[PATCH 0/4] x86: make e820 memmap to be static and initdata

[PATCH 0/4] x86: make e820 memmap to be static and initdata

[Yinghai Lu]

use wake_system_ram_range instead if needed.

Thanks

Yinghai

[PATCH 1/4] x86: add get_centaur_ram_top

[Yinghai Lu]

so we can avoid to access e820.map[] directly.

later we could move e820 to static and _initdata

Signed-off-by: Yinghai Lu <yinghai@kernel.org>



---
 arch/x86/include/asm/e820.h   |    9 ++++++
 arch/x86/kernel/cpu/centaur.c |   53 +--------------------------------------
 arch/x86/kernel/e820.c        |   57 ++++++++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/setup.c       |    2 +
 4 files changed, 70 insertions(+), 51 deletions(-)

Index: linux-2.6/arch/x86/kernel/e820.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/e820.c
+++ linux-2.6/arch/x86/kernel/e820.c
@@ -1194,3 +1194,60 @@ void __init setup_memory_map(void)
 	printk(KERN_INFO "BIOS-provided physical RAM map:\n");
 	e820_print_map(who);
 }
+
+#ifdef CONFIG_X86_OOSTORE
+/*
+ * Figure what we can cover with MCR's
+ *
+ * Shortcut: We know you can't put 4Gig of RAM on a winchip
+ */
+void __init get_centaur_ram_top(void)
+{
+	u32 clip = 0xFFFFFFFFUL;
+	u32 top = 0;
+	int i;
+
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_CENTAUR)
+		return;
+
+	for (i = 0; i < e820.nr_map; i++) {
+		unsigned long start, end;
+
+		if (e820.map[i].addr > 0xFFFFFFFFUL)
+			continue;
+		/*
+		 * Don't MCR over reserved space. Ignore the ISA hole
+		 * we frob around that catastrophe already
+		 */
+		if (e820.map[i].type == E820_RESERVED) {
+			if (e820.map[i].addr >= 0x100000UL &&
+			    e820.map[i].addr < clip)
+				clip = e820.map[i].addr;
+			continue;
+		}
+		start = e820.map[i].addr;
+		end = e820.map[i].addr + e820.map[i].size;
+		if (start >= end)
+			continue;
+		if (end > top)
+			top = end;
+	}
+	/*
+	 * Everything below 'top' should be RAM except for the ISA hole.
+	 * Because of the limited MCR's we want to map NV/ACPI into our
+	 * MCR range for gunk in RAM
+	 *
+	 * Clip might cause us to MCR insufficient RAM but that is an
+	 * acceptable failure mode and should only bite obscure boxes with
+	 * a VESA hole at 15Mb
+	 *
+	 * The second case Clip sometimes kicks in is when the EBDA is marked
+	 * as reserved. Again we fail safe with reasonable results
+	 */
+	if (top > clip)
+		top = clip;
+
+	centaur_ram_top = top;
+}
+#endif
+
Index: linux-2.6/arch/x86/kernel/setup.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/setup.c
+++ linux-2.6/arch/x86/kernel/setup.c
@@ -875,6 +875,8 @@ void __init setup_arch(char **cmdline_p)
 	if (mtrr_trim_uncached_memory(max_pfn))
 		max_pfn = e820_end_of_ram_pfn();
 
+	get_centaur_ram_top();
+
 #ifdef CONFIG_X86_32
 	/* max_low_pfn get updated here */
 	find_low_pfn_range();
Index: linux-2.6/arch/x86/kernel/cpu/centaur.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/centaur.c
+++ linux-2.6/arch/x86/kernel/cpu/centaur.c
@@ -37,63 +37,14 @@ static void __cpuinit centaur_mcr_insert
 	mtrr_centaur_report_mcr(reg, lo, hi);	/* Tell the mtrr driver */
 }
 
