SPM: Implement global response buffer helpers
This buffer is where all the responses from Secure Partitions are stored
until they are requested.
Change-Id: Iafeb8f0848c5ff6f3e187060cd3a47702484dc45
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/services/std_svc/spm/spm_buffers.c b/services/std_svc/spm/spm_buffers.c
new file mode 100644
index 0000000..747337a
--- /dev/null
+++ b/services/std_svc/spm/spm_buffers.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2018, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch_helpers.h>
+#include <platform_def.h>
+#include <spinlock.h>
+#include <utils_def.h>
+
+/*******************************************************************************
+ * Secure Service response global array. All the responses to the requests done
+ * to the Secure Partition are stored here. They are removed from the array as
+ * soon as their value is read.
+ ******************************************************************************/
+struct sprt_response {
+ int is_valid;
+ uint32_t token;
+ uint16_t client_id, handle;
+ u_register_t x1, x2, x3;
+};
+
+static struct sprt_response responses[PLAT_SPM_RESPONSES_MAX];
+
+static spinlock_t responses_lock;
+
+/* Add response to the global response buffer. Returns 0 on success else -1. */
+int spm_response_add(uint16_t client_id, uint16_t handle, uint32_t token,
+ u_register_t x1, u_register_t x2, u_register_t x3)
+{
+ spin_lock(&responses_lock);
+
+ /* Make sure that there isn't any other response with the same token. */
+ for (unsigned int i = 0U; i < ARRAY_SIZE(responses); i++) {
+ struct sprt_response *resp = &(responses[i]);
+
+ if ((resp->is_valid == 1) && (resp->token == token)) {
+ return -1;
+ }
+ }
+
+ for (int i = 0; i < ARRAY_SIZE(responses); i++) {
+ struct sprt_response *resp = &(responses[i]);
+
+ if (resp->is_valid == 0) {
+ resp->token = token;
+ resp->client_id = client_id;
+ resp->handle = handle;
+ resp->x1 = x1;
+ resp->x2 = x2;
+ resp->x3 = x3;
+
+ dmbish();
+
+ resp->is_valid = 1;
+
+ spin_unlock(&responses_lock);
+
+ return 0;
+ }
+ }
+
+ spin_unlock(&responses_lock);
+
+ return -1;
+}
+
+/*
+ * Returns a response from the requests array and removes it from it. Returns 0
+ * on success, -1 if it wasn't found.
+ */
+int spm_response_get(uint16_t client_id, uint16_t handle, uint32_t token,
+ u_register_t *x1, u_register_t *x2, u_register_t *x3)
+{
+ spin_lock(&responses_lock);
+
+ for (unsigned int i = 0U; i < ARRAY_SIZE(responses); i++) {
+ struct sprt_response *resp = &(responses[i]);
+
+ /* Ignore invalid entries */
+ if (resp->is_valid == 0) {
+ continue;
+ }
+
+ /* Make sure that all the information matches the stored one */
+ if ((resp->token != token) || (resp->client_id != client_id) ||
+ (resp->handle != handle)) {
+ continue;
+ }
+
+ *x1 = resp->x1;
+ *x2 = resp->x2;
+ *x3 = resp->x3;
+
+ dmbish();
+
+ resp->is_valid = 0;
+
+ spin_unlock(&responses_lock);
+
+ return 0;
+ }
+
+ spin_unlock(&responses_lock);
+
+ return -1;
+}