[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>

1 files changed, 21 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/e820.c b/arch/x86_64/kernel/e820.c
index 17579a1a174b..293cd71a266a 100644
--- a/arch/x86_64/kernel/e820.c
+++ b/arch/x86_64/kernel/e820.c
@@ -559,6 +559,27 @@ void __init parse_memopt(char *p, char **from)
         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;
 
 /*