-/*
- * Figure what we can cover with MCR's
- *
- * Shortcut: We know you can't put 4Gig of RAM on a winchip
- */
-static u32 __cpuinit ramtop(void)
-{
-	u32 clip = 0xFFFFFFFFUL;
-	u32 top = 0;
-	int i;
-
-	for (i = 0; i < e820.nr_map; i++) {
-		unsigned long start, end;
-
-		if (e820.map[i].addr > 0xFFFFFFFFUL)
-			continue;
-		/*
-		 * Don't MCR over reserved space. Ignore the ISA hole
-		 * we frob around that catastrophe already
-		 */
-		if (e820.map[i].type == E820_RESERVED) {
-			if (e820.map[i].addr >= 0x100000UL &&
-			    e820.map[i].addr < clip)
-				clip = e820.map[i].addr;
-			continue;
-		}
-		start = e820.map[i].addr;
-		end = e820.map[i].addr + e820.map[i].size;
-		if (start >= end)
-			continue;
-		if (end > top)
-			top = end;
-	}
-	/*
-	 * Everything below 'top' should be RAM except for the ISA hole.
-	 * Because of the limited MCR's we want to map NV/ACPI into our
-	 * MCR range for gunk in RAM
-	 *
-	 * Clip might cause us to MCR insufficient RAM but that is an
-	 * acceptable failure mode and should only bite obscure boxes with
-	 * a VESA hole at 15Mb
-	 *
-	 * The second case Clip sometimes kicks in is when the EBDA is marked
-	 * as reserved. Again we fail safe with reasonable results
-	 */
-	if (top > clip)
-		top = clip;
-
-	return top;
-}
+int __cpuinitdata centaur_ram_top;
 
 /*
  * Compute a set of MCR's to give maximum coverage
  */
 static int __cpuinit centaur_mcr_compute(int nr, int key)
 {
-	u32 mem = ramtop();
+	u32 mem = centaur_ram_top;
 	u32 root = power2(mem);
 	u32 base = root;
 	u32 top = root;
Index: linux-2.6/arch/x86/include/asm/e820.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/e820.h
+++ linux-2.6/arch/x86/include/asm/e820.h
@@ -72,6 +72,15 @@ struct e820map {
 extern struct e820map e820;
 extern struct e820map e820_saved;
 
+#ifdef CONFIG_X86_OOSTORE
+extern int centaur_ram_top;
+void get_centaur_ram_top(void);
+#else
+static inline void get_centaur_ram_top(void)
+{
+}
+#endif
+
 extern unsigned long pci_mem_start;
 extern int e820_any_mapped(u64 start, u64 end, unsigned type);
 extern int e820_all_mapped(u64 start, u64 end, unsigned type);

[PATCH 2/4] x86: make 820 to be static

[Yinghai Lu]

make sanitize_e820_map() not take e820.map directly.

and could change e820_saved to initdata

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 arch/x86/include/asm/e820.h |    7 ++-----
 arch/x86/kernel/e820.c      |   28 +++++++++++++++++++---------
 arch/x86/kernel/efi.c       |    2 +-
 arch/x86/kernel/setup.c     |   10 +++++-----
 arch/x86/xen/setup.c        |    4 +---
 5 files changed, 28 insertions(+), 23 deletions(-)

Index: linux-2.6/arch/x86/kernel/e820.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/e820.c
+++ linux-2.6/arch/x86/kernel/e820.c
@@ -34,8 +34,8 @@
  * user can e.g. boot the original kernel with mem=1G while still booting the
  * next kernel with full memory.
  */
-struct e820map e820;
-struct e820map e820_saved;
+static struct e820map e820;
+static struct e820map __initdata e820_saved;
 
 /* For PCI or other memory-mapped resources */
 unsigned long pci_mem_start = 0xaeedbabe;
@@ -224,7 +224,7 @@ void __init e820_print_map(char *who)
  *	   ______________________4_
  */
 
-int __init sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
+static int __init __sanitize_e820_map(struct e820entry *biosmap, int max_nr_map,
 			     u32 *pnr_map)
 {
 	struct change_member {
@@ -383,6 +383,11 @@ int __init sanitize_e820_map(struct e820
 	return 0;
 }
 
