[PATCH 1/3] x86/e820: Mark some static functions __init

[PATCH 1/3] x86/e820: Mark some static functions __init

[Denys Vlasenko]

They are all called only from other __init functions in e820.c

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Ingo Molnar <mingo@kernel.org>
CC: Andy Lutomirski <luto@amacapital.net>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Borislav Petkov <bp@alien8.de>
CC: Brian Gerst <brgerst@gmail.com>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---
 arch/x86/kernel/e820.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 621b501..a6d4f10 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -802,7 +802,7 @@ unsigned long __init e820_end_of_low_ram_pfn(void)
 	return e820_end_pfn(1UL << (32-PAGE_SHIFT));
 }
 
-static void early_panic(char *msg)
+static void __init early_panic(char *msg)
 {
 	early_printk(msg);
 	panic(msg);
@@ -912,7 +912,7 @@ void __init finish_e820_parsing(void)
 	}
 }
 
-static const char *e820_type_to_string(int e820_type)
+static const char *__init e820_type_to_string(int e820_type)
 {
 	switch (e820_type) {
 	case E820_RESERVED_KERN:
@@ -926,7 +926,7 @@ static const char *e820_type_to_string(int e820_type)
 	}
 }
 
-static unsigned long e820_type_to_iomem_type(int e820_type)
+static unsigned long __init e820_type_to_iomem_type(int e820_type)
 {
 	switch (e820_type) {
 	case E820_RESERVED_KERN:
@@ -942,7 +942,7 @@ static unsigned long e820_type_to_iomem_type(int e820_type)
 	}
 }
 
-static unsigned long e820_type_to_iores_desc(int e820_type)
+static unsigned long __init e820_type_to_iores_desc(int e820_type)
 {
 	switch (e820_type) {
 	case E820_ACPI:
@@ -961,7 +961,7 @@ static unsigned long e820_type_to_iores_desc(int e820_type)
 	}
 }
 
-static bool do_mark_busy(u32 type, struct resource *res)
+static bool __init do_mark_busy(u32 type, struct resource *res)
 {
 	/* this is the legacy bios/dos rom-shadow + mmio region */
 	if (res->start < (1ULL<<20))
@@ -1027,7 +1027,7 @@ void __init e820_reserve_resources(void)
 }
 
 /* How much should we pad RAM ending depending on where it is? */
-static unsigned long ram_alignment(resource_size_t pos)
+static unsigned long __init ram_alignment(resource_size_t pos)
 {
 	unsigned long mb = pos >> 20;
 
-- 
2.9.2

[PATCH 2/3] x86/e820: Prepare e280 code for switch to dynamic storage

[Denys Vlasenko]

This patch turns e820 and e820_saved into pointers to e820 tables,
of the same size as before.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Ingo Molnar <mingo@kernel.org>
CC: Andy Lutomirski <luto@amacapital.net>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Borislav Petkov <bp@alien8.de>
CC: Brian Gerst <brgerst@gmail.com>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
---
 arch/x86/include/asm/e820.h       |   6 +-
 arch/x86/kernel/e820.c            | 125 +++++++++++++++++++++++---------------
 arch/x86/kernel/early-quirks.c    |   2 +-
 arch/x86/kernel/kexec-bzimage64.c |   4 +-
 arch/x86/kernel/resource.c        |   4 +-
 arch/x86/kernel/setup.c           |   8 +--
 arch/x86/kernel/tboot.c           |   8 +--
 arch/x86/mm/init.c                |   2 +
 arch/x86/platform/efi/efi.c       |   2 +-
 arch/x86/xen/setup.c              |   2 +-
 10 files changed, 98 insertions(+), 65 deletions(-)

diff --git a/arch/x86/include/asm/e820.h b/arch/x86/include/asm/e820.h
index 3ab0537..476b574 100644
--- a/arch/x86/include/asm/e820.h
+++ b/arch/x86/include/asm/e820.h
@@ -10,8 +10,8 @@
 #include <uapi/asm/e820.h>
 #ifndef __ASSEMBLY__
 /* see comment in arch/x86/kernel/e820.c */
-extern struct e820map e820;
-extern struct e820map e820_saved;
+extern struct e820map *e820;
+extern struct e820map *e820_saved;
 
 extern unsigned long pci_mem_start;
 extern int e820_any_mapped(u64 start, u64 end, unsigned type);
@@ -53,6 +53,8 @@ extern void e820_reserve_resources_late(void);
 extern void setup_memory_map(void);
 extern char *default_machine_specific_memory_setup(void);
 
+extern void e820_reallocate_tables(void);
+
 /*
  * Returns true iff the specified range [s,e) is completely contained inside
  * the ISA region.
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index a6d4f10..cf7c9ad 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -40,8 +40,10 @@
  * 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 initial_e820;
+static struct e820map initial_e820_saved;
+struct e820map *e820 = &initial_e820;
+struct e820map *e820_saved = &initial_e820_saved;
 
