locks: linker variables to calculate per-cpu bakery lock size

This patch introduces explicit linker variables to mark the start and
end of the per-cpu bakery lock section to help bakery_lock_normal.c
calculate the size of the section. This patch removes the previously
used '__PERCPU_BAKERY_LOCK_SIZE__' linker variable to make the code
uniform across GNU linker and ARM linker.

Change-Id: Ie0c51702cbc0fe8a2076005344a1fcebb48e7cca
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

bl31/bl31.ld.S

@@ -224,9 +224,11 @@ SECTIONS
          */
         . = ALIGN(CACHE_WRITEBACK_GRANULE);
         __BAKERY_LOCK_START__ = .;
+        __PERCPU_BAKERY_LOCK_START__ = .;
         *(bakery_lock)
         . = ALIGN(CACHE_WRITEBACK_GRANULE);
-        __PERCPU_BAKERY_LOCK_SIZE__ = ABSOLUTE(. - __BAKERY_LOCK_START__);
+        __PERCPU_BAKERY_LOCK_END__ = .;
+        __PERCPU_BAKERY_LOCK_SIZE__ = ABSOLUTE(__PERCPU_BAKERY_LOCK_END__ - __PERCPU_BAKERY_LOCK_START__);
         . = . + (__PERCPU_BAKERY_LOCK_SIZE__ * (PLATFORM_CORE_COUNT - 1));
         __BAKERY_LOCK_END__ = .;
 

bl32/sp_min/sp_min.ld.S

@@ -151,9 +151,11 @@ SECTIONS
          */
         . = ALIGN(CACHE_WRITEBACK_GRANULE);
         __BAKERY_LOCK_START__ = .;
+        __PERCPU_BAKERY_LOCK_START__ = .;
         *(bakery_lock)
         . = ALIGN(CACHE_WRITEBACK_GRANULE);
-        __PERCPU_BAKERY_LOCK_SIZE__ = ABSOLUTE(. - __BAKERY_LOCK_START__);
+        __PERCPU_BAKERY_LOCK_END__ = .;
+        __PERCPU_BAKERY_LOCK_SIZE__ = ABSOLUTE(__PERCPU_BAKERY_LOCK_END__ - __PERCPU_BAKERY_LOCK_START__);
         . = . + (__PERCPU_BAKERY_LOCK_SIZE__ * (PLATFORM_CORE_COUNT - 1));
         __BAKERY_LOCK_END__ = .;
 #ifdef PLAT_PERCPU_BAKERY_LOCK_SIZE

lib/locks/bakery/bakery_lock_normal.c

@@ -51,7 +51,9 @@ CASSERT((PLAT_PERCPU_BAKERY_LOCK_SIZE & (CACHE_WRITEBACK_GRANULE - 1)) == 0, \
  * Use the linker defined symbol which has evaluated the size reqiurement.
  * This is not as efficient as using a platform defined constant
  */
-IMPORT_SYM(uintptr_t, __PERCPU_BAKERY_LOCK_SIZE__, PERCPU_BAKERY_LOCK_SIZE);
+IMPORT_SYM(uintptr_t, __PERCPU_BAKERY_LOCK_START__, BAKERY_LOCK_START);
+IMPORT_SYM(uintptr_t, __PERCPU_BAKERY_LOCK_END__, BAKERY_LOCK_END);
+#define PERCPU_BAKERY_LOCK_SIZE (BAKERY_LOCK_END - BAKERY_LOCK_START)
 #endif
 
 static inline bakery_lock_t *get_bakery_info(unsigned int cpu_ix,

plat/mediatek/mt6795/bl31.ld.S

@@ -113,9 +113,11 @@ SECTIONS
          */
         . = ALIGN(CACHE_WRITEBACK_GRANULE);
         __BAKERY_LOCK_START__ = .;
+        __PERCPU_BAKERY_LOCK_START__ = .;
         *(bakery_lock)
         . = ALIGN(CACHE_WRITEBACK_GRANULE);
-        __PERCPU_BAKERY_LOCK_SIZE__ = ABSOLUTE(. - __BAKERY_LOCK_START__);
+        __PERCPU_BAKERY_LOCK_END__ = .;
+        __PERCPU_BAKERY_LOCK_SIZE__ = ABSOLUTE(__PERCPU_BAKERY_LOCK_END__ - __PERCPU_BAKERY_LOCK_START__);
         . = . + (__PERCPU_BAKERY_LOCK_SIZE__ * (PLATFORM_CORE_COUNT - 1));
         __BAKERY_LOCK_END__ = .;
 #ifdef PLAT_PERCPU_BAKERY_LOCK_SIZE