[PATCH] x86_64: x86_64 version of the smp alternative patch.

Changes are largely identical to the i386 version:

 * alternative #define are moved to the new alternative.h file.
 * one new elf section with pointers to the lock prefixes which can be
   nop'ed out for non-smp.
 * two new elf sections simliar to the "classic" alternatives to
   replace SMP code with simpler UP code.
 * fixup headers to use alternative.h instead of defining their own
   LOCK / LOCK_PREFIX macros.

The patch reuses the i386 version of the alternatives code to avoid code
duplication.  The code in alternatives.c was shuffled around a bit to
reduce the number of #ifdefs needed.  It also got some tweaks needed for
x86_64 (vsyscall page handling) and new features (noreplacement option
which was x86_64 only up to now).  Debug printk's are changed from
compile-time to runtime.

Loosely based on a early version from Bastian Blank <waldi@debian.org>

Signed-off-by: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 14 insertions, 13 deletions

diff --git a/arch/x86_64/mm/init.c b/arch/x86_64/mm/init.c
index 4ba34e95d835..a70a8e3e312d 100644
--- a/arch/x86_64/mm/init.c
+++ b/arch/x86_64/mm/init.c
@@ -644,20 +644,29 @@ void __init mem_init(void)
 #endif
 }
 
-void free_initmem(void)
+void free_init_pages(char *what, unsigned long begin, unsigned long end)
 {
         unsigned long addr;
 
-        addr = (unsigned long)(&__init_begin);
-        for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
+        if (begin >= end)
+                return;
+
+        printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
+        for (addr = begin; addr < end; addr += PAGE_SIZE) {
                 ClearPageReserved(virt_to_page(addr));
                 init_page_count(virt_to_page(addr));
                 memset((void *)(addr & ~(PAGE_SIZE-1)), 0xcc, PAGE_SIZE); 
                 free_page(addr);
                 totalram_pages++;
         }
+}
+
+void free_initmem(void)
+{
         memset(__initdata_begin, 0xba, __initdata_end - __initdata_begin);
-        printk ("Freeing unused kernel memory: %luk freed\n", (__init_end - __init_begin) >> 10);
+        free_init_pages("unused kernel memory",
+                        (unsigned long)(&__init_begin),
+                        (unsigned long)(&__init_end));
 }
 
 #ifdef CONFIG_DEBUG_RODATA
@@ -686,15 +695,7 @@ void mark_rodata_ro(void)
 #ifdef CONFIG_BLK_DEV_INITRD
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
-        if (start >= end)
-                return;
-        printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
-        for (; start < end; start += PAGE_SIZE) {
-                ClearPageReserved(virt_to_page(start));
-                init_page_count(virt_to_page(start));
-                free_page(start);
-                totalram_pages++;
-        }
+        free_init_pages("initrd memory", start, end);
 }
 #endif