 /* For PCI or other memory-mapped resources */
 unsigned long pci_mem_start = 0xaeedbabe;
@@ -58,8 +60,8 @@ e820_any_mapped(u64 start, u64 end, unsigned type)
 {
 	int i;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 
 		if (type && ei->type != type)
 			continue;
@@ -81,8 +83,8 @@ int __init e820_all_mapped(u64 start, u64 end, unsigned type)
 {
 	int i;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 
 		if (type && ei->type != type)
 			continue;
@@ -128,7 +130,7 @@ static void __init __e820_add_region(struct e820map *e820x, u64 start, u64 size,
 
 void __init e820_add_region(u64 start, u64 size, int type)
 {
-	__e820_add_region(&e820, start, size, type);
+	__e820_add_region(e820, start, size, type);
 }
 
 static void __init e820_print_type(u32 type)
@@ -164,12 +166,12 @@ void __init e820_print_map(char *who)
 {
 	int i;
 
-	for (i = 0; i < e820.nr_map; i++) {
+	for (i = 0; i < e820->nr_map; i++) {
 		printk(KERN_INFO "%s: [mem %#018Lx-%#018Lx] ", who,
-		       (unsigned long long) e820.map[i].addr,
+		       (unsigned long long) e820->map[i].addr,
 		       (unsigned long long)
-		       (e820.map[i].addr + e820.map[i].size - 1));
-		e820_print_type(e820.map[i].type);
+		       (e820->map[i].addr + e820->map[i].size - 1));
+		e820_print_type(e820->map[i].type);
 		printk(KERN_CONT "\n");
 	}
 }
@@ -493,13 +495,13 @@ static u64 __init __e820_update_range(struct e820map *e820x, u64 start,
 u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
 			     unsigned new_type)
 {
-	return __e820_update_range(&e820, start, size, old_type, new_type);
+	return __e820_update_range(e820, start, size, old_type, new_type);
 }
 
 static u64 __init e820_update_range_saved(u64 start, u64 size,
 					  unsigned old_type, unsigned new_type)
 {
-	return __e820_update_range(&e820_saved, start, size, old_type,
+	return __e820_update_range(e820_saved, start, size, old_type,
 				     new_type);
 }
 
@@ -521,8 +523,8 @@ u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
 		e820_print_type(old_type);
 	printk(KERN_CONT "\n");
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 		u64 final_start, final_end;
 		u64 ei_end;
 
@@ -566,15 +568,15 @@ u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
 
 void __init update_e820(void)
 {
-	if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map))
+	if (sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map))
 		return;
 	printk(KERN_INFO "e820: modified physical RAM map:\n");
 	e820_print_map("modified");
 }
 static void __init update_e820_saved(void)
 {
-	sanitize_e820_map(e820_saved.map, ARRAY_SIZE(e820_saved.map),
-				&e820_saved.nr_map);
+	sanitize_e820_map(e820_saved->map, ARRAY_SIZE(e820_saved->map),
+				&e820_saved->nr_map);
 }
 #define MAX_GAP_END 0x100000000ull
 /*
@@ -584,14 +586,14 @@ __init int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize,
 		unsigned long start_addr, unsigned long long end_addr)
 {
 	unsigned long long last;
-	int i = e820.nr_map;
+	int i = e820->nr_map;
 	int found = 0;
 
 	last = (end_addr && end_addr < MAX_GAP_END) ? end_addr : MAX_GAP_END;
 
 	while (--i >= 0) {
-		unsigned long long start = e820.map[i].addr;
-		unsigned long long end = start + e820.map[i].size;
+		unsigned long long start = e820->map[i].addr;
+		unsigned long long end = start + e820->map[i].size;
 
 		if (end < start_addr)
 			continue;
@@ -649,6 +651,33 @@ __init void e820_setup_gap(void)
 	       gapstart, gapstart + gapsize - 1);
 }
 
+/*
+ * Called late during init, in free_initmem().
+ *
+ * Initial e820 and e820_saved are largish __initdata arrays.
+ * Copy them to (usually much smaller) dynamically allocated area.
+ * This is done after all tweaks we ever do to them:
+ * all functions which modify them are __init functions,
+ * they won't exist after this point.
+ */
+__init void e820_reallocate_tables(void)
+{
+	struct e820map *n;
+	int size;
+
+	size = offsetof(struct e820map, map) + sizeof(struct e820entry) * e820->nr_map;
+	n = kmalloc(size, GFP_KERNEL);
+	BUG_ON(!n);
+	memcpy(n, e820, size);
+	e820 = n;
+
+	size = offsetof(struct e820map, map) + sizeof(struct e820entry) * e820_saved->nr_map;
+	n = kmalloc(size, GFP_KERNEL);
+	BUG_ON(!n);
+	memcpy(n, e820_saved, size);
+	e820_saved = n;
+}
+
 /**
  * Because of the size limitation of struct boot_params, only first
  * 128 E820 memory entries are passed to kernel via
@@ -665,7 +694,7 @@ void __init parse_e820_ext(u64 phys_addr, u32 data_len)
 	entries = sdata->len / sizeof(struct e820entry);
 	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(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
 	early_memunmap(sdata, data_len);
 	printk(KERN_INFO "e820: extended physical RAM map:\n");
 	e820_print_map("extended");
@@ -686,8 +715,8 @@ void __init e820_mark_nosave_regions(unsigned long limit_pfn)
 	int i;
 	unsigned long pfn = 0;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 
 		if (pfn < PFN_UP(ei->addr))
 			register_nosave_region(pfn, PFN_UP(ei->addr));
@@ -712,8 +741,8 @@ static int __init e820_mark_nvs_memory(void)
 {
 	int i;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 
 		if (ei->type == E820_NVS)
 			acpi_nvs_register(ei->addr, ei->size);
@@ -760,8 +789,8 @@ static unsigned long __init e820_end_pfn(unsigned long limit_pfn)
 	unsigned long last_pfn = 0;
 	unsigned long max_arch_pfn = MAX_ARCH_PFN;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 		unsigned long start_pfn;
 		unsigned long end_pfn;
 
