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-rw-r--r--arch/x86/kernel/e820.c49
1 files changed, 36 insertions, 13 deletions
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index d78a586ba8dc..532da61d605c 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -20,10 +20,12 @@
#include <asm/setup.h>
/*
- * We organize the E820 table into two main data structures:
+ * We organize the E820 table into three main data structures:
*
* - 'e820_table_firmware': the original firmware version passed to us by the
- * bootloader - not modified by the kernel. We use this to:
+ * bootloader - not modified by the kernel. It is composed of two parts:
+ * the first 128 E820 memory entries in boot_params.e820_table and the remaining
+ * (if any) entries of the SETUP_E820_EXT nodes. We use this to:
*
* - inform the user about the firmware's notion of memory layout
* via /sys/firmware/memmap
@@ -31,6 +33,14 @@
* - the hibernation code uses it to generate a kernel-independent MD5
* fingerprint of the physical memory layout of a system.
*
+ * - 'e820_table_kexec': a slightly modified (by the kernel) firmware version
+ * passed to us by the bootloader - the major difference between
+ * e820_table_firmware[] and this one is that, the latter marks the setup_data
+ * list created by the EFI boot stub as reserved, so that kexec can reuse the
+ * setup_data information in the second kernel. Besides, e820_table_kexec[]
+ * might also be modified by the kexec itself to fake a mptable.
+ * We use this to:
+ *
* - kexec, which is a bootloader in disguise, uses the original E820
* layout to pass to the kexec-ed kernel. This way the original kernel
* can have a restricted E820 map while the kexec()-ed kexec-kernel
@@ -46,9 +56,11 @@
* specific memory layout data during early bootup.
*/
static struct e820_table e820_table_init __initdata;
+static struct e820_table e820_table_kexec_init __initdata;
static struct e820_table e820_table_firmware_init __initdata;
struct e820_table *e820_table __refdata = &e820_table_init;
+struct e820_table *e820_table_kexec __refdata = &e820_table_kexec_init;
struct e820_table *e820_table_firmware __refdata = &e820_table_firmware_init;
/* For PCI or other memory-mapped resources */
@@ -470,9 +482,9 @@ u64 __init e820__range_update(u64 start, u64 size, enum e820_type old_type, enum
return __e820__range_update(e820_table, start, size, old_type, new_type);
}
-static u64 __init e820__range_update_firmware(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
+static u64 __init e820__range_update_kexec(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
{
- return __e820__range_update(e820_table_firmware, start, size, old_type, new_type);
+ return __e820__range_update(e820_table_kexec, start, size, old_type, new_type);
}
/* Remove a range of memory from the E820 table: */
@@ -546,9 +558,9 @@ void __init e820__update_table_print(void)
e820__print_table("modified");
}
-static void __init e820__update_table_firmware(void)
+static void __init e820__update_table_kexec(void)
{
- e820__update_table(e820_table_firmware);
+ e820__update_table(e820_table_kexec);
}
#define MAX_GAP_END 0x100000000ull
@@ -623,7 +635,7 @@ __init void e820__setup_pci_gap(void)
/*
* Called late during init, in free_initmem().
*
- * Initial e820_table and e820_table_firmware are largish __initdata arrays.
+ * Initial e820_table and e820_table_kexec are largish __initdata arrays.
*
* Copy them to a (usually much smaller) dynamically allocated area that is
* sized precisely after the number of e820 entries.
@@ -643,6 +655,12 @@ __init void e820__reallocate_tables(void)
memcpy(n, e820_table, size);
e820_table = n;
+ size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_kexec->nr_entries;
+ n = kmalloc(size, GFP_KERNEL);
+ BUG_ON(!n);
+ memcpy(n, e820_table_kexec, size);
+ e820_table_kexec = n;
+
size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_firmware->nr_entries;
n = kmalloc(size, GFP_KERNEL);
BUG_ON(!n);
@@ -669,6 +687,9 @@ void __init e820__memory_setup_extended(u64 phys_addr, u32 data_len)
__append_e820_table(extmap, entries);
e820__update_table(e820_table);
+ memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec));
+ memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
+
early_memunmap(sdata, data_len);
pr_info("e820: extended physical RAM map:\n");
e820__print_table("extended");
@@ -727,7 +748,7 @@ core_initcall(e820__register_nvs_regions);
/*
* Allocate the requested number of bytes with the requsted alignment
* and return (the physical address) to the caller. Also register this
- * range in the 'firmware' E820 table as a reserved range.
+ * range in the 'kexec' E820 table as a reserved range.
*
* This allows kexec to fake a new mptable, as if it came from the real
* system.
@@ -738,9 +759,9 @@ u64 __init e820__memblock_alloc_reserved(u64 size, u64 align)
addr = __memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
if (addr) {
- e820__range_update_firmware(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED);
- pr_info("e820: update e820_table_firmware for e820__memblock_alloc_reserved()\n");
- e820__update_table_firmware();
+ e820__range_update_kexec(addr, size, E820_TYPE_RAM, E820_TYPE_RESERVED);
+ pr_info("e820: update e820_table_kexec for e820__memblock_alloc_reserved()\n");
+ e820__update_table_kexec();
}
return addr;
@@ -923,13 +944,13 @@ void __init e820__reserve_setup_data(void)
while (pa_data) {
data = early_memremap(pa_data, sizeof(*data));
e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
+ e820__range_update_kexec(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
pa_data = data->next;
early_memunmap(data, sizeof(*data));
}
e820__update_table(e820_table);
-
- memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
+ e820__update_table(e820_table_kexec);
pr_info("extended physical RAM map:\n");
e820__print_table("reserve setup_data");
@@ -1062,6 +1083,7 @@ void __init e820__reserve_resources(void)
res++;
}
+ /* Expose the bootloader-provided memory layout to the sysfs. */
for (i = 0; i < e820_table_firmware->nr_entries; i++) {
struct e820_entry *entry = e820_table_firmware->entries + i;
@@ -1175,6 +1197,7 @@ void __init e820__memory_setup(void)
who = x86_init.resources.memory_setup();
+ memcpy(e820_table_kexec, e820_table, sizeof(*e820_table_kexec));
memcpy(e820_table_firmware, e820_table, sizeof(*e820_table_firmware));
pr_info("e820: BIOS-provided physical RAM map:\n");