Add TLK Dispatcher (tlkd) based on the Test Dispatcher (tspd)

TLK Dispatcher (tlkd) is based on the tspd and is the glue required
to run TLK as a Secure Payload with the Trusted Firmware.

Change-Id: I69e573d26d52342eb049feef773dd7d2a506f4ab
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
diff --git a/services/spd/tlkd/tlkd_common.c b/services/spd/tlkd/tlkd_common.c
new file mode 100644
index 0000000..5944174
--- /dev/null
+++ b/services/spd/tlkd/tlkd_common.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright (c) 2015, 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 <assert.h>
+#include <bl_common.h>
+#include <context_mgmt.h>
+#include <string.h>
+#include "tlkd_private.h"
+
+/*******************************************************************************
+ * Given a secure payload entrypoint, register width, cpu id & pointer to a
+ * context data structure, this function will create a secure context ready for
+ * programming an entry into the secure payload.
+ ******************************************************************************/
+void tlkd_init_tlk_ep_state(struct entry_point_info *tlk_entry_point,
+			    uint32_t rw,
+			    uint64_t pc,
+			    tlk_context_t *tlk_ctx)
+{
+	uint32_t ep_attr, spsr;
+
+	/* Passing a NULL context is a critical programming error */
+	assert(tlk_ctx);
+	assert(tlk_entry_point);
+	assert(pc);
+
+	/* Associate this context with the cpu specified */
+	tlk_ctx->mpidr = read_mpidr_el1();
+	clr_std_smc_active_flag(tlk_ctx->state);
+	cm_set_context(&tlk_ctx->cpu_ctx, SECURE);
+
+	if (rw == SP_AARCH64)
+		spsr = SPSR_64(MODE_EL1, MODE_SP_ELX, DISABLE_ALL_EXCEPTIONS);
+	else
+		spsr = SPSR_MODE32(MODE32_svc,
+				   SPSR_T_ARM,
+				   read_sctlr_el3() & SCTLR_EE_BIT,
+				   DISABLE_ALL_EXCEPTIONS);
+
+	/* initialise an entrypoint to set up the CPU context */
+	ep_attr = SECURE | EP_ST_ENABLE;
+	if (read_sctlr_el3() & SCTLR_EE_BIT)
+		ep_attr |= EP_EE_BIG;
+	SET_PARAM_HEAD(tlk_entry_point, PARAM_EP, VERSION_1, ep_attr);
+
+	tlk_entry_point->pc = pc;
+	tlk_entry_point->spsr = spsr;
+}
+
+/*******************************************************************************
+ * This function takes a TLK context pointer and:
+ * 1. Applies the S-EL1 system register context from tlk_ctx->cpu_ctx.
+ * 2. Saves the current C runtime state (callee saved registers) on the stack
+ *    frame and saves a reference to this state.
+ * 3. Calls el3_exit() so that the EL3 system and general purpose registers
+ *    from the tlk_ctx->cpu_ctx are used to enter the secure payload image.
+ ******************************************************************************/
+uint64_t tlkd_synchronous_sp_entry(tlk_context_t *tlk_ctx)
+{
+	uint64_t rc;
+
+	/* Passing a NULL context is a critical programming error */
+	assert(tlk_ctx);
+	assert(tlk_ctx->c_rt_ctx == 0);
+
+	/* Apply the Secure EL1 system register context and switch to it */
+	assert(cm_get_context(SECURE) == &tlk_ctx->cpu_ctx);
+	cm_el1_sysregs_context_restore(SECURE);
+	cm_set_next_eret_context(SECURE);
+
+	rc = tlkd_enter_sp(&tlk_ctx->c_rt_ctx);
+#if DEBUG
+	tlk_ctx->c_rt_ctx = 0;
+#endif
+
+	return rc;
+}
+
+/*******************************************************************************
+ * This function takes a TLK context pointer and:
+ * 1. Saves the S-EL1 system register context to tlk_ctx->cpu_ctx.
+ * 2. Restores the current C runtime state (callee saved registers) from the
+ *    stack frame using reference to this state saved in tlkd_enter_sp().
+ * 3. It does not need to save any general purpose or EL3 system register state
+ *    as the generic smc entry routine should have saved those.
+ ******************************************************************************/
+void tlkd_synchronous_sp_exit(tlk_context_t *tlk_ctx, uint64_t ret)
+{
+	/* Passing a NULL context is a critical programming error */
+	assert(tlk_ctx);
+
+	/* Save the Secure EL1 system register context */
+	assert(cm_get_context(SECURE) == &tlk_ctx->cpu_ctx);
+	cm_el1_sysregs_context_save(SECURE);
+
+	assert(tlk_ctx->c_rt_ctx != 0);
+	tlkd_exit_sp(tlk_ctx->c_rt_ctx, ret);
+
+	/* Should never reach here */
+	assert(0);
+}