+int __init sanitize_e820_map(void)
+{
+	return __sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+}
+
 static int __init __append_e820_map(struct e820entry *biosmap, int nr_map)
 {
 	while (nr_map) {
@@ -555,7 +560,7 @@ void __init update_e820(void)
 	u32 nr_map;
 
 	nr_map = e820.nr_map;
-	if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map))
+	if (__sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map))
 		return;
 	e820.nr_map = nr_map;
 	printk(KERN_INFO "modified physical RAM map:\n");
@@ -566,7 +571,7 @@ static void __init update_e820_saved(voi
 	u32 nr_map;
 
 	nr_map = e820_saved.nr_map;
-	if (sanitize_e820_map(e820_saved.map, ARRAY_SIZE(e820_saved.map), &nr_map))
+	if (__sanitize_e820_map(e820_saved.map, ARRAY_SIZE(e820_saved.map), &nr_map))
 		return;
 	e820_saved.nr_map = nr_map;
 }
@@ -661,7 +666,7 @@ void __init parse_e820_ext(struct setup_
 		sdata = early_ioremap(pa_data, map_len);
 	extmap = (struct e820entry *)(sdata->data);
 	__append_e820_map(extmap, entries);
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+	sanitize_e820_map();
 	if (map_len > PAGE_SIZE)
 		early_iounmap(sdata, map_len);
 	printk(KERN_INFO "extended physical RAM map:\n");
@@ -1028,7 +1033,7 @@ void __init finish_e820_parsing(void)
 	if (userdef) {
 		u32 nr = e820.nr_map;
 
-		if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr) < 0)
+		if (__sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr) < 0)
 			early_panic("Invalid user supplied memory map");
 		e820.nr_map = nr;
 
@@ -1158,7 +1163,7 @@ char *__init default_machine_specific_me
 	 * the next section from 1mb->appropriate_mem_k
 	 */
 	new_nr = boot_params.e820_entries;
-	sanitize_e820_map(boot_params.e820_map,
+	__sanitize_e820_map(boot_params.e820_map,
 			ARRAY_SIZE(boot_params.e820_map),
 			&new_nr);
 	boot_params.e820_entries = new_nr;
@@ -1185,12 +1190,17 @@ char *__init default_machine_specific_me
 	return who;
 }
 
+void __init save_e820_map(void)
+{
+	memcpy(&e820_saved, &e820, sizeof(struct e820map));
+}
+
 void __init setup_memory_map(void)
 {
 	char *who;
 
 	who = x86_init.resources.memory_setup();
-	memcpy(&e820_saved, &e820, sizeof(struct e820map));
+	save_e820_map();
 	printk(KERN_INFO "BIOS-provided physical RAM map:\n");
 	e820_print_map(who);
 }
Index: linux-2.6/arch/x86/kernel/efi.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/efi.c
+++ linux-2.6/arch/x86/kernel/efi.c
@@ -272,7 +272,7 @@ static void __init do_add_efi_memmap(voi
 		}
 		e820_add_region(start, size, e820_type);
 	}
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+	sanitize_e820_map();
 }
 
 void __init efi_reserve_early(void)
Index: linux-2.6/arch/x86/kernel/setup.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/setup.c
+++ linux-2.6/arch/x86/kernel/setup.c
@@ -461,8 +461,8 @@ static void __init e820_reserve_setup_da
 	if (!found)
 		return;
 
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
-	memcpy(&e820_saved, &e820, sizeof(struct e820map));
+	sanitize_e820_map();
+	save_e820_map();
 	printk(KERN_INFO "extended physical RAM map:\n");
 	e820_print_map("reserve setup_data");
 }
@@ -614,7 +614,7 @@ static int __init dmi_low_memory_corrupt
 		d->ident);
 
 	e820_update_range(0, 0x10000, E820_RAM, E820_RESERVED);
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+	sanitize_e820_map();
 
 	return 0;
 }
@@ -683,7 +683,7 @@ static void __init trim_bios_range(void)
 	 * take them out.
 	 */
 	e820_remove_range(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_RAM, 1);
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+	sanitize_e820_map();
 }
 
