Changeset 128359eb in mainline for kernel/generic/src

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/generic/src

Files:

• cpu/cpu.c (modified) (1 diff)
• main/main.c (modified) (1 diff)
• proc/thread.c (modified) (1 diff)

kernel/generic/src/cpu/cpu.c

@@ -71 +71 @@
                 memsetb(cpus, sizeof(cpu_t) * config.cpu_count, 0);
 
-                // NOTE: All kernel stacks must be aligned to STACK_SIZE,
-                //       see get_stack_base().
-                size_t i;
-                for (i = 0; i < config.cpu_count; i++) {
+                /*
+                 * NOTE: All kernel stacks must be aligned to STACK_SIZE,
+                 *       see CURRENT.
+                 */
+                for (size_t i = 0; i < config.cpu_count; i++) {
                         uintptr_t stack_phys = frame_alloc(STACK_FRAMES,
                             FRAME_LOWMEM | FRAME_ATOMIC, STACK_SIZE - 1);

kernel/generic/src/main/main.c

@@ -170 +170 @@
             ALIGN_UP((uintptr_t) kdata_end - config.base, PAGE_SIZE);
 
-        // NOTE: All kernel stacks must be aligned to STACK_SIZE,
-        //       see get_stack_base().
+        /*
+         * NOTE: All kernel stacks must be aligned to STACK_SIZE,
+         *       see CURRENT.
+         */
 
         /* Place the stack after the kernel, init and ballocs. */

kernel/generic/src/proc/thread.c

@@ -191 +191 @@
         kmflags &= ~FRAME_HIGHMEM;
 
-        // NOTE: All kernel stacks must be aligned to STACK_SIZE,
-        //       see get_stack_base().
+        /*
+         * NOTE: All kernel stacks must be aligned to STACK_SIZE,
+         *       see CURRENT.
+         */
 
         uintptr_t stack_phys =