resource_size_t start, resource_size_t end,
 
 void io_free_memtype(resource_size_t start, resource_size_t end);
 
+int default_is_untracked_pat_range(u64 start, u64 end);
+
 #endif /* _ASM_X86_PAT_H */

arch/x86/include/asm/x86_init.h

@@ -113,11 +113,13 @@ struct x86_cpuinit_ops {
 
 /**
  * struct x86_platform_ops - platform specific runtime functions
+ * @is_untracked_pat_range	exclude from PAT logic
  * @calibrate_tsc:		calibrate TSC
  * @get_wallclock:		get time from HW clock like RTC etc.
  * @set_wallclock:		set time back to HW clock
  */
 struct x86_platform_ops {
+	int (*is_untracked_pat_range)(u64 start, u64 end);
 	unsigned long (*calibrate_tsc)(void);
 	unsigned long (*get_wallclock)(void);
 	int (*set_wallclock)(unsigned long nowtime);

arch/x86/kernel/apic/x2apic_uv_x.c

@@ -30,10 +30,22 @@
 #include <asm/apic.h>
 #include <asm/ipi.h>
 #include <asm/smp.h>
+#include <asm/x86_init.h>
 
 DEFINE_PER_CPU(int, x2apic_extra_bits);
 
 static enum uv_system_type uv_system_type;
+static u64 gru_start_paddr, gru_end_paddr;
+
+static int is_GRU_range(u64 start, u64 end)
+{
+	return start >= gru_start_paddr && end < gru_end_paddr;
+}
+
+static int uv_is_untracked_pat_range(u64 start, u64 end)
+{
+	return is_ISA_range(start, end) || is_GRU_range(start, end);
+}
 
 static int early_get_nodeid(void)
 {
@@ -49,6 +61,7 @@ static int early_get_nodeid(void)
 static int __init uv_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
 {
 	if (!strcmp(oem_id, "SGI")) {
+		x86_platform.is_untracked_pat_range =  uv_is_untracked_pat_range;
 		if (!strcmp(oem_table_id, "UVL"))
 			uv_system_type = UV_LEGACY_APIC;
 		else if (!strcmp(oem_table_id, "UVX"))
@@ -385,8 +398,12 @@ static __init void map_gru_high(int max_pnode)
 	int shift = UVH_RH_GAM_GRU_OVERLAY_CONFIG_MMR_BASE_SHFT;
 
 	gru.v = uv_read_local_mmr(UVH_RH_GAM_GRU_OVERLAY_CONFIG_MMR);
-	if (gru.s.enable)
+	if (gru.s.enable) {
 		map_high("GRU", gru.s.base, shift, max_pnode, map_wb);
+		gru_start_paddr = ((u64)gru.s.base << shift);
+		gru_end_paddr = gru_start_paddr + (1UL << shift) * (max_pnode + 1);
+
+	}
 }
 
 static __init void map_mmr_high(int max_pnode)

arch/x86/kernel/x86_init.c

@@ -13,6 +13,7 @@
 #include <asm/e820.h>
 #include <asm/time.h>
 #include <asm/irq.h>
+#include <asm/pat.h>
 #include <asm/tsc.h>
 
 void __cpuinit x86_init_noop(void) { }
@@ -69,6 +70,7 @@ struct x86_cpuinit_ops x86_cpuinit __cpuinitdata = {
 };
 
 struct x86_platform_ops x86_platform = {
+	.is_untracked_pat_range		= default_is_untracked_pat_range,
 	.calibrate_tsc			= native_calibrate_tsc,
 	.get_wallclock			= mach_get_cmos_time,
 	.set_wallclock			= mach_set_rtc_mmss,

arch/x86/mm/pat.c

@@ -20,6 +20,7 @@
 #include <asm/cacheflush.h>
 #include <asm/processor.h>
 #include <asm/tlbflush.h>
+#include <asm/x86_init.h>
 #include <asm/pgtable.h>
 #include <asm/fcntl.h>
 #include <asm/e820.h>
@@ -348,6 +349,11 @@ static int free_ram_pages_type(u64 start, u64 end)
 	return 0;
 }
 
+int default_is_untracked_pat_range(u64 start, u64 end)
+{
+	return is_ISA_range(start, end);
+}
+
 /*
  * req_type typically has one of the:
  * - _PAGE_CACHE_WB
@@ -388,7 +394,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
 	}
 
 	/* Low ISA region is always mapped WB in page table. No need to track */
-	if (is_ISA_range(start, end - 1)) {
+	if (x86_platform.is_untracked_pat_range(start, end - 1)) {
 		if (new_type)
 			*new_type = _PAGE_CACHE_WB;
 		return 0;
@@ -499,7 +505,7 @@ int free_memtype(u64 start, u64 end)
 		return 0;
 
 	/* Low ISA region is always mapped WB. No need to track */
-	if (is_ISA_range(start, end - 1))
+	if (x86_platform.is_untracked_pat_range(start, end - 1))
 		return 0;
 
 	is_range_ram = pat_pagerange_is_ram(start, end);
@@ -582,7 +588,7 @@ static unsigned long lookup_memtype(u64 paddr)
 	int rettype = _PAGE_CACHE_WB;
 	struct memtype *entry;
 
-	if (is_ISA_range(paddr, paddr + PAGE_SIZE - 1))
+	if (x86_platform.is_untracked_pat_range(paddr, paddr + PAGE_SIZE - 1))
 		return rettype;
 
 	if (pat_pagerange_is_ram(paddr, paddr + PAGE_SIZE)) {