 /*
@@ -854,7 +854,7 @@ void __init setup_arch(char **cmdline_p)
 	if (ppro_with_ram_bug()) {
 		e820_update_range(0x70000000ULL, 0x40000ULL, E820_RAM,
 				  E820_RESERVED);
-		sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+		sanitize_e820_map();
 		printk(KERN_INFO "fixed physical RAM map:\n");
 		e820_print_map("bad_ppro");
 	}
Index: linux-2.6/arch/x86/xen/setup.c
===================================================================
--- linux-2.6.orig/arch/x86/xen/setup.c
+++ linux-2.6/arch/x86/xen/setup.c
@@ -43,8 +43,6 @@ char * __init xen_memory_setup(void)
 
 	max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
 
-	e820.nr_map = 0;
-
 	e820_add_region(0, PFN_PHYS((u64)max_pfn), E820_RAM);
 
 	/*
@@ -65,7 +63,7 @@ char * __init xen_memory_setup(void)
 		      __pa(xen_start_info->pt_base),
 			"XEN START INFO");
 
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+	sanitize_e820_map();
 
 	return "Xen";
 }
Index: linux-2.6/arch/x86/include/asm/e820.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/e820.h
+++ linux-2.6/arch/x86/include/asm/e820.h
@@ -68,9 +68,6 @@ struct e820map {
 #define BIOS_END		0x00100000
 
 #ifdef __KERNEL__
-/* see comment in arch/x86/kernel/e820.c */
-extern struct e820map e820;
-extern struct e820map e820_saved;
 
 #ifdef CONFIG_X86_OOSTORE
 extern int centaur_ram_top;
@@ -86,8 +83,8 @@ extern int e820_any_mapped(u64 start, u6
 extern int e820_all_mapped(u64 start, u64 end, unsigned type);
 extern void e820_add_region(u64 start, u64 size, int type);
 extern void e820_print_map(char *who);
-extern int
-sanitize_e820_map(struct e820entry *biosmap, int max_nr_map, u32 *pnr_map);
+int sanitize_e820_map(void);
+void save_e820_map(void);
 extern u64 e820_update_range(u64 start, u64 size, unsigned old_type,
 			       unsigned new_type);
 extern u64 e820_remove_range(u64 start, u64 size, unsigned old_type,

[PATCH 2/4] x86: make 820 to be static

[Yinghai Lu]

put apterture_valid back to .c
and early path still use e820_any_mapped()

Signed-off-by: Yinghai <yinghai@kernel.org>

---
 arch/x86/include/asm/gart.h   |   22 ----------------------
 arch/x86/kernel/aperture_64.c |   22 ++++++++++++++++++++++
 drivers/char/agp/amd64-agp.c  |   39 ++++++++++++++++++++++++++++++++++++++-
 3 files changed, 60 insertions(+), 23 deletions(-)

Index: linux-2.6/arch/x86/include/asm/gart.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/gart.h
+++ linux-2.6/arch/x86/include/asm/gart.h
@@ -74,26 +74,4 @@ static inline void enable_gart_translati
         pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, ctl);
 }
 
-static inline int aperture_valid(u64 aper_base, u32 aper_size, u32 min_size)
-{
-	if (!aper_base)
-		return 0;
-
-	if (aper_base + aper_size > 0x100000000ULL) {
-		printk(KERN_INFO "Aperture beyond 4GB. Ignoring.\n");
-		return 0;
-	}
-	if (e820_any_mapped(aper_base, aper_base + aper_size, E820_RAM)) {
-		printk(KERN_INFO "Aperture pointing to e820 RAM. Ignoring.\n");
-		return 0;
-	}
-	if (aper_size < min_size) {
-		printk(KERN_INFO "Aperture too small (%d MB) than (%d MB)\n",
-				 aper_size>>20, min_size>>20);
-		return 0;
-	}
-
-	return 1;
-}
-
 #endif /* _ASM_X86_GART_H */
Index: linux-2.6/arch/x86/kernel/aperture_64.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/aperture_64.c
+++ linux-2.6/arch/x86/kernel/aperture_64.c
@@ -146,6 +146,28 @@ static u32 __init find_cap(int bus, int
 	return 0;
 }
 
