Changeset 128359eb in mainline for kernel/arch/arm32

Timestamp:

2020-06-12T16:46:32Z (5 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.

Location:

kernel/arch/arm32/include/arch

Files:

• asm.h (modified) (1 diff)
• context.h (modified) (1 diff)

kernel/arch/arm32/include/arch/asm.h

@@ -95 +95 @@
 }
 
-/** 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 (
-            "and %[v], sp, %[size]\n"
-            : [v] "=r" (v)
-            : [size] "r" (~(STACK_SIZE - 1))
-        );
-
-        return v;
-}
-
 extern void cpu_halt(void) __attribute__((noreturn));
 extern void asm_delay_loop(uint32_t t);

kernel/arch/arm32/include/arch/context.h

@@ -42 +42 @@
 #include <arch/regutils.h>
 
-/* Put one item onto the stack to support get_stack_base() and align it up. */
+/* Put one item onto the stack to support CURRENT and align it up. */
 #define SP_DELTA  (0 + ALIGN_UP(STACK_ITEM_SIZE, STACK_ALIGNMENT))