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-rw-r--r--services/spd/pncd/pncd_common.c102
1 files changed, 102 insertions, 0 deletions
diff --git a/services/spd/pncd/pncd_common.c b/services/spd/pncd/pncd_common.c
new file mode 100644
index 0000000..6fdb629
--- /dev/null
+++ b/services/spd/pncd/pncd_common.c
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2021-2022, ProvenRun S.A.S. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <string.h>
+
+#include <arch_helpers.h>
+#include <common/bl_common.h>
+#include <common/debug.h>
+#include <lib/el3_runtime/context_mgmt.h>
+#include <lib/utils.h>
+#include <plat/common/platform.h>
+
+#include "pncd_private.h"
+
+/*******************************************************************************
+ * Given a secure payload entrypoint info pointer, entry point PC & pointer to a
+ * context data structure, this function will initialize pnc context and entry
+ * point info for the secure payload
+ ******************************************************************************/
+void pncd_init_pnc_ep_state(struct entry_point_info *pnc_entry_point,
+ uint64_t pc,
+ pnc_context_t *pnc_ctx)
+{
+ uint32_t ep_attr;
+
+ /* Passing a NULL context is a critical programming error */
+ assert(pnc_ctx);
+ assert(pnc_entry_point);
+ assert(pc);
+
+ /* Associate this context with the current cpu */
+ pnc_ctx->mpidr = read_mpidr();
+
+ cm_set_context(&pnc_ctx->cpu_ctx, SECURE);
+
+ /* 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(pnc_entry_point, PARAM_EP, VERSION_1, ep_attr);
+
+ pnc_entry_point->pc = pc;
+ pnc_entry_point->spsr = SPSR_64(MODE_EL1,
+ MODE_SP_ELX,
+ DISABLE_ALL_EXCEPTIONS);
+ memset(&pnc_entry_point->args, 0, sizeof(pnc_entry_point->args));
+}
+
+/*******************************************************************************
+ * This function takes an SP context pointer and:
+ * 1. Applies the S-EL1 system register context from pnc_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 pnc_ctx->cpu_ctx are used to enter the secure payload image.
+ ******************************************************************************/
+uint64_t pncd_synchronous_sp_entry(pnc_context_t *pnc_ctx)
+{
+ assert(pnc_ctx != NULL);
+ assert(pnc_ctx->c_rt_ctx == 0U);
+
+ /* Apply the Secure EL1 system register context and switch to it */
+ assert(cm_get_context(SECURE) == &pnc_ctx->cpu_ctx);
+ cm_el1_sysregs_context_restore(SECURE);
+#if CTX_INCLUDE_FPREGS
+ fpregs_context_restore(get_fpregs_ctx(cm_get_context(SECURE)));
+#endif
+ cm_set_next_eret_context(SECURE);
+
+ return pncd_enter_sp(&pnc_ctx->c_rt_ctx);
+}
+
+
+/*******************************************************************************
+ * This function takes an SP context pointer and:
+ * 1. Saves the S-EL1 system register context tp pnc_ctx->cpu_ctx.
+ * 2. Restores the current C runtime state (callee saved registers) from the
+ * stack frame using the reference to this state saved in pncd_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 pncd_synchronous_sp_exit(pnc_context_t *pnc_ctx, uint64_t ret)
+{
+ assert(pnc_ctx != NULL);
+ /* Save the Secure EL1 system register context */
+ assert(cm_get_context(SECURE) == &pnc_ctx->cpu_ctx);
+ cm_el1_sysregs_context_save(SECURE);
+#if CTX_INCLUDE_FPREGS
+ fpregs_context_save(get_fpregs_ctx(cm_get_context(SECURE)));
+#endif
+
+ assert(pnc_ctx->c_rt_ctx != 0);
+ pncd_exit_sp(pnc_ctx->c_rt_ctx, ret);
+
+ /* Should never reach here */
+ panic();
+}