@@ -856,7 +885,7 @@ static int __init parse_memmap_one(char *p)
 		 */
 		saved_max_pfn = e820_end_of_ram_pfn();
 #endif
-		e820.nr_map = 0;
+		e820->nr_map = 0;
 		userdef = 1;
 		return 0;
 	}
@@ -903,8 +932,8 @@ early_param("memmap", parse_memmap_opt);
 void __init finish_e820_parsing(void)
 {
 	if (userdef) {
-		if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map),
-					&e820.nr_map) < 0)
+		if (sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map),
+					&e820->nr_map) < 0)
 			early_panic("Invalid user supplied memory map");
 
 		printk(KERN_INFO "e820: user-defined physical RAM map:\n");
@@ -991,35 +1020,35 @@ void __init e820_reserve_resources(void)
 	struct resource *res;
 	u64 end;
 
-	res = alloc_bootmem(sizeof(struct resource) * e820.nr_map);
+	res = alloc_bootmem(sizeof(struct resource) * e820->nr_map);
 	e820_res = res;
-	for (i = 0; i < e820.nr_map; i++) {
-		end = e820.map[i].addr + e820.map[i].size - 1;
+	for (i = 0; i < e820->nr_map; i++) {
+		end = e820->map[i].addr + e820->map[i].size - 1;
 		if (end != (resource_size_t)end) {
 			res++;
 			continue;
 		}
-		res->name = e820_type_to_string(e820.map[i].type);
-		res->start = e820.map[i].addr;
+		res->name = e820_type_to_string(e820->map[i].type);
+		res->start = e820->map[i].addr;
 		res->end = end;
 
-		res->flags = e820_type_to_iomem_type(e820.map[i].type);
-		res->desc = e820_type_to_iores_desc(e820.map[i].type);
+		res->flags = e820_type_to_iomem_type(e820->map[i].type);
+		res->desc = e820_type_to_iores_desc(e820->map[i].type);
 
 		/*
 		 * don't register the region that could be conflicted with
 		 * pci device BAR resource and insert them later in
 		 * pcibios_resource_survey()
 		 */
-		if (do_mark_busy(e820.map[i].type, res)) {
+		if (do_mark_busy(e820->map[i].type, res)) {
 			res->flags |= IORESOURCE_BUSY;
 			insert_resource(&iomem_resource, res);
 		}
 		res++;
 	}
 
-	for (i = 0; i < e820_saved.nr_map; i++) {
-		struct e820entry *entry = &e820_saved.map[i];
+	for (i = 0; i < e820_saved->nr_map; i++) {
+		struct e820entry *entry = &e820_saved->map[i];
 		firmware_map_add_early(entry->addr,
 			entry->addr + entry->size,
 			e820_type_to_string(entry->type));
@@ -1051,7 +1080,7 @@ void __init e820_reserve_resources_late(void)
 	struct resource *res;
 
 	res = e820_res;
-	for (i = 0; i < e820.nr_map; i++) {
+	for (i = 0; i < e820->nr_map; i++) {
 		if (!res->parent && res->end)
 			insert_resource_expand_to_fit(&iomem_resource, res);
 		res++;
@@ -1061,8 +1090,8 @@ void __init e820_reserve_resources_late(void)
 	 * Try to bump up RAM regions to reasonable boundaries to
 	 * avoid stolen RAM:
 	 */
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *entry = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *entry = &e820->map[i];
 		u64 start, end;
 
 		if (entry->type != E820_RAM)
@@ -1110,7 +1139,7 @@ char *__init default_machine_specific_memory_setup(void)
 			who = "BIOS-e801";
 		}
 
-		e820.nr_map = 0;
+		e820->nr_map = 0;
 		e820_add_region(0, LOWMEMSIZE(), E820_RAM);
 		e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
 	}
@@ -1124,7 +1153,7 @@ void __init setup_memory_map(void)
 	char *who;
 
 	who = x86_init.resources.memory_setup();
-	memcpy(&e820_saved, &e820, sizeof(struct e820map));
+	memcpy(e820_saved, e820, sizeof(struct e820map));
 	printk(KERN_INFO "e820: BIOS-provided physical RAM map:\n");
 	e820_print_map(who);
 }
@@ -1141,8 +1170,8 @@ void __init memblock_x86_fill(void)
 	 */
 	memblock_allow_resize();
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 
 		end = ei->addr + ei->size;
 		if (end != (resource_size_t)end)
diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
index de7501e..18bb3a6 100644
--- a/arch/x86/kernel/early-quirks.c
+++ b/arch/x86/kernel/early-quirks.c
@@ -555,7 +555,7 @@ intel_graphics_stolen(int num, int slot, int func,
 
 	/* Mark this space as reserved */
 	e820_add_region(base, size, E820_RESERVED);
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+	sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
 }
 
 static void __init intel_graphics_quirks(int num, int slot, int func)
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index f2356bd..3407b14 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -99,14 +99,14 @@ static int setup_e820_entries(struct boot_params *params)
 {
 	unsigned int nr_e820_entries;
 
-	nr_e820_entries = e820_saved.nr_map;
+	nr_e820_entries = e820_saved->nr_map;
 
