Merge pull request #1426 from antonio-nino-diaz-arm/an/spm-sync
SPM: Refactor entry and exit of the SP
diff --git a/services/std_svc/spm/spm_main.c b/services/std_svc/spm/spm_main.c
index be76dc2..f63f9c4 100644
--- a/services/std_svc/spm/spm_main.c
+++ b/services/std_svc/spm/spm_main.c
@@ -81,10 +81,13 @@
}
/*******************************************************************************
- * This function takes an SP context pointer and prepares the CPU to enter.
+ * This function takes an SP context pointer and performs a synchronous entry
+ * into it.
******************************************************************************/
-static void spm_sp_prepare_enter(sp_context_t *sp_ctx)
+static uint64_t spm_sp_synchronous_entry(sp_context_t *sp_ctx)
{
+ uint64_t rc;
+
assert(sp_ctx != NULL);
/* Assign the context of the SP to this CPU */
@@ -97,15 +100,32 @@
/* Invalidate TLBs at EL1. */
tlbivmalle1();
dsbish();
+
+ /* Enter Secure Partition */
+ rc = spm_secure_partition_enter(&sp_ctx->c_rt_ctx);
+
+ /* Save secure state */
+ cm_el1_sysregs_context_save(SECURE);
+
+ return rc;
}
/*******************************************************************************
- * Enter SP after preparing it with spm_sp_prepare_enter().
+ * This function returns to the place where spm_sp_synchronous_entry() was
+ * called originally.
******************************************************************************/
-static uint64_t spm_sp_enter(sp_context_t *sp_ctx)
+__dead2 static void spm_sp_synchronous_exit(uint64_t rc)
{
- /* Enter Secure Partition */
- return spm_secure_partition_enter(&sp_ctx->c_rt_ctx);
+ sp_context_t *ctx = &sp_ctx;
+
+ /*
+ * The SPM must have initiated the original request through a
+ * synchronous entry into the secure partition. Jump back to the
+ * original C runtime context with the value of rc in x0;
+ */
+ spm_secure_partition_exit(ctx->c_rt_ctx, rc);
+
+ panic();
}
/*******************************************************************************
@@ -113,7 +133,7 @@
******************************************************************************/
static int32_t spm_init(void)
{
- uint64_t rc = 0;
+ uint64_t rc;
sp_context_t *ctx;
INFO("Secure Partition init...\n");
@@ -122,8 +142,7 @@
ctx->state = SP_STATE_RESET;
- spm_sp_prepare_enter(ctx);
- rc |= spm_sp_enter(ctx);
+ rc = spm_sp_synchronous_entry(ctx);
assert(rc == 0);
ctx->state = SP_STATE_IDLE;
@@ -168,6 +187,7 @@
uint64_t comm_buffer_address,
uint64_t comm_size_address, void *handle)
{
+ uint64_t rc;
sp_context_t *ctx = &sp_ctx;
/* Cookie. Reserved for future use. It must be zero. */
@@ -188,59 +208,29 @@
/* Save the Normal world context */
cm_el1_sysregs_context_save(NON_SECURE);
- /* Wait until the Secure Partition is IDLE and set it to BUSY. */
+ /* Wait until the Secure Partition is idle and set it to busy. */
sp_state_wait_switch(ctx, SP_STATE_IDLE, SP_STATE_BUSY);
- /* Jump to the Secure Partition. */
- spm_sp_prepare_enter(ctx);
-
- SMC_RET4(&(ctx->cpu_ctx), smc_fid, comm_buffer_address,
- comm_size_address, plat_my_core_pos());
-}
-
-/*******************************************************************************
- * SP_EVENT_COMPLETE_AARCH64 handler
- ******************************************************************************/
-static uint64_t sp_event_complete(uint64_t x1)
-{
- sp_context_t *ctx = &sp_ctx;
+ /* Set values for registers on SP entry */
+ cpu_context_t *cpu_ctx = &(ctx->cpu_ctx);
- /* Save secure state */
- cm_el1_sysregs_context_save(SECURE);
+ write_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X0, smc_fid);
+ write_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X1, comm_buffer_address);
+ write_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X2, comm_size_address);
+ write_ctx_reg(get_gpregs_ctx(cpu_ctx), CTX_GPREG_X3, plat_my_core_pos());
- if (ctx->state == SP_STATE_RESET) {
- /*
- * SPM reports completion. The SPM must have initiated the
- * original request through a synchronous entry into the secure
- * partition. Jump back to the original C runtime context.
- */
- spm_secure_partition_exit(ctx->c_rt_ctx, x1);
-
- /* spm_secure_partition_exit doesn't return */
- }
-
- /*
- * This is the result from the Secure partition of an earlier request.
- * Copy the result into the non-secure context and return to the
- * non-secure state.
- */
+ /* Jump to the Secure Partition. */
+ rc = spm_sp_synchronous_entry(ctx);
- /* Mark Secure Partition as idle */
+ /* Flag Secure Partition as idle. */
assert(ctx->state == SP_STATE_BUSY);
-
sp_state_set(ctx, SP_STATE_IDLE);
- /* Get a reference to the non-secure context */
- cpu_context_t *ns_cpu_context = cm_get_context(NON_SECURE);
-
- assert(ns_cpu_context != NULL);
-
/* Restore non-secure state */
cm_el1_sysregs_context_restore(NON_SECURE);
cm_set_next_eret_context(NON_SECURE);
- /* Return to non-secure world */
- SMC_RET1(ns_cpu_context, x1);
+ SMC_RET1(handle, rc);
}
/*******************************************************************************
@@ -275,7 +265,7 @@
SMC_RET1(handle, SPM_VERSION_COMPILED);
case SP_EVENT_COMPLETE_AARCH64:
- return sp_event_complete(x1);
+ spm_sp_synchronous_exit(x1);
case SP_MEMORY_ATTRIBUTES_GET_AARCH64:
INFO("Received SP_MEMORY_ATTRIBUTES_GET_AARCH64 SMC\n");
@@ -305,6 +295,8 @@
/* Handle SMCs from Non-secure world. */
+ assert(handle == cm_get_context(NON_SECURE));
+
switch (smc_fid) {
case MM_VERSION_AARCH32:
diff --git a/services/std_svc/spm/spm_private.h b/services/std_svc/spm/spm_private.h
index 64d8cf8..f094739 100644
--- a/services/std_svc/spm/spm_private.h
+++ b/services/std_svc/spm/spm_private.h
@@ -35,7 +35,7 @@
#include <stdint.h>
#include <xlat_tables_v2.h>
-typedef enum secure_partition_state {
+typedef enum sp_state {
SP_STATE_RESET = 0,
SP_STATE_IDLE,
SP_STATE_BUSY