AArch32: Add SP_MIN support for JUNO

This patch adds support for SP_MIN on JUNO platform.
The changes include addition of AArch32 assembly files,
JUNO specific SP_MIN make file and miscellaneous changes
in ARM platform files to enable support for SP_MIN.

Change-Id: Id1303f422fc9b98b9362c757b1a4225a16fffc0b
Signed-off-by: Yatharth Kochar <yatharth.kochar@arm.com>
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
diff --git a/plat/arm/css/common/aarch32/css_helpers.S b/plat/arm/css/common/aarch32/css_helpers.S
new file mode 100644
index 0000000..b7075bd
--- /dev/null
+++ b/plat/arm/css/common/aarch32/css_helpers.S
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <arch.h>
+#include <asm_macros.S>
+#include <cpu_macros.S>
+#include <css_def.h>
+
+	.weak	plat_secondary_cold_boot_setup
+	.weak	plat_get_my_entrypoint
+	.globl	css_calc_core_pos_swap_cluster
+	.weak	plat_is_my_cpu_primary
+
+	/* ---------------------------------------------------------------------
+	 * void plat_secondary_cold_boot_setup(void);
+	 * In the normal boot flow, cold-booting secondary
+	 * CPUs is not yet implemented and they panic.
+	 * ---------------------------------------------------------------------
+	 */
+func plat_secondary_cold_boot_setup
+	/* TODO: Implement secondary CPU cold boot setup on CSS platforms */
+cb_panic:
+	b	cb_panic
+endfunc plat_secondary_cold_boot_setup
+
+	/* ---------------------------------------------------------------------
+	 * uintptr_t plat_get_my_entrypoint (void);
+	 *
+	 * Main job of this routine is to distinguish between a cold and a warm
+	 * boot. On CSS platforms, this distinction is based on the contents of
+	 * the Trusted Mailbox. It is initialised to zero by the SCP before the
+	 * AP cores are released from reset. Therefore, a zero mailbox means
+	 * it's a cold reset.
+	 *
+	 * This functions returns the contents of the mailbox, i.e.:
+	 *  - 0 for a cold boot;
+	 *  - the warm boot entrypoint for a warm boot.
+	 * ---------------------------------------------------------------------
+	 */
+func plat_get_my_entrypoint
+	ldr	r0, =PLAT_ARM_TRUSTED_MAILBOX_BASE
+	ldr	r0, [r0]
+	bx	lr
+endfunc plat_get_my_entrypoint
+
+	/* -----------------------------------------------------------
+	 * unsigned int css_calc_core_pos_swap_cluster(u_register_t mpidr)
+	 * Utility function to calculate the core position by
+	 * swapping the cluster order. This is necessary in order to
+	 * match the format of the boot information passed by the SCP
+	 * and read in plat_is_my_cpu_primary below.
+	 * -----------------------------------------------------------
+	 */
+func css_calc_core_pos_swap_cluster
+	and	r1, r0, #MPIDR_CPU_MASK
+	and	r0, r0, #MPIDR_CLUSTER_MASK
+	eor	r0, r0, #(1 << MPIDR_AFFINITY_BITS)  // swap cluster order
+	add	r0, r1, r0, LSR #6
+	bx	lr
+endfunc css_calc_core_pos_swap_cluster
+
+	/* -----------------------------------------------------
+	 * unsigned int plat_is_my_cpu_primary (void);
+	 *
+	 * Find out whether the current cpu is the primary
+	 * cpu (applicable ony after a cold boot)
+	 * -----------------------------------------------------
+	 */
+func plat_is_my_cpu_primary
+	mov	r10, lr
+	bl	plat_my_core_pos
+	ldr	r1, =SCP_BOOT_CFG_ADDR
+	ldr	r1, [r1]
+	ubfx	r1, r1, #PLAT_CSS_PRIMARY_CPU_SHIFT, \
+			#PLAT_CSS_PRIMARY_CPU_BIT_WIDTH
+	cmp	r0, r1
+	moveq	r0, #1
+	movne	r0, #0
+	bx	r10
+endfunc plat_is_my_cpu_primary
diff --git a/plat/arm/css/common/css_common.mk b/plat/arm/css/common/css_common.mk
index 7829e8b..24215a5 100644
--- a/plat/arm/css/common/css_common.mk
+++ b/plat/arm/css/common/css_common.mk
@@ -36,7 +36,7 @@
 				-Iinclude/plat/arm/css/common/aarch64
 
 
-PLAT_BL_COMMON_SOURCES	+=	plat/arm/css/common/aarch64/css_helpers.S
+PLAT_BL_COMMON_SOURCES	+=	plat/arm/css/common/${ARCH}/css_helpers.S
 
 BL1_SOURCES		+=	plat/arm/css/common/css_bl1_setup.c