 	/* TODO: Pass entries more than E820MAX in bootparams setup data */
 	if (nr_e820_entries > E820MAX)
 		nr_e820_entries = E820MAX;
 
 	params->e820_entries = nr_e820_entries;
-	memcpy(&params->e820_map, &e820_saved.map,
+	memcpy(&params->e820_map, &e820_saved->map,
 	       nr_e820_entries * sizeof(struct e820entry));
 
 	return 0;
diff --git a/arch/x86/kernel/resource.c b/arch/x86/kernel/resource.c
index 80eab01..2408c16 100644
--- a/arch/x86/kernel/resource.c
+++ b/arch/x86/kernel/resource.c
@@ -27,8 +27,8 @@ static void remove_e820_regions(struct resource *avail)
 	int i;
 	struct e820entry *entry;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		entry = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		entry = &e820->map[i];
 
 		resource_clip(avail, entry->addr,
 			      entry->addr + entry->size - 1);
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 0fa60f5..cc43d66 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -458,8 +458,8 @@ static void __init e820_reserve_setup_data(void)
 		early_memunmap(data, sizeof(*data));
 	}
 
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
-	memcpy(&e820_saved, &e820, sizeof(struct e820map));
+	sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
+	memcpy(e820_saved, e820, sizeof(struct e820map));
 	printk(KERN_INFO "extended physical RAM map:\n");
 	e820_print_map("reserve setup_data");
 }
@@ -763,7 +763,7 @@ static void __init trim_bios_range(void)
 	 */
 	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(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
 }
 
 /* called before trim_bios_range() to spare extra sanitize */
@@ -1032,7 +1032,7 @@ 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(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
 		printk(KERN_INFO "fixed physical RAM map:\n");
 		e820_print_map("bad_ppro");
 	}
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index 654f6c6..8402907 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -188,12 +188,12 @@ static int tboot_setup_sleep(void)
 
 	tboot->num_mac_regions = 0;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		if ((e820.map[i].type != E820_RAM)
-		 && (e820.map[i].type != E820_RESERVED_KERN))
+	for (i = 0; i < e820->nr_map; i++) {
+		if ((e820->map[i].type != E820_RAM)
+		 && (e820->map[i].type != E820_RESERVED_KERN))
 			continue;
 
-		add_mac_region(e820.map[i].addr, e820.map[i].size);
+		add_mac_region(e820->map[i].addr, e820->map[i].size);
 	}
 
 	tboot->acpi_sinfo.kernel_s3_resume_vector =
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index d28a2d7..167deae 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -701,6 +701,8 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
 
 void free_initmem(void)
 {
+	/* e820_reallocate_tables(); - disabled for now */
+
 	free_init_pages("unused kernel",
 			(unsigned long)(&__init_begin),
 			(unsigned long)(&__init_end));
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 1fbb408..2e34334 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -166,7 +166,7 @@ static void __init do_add_efi_memmap(void)
 		}
 		e820_add_region(start, size, e820_type);
 	}
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+	sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
 }
 
 int __init efi_memblock_x86_reserve_range(void)
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 1764252..f8960fc 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -861,7 +861,7 @@ char * __init xen_memory_setup(void)
 	e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
 			E820_RESERVED);
 
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+	sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
 
 	/*
 	 * Check whether the kernel itself conflicts with the target E820 map.
-- 
2.9.2

[tip:x86/boot] x86/e820: Prepare e280 code for switch to dynamic storage

[tip-bot for Denys Vlasenko]

Commit-ID:  475339684ef19e46f4702e2d185a869a5c454688
Gitweb:     http://git.kernel.org/tip/475339684ef19e46f4702e2d185a869a5c454688
Author:     Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Sat, 17 Sep 2016 23:39:26 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 21 Sep 2016 15:02:12 +0200

x86/e820: Prepare e280 code for switch to dynamic storage

This patch turns e820 and e820_saved into pointers to e820 tables,
of the same size as before.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20160917213927.1787-2-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/include/asm/e820.h       |   6 +-
 arch/x86/kernel/e820.c            | 125 +++++++++++++++++++++++---------------
 arch/x86/kernel/early-quirks.c    |   2 +-
 arch/x86/kernel/kexec-bzimage64.c |   4 +-
 arch/x86/kernel/resource.c        |   4 +-
 arch/x86/kernel/setup.c           |   8 +--
 arch/x86/kernel/tboot.c           |   8 +--
 arch/x86/mm/init.c                |   2 +
 arch/x86/platform/efi/efi.c       |   2 +-
 arch/x86/xen/setup.c              |   2 +-
 10 files changed, 98 insertions(+), 65 deletions(-)

diff --git a/arch/x86/include/asm/e820.h b/arch/x86/include/asm/e820.h
index 3ab0537..476b574 100644
--- a/arch/x86/include/asm/e820.h
+++ b/arch/x86/include/asm/e820.h
@@ -10,8 +10,8 @@
 #include <uapi/asm/e820.h>
 #ifndef __ASSEMBLY__
 /* see comment in arch/x86/kernel/e820.c */
-extern struct e820map e820;
-extern struct e820map e820_saved;
+extern struct e820map *e820;
+extern struct e820map *e820_saved;
 
 extern unsigned long pci_mem_start;
 extern int e820_any_mapped(u64 start, u64 end, unsigned type);
@@ -53,6 +53,8 @@ extern void e820_reserve_resources_late(void);
 extern void setup_memory_map(void);
 extern char *default_machine_specific_memory_setup(void);
 
+extern void e820_reallocate_tables(void);
+
 /*
  * Returns true iff the specified range [s,e) is completely contained inside
  * the ISA region.
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 4d3dd9a..585000c9 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -40,8 +40,10 @@
  * 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 initial_e820;
+static struct e820map initial_e820_saved;
+struct e820map *e820 = &initial_e820;
+struct e820map *e820_saved = &initial_e820_saved;
 
 /* For PCI or other memory-mapped resources */
 unsigned long pci_mem_start = 0xaeedbabe;
@@ -58,8 +60,8 @@ e820_any_mapped(u64 start, u64 end, unsigned type)
 {
 	int i;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 
 		if (type && ei->type != type)
 			continue;
@@ -81,8 +83,8 @@ int __init e820_all_mapped(u64 start, u64 end, unsigned type)
 {
 	int i;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 
 		if (type && ei->type != type)
 			continue;
@@ -128,7 +130,7 @@ static void __init __e820_add_region(struct e820map *e820x, u64 start, u64 size,
 
 void __init e820_add_region(u64 start, u64 size, int type)
 {
-	__e820_add_region(&e820, start, size, type);
+	__e820_add_region(e820, start, size, type);
 }
 
 static void __init e820_print_type(u32 type)
@@ -164,12 +166,12 @@ void __init e820_print_map(char *who)
 {
 	int i;
 
-	for (i = 0; i < e820.nr_map; i++) {
+	for (i = 0; i < e820->nr_map; i++) {
 		printk(KERN_INFO "%s: [mem %#018Lx-%#018Lx] ", who,
-		       (unsigned long long) e820.map[i].addr,
+		       (unsigned long long) e820->map[i].addr,
 		       (unsigned long long)
-		       (e820.map[i].addr + e820.map[i].size - 1));
-		e820_print_type(e820.map[i].type);
+		       (e820->map[i].addr + e820->map[i].size - 1));
+		e820_print_type(e820->map[i].type);
 		printk(KERN_CONT "\n");
 	}
 }
@@ -493,13 +495,13 @@ static u64 __init __e820_update_range(struct e820map *e820x, u64 start,
 u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
 			     unsigned new_type)
 {
-	return __e820_update_range(&e820, start, size, old_type, new_type);
+	return __e820_update_range(e820, start, size, old_type, new_type);
 }
 
 static u64 __init e820_update_range_saved(u64 start, u64 size,
 					  unsigned old_type, unsigned new_type)
 {
-	return __e820_update_range(&e820_saved, start, size, old_type,
+	return __e820_update_range(e820_saved, start, size, old_type,
 				     new_type);
 }
 
@@ -521,8 +523,8 @@ u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
 		e820_print_type(old_type);
 	printk(KERN_CONT "\n");
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 		u64 final_start, final_end;
 		u64 ei_end;
 
@@ -566,15 +568,15 @@ u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
 
 void __init update_e820(void)
 {
-	if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map))
+	if (sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map))
 		return;
 	printk(KERN_INFO "e820: modified physical RAM map:\n");
 	e820_print_map("modified");
 }
 static void __init update_e820_saved(void)
 {
-	sanitize_e820_map(e820_saved.map, ARRAY_SIZE(e820_saved.map),
-				&e820_saved.nr_map);
+	sanitize_e820_map(e820_saved->map, ARRAY_SIZE(e820_saved->map),
+				&e820_saved->nr_map);
 }
 #define MAX_GAP_END 0x100000000ull
 /*
@@ -584,14 +586,14 @@ __init int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize,
 		unsigned long start_addr, unsigned long long end_addr)
 {
 	unsigned long long last;
-	int i = e820.nr_map;
+	int i = e820->nr_map;
 	int found = 0;
 
 	last = (end_addr && end_addr < MAX_GAP_END) ? end_addr : MAX_GAP_END;
 
 	while (--i >= 0) {
-		unsigned long long start = e820.map[i].addr;
-		unsigned long long end = start + e820.map[i].size;
+		unsigned long long start = e820->map[i].addr;
+		unsigned long long end = start + e820->map[i].size;
 
 		if (end < start_addr)
 			continue;
@@ -649,6 +651,33 @@ __init void e820_setup_gap(void)
 	       gapstart, gapstart + gapsize - 1);
 }
 
