Tegra: lib: library for profiling the cold boot path
The non secure world would like to profile the boot path for
the EL3 and S-EL1 firmwares. To allow it to do that, a non-secure
DRAM region (4K) is allocated and the base address is passed to
the EL3 firmware.
This patch adds a library to allow the platform code to store the
tag:timestamp pair to the shared memory. The tegra platform code
then uses the `record` method to add timestamps.
Original change by Akshay Sharan <asharan@nvidia.com>
Change-Id: Idbbef9c83ed84a508b04d85a6637775960dc94ba
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
diff --git a/plat/nvidia/tegra/common/lib/debug/profiler.c b/plat/nvidia/tegra/common/lib/debug/profiler.c
new file mode 100644
index 0000000..f40244b
--- /dev/null
+++ b/plat/nvidia/tegra/common/lib/debug/profiler.c
@@ -0,0 +1,146 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/*******************************************************************************
+ * The profiler stores the timestamps captured during cold boot to the shared
+ * memory for the non-secure world. The non-secure world driver parses the
+ * shared memory block and writes the contents to a file on the device, which
+ * can be later extracted for analysis.
+ *
+ * Profiler memory map
+ *
+ * TOP --------------------------- ---
+ * Trusted OS timestamps 3KB
+ * --------------------------- ---
+ * Trusted Firmware timestamps 1KB
+ * BASE --------------------------- ---
+ *
+ ******************************************************************************/
+
+#include <arch.h>
+#include <arch_helpers.h>
+#include <assert.h>
+#include <mmio.h>
+#include <profiler.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <utils_def.h>
+#include <xlat_tables_v2.h>
+
+static uint64_t shmem_base_addr;
+
+#define MAX_PROFILER_RECORDS U(16)
+#define TAG_LEN_BYTES U(56)
+
+/*******************************************************************************
+ * Profiler entry format
+ ******************************************************************************/
+typedef struct {
+ /* text explaining the timestamp location in code */
+ uint8_t tag[TAG_LEN_BYTES];
+ /* timestamp value */
+ uint64_t timestamp;
+} profiler_rec_t;
+
+static profiler_rec_t *head, *cur, *tail;
+static uint32_t tmr;
+static bool is_shmem_buf_mapped;
+
+/*******************************************************************************
+ * Initialise the profiling library
+ ******************************************************************************/
+void boot_profiler_init(uint64_t shmem_base, uint32_t tmr_base)
+{
+ uint64_t shmem_end_base;
+
+ assert(shmem_base != ULL(0));
+ assert(tmr_base != U(0));
+
+ /* store the buffer address */
+ shmem_base_addr = shmem_base;
+
+ /* calculate the base address of the last record */
+ shmem_end_base = shmem_base + (sizeof(profiler_rec_t) *
+ (MAX_PROFILER_RECORDS - U(1)));
+
+ /* calculate the head, tail and cur values */
+ head = (profiler_rec_t *)shmem_base;
+ tail = (profiler_rec_t *)shmem_end_base;
+ cur = head;
+
+ /* timer used to get the current timestamp */
+ tmr = tmr_base;
+}
+
+/*******************************************************************************
+ * Add tag and timestamp to profiler
+ ******************************************************************************/
+void boot_profiler_add_record(const char *str)
+{
+ unsigned int len;
+
+ /* calculate the length of the tag */
+ if (((unsigned int)strlen(str) + U(1)) > TAG_LEN_BYTES) {
+ len = TAG_LEN_BYTES;
+ } else {
+ len = (unsigned int)strlen(str) + U(1);
+ }
+
+ if (head != NULL) {
+
+ /*
+ * The profiler runs with/without MMU enabled. Check
+ * if MMU is enabled and memmap the shmem buffer, in
+ * case it is.
+ */
+ if ((!is_shmem_buf_mapped) &&
+ ((read_sctlr_el3() & SCTLR_M_BIT) != U(0))) {
+
+ (void)mmap_add_dynamic_region(shmem_base_addr,
+ shmem_base_addr,
+ PROFILER_SIZE_BYTES,
+ (MT_NS | MT_RW | MT_EXECUTE_NEVER));
+
+ is_shmem_buf_mapped = true;
+ }
+
+ /* write the tag and timestamp to