feat(psa): interface with RSS for NV counters

Adding AP/RSS interface for retrieving and incrementing non-volatile
counters.

The read interface implements the psa_call:
psa_call(RSS_PLATFORM_SERVICE_HANDLE,
         RSS_PLATFORM_API_ID_NV_READ,
         in_vec, 1, out_vec, 1);

where the in_vec indicates which of the 3 counters we want, and the
out_vec stores the counter value we get back from RSS.

The increment interface implements the psa_call:
psa_call(RSS_PLATFORM_SERVICE_HANDLE,
         RSS_PLATFORM_API_ID_NV_INCREMENT,
         in_vec, 1, (psa_outvec *)NULL, 0);

where, again, in_vec indicates the counter to increment, and we don't
get any output parameter from RSS.

Through this service, we will be able to get/increment any of the 3 NV
counters used on a CCA platform:
- NV counter for CCA firmware (BL2, BL31, RMM).
- NV counter for secure firmware.
- NV counter for non-secure firmware.

Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>
Signed-off-by: Raef Coles <raef.coles@arm.com>
Change-Id: I4c1c7f4837ebff30de16bb0ce7ecd416b70b1f62

1 files changed, 43 insertions, 0 deletions

diff --git a/lib/psa/rss_platform.c b/lib/psa/rss_platform.c
new file mode 100644
index 000000000..359f89499
--- /dev/null
+++ b/lib/psa/rss_platform.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2023, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#include <stdint.h>
+
+#include <psa/client.h>
+#include <psa_manifest/sid.h>
+#include <rss_platform_api.h>
+
+psa_status_t
+rss_platform_nv_counter_increment(uint32_t counter_id)
+{
+	struct psa_invec in_vec[1];
+
+	in_vec[0].base = &counter_id;
+	in_vec[0].len = sizeof(counter_id);
+
+	return psa_call(RSS_PLATFORM_SERVICE_HANDLE,
+			RSS_PLATFORM_API_ID_NV_INCREMENT,
+			in_vec, 1, NULL, 0);
+}
+
+psa_status_t
+rss_platform_nv_counter_read(uint32_t counter_id,
+		uint32_t size, uint8_t *val)
+{
+	struct psa_invec in_vec[1];
+	struct psa_outvec out_vec[1];
+
+	in_vec[0].base = &counter_id;
+	in_vec[0].len = sizeof(counter_id);
+
+	out_vec[0].base = val;
+	out_vec[0].len = size;
+
+	return psa_call(RSS_PLATFORM_SERVICE_HANDLE,
+			RSS_PLATFORM_API_ID_NV_READ,
+			in_vec, 1, out_vec, 1);
+}