+/*
+ * Called late during init, in free_initmem().
+ *
+ * Initial e820 and e820_saved are largish __initdata arrays.
+ * Copy them to (usually much smaller) dynamically allocated area.
+ * This is done after all tweaks we ever do to them:
+ * all functions which modify them are __init functions,
+ * they won't exist after this point.
+ */
+__init void e820_reallocate_tables(void)
+{
+	struct e820map *n;
+	int size;
+
+	size = offsetof(struct e820map, map) + sizeof(struct e820entry) * e820->nr_map;
+	n = kmalloc(size, GFP_KERNEL);
+	BUG_ON(!n);
+	memcpy(n, e820, size);
+	e820 = n;
+
+	size = offsetof(struct e820map, map) + sizeof(struct e820entry) * e820_saved->nr_map;
+	n = kmalloc(size, GFP_KERNEL);
+	BUG_ON(!n);
+	memcpy(n, e820_saved, size);
+	e820_saved = n;
+}
+
 /**
  * Because of the size limitation of struct boot_params, only first
  * 128 E820 memory entries are passed to kernel via
@@ -665,7 +694,7 @@ void __init parse_e820_ext(u64 phys_addr, u32 data_len)
 	entries = sdata->len / sizeof(struct e820entry);
 	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(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
 	early_memunmap(sdata, data_len);
 	printk(KERN_INFO "e820: extended physical RAM map:\n");
 	e820_print_map("extended");
@@ -686,8 +715,8 @@ void __init e820_mark_nosave_regions(unsigned long limit_pfn)
 	int i;
 	unsigned long pfn = 0;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 
 		if (pfn < PFN_UP(ei->addr))
 			register_nosave_region(pfn, PFN_UP(ei->addr));
@@ -712,8 +741,8 @@ static int __init e820_mark_nvs_memory(void)
 {
 	int i;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 
 		if (ei->type == E820_NVS)
 			acpi_nvs_register(ei->addr, ei->size);
@@ -760,8 +789,8 @@ static unsigned long __init e820_end_pfn(unsigned long limit_pfn)
 	unsigned long last_pfn = 0;
 	unsigned long max_arch_pfn = MAX_ARCH_PFN;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 		unsigned long start_pfn;
 		unsigned long end_pfn;
 
@@ -856,7 +885,7 @@ static int __init parse_memmap_one(char *p)
 		 */
 		saved_max_pfn = e820_end_of_ram_pfn();
 #endif
-		e820.nr_map = 0;
+		e820->nr_map = 0;
 		userdef = 1;
 		return 0;
 	}
@@ -903,8 +932,8 @@ early_param("memmap", parse_memmap_opt);
 void __init finish_e820_parsing(void)
 {
 	if (userdef) {
-		if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map),
-					&e820.nr_map) < 0)
+		if (sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map),
+					&e820->nr_map) < 0)
 			early_panic("Invalid user supplied memory map");
 
 		printk(KERN_INFO "e820: user-defined physical RAM map:\n");
@@ -991,35 +1020,35 @@ void __init e820_reserve_resources(void)
 	struct resource *res;
 	u64 end;
 
-	res = alloc_bootmem(sizeof(struct resource) * e820.nr_map);
+	res = alloc_bootmem(sizeof(struct resource) * e820->nr_map);
 	e820_res = res;
-	for (i = 0; i < e820.nr_map; i++) {
-		end = e820.map[i].addr + e820.map[i].size - 1;
+	for (i = 0; i < e820->nr_map; i++) {
+		end = e820->map[i].addr + e820->map[i].size - 1;
 		if (end != (resource_size_t)end) {
 			res++;
 			continue;
 		}
-		res->name = e820_type_to_string(e820.map[i].type);
-		res->start = e820.map[i].addr;
+		res->name = e820_type_to_string(e820->map[i].type);
+		res->start = e820->map[i].addr;
 		res->end = end;
 
-		res->flags = e820_type_to_iomem_type(e820.map[i].type);
-		res->desc = e820_type_to_iores_desc(e820.map[i].type);
+		res->flags = e820_type_to_iomem_type(e820->map[i].type);
+		res->desc = e820_type_to_iores_desc(e820->map[i].type);
 
 		/*
 		 * don't register the region that could be conflicted with
 		 * pci device BAR resource and insert them later in
 		 * pcibios_resource_survey()
 		 */
-		if (do_mark_busy(e820.map[i].type, res)) {
+		if (do_mark_busy(e820->map[i].type, res)) {
 			res->flags |= IORESOURCE_BUSY;
 			insert_resource(&iomem_resource, res);
 		}
 		res++;
 	}
 
-	for (i = 0; i < e820_saved.nr_map; i++) {
-		struct e820entry *entry = &e820_saved.map[i];
+	for (i = 0; i < e820_saved->nr_map; i++) {
+		struct e820entry *entry = &e820_saved->map[i];
 		firmware_map_add_early(entry->addr,
 			entry->addr + entry->size,
 			e820_type_to_string(entry->type));
@@ -1051,7 +1080,7 @@ void __init e820_reserve_resources_late(void)
 	struct resource *res;
 
 	res = e820_res;
-	for (i = 0; i < e820.nr_map; i++) {
+	for (i = 0; i < e820->nr_map; i++) {
 		if (!res->parent && res->end)
 			insert_resource_expand_to_fit(&iomem_resource, res);
 		res++;
@@ -1061,8 +1090,8 @@ void __init e820_reserve_resources_late(void)
 	 * Try to bump up RAM regions to reasonable boundaries to
 	 * avoid stolen RAM:
 	 */
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *entry = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *entry = &e820->map[i];
 		u64 start, end;
 
 		if (entry->type != E820_RAM)
@@ -1110,7 +1139,7 @@ char *__init default_machine_specific_memory_setup(void)
 			who = "BIOS-e801";
 		}
 
-		e820.nr_map = 0;
+		e820->nr_map = 0;
 		e820_add_region(0, LOWMEMSIZE(), E820_RAM);
 		e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM);
 	}
@@ -1124,7 +1153,7 @@ void __init setup_memory_map(void)
 	char *who;
 
 	who = x86_init.resources.memory_setup();
-	memcpy(&e820_saved, &e820, sizeof(struct e820map));
+	memcpy(e820_saved, e820, sizeof(struct e820map));
 	printk(KERN_INFO "e820: BIOS-provided physical RAM map:\n");
 	e820_print_map(who);
 }
@@ -1141,8 +1170,8 @@ void __init memblock_x86_fill(void)
 	 */
 	memblock_allow_resize();
 
