From 5dfcf14d5b28174f94cbe9b4fb35d415db61c64a Mon Sep 17 00:00:00 2001 From: Bernhard Walle Date: Fri, 27 Jun 2008 13:12:55 +0200 Subject: [PATCH] x86: use FIRMWARE_MEMMAP on x86/E820 This patch uses the /sys/firmware/memmap interface provided in the last patch on the x86 architecture when E820 is used. The patch copies the E820 memory map very early, and registers the E820 map afterwards via firmware_map_add_early(). Signed-off-by: Bernhard Walle Acked-by: Greg KH Acked-by: Vivek Goyal Cc: kexec@lists.infradead.org Cc: yhlu.kernel@gmail.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/e820.c | 44 +++++++++++++++++++++++++++++++++++------- include/asm-x86/e820.h | 2 ++ 2 files changed, 39 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index d0335853ff52..fc1d579f212b 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include @@ -27,7 +28,22 @@ #include #include +/* + * The e820 map is the map that gets modified e.g. with command line parameters + * and that is also registered with modifications in the kernel resource tree + * with the iomem_resource as parent. + * + * The e820_saved is directly saved after the BIOS-provided memory map is + * copied. It doesn't get modified afterwards. It's registered for the + * /sys/firmware/memmap interface. + * + * That memory map is not modified and is used as base for kexec. The kexec'd + * kernel should get the same memory map as the firmware provides. Then the + * 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; /* For PCI or other memory-mapped resources */ unsigned long pci_mem_start = 0xaeedbabe; @@ -1198,6 +1214,17 @@ void __init finish_e820_parsing(void) } } +static inline const char *e820_type_to_string(int e820_type) +{ + switch (e820_type) { + case E820_RESERVED_KERN: + case E820_RAM: return "System RAM"; + case E820_ACPI: return "ACPI Tables"; + case E820_NVS: return "ACPI Non-volatile Storage"; + default: return "reserved"; + } +} + /* * Mark e820 reserved areas as busy for the resource manager. */ @@ -1209,13 +1236,6 @@ void __init e820_reserve_resources(void) res = alloc_bootmem_low(sizeof(struct resource) * e820.nr_map); for (i = 0; i < e820.nr_map; i++) { - switch (e820.map[i].type) { - case E820_RESERVED_KERN: - case E820_RAM: res->name = "System RAM"; break; - case E820_ACPI: res->name = "ACPI Tables"; break; - case E820_NVS: res->name = "ACPI Non-volatile Storage"; break; - default: res->name = "reserved"; - } end = e820.map[i].addr + e820.map[i].size - 1; #ifndef CONFIG_RESOURCES_64BIT if (end > 0x100000000ULL) { @@ -1223,6 +1243,7 @@ void __init e820_reserve_resources(void) continue; } #endif + res->name = e820_type_to_string(e820.map[i].type); res->start = e820.map[i].addr; res->end = end; @@ -1230,6 +1251,13 @@ void __init e820_reserve_resources(void) insert_resource(&iomem_resource, res); res++; } + + 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 - 1, + e820_type_to_string(entry->type)); + } } char *__init default_machine_specific_memory_setup(void) @@ -1266,6 +1294,8 @@ char *__init default_machine_specific_memory_setup(void) e820_add_region(HIGH_MEMORY, mem_size << 10, E820_RAM); } + memcpy(&e820_saved, &e820, sizeof(struct e820map)); + /* In case someone cares... */ return who; } diff --git a/include/asm-x86/e820.h b/include/asm-x86/e820.h index 4b26604b3c19..a20d0a7f5892 100644 --- a/include/asm-x86/e820.h +++ b/include/asm-x86/e820.h @@ -59,7 +59,9 @@ struct e820map { struct e820entry map[E820_X_MAX]; }; +/* see comment in arch/x86/kernel/e820.c */ extern struct e820map e820; +extern struct e820map e820_saved; extern int e820_any_mapped(u64 start, u64 end, unsigned type); extern int e820_all_mapped(u64 start, u64 end, unsigned type); -- 2.39.5