1 files changed, 35 insertions, 4 deletions

diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
index 05c6f6b11fd5..bdc2ada05ae0 100644
--- a/arch/x86/include/asm/setup.h
+++ b/arch/x86/include/asm/setup.h
@@ -64,7 +64,7 @@ extern void x86_quirk_time_init(void);
 #include <asm/bootparam.h>
 
 /* Interrupt control for vSMPowered x86_64 systems */
-#ifdef CONFIG_X86_VSMP
+#ifdef CONFIG_X86_64
 void vsmp_init(void);
 #else
 static inline void vsmp_init(void) { }
@@ -100,20 +100,51 @@ extern struct boot_params boot_params;
  */
 #define LOWMEMSIZE()    (0x9f000)
 
+/* exceedingly early brk-like allocator */
+extern unsigned long _brk_end;
+void *extend_brk(size_t size, size_t align);
+
+/*
+ * Reserve space in the brk section.  The name must be unique within
+ * the file, and somewhat descriptive.  The size is in bytes.  Must be
+ * used at file scope.
+ *
+ * (This uses a temp function to wrap the asm so we can pass it the
+ * size parameter; otherwise we wouldn't be able to.  We can't use a
+ * "section" attribute on a normal variable because it always ends up
+ * being @progbits, which ends up allocating space in the vmlinux
+ * executable.)
+ */
+#define RESERVE_BRK(name,sz)                                            \
+        static void __section(.discard) __used                          \
+        __brk_reservation_fn_##name##__(void) {                         \
+                asm volatile (                                          \
+                        ".pushsection .brk_reservation,\"aw\",@nobits;" \
+                        ".brk." #name ":"                               \
+                        " 1:.skip %c0;"                                 \
+                        " .size .brk." #name ", . - 1b;"                \
+                        " .popsection"                                  \
+                        : : "i" (sz));                                  \
+        }
+
 #ifdef __i386__
 
 void __init i386_start_kernel(void);
 extern void probe_roms(void);
 
-extern unsigned long init_pg_tables_start;
-extern unsigned long init_pg_tables_end;
-
 #else
 void __init x86_64_start_kernel(char *real_mode);
 void __init x86_64_start_reservations(char *real_mode_data);
 
 #endif /* __i386__ */
 #endif /* _SETUP */
+#else
+#define RESERVE_BRK(name,sz)                            \
+        .pushsection .brk_reservation,"aw",@nobits;     \
+.brk.name:                                              \
+1:      .skip sz;                                       \
+        .size .brk.name,.-1b;                           \
+        .popsection
 #endif /* __ASSEMBLY__ */
 #endif  /*  __KERNEL__  */