-	for (i = 0; i < e820.nr_map; i++) {
-		struct e820entry *ei = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		struct e820entry *ei = &e820->map[i];
 
 		end = ei->addr + ei->size;
 		if (end != (resource_size_t)end)
diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
index de7501e..18bb3a6 100644
--- a/arch/x86/kernel/early-quirks.c
+++ b/arch/x86/kernel/early-quirks.c
@@ -555,7 +555,7 @@ intel_graphics_stolen(int num, int slot, int func,
 
 	/* Mark this space as reserved */
 	e820_add_region(base, size, E820_RESERVED);
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+	sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
 }
 
 static void __init intel_graphics_quirks(int num, int slot, int func)
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index f2356bd..3407b14 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -99,14 +99,14 @@ static int setup_e820_entries(struct boot_params *params)
 {
 	unsigned int nr_e820_entries;
 
-	nr_e820_entries = e820_saved.nr_map;
+	nr_e820_entries = e820_saved->nr_map;
 
 	/* TODO: Pass entries more than E820MAX in bootparams setup data */
 	if (nr_e820_entries > E820MAX)
 		nr_e820_entries = E820MAX;
 
 	params->e820_entries = nr_e820_entries;
-	memcpy(&params->e820_map, &e820_saved.map,
+	memcpy(&params->e820_map, &e820_saved->map,
 	       nr_e820_entries * sizeof(struct e820entry));
 
 	return 0;
diff --git a/arch/x86/kernel/resource.c b/arch/x86/kernel/resource.c
index 80eab01..2408c16 100644
--- a/arch/x86/kernel/resource.c
+++ b/arch/x86/kernel/resource.c
@@ -27,8 +27,8 @@ static void remove_e820_regions(struct resource *avail)
 	int i;
 	struct e820entry *entry;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		entry = &e820.map[i];
+	for (i = 0; i < e820->nr_map; i++) {
+		entry = &e820->map[i];
 
 		resource_clip(avail, entry->addr,
 			      entry->addr + entry->size - 1);
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 0fa60f5..cc43d66 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -458,8 +458,8 @@ static void __init e820_reserve_setup_data(void)
 		early_memunmap(data, sizeof(*data));
 	}
 
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
-	memcpy(&e820_saved, &e820, sizeof(struct e820map));
+	sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
+	memcpy(e820_saved, e820, sizeof(struct e820map));
 	printk(KERN_INFO "extended physical RAM map:\n");
 	e820_print_map("reserve setup_data");
 }
@@ -763,7 +763,7 @@ static void __init trim_bios_range(void)
 	 */
 	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(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
 }
 
 /* called before trim_bios_range() to spare extra sanitize */
@@ -1032,7 +1032,7 @@ 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(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
 		printk(KERN_INFO "fixed physical RAM map:\n");
 		e820_print_map("bad_ppro");
 	}
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index 654f6c6..8402907 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -188,12 +188,12 @@ static int tboot_setup_sleep(void)
 
 	tboot->num_mac_regions = 0;
 
-	for (i = 0; i < e820.nr_map; i++) {
-		if ((e820.map[i].type != E820_RAM)
-		 && (e820.map[i].type != E820_RESERVED_KERN))
+	for (i = 0; i < e820->nr_map; i++) {
+		if ((e820->map[i].type != E820_RAM)
+		 && (e820->map[i].type != E820_RESERVED_KERN))
 			continue;
 
-		add_mac_region(e820.map[i].addr, e820.map[i].size);
+		add_mac_region(e820->map[i].addr, e820->map[i].size);
 	}
 
 	tboot->acpi_sinfo.kernel_s3_resume_vector =
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index d28a2d7..167deae 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -701,6 +701,8 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
 
 void free_initmem(void)
 {
+	/* e820_reallocate_tables(); - disabled for now */
+
 	free_init_pages("unused kernel",
 			(unsigned long)(&__init_begin),
 			(unsigned long)(&__init_end));
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 1fbb408..2e34334 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -166,7 +166,7 @@ static void __init do_add_efi_memmap(void)
 		}
 		e820_add_region(start, size, e820_type);
 	}
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+	sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
 }
 
 int __init efi_memblock_x86_reserve_range(void)
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 1764252..f8960fc 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -861,7 +861,7 @@ char * __init xen_memory_setup(void)
 	e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
 			E820_RESERVED);
 
-	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+	sanitize_e820_map(e820->map, ARRAY_SIZE(e820->map), &e820->nr_map);
 
 	/*
 	 * Check whether the kernel itself conflicts with the target E820 map.

[PATCH 3/3] x86/e820: Use much less memory for e820/e820_saved, save up to 120k

[Denys Vlasenko]

The maximum size of e820 map array for EFI systems is defined as
E820_X_MAX (E820MAX + 3 * MAX_NUMNODES).

In x86_64 defconfig, this ends up with E820_X_MAX = 320, e820 and e820_saved
are 6404 bytes each.

With larger configs, for example Fedora kernels, E820_X_MAX = 3200, e820
and e820_saved are 64004 bytes each. Most of this space is wasted.
Typical machines have some 20-30 e820 areas at most.

After previous patch, e820 and e820_saved are pointers to e280 maps.

Change them to initially point to maps which are __initdata.

