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-rw-r--r--arch/x86/include/asm/setup.h30
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
index 366d3663994..61b126b9788 100644
--- a/arch/x86/include/asm/setup.h
+++ b/arch/x86/include/asm/setup.h
@@ -104,6 +104,29 @@ extern struct boot_params boot_params;
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_reservation_" #name "__:" \
+ " 1:.skip %c0;" \
+ " .size __brk_reservation_" #name "__, . - 1b;" \
+ " .popsection" \
+ : : "i" (sz)); \
+ }
+
#ifdef __i386__
void __init i386_start_kernel(void);
@@ -115,6 +138,13 @@ 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_reservation_##name##__: \
+1: .skip sz; \
+ .size __brk_reservation_##name##__,.-1b; \
+ .popsection
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */