Changeset 128359eb in mainline for kernel/arch/ia32

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/ia32/include/arch

Files:

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

kernel/arch/ia32/include/arch/asm.h

@@ -348 +348 @@
 
 #endif /* PROCESSOR_i486 */
-
-/** 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 (
-            "andl %%esp, %[v]\n"
-            : [v] "=r" (v)
-            : "0" (~(STACK_SIZE - 1))
-        );
-
-        return v;
-}
 
 /** Invalidate TLB Entry.

kernel/arch/ia32/include/arch/context.h

@@ -45 +45 @@
  * First for pop of the saved register, second during ret instruction.
  *
- * One item is put onto stack to support get_stack_base().
+ * One item is put onto stack to support CURRENT.
  */
 #define SP_DELTA  (8 + STACK_ITEM_SIZE)