platform_mp_stack.S

/*
 * Copyright (c) 2014-2020, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <arch.h>
#include <asm_macros.S>
#include <assert_macros.S>
#include <platform_def.h>

	.local	platform_normal_stacks
	.weak	plat_get_my_stack
	.weak	plat_set_my_stack

	/* ---------------------------------------------------------------------
	 * When the compatility layer is disabled, the platform APIs
	 * plat_get_my_stack() and plat_set_my_stack() are supported by the
	 * platform and the previous APIs platform_get_stack() and
	 * platform_set_stack() are defined in terms of new APIs making use of
	 * the fact that they are only ever invoked for the current CPU.  This
	 * is to enable components of Trusted Firmware like SPDs using the old
	 * platform APIs to continue to work.
	 * --------------------------------------------------------------------
	 */

	/* -----------------------------------------------------
	 * uintptr_t plat_get_my_stack ()
	 *
	 * For the current CPU, this function returns the stack
	 * pointer for a stack allocated in device memory.
	 * -----------------------------------------------------
	 */
func plat_get_my_stack
#if (defined(IMAGE_BL31) && RECLAIM_INIT_CODE)
#if (PLATFORM_CORE_COUNT == 1)
	/* Single CPU */
	adrp	x0, __PRIMARY_STACK__
	add	x0, x0, :lo12:__PRIMARY_STACK__
	ret
#else
	mov	x10, x30
	bl	plat_my_core_pos
	cbnz	x0, 2f

	/* Primary CPU */
	adrp	x0, __PRIMARY_STACK__
	add	x0, x0, :lo12:__PRIMARY_STACK__
	ret	x10

	/* Secondary CPU */
2:	sub	x0, x0, #(PLATFORM_CORE_COUNT - 1)
	adrp	x1, __STACKS_END__
	adrp	x2, __STACK_SIZE__
	add	x1, x1, :lo12:__STACKS_END__
	add	x2, x2, :lo12:__STACK_SIZE__

	madd	x0, x0, x2, x1
	bic	x0, x0, #(CACHE_WRITEBACK_GRANULE - 1)
	ret	x10
#endif
	/* Prevent linker from removal of stack section */
	.quad	platform_normal_stacks

#else /* !(IMAGE_BL31 && RECLAIM_INIT_CODE) */
	mov	x10, x30
	get_my_mp_stack platform_normal_stacks, PLATFORM_STACK_SIZE
	ret	x10

#endif /* IMAGE_BL31 && RECLAIM_INIT_CODE */
endfunc plat_get_my_stack

	/* -----------------------------------------------------
	 * void plat_set_my_stack ()
	 *
	 * For the current CPU, this function sets the stack
	 * pointer to a stack allocated in normal memory.
	 * -----------------------------------------------------
	 */
func plat_set_my_stack
	mov	x9, x30
	bl 	plat_get_my_stack
	mov	sp, x0
	ret	x9
endfunc plat_set_my_stack

	/* -----------------------------------------------------
	 * 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, \
		CACHE_WRITEBACK_GRANULE