[PATCH] kdump: x86_64: add memmmap command line option
)
From: Vivek Goyal <vgoyal@in.ibm.com>
- This patch introduces the memmap option for x86_64 similar to i386.
- memmap=exactmap enables setting of an exact E820 memory map, as specified
by the user.
Changes in this version:
- Used e820_end_of_ram() to find the max_pfn as suggested by Andi kleen.
- removed PFN_UP & PFN_DOWN macros
- Printing the user defined map also.
Signed-off-by: Murali M Chakravarthy <muralim@in.ibm.com>
Signed-off-by: Hariprasad Nellitheertha <nharipra@gmail.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 0dc848b..12b7d93 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -832,7 +832,7 @@
mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel
memory.
- memmap=exactmap [KNL,IA-32] Enable setting of an exact
+ memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact
E820 memory map, as specified by the user.
Such memmap=exactmap lines can be constructed based on
BIOS output or other requirements. See the memmap=nn@ss
diff --git a/arch/x86_64/kernel/e820.c b/arch/x86_64/kernel/e820.c
index 17579a1..293cd71 100644
--- a/arch/x86_64/kernel/e820.c
+++ b/arch/x86_64/kernel/e820.c
@@ -559,6 +559,27 @@
end_user_pfn >>= PAGE_SHIFT;
}
+void __init parse_memmapopt(char *p, char **from)
+{
+ unsigned long long start_at, mem_size;
+
+ mem_size = memparse(p, from);
+ p = *from;
+ if (*p == '@') {
+ start_at = memparse(p+1, from);
+ add_memory_region(start_at, mem_size, E820_RAM);
+ } else if (*p == '#') {
+ start_at = memparse(p+1, from);
+ add_memory_region(start_at, mem_size, E820_ACPI);
+ } else if (*p == '$') {
+ start_at = memparse(p+1, from);
+ add_memory_region(start_at, mem_size, E820_RESERVED);
+ } else {
+ end_user_pfn = (mem_size >> PAGE_SHIFT);
+ }
+ p = *from;
+}
+
unsigned long pci_mem_start = 0xaeedbabe;
/*
diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index 64c4534..ff9620b 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -275,6 +275,7 @@
{
char c = ' ', *to = command_line, *from = COMMAND_LINE;
int len = 0;
+ int userdef = 0;
/* Save unparsed command line copy for /proc/cmdline */
memcpy(saved_command_line, COMMAND_LINE, COMMAND_LINE_SIZE);
@@ -357,6 +358,28 @@
if (!memcmp(from, "mem=", 4))
parse_memopt(from+4, &from);
+ if (!memcmp(from, "memmap=", 7)) {
+ /* exactmap option is for used defined memory */
+ if (!memcmp(from+7, "exactmap", 8)) {
+#ifdef CONFIG_CRASH_DUMP
+ /* If we are doing a crash dump, we
+ * still need to know the real mem
+ * size before original memory map is
+ * reset.
+ */
+ saved_max_pfn = e820_end_of_ram();
+#endif
+ from += 8+7;
+ end_pfn_map = 0;
+ e820.nr_map = 0;
+ userdef = 1;
+ }
+ else {
+ parse_memmapopt(from+7, &from);
+ userdef = 1;
+ }
+ }
+
#ifdef CONFIG_NUMA
if (!memcmp(from, "numa=", 5))
numa_setup(from+5);
@@ -403,6 +426,10 @@
break;
*(to++) = c;
}
+ if (userdef) {
+ printk(KERN_INFO "user-defined physical RAM map:\n");
+ e820_print_map("user");
+ }
*to = '\0';
*cmdline_p = command_line;
}
diff --git a/include/asm-x86_64/e820.h b/include/asm-x86_64/e820.h
index e682edc..8dcc326 100644
--- a/include/asm-x86_64/e820.h
+++ b/include/asm-x86_64/e820.h
@@ -55,6 +55,7 @@
unsigned long end_pfn);
extern void __init parse_memopt(char *p, char **end);
+extern void __init parse_memmapopt(char *p, char **end);
extern struct e820map e820;
#endif/*!__ASSEMBLY__*/