At the very end of kernel init, just before __init[data] sections are freed
in free_initmem(), allocate smaller blocks, copy maps there,
and change pointers.

The late switch makes sure that all functions which can be used to change
e820 maps are no longer accessible (they are all __init functions).

Run-tested.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Ingo Molnar <mingo@kernel.org>
CC: Andy Lutomirski <luto@amacapital.net>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Borislav Petkov <bp@alien8.de>
CC: Brian Gerst <brgerst@gmail.com>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---
 arch/x86/kernel/e820.c | 8 ++++----
 arch/x86/mm/init.c     | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index cf7c9ad..7e9249c 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -40,10 +40,10 @@
  * user can e.g. boot the original kernel with mem=1G while still booting the
  * next kernel with full memory.
  */
-static struct e820map initial_e820;
-static struct e820map initial_e820_saved;
-struct e820map *e820 = &initial_e820;
-struct e820map *e820_saved = &initial_e820_saved;
+static struct e820map initial_e820  __initdata;
+static struct e820map initial_e820_saved  __initdata;
+struct e820map *e820 __refdata = &initial_e820;
+struct e820map *e820_saved __refdata = &initial_e820_saved;
 
 /* For PCI or other memory-mapped resources */
 unsigned long pci_mem_start = 0xaeedbabe;
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 167deae..7be8dbf 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -701,7 +701,7 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
 
 void free_initmem(void)
 {
-	/* e820_reallocate_tables(); - disabled for now */
+	e820_reallocate_tables();
 
 	free_init_pages("unused kernel",
 			(unsigned long)(&__init_begin),
-- 
2.9.2

Re: [PATCH 3/3] x86/e820: Use much less memory for e820/e820_saved, save up to 120k

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 1357 bytes --]

Hi Denys,

[auto build test WARNING on tip/auto-latest]
[also build test WARNING on v4.8-rc6 next-20160916]
[cannot apply to tip/x86/core]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
[Suggest to use git(>=2.9.0) format-patch --base=<commit> (or --base=auto for convenience) to record what (public, well-known) commit your patch series was built on]
[Check https://git-scm.com/docs/git-format-patch for more information]

url:    https://github.com/0day-ci/linux/commits/Denys-Vlasenko/x86-e820-Mark-some-static-functions-__init/20160918-054310
config: i386-randconfig-i1-09171826 (attached as .config)
compiler: gcc-4.8 (Debian 4.8.4-1) 4.8.4
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All warnings (new ones prefixed by >>):

>> WARNING: vmlinux.o(.text+0x37714): Section mismatch in reference from the function free_initmem() to the function .init.text:e820_reallocate_tables()
   The function free_initmem() references
   the function __init e820_reallocate_tables().
   This is often because free_initmem lacks a __init
   annotation or the annotation of e820_reallocate_tables is wrong.

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 23203 bytes --]

[tip:x86/boot] x86/e820: Mark some static functions __init

[tip-bot for Denys Vlasenko]

Commit-ID:  8c2103f224216a45c1a4d7aebbc13f3e007cde34
Gitweb:     http://git.kernel.org/tip/8c2103f224216a45c1a4d7aebbc13f3e007cde34
Author:     Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Sat, 17 Sep 2016 23:39:25 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 21 Sep 2016 15:02:11 +0200

x86/e820: Mark some static functions __init

They are all called only from other __init functions in e820.c

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20160917213927.1787-1-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/e820.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 871f186..4d3dd9a 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -802,7 +802,7 @@ unsigned long __init e820_end_of_low_ram_pfn(void)
 	return e820_end_pfn(1UL << (32-PAGE_SHIFT));
 }
 
-static void early_panic(char *msg)
+static void __init early_panic(char *msg)
 {
 	early_printk(msg);
 	panic(msg);
@@ -912,7 +912,7 @@ void __init finish_e820_parsing(void)
 	}
 }
 
-static const char *e820_type_to_string(int e820_type)
+static const char *__init e820_type_to_string(int e820_type)
 {
 	switch (e820_type) {
 	case E820_RESERVED_KERN:
@@ -926,7 +926,7 @@ static const char *e820_type_to_string(int e820_type)
 	}
 }
 
-static unsigned long e820_type_to_iomem_type(int e820_type)
+static unsigned long __init e820_type_to_iomem_type(int e820_type)
 {
 	switch (e820_type) {
 	case E820_RESERVED_KERN:
@@ -942,7 +942,7 @@ static unsigned long e820_type_to_iomem_type(int e820_type)
 	}
 }
 
-static unsigned long e820_type_to_iores_desc(int e820_type)
+static unsigned long __init e820_type_to_iores_desc(int e820_type)
 {
 	switch (e820_type) {
 	case E820_ACPI:
@@ -961,7 +961,7 @@ static unsigned long e820_type_to_iores_desc(int e820_type)
 	}
 }
 
-static bool do_mark_busy(u32 type, struct resource *res)
+static bool __init do_mark_busy(u32 type, struct resource *res)
 {
 	/* this is the legacy bios/dos rom-shadow + mmio region */
 	if (res->start < (1ULL<<20))
@@ -1027,7 +1027,7 @@ void __init e820_reserve_resources(void)
 }
 
 /* How much should we pad RAM ending depending on where it is? */
-static unsigned long ram_alignment(resource_size_t pos)
+static unsigned long __init ram_alignment(resource_size_t pos)
 {
 	unsigned long mb = pos >> 20;