Remove the concept of coherent stacks
This patch removes the allocation of memory for coherent stacks, associated
accessor function and some dead code which called the accessor function. It also
updates the porting guide to remove the concept and the motivation behind using
stacks allocated in coherent memory.
Fixes ARM-software/tf-issues#198
Change-Id: I00ff9a04f693a03df3627ba39727e3497263fc38
diff --git a/plat/common/aarch64/platform_mp_stack.S b/plat/common/aarch64/platform_mp_stack.S
index 801ec7f..8eb1aa6 100644
--- a/plat/common/aarch64/platform_mp_stack.S
+++ b/plat/common/aarch64/platform_mp_stack.S
@@ -33,29 +33,12 @@
#include <platform_def.h>
- .local pcpu_dv_mem_stack
.local platform_normal_stacks
.weak platform_set_stack
.weak platform_get_stack
- .weak platform_set_coherent_stack
/* -----------------------------------------------------
- * void platform_set_coherent_stack (unsigned long mpidr)
- *
- * For a given CPU, this function sets the stack pointer
- * to a stack allocated in device memory. This stack can
- * be used by C code which enables/disables the SCTLR.M
- * SCTLR.C bit e.g. while powering down a cpu
- * -----------------------------------------------------
- */
-func platform_set_coherent_stack
- mov x5, x30 // lr
- get_mp_stack pcpu_dv_mem_stack, PCPU_DV_MEM_STACK_SIZE
- mov sp, x0
- ret x5
-
- /* -----------------------------------------------------
* unsigned long platform_get_stack (unsigned long mpidr)
*
* For a given CPU, this function returns the stack
@@ -81,22 +64,9 @@
ret x9
/* -----------------------------------------------------
- * Per-cpu stacks in normal memory.
- * Used for C code during runtime execution (when coherent
- * stacks are not required).
- * Each cpu gets a stack of PLATFORM_STACK_SIZE bytes.
+ * Per-cpu stacks in normal memory. Each cpu gets a
+ * stack of PLATFORM_STACK_SIZE bytes.
* -----------------------------------------------------
*/
declare_stack platform_normal_stacks, tzfw_normal_stacks, \
PLATFORM_STACK_SIZE, PLATFORM_CORE_COUNT
-
- /* -----------------------------------------------------
- * Per-cpu stacks in device memory.
- * Used for C code just before power down or right after
- * power up when the MMU or caches need to be turned on
- * or off.
- * Each cpu gets a stack of PCPU_DV_MEM_STACK_SIZE bytes.
- * -----------------------------------------------------
- */
-declare_stack pcpu_dv_mem_stack, tzfw_coherent_mem, \
- PCPU_DV_MEM_STACK_SIZE, PLATFORM_CORE_COUNT
diff --git a/plat/common/aarch64/platform_up_stack.S b/plat/common/aarch64/platform_up_stack.S
index 45a96a6..73b74b2 100644
--- a/plat/common/aarch64/platform_up_stack.S
+++ b/plat/common/aarch64/platform_up_stack.S
@@ -33,28 +33,11 @@
#include <platform_def.h>
- .local pcpu_dv_mem_stack
.local platform_normal_stacks
.globl platform_set_stack
.globl platform_get_stack
- .globl platform_set_coherent_stack
-
/* -----------------------------------------------------
- * void platform_set_coherent_stack (unsigned long)
- *
- * For cold-boot BL images, only the primary CPU needs a
- * stack. This function sets the stack pointer to a stack
- * allocated in device memory.
- * -----------------------------------------------------
- */
-func platform_set_coherent_stack
- get_up_stack pcpu_dv_mem_stack, PCPU_DV_MEM_STACK_SIZE
- mov sp, x0
- ret
-
-
- /* -----------------------------------------------------
* unsigned long platform_get_stack (unsigned long)
*
* For cold-boot BL images, only the primary CPU needs a
@@ -87,11 +70,3 @@
*/
declare_stack platform_normal_stacks, tzfw_normal_stacks, \
PLATFORM_STACK_SIZE, 1
-
- /* -----------------------------------------------------
- * Single cpu stack in device/coherent memory.
- * PCPU_DV_MEM_STACK_SIZE bytes are allocated.
- * -----------------------------------------------------
- */
-declare_stack pcpu_dv_mem_stack, tzfw_coherent_mem, \
- PCPU_DV_MEM_STACK_SIZE, 1
diff --git a/plat/fvp/fvp_pm.c b/plat/fvp/fvp_pm.c
index 55f465b..22e53e1 100644
--- a/plat/fvp/fvp_pm.c
+++ b/plat/fvp/fvp_pm.c
@@ -120,11 +120,10 @@
* platform to decide whether the cluster is being turned off and take apt
* actions.
*
- * CAUTION: This function is called with coherent stacks so that caches can be
- * turned off, flushed and coherency disabled. There is no guarantee that caches
- * will remain turned on across calls to this function as each affinity level is
- * dealt with. So do not write & read global variables across calls. It will be
- * wise to do flush a write to the global to prevent unpredictable results.
+ * CAUTION: There is no guarantee that caches will remain turned on across calls
+ * to this function as each affinity level is dealt with. So do not write & read
+ * global variables across calls. It will be wise to do flush a write to the
+ * global to prevent unpredictable results.
******************************************************************************/
int fvp_affinst_off(unsigned long mpidr,
unsigned int afflvl,
@@ -192,11 +191,10 @@
* platform to decide whether the cluster is being turned off and take apt
* actions.
*
- * CAUTION: This function is called with coherent stacks so that caches can be
- * turned off, flushed and coherency disabled. There is no guarantee that caches
- * will remain turned on across calls to this function as each affinity level is
- * dealt with. So do not write & read global variables across calls. It will be
- * wise to do flush a write to the global to prevent unpredictable results.
+ * CAUTION: There is no guarantee that caches will remain turned on across calls
+ * to this function as each affinity level is dealt with. So do not write & read
+ * global variables across calls. It will be wise to do flush a write to the
+ * global to prevent unpredictable results.
******************************************************************************/
int fvp_affinst_suspend(unsigned long mpidr,
unsigned long sec_entrypoint,
diff --git a/plat/fvp/include/platform_def.h b/plat/fvp/include/platform_def.h
index ec4cf52..9983266 100644
--- a/plat/fvp/include/platform_def.h
+++ b/plat/fvp/include/platform_def.h
@@ -47,13 +47,6 @@
/* Size of cacheable stacks */
#define PLATFORM_STACK_SIZE 0x800
-/* Size of coherent stacks for debug and release builds */
-#if DEBUG
-#define PCPU_DV_MEM_STACK_SIZE 0x400
-#else
-#define PCPU_DV_MEM_STACK_SIZE 0x300
-#endif
-
#define FIRMWARE_WELCOME_STR "Booting trusted firmware boot loader stage 1\n\r"
/* Trusted Boot Firmware BL2 */