Add common ARM and CSS platform code

This major change pulls out the common functionality from the
FVP and Juno platform ports into the following categories:

*   (include/)plat/common. Common platform porting functionality that
typically may be used by all platforms.

*   (include/)plat/arm/common. Common platform porting functionality
that may be used by all ARM standard platforms. This includes all
ARM development platforms like FVP and Juno but may also include
non-ARM-owned platforms.

*   (include/)plat/arm/board/common. Common platform porting
functionality for ARM development platforms at the board
(off SoC) level.

*   (include/)plat/arm/css/common. Common platform porting
functionality at the ARM Compute SubSystem (CSS) level. Juno
is an example of a CSS-based platform.

*   (include/)plat/arm/soc/common. Common platform porting
functionality at the ARM SoC level, which is not already defined
at the ARM CSS level.

No guarantees are made about the backward compatibility of
functionality provided in (include/)plat/arm.

Also remove any unnecessary variation between the ARM development
platform ports, including:

*   Unify the way BL2 passes `bl31_params_t` to BL3-1. Use the
Juno implementation, which copies the information from BL2 memory
instead of expecting it to persist in shared memory.

*   Unify the TZC configuration. There is no need to add a region
for SCP in Juno; it's enough to simply not allow any access to
this reserved region. Also set region 0 to provide no access by
default instead of assuming this is the case.

*   Unify the number of memory map regions required for ARM
development platforms, although the actual ranges mapped for each
platform may be different. For the FVP port, this reduces the
mapped peripheral address space.

These latter changes will only be observed when the platform ports
are migrated to use the new common platform code in subsequent
patches.

Change-Id: Id9c269dd3dc6e74533d0e5116fdd826d53946dc8
diff --git a/plat/arm/css/common/css_scpi.c b/plat/arm/css/common/css_scpi.c
new file mode 100644
index 0000000..5bfa2cf
--- /dev/null
+++ b/plat/arm/css/common/css_scpi.c
@@ -0,0 +1,140 @@
+/*
+ * Copyright (c) 2014, 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_helpers.h>
+#include <css_def.h>
+#include <platform.h>
+#include "css_mhu.h"
+#include "css_scpi.h"
+
+#define MHU_SECURE_SCP_TO_AP_PAYLOAD	(MHU_SECURE_BASE+0x0080)
+#define MHU_SECURE_AP_TO_SCP_PAYLOAD	(MHU_SECURE_BASE+0x0280)
+
+#define SIZE_SHIFT	20	/* Bit position for size value in MHU header */
+#define SIZE_MASK	0x1ff	/* Mask to extract size value in MHU header*/
+
+
+void *scpi_secure_message_start(void)
+{
+	mhu_secure_message_start();
+
+	/* Return address of payload area. */
+	return (void *)MHU_SECURE_AP_TO_SCP_PAYLOAD;
+}
+
+void scpi_secure_message_send(unsigned command, size_t size)
+{
+	/* Make sure payload can be seen by SCP */
+	if (MHU_PAYLOAD_CACHED)
+		flush_dcache_range(MHU_SECURE_AP_TO_SCP_PAYLOAD, size);
+
+	mhu_secure_message_send(command | (size << SIZE_SHIFT));
+}
+
+unsigned scpi_secure_message_receive(void **message_out, size_t *size_out)
+{
+	uint32_t response =  mhu_secure_message_wait();
+
+	/* Get size of payload */
+	size_t size = (response >> SIZE_SHIFT) & SIZE_MASK;
+
+	/* Clear size from response */
+	response &= ~(SIZE_MASK << SIZE_SHIFT);
+
+	/* Make sure we don't read stale data */
+	if (MHU_PAYLOAD_CACHED)
+		inv_dcache_range(MHU_SECURE_SCP_TO_AP_PAYLOAD, size);
+
+	if (size_out)
+		*size_out = size;
+
+	if (message_out)
+		*message_out = (void *)MHU_SECURE_SCP_TO_AP_PAYLOAD;
+
+	return response;
+}
+
+void scpi_secure_message_end(void)
+{
+	mhu_secure_message_end();
+}
+
+static void scpi_secure_send32(unsigned command, uint32_t message)
+{
+	*(__typeof__(message) *)scpi_secure_message_start() = message;
+	scpi_secure_message_send(command, sizeof(message));
+	scpi_secure_message_end();
+}
+
+int scpi_wait_ready(void)
+{
+	/* Get a message from the SCP */
+	scpi_secure_message_start();
+	size_t size;
+	unsigned command = scpi_secure_message_receive(NULL, &size);
+	scpi_secure_message_end();
+
+	/* We are expecting 'SCP Ready', produce correct error if it's not */
+	scpi_status_t response = SCP_OK;
+	if (command != SCPI_CMD_SCP_READY)
+		response = SCP_E_SUPPORT;
+	else if (size != 0)
+		response = SCP_E_SIZE;
+
+	/* Send our response back to SCP */
+	scpi_secure_send32(command, response);
+
+	return response == SCP_OK ? 0 : -1;
+}
+
+void scpi_set_css_power_state(unsigned mpidr, scpi_power_state_t cpu_state,
+		scpi_power_state_t cluster_state, scpi_power_state_t css_state)
+{
+	uint32_t state = mpidr & 0x0f;	/* CPU ID */
+	state |= (mpidr & 0xf00) >> 4;	/* Cluster ID */
+	state |= cpu_state << 8;
+	state |= cluster_state << 12;
+	state |= css_state << 16;
+	scpi_secure_send32(SCPI_CMD_SET_CSS_POWER_STATE, state);
+}
+
+uint32_t scpi_sys_power_state(scpi_system_state_t system_state)
+{
+	uint32_t *response;
+	size_t size;
+	uint8_t state = system_state & 0xff;
+
+	/* Send the command */
+	*(__typeof__(state) *)scpi_secure_message_start() = state;
+	scpi_secure_message_send(SCPI_CMD_SYS_POWER_STATE, sizeof(state));
+	scpi_secure_message_receive((void *)&response, &size);
+	scpi_secure_message_end();
+	return *response;
+}