Changeset 128359eb in mainline for kernel/arch/amd64/include/arch/asm.h

Timestamp:

2020-06-12T16:46:32Z (4 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

ffccdff0

Parents:

94e75cf

Message:

Replace get_stack_base() with builtin_frame_address(0)

The usage of an intrinsic function to obtain the current stack pointer
should provide the compuler more room for performance optimizations than
the hand-written (and volatile) inline assembly block.

File:

• kernel/arch/amd64/include/arch/asm.h (modified) (1 diff)

kernel/arch/amd64/include/arch/asm.h

@@ -42 +42 @@
 
 #define IO_SPACE_BOUNDARY       ((void *) (64 * 1024))
-
-/** Return base address of current stack.
- *
- * Return the base address of the current stack.
- * The stack is assumed to be STACK_SIZE bytes long.
- * The stack must start on page boundary.
- *
- */
-_NO_TRACE static inline uintptr_t get_stack_base(void)
-{
-        uintptr_t v;
-
-        asm volatile (
-            "andq %%rsp, %[v]\n"
-            : [v] "=r" (v)
-            : "0" (~((uint64_t) STACK_SIZE - 1))
-        );
-
-        return v;
-}
 
 _NO_TRACE static inline void cpu_sleep(void)