+static int __init aperture_valid(u64 aper_base, u32 aper_size, u32 min_size)
+{
+	if (!aper_base)
+		return 0;
+
+	if (aper_base + aper_size > 0x100000000ULL) {
+		printk(KERN_INFO "Aperture beyond 4GB. Ignoring.\n");
+		return 0;
+	}
+	if (e820_any_mapped(aper_base, aper_base + aper_size, E820_RAM)) {
+		printk(KERN_INFO "Aperture pointing to e820 RAM. Ignoring.\n");
+		return 0;
+	}
+	if (aper_size < min_size) {
+		printk(KERN_INFO "Aperture too small (%d MB) than (%d MB)\n",
+				 aper_size>>20, min_size>>20);
+		return 0;
+	}
+
+	return 1;
+}
+
 /* Read a standard AGPv3 bridge header */
 static u32 __init read_agp(int bus, int slot, int func, int cap, u32 *order)
 {
Index: linux-2.6/drivers/char/agp/amd64-agp.c
===================================================================
--- linux-2.6.orig/drivers/char/agp/amd64-agp.c
+++ linux-2.6/drivers/char/agp/amd64-agp.c
@@ -14,7 +14,6 @@
 #include <linux/agp_backend.h>
 #include <linux/mmzone.h>
 #include <asm/page.h>		/* PAGE_SIZE */
-#include <asm/e820.h>
 #include <asm/k8.h>
 #include <asm/gart.h>
 #include "agp.h"
@@ -231,6 +230,44 @@ static const struct agp_bridge_driver am
 	.agp_type_to_mask_type  = agp_generic_type_to_mask_type,
 };
 
+static int __devinit
+__is_ram(unsigned long pfn, unsigned long nr_pages, void *arg)
+{
+	return 1;
+}
+
+static int __devinit any_ram_in_range(u64 base, u64 size)
+{
+	unsigned long pfn, nr_pages;
+
+	pfn = base >> PAGE_SHIFT;
+	nr_pages = size >> PAGE_SHIFT;
+
+	return walk_system_ram_range(pfn, nr_pages, NULL, __is_ram) == 1;
+}
+
+static int __devinit aperture_valid(u64 aper_base, u32 aper_size, u32 min_size)
+{
+	if (!aper_base)
+		return 0;
+
+	if (aper_base + aper_size > 0x100000000ULL) {
+		printk(KERN_INFO "Aperture beyond 4GB. Ignoring.\n");
+		return 0;
+	}
+	if (any_ram_in_range(aper_base, aper_size)) {
+		printk(KERN_INFO "Aperture pointing to E820 RAM. Ignoring.\n");
+		return 0;
+	}
+	if (aper_size < min_size) {
+		printk(KERN_INFO "Aperture too small (%d MB) than (%d MB)\n",
+				 aper_size>>20, min_size>>20);
+		return 0;
+	}
+
+	return 1;
+}
+
 /* Some basic sanity checks for the aperture. */
 static int __devinit agp_aperture_valid(u64 aper, u32 size)
 {

[PATCH 2/4] x86: make 820 to be static

[Yinghai Lu]

and we don't need to expose e820_any_mapped anymore

Signed-off-by: Yinghai Lu <yinghai@kernel.org.

---
 arch/x86/kernel/e820.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Index: linux-2.6/arch/x86/kernel/e820.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/e820.c
+++ linux-2.6/arch/x86/kernel/e820.c
@@ -34,7 +34,7 @@
  * user can e.g. boot the original kernel with mem=1G while still booting the
  * next kernel with full memory.
  */
-static struct e820map e820;
+static struct e820map __initdata e820;
 static struct e820map __initdata e820_saved;
 
 /* For PCI or other memory-mapped resources */
@@ -46,9 +46,10 @@ EXPORT_SYMBOL(pci_mem_start);
 /*
  * This function checks if any part of the range <start,end> is mapped
  * with type.
+ * phys_pud_init() is using it and is _meminit, but we have !after_bootmem
+ * so could use refok here
  */
-int
-e820_any_mapped(u64 start, u64 end, unsigned type)
+int __init_refok e820_any_mapped(u64 start, u64 end, unsigned type)
 {
 	int i;
 
@@ -63,7 +64,6 @@ e820_any_mapped(u64 start, u64 end, unsi
 	}
 	return 0;
 }
-EXPORT_SYMBOL_GPL(e820_any_mapped);
 
 /*
  * This function checks if the entire range <start,end> is mapped with type.

[PATCH 1/4] x86: add get_centaur_ram_top

[Yinghai Lu]

so we can avoid to access e820.map[] directly.

later we could move e820 to static and _initdata

Signed-off-by: Yinghai Lu <yinghai@kernel.org>



---
 arch/x86/include/asm/e820.h   |    9 ++++++
 arch/x86/kernel/cpu/centaur.c |   53 +--------------------------------------
 arch/x86/kernel/e820.c        |   57 ++++++++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/setup.c       |    2 +
 4 files changed, 70 insertions(+), 51 deletions(-)

Index: linux-2.6/arch/x86/kernel/e820.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/e820.c
+++ linux-2.6/arch/x86/kernel/e820.c
@@ -1194,3 +1194,60 @@ void __init setup_memory_map(void)
 	printk(KERN_INFO "BIOS-provided physical RAM map:\n");
 	e820_print_map(who);
 }
+
+#ifdef CONFIG_X86_OOSTORE
+/*
+ * Figure what we can cover with MCR's
+ *
+ * Shortcut: We know you can't put 4Gig of RAM on a winchip
+ */
+void __init get_centaur_ram_top(void)
+{
+	u32 clip = 0xFFFFFFFFUL;
+	u32 top = 0;
+	int i;
+
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_CENTAUR)
+		return;
+
+	for (i = 0; i < e820.nr_map; i++) {
+		unsigned long start, end;
+
+		if (e820.map[i].addr > 0xFFFFFFFFUL)
+			continue;
+		/*
+		 * Don't MCR over reserved space. Ignore the ISA hole
+		 * we frob around that catastrophe already
+		 */
+		if (e820.map[i].type == E820_RESERVED) {
+			if (e820.map[i].addr >= 0x100000UL &&
+			    e820.map[i].addr < clip)
+				clip = e820.map[i].addr;
+			continue;
+		}
+		start = e820.map[i].addr;
+		end = e820.map[i].addr + e820.map[i].size;
+		if (start >= end)
+			continue;
+		if (end > top)
+			top = end;
+	}
+	/*
+	 * Everything below 'top' should be RAM except for the ISA hole.
+	 * Because of the limited MCR's we want to map NV/ACPI into our
+	 * MCR range for gunk in RAM
+	 *
+	 * Clip might cause us to MCR insufficient RAM but that is an
+	 * acceptable failure mode and should only bite obscure boxes with
+	 * a VESA hole at 15Mb
+	 *
+	 * The second case Clip sometimes kicks in is when the EBDA is marked
+	 * as reserved. Again we fail safe with reasonable results
+	 */
+	if (top > clip)
+		top = clip;
+
+	centaur_ram_top = top;
+}
+#endif
+
Index: linux-2.6/arch/x86/kernel/setup.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/setup.c
+++ linux-2.6/arch/x86/kernel/setup.c
@@ -875,6 +875,8 @@ void __init setup_arch(char **cmdline_p)
 	if (mtrr_trim_uncached_memory(max_pfn))
 		max_pfn = e820_end_of_ram_pfn();
 
+	get_centaur_ram_top();
+
 #ifdef CONFIG_X86_32
 	/* max_low_pfn get updated here */
 	find_low_pfn_range();
Index: linux-2.6/arch/x86/kernel/cpu/centaur.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/centaur.c
+++ linux-2.6/arch/x86/kernel/cpu/centaur.c
@@ -37,63 +37,14 @@ static void __cpuinit centaur_mcr_insert
 	mtrr_centaur_report_mcr(reg, lo, hi);	/* Tell the mtrr driver */
 }
 
-/*
- * Figure what we can cover with MCR's
- *
- * Shortcut: We know you can't put 4Gig of RAM on a winchip
- */
-static u32 __cpuinit ramtop(void)
-{
-	u32 clip = 0xFFFFFFFFUL;
-	u32 top = 0;
-	int i;
-
-	for (i = 0; i < e820.nr_map; i++) {
-		unsigned long start, end;
-
-		if (e820.map[i].addr > 0xFFFFFFFFUL)
-			continue;
-		/*
-		 * Don't MCR over reserved space. Ignore the ISA hole
-		 * we frob around that catastrophe already
-		 */
-		if (e820.map[i].type == E820_RESERVED) {
-			if (e820.map[i].addr >= 0x100000UL &&
-			    e820.map[i].addr < clip)
-				clip = e820.map[i].addr;
-			continue;
-		}
-		start = e820.map[i].addr;
-		end = e820.map[i].addr + e820.map[i].size;
-		if (start >= end)
-			continue;
-		if (end > top)
-			top = end;
-	}
-	/*
-	 * Everything below 'top' should be RAM except for the ISA hole.
-	 * Because of the limited MCR's we want to map NV/ACPI into our
-	 * MCR range for gunk in RAM
-	 *
-	 * Clip might cause us to MCR insufficient RAM but that is an
-	 * acceptable failure mode and should only bite obscure boxes with
-	 * a VESA hole at 15Mb
-	 *
-	 * The second case Clip sometimes kicks in is when the EBDA is marked
-	 * as reserved. Again we fail safe with reasonable results
-	 */
-	if (top > clip)
-		top = clip;
-
-	return top;
-}
+int __cpuinitdata centaur_ram_top;
 
 /*
  * Compute a set of MCR's to give maximum coverage
  */
 static int __cpuinit centaur_mcr_compute(int nr, int key)
 {
-	u32 mem = ramtop();
+	u32 mem = centaur_ram_top;
 	u32 root = power2(mem);
 	u32 base = root;
 	u32 top = root;
Index: linux-2.6/arch/x86/include/asm/e820.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/e820.h
+++ linux-2.6/arch/x86/include/asm/e820.h
@@ -72,6 +72,15 @@ struct e820map {
 extern struct e820map e820;
 extern struct e820map e820_saved;
 
+#ifdef CONFIG_X86_OOSTORE
+extern int centaur_ram_top;
+void get_centaur_ram_top(void);
+#else
+static inline void get_centaur_ram_top(void)
+{
+}
+#endif
+
 extern unsigned long pci_mem_start;
 extern int e820_any_mapped(u64 start, u64 end, unsigned type);
 extern int e820_all_mapped(u64 start, u64 end, unsigned type);

[PATCH 1/4] x86: add get_centaur_ram_top

[Yinghai Lu]

so we can avoid to access e820.map[] directly.

later we could move e820 to static and _initdata

Signed-off-by: Yinghai Lu <yinghai@kernel.org>



---
 arch/x86/include/asm/e820.h   |    9 ++++++
 arch/x86/kernel/cpu/centaur.c |   53 +--------------------------------------
 arch/x86/kernel/e820.c        |   57 ++++++++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/setup.c       |    2 +
 4 files changed, 70 insertions(+), 51 deletions(-)

Index: linux-2.6/arch/x86/kernel/e820.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/e820.c
+++ linux-2.6/arch/x86/kernel/e820.c
@@ -1194,3 +1194,60 @@ void __init setup_memory_map(void)
 	printk(KERN_INFO "BIOS-provided physical RAM map:\n");
 	e820_print_map(who);
 }
+
+#ifdef CONFIG_X86_OOSTORE
+/*
+ * Figure what we can cover with MCR's
+ *
+ * Shortcut: We know you can't put 4Gig of RAM on a winchip
+ */
+void __init get_centaur_ram_top(void)
+{
+	u32 clip = 0xFFFFFFFFUL;
+	u32 top = 0;
+	int i;
+
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_CENTAUR)
+		return;
+
+	for (i = 0; i < e820.nr_map; i++) {
+		unsigned long start, end;
+
+		if (e820.map[i].addr > 0xFFFFFFFFUL)
+			continue;
+		/*
+		 * Don't MCR over reserved space. Ignore the ISA hole
+		 * we frob around that catastrophe already
+		 */
+		if (e820.map[i].type == E820_RESERVED) {
+			if (e820.map[i].addr >= 0x100000UL &&
+			    e820.map[i].addr < clip)
+				clip = e820.map[i].addr;
+			continue;
+		}
+		start = e820.map[i].addr;
+		end = e820.map[i].addr + e820.map[i].size;
+		if (start >= end)
+			continue;
+		if (end > top)
+			top = end;
+	}
+	/*
+	 * Everything below 'top' should be RAM except for the ISA hole.
+	 * Because of the limited MCR's we want to map NV/ACPI into our
+	 * MCR range for gunk in RAM
+	 *
+	 * Clip might cause us to MCR insufficient RAM but that is an
+	 * acceptable failure mode and should only bite obscure boxes with
+	 * a VESA hole at 15Mb
+	 *
+	 * The second case Clip sometimes kicks in is when the EBDA is marked
+	 * as reserved. Again we fail safe with reasonable results
+	 */
+	if (top > clip)
+		top = clip;
+
+	centaur_ram_top = top;
+}
+#endif
+
Index: linux-2.6/arch/x86/kernel/setup.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/setup.c
+++ linux-2.6/arch/x86/kernel/setup.c
@@ -875,6 +875,8 @@ void __init setup_arch(char **cmdline_p)
 	if (mtrr_trim_uncached_memory(max_pfn))
 		max_pfn = e820_end_of_ram_pfn();
 
+	get_centaur_ram_top();
+
 #ifdef CONFIG_X86_32
 	/* max_low_pfn get updated here */
 	find_low_pfn_range();
Index: linux-2.6/arch/x86/kernel/cpu/centaur.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/centaur.c
+++ linux-2.6/arch/x86/kernel/cpu/centaur.c
@@ -37,63 +37,14 @@ static void __cpuinit centaur_mcr_insert
 	mtrr_centaur_report_mcr(reg, lo, hi);	/* Tell the mtrr driver */
 }
 
-/*
- * Figure what we can cover with MCR's
- *
- * Shortcut: We know you can't put 4Gig of RAM on a winchip
- */
-static u32 __cpuinit ramtop(void)
-{
-	u32 clip = 0xFFFFFFFFUL;
-	u32 top = 0;
-	int i;
-
-	for (i = 0; i < e820.nr_map; i++) {
-		unsigned long start, end;
-
-		if (e820.map[i].addr > 0xFFFFFFFFUL)
-			continue;
-		/*
-		 * Don't MCR over reserved space. Ignore the ISA hole
-		 * we frob around that catastrophe already
-		 */
-		if (e820.map[i].type == E820_RESERVED) {
-			if (e820.map[i].addr >= 0x100000UL &&
-			    e820.map[i].addr < clip)
-				clip = e820.map[i].addr;
-			continue;
-		}
-		start = e820.map[i].addr;
-		end = e820.map[i].addr + e820.map[i].size;
-		if (start >= end)
-			continue;
-		if (end > top)
-			top = end;
-	}
-	/*
-	 * Everything below 'top' should be RAM except for the ISA hole.
-	 * Because of the limited MCR's we want to map NV/ACPI into our
-	 * MCR range for gunk in RAM
-	 *
-	 * Clip might cause us to MCR insufficient RAM but that is an
-	 * acceptable failure mode and should only bite obscure boxes with
-	 * a VESA hole at 15Mb
-	 *
-	 * The second case Clip sometimes kicks in is when the EBDA is marked
-	 * as reserved. Again we fail safe with reasonable results
-	 */
-	if (top > clip)
-		top = clip;
-
-	return top;
-}
+int __cpuinitdata centaur_ram_top;
 
 /*
  * Compute a set of MCR's to give maximum coverage
  */
 static int __cpuinit centaur_mcr_compute(int nr, int key)
 {
-	u32 mem = ramtop();
+	u32 mem = centaur_ram_top;
 	u32 root = power2(mem);
 	u32 base = root;
 	u32 top = root;
Index: linux-2.6/arch/x86/include/asm/e820.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/e820.h
+++ linux-2.6/arch/x86/include/asm/e820.h
@@ -72,6 +72,15 @@ struct e820map {
 extern struct e820map e820;
 extern struct e820map e820_saved;
 
+#ifdef CONFIG_X86_OOSTORE
+extern int centaur_ram_top;
+void get_centaur_ram_top(void);
+#else
+static inline void get_centaur_ram_top(void)
+{
+}
+#endif
+
 extern unsigned long pci_mem_start;
 extern int e820_any_mapped(u64 start, u64 end, unsigned type);
 extern int e820_all_mapped(u64 start, u64 end, unsigned type);