Replace some memset call by zeromem

Replace all use of memset by zeromem when zeroing moderately-sized
structure by applying the following transformation:
memset(x, 0, sizeof(x)) => zeromem(x, sizeof(x))

As the Trusted Firmware is compiled with -ffreestanding, it forbids the
compiler from using __builtin_memset and forces it to generate calls to
the slow memset implementation. Zeromem is a near drop in replacement
for this use case, with a more efficient implementation on both AArch32
and AArch64.

Change-Id: Ia7f3a90e888b96d056881be09f0b4d65b41aa79e
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>

3 files changed, 11 insertions, 8 deletions

diff --git a/lib/el3_runtime/aarch32/context_mgmt.c b/lib/el3_runtime/aarch32/context_mgmt.c
index 51b77595..df22eaf5 100644
--- a/lib/el3_runtime/aarch32/context_mgmt.c
+++ b/lib/el3_runtime/aarch32/context_mgmt.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2017, 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:
@@ -38,6 +38,7 @@
 #include <platform_def.h>
 #include <smcc_helpers.h>
 #include <string.h>
+#include <utils.h>
 
 /*******************************************************************************
  * Context management library initialisation routine. This library is used by
@@ -84,7 +85,7 @@ static void cm_init_context_common(cpu_context_t *ctx, const entry_point_info_t
 	security_state = GET_SECURITY_STATE(ep->h.attr);
 
 	/* Clear any residual register values from the context */
-	memset(ctx, 0, sizeof(*ctx));
+	zeromem(ctx, sizeof(*ctx));
 
 	reg_ctx = get_regs_ctx(ctx);
 
diff --git a/lib/el3_runtime/aarch64/context_mgmt.c b/lib/el3_runtime/aarch64/context_mgmt.c
index e26950df..5cce8793 100644
--- a/lib/el3_runtime/aarch64/context_mgmt.c
+++ b/lib/el3_runtime/aarch64/context_mgmt.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2017, 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:
@@ -39,6 +39,7 @@
 #include <platform_def.h>
 #include <smcc_helpers.h>
 #include <string.h>
+#include <utils.h>
 
 
 /*******************************************************************************
@@ -91,7 +92,7 @@ static void cm_init_context_common(cpu_context_t *ctx, const entry_point_info_t
 	security_state = GET_SECURITY_STATE(ep->h.attr);
 
 	/* Clear any residual register values from the context */
-	memset(ctx, 0, sizeof(*ctx));
+	zeromem(ctx, sizeof(*ctx));
 
 	/*
 	 * Base the context SCR on the current value, adjust for entry point
diff --git a/lib/psci/psci_common.c b/lib/psci/psci_common.c
index 68cdd6eb..b6e162be 100644
--- a/lib/psci/psci_common.c
+++ b/lib/psci/psci_common.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2017, 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:
@@ -37,6 +37,7 @@
 #include <debug.h>
 #include <platform.h>
 #include <string.h>
+#include <utils.h>
 #include "psci_private.h"
 
 /*
@@ -622,7 +623,7 @@ static int psci_get_ns_ep_info(entry_point_info_t *ep,
 	SET_PARAM_HEAD(ep, PARAM_EP, VERSION_1, ep_attr);
 
 	ep->pc = entrypoint;
-	memset(&ep->args, 0, sizeof(ep->args));
+	zeromem(&ep->args, sizeof(ep->args));
 	ep->args.arg0 = context_id;
 
 	mode = scr & SCR_HCE_BIT ? MODE32_hyp : MODE32_svc;
@@ -659,7 +660,7 @@ static int psci_get_ns_ep_info(entry_point_info_t *ep,
 	SET_PARAM_HEAD(ep, PARAM_EP, VERSION_1, ep_attr);
 
 	ep->pc = entrypoint;
-	memset(&ep->args, 0, sizeof(ep->args));
+	zeromem(&ep->args, sizeof(ep->args));
 	ep->args.arg0 = context_id;
 
 	/*
@@ -957,7 +958,7 @@ unsigned int psci_get_max_phys_off_afflvl(void)
 {
 	psci_power_state_t state_info;
 
-	memset(&state_info, 0, sizeof(state_info));
+	zeromem(&state_info, sizeof(state_info));
 	psci_get_target_local_pwr_states(PLAT_MAX_PWR_LVL, &state_info);
 
 	return psci_find_target_suspend_lvl(&state_info);