Changeset 128359eb in mainline for kernel/arch/ia64/include

Timestamp:

2020-06-12T16:46:32Z (6 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/ia64/include/arch

Files:

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

kernel/arch/ia64/include/arch/asm.h

@@ -160 +160 @@
 }
 
-/** Return base address of current memory stack.
- *
- * The memory stack is assumed to be STACK_SIZE / 2 long. Note that there is
- * also the RSE stack, which takes up the upper half of STACK_SIZE.
- * The memory stack must start on page boundary.
- */
-_NO_TRACE static inline uintptr_t get_stack_base(void)
-{
-        uint64_t value;
-
-        asm volatile (
-            "mov %[value] = r12"
-            : [value] "=r" (value)
-        );
-
-        return (value & (~(STACK_SIZE / 2 - 1)));
-}
-
 /** Return Processor State Register.
  *

kernel/arch/ia64/include/arch/context.h

@@ -46 +46 @@
  * No need to allocate scratch area.
  *
- * One item is put onto the stack to support get_stack_base().
+ * One item is put onto the stack to support CURRENT.
  */
 #define SP_DELTA  (0 + ALIGN_UP(STACK_ITEM_SIZE, STACK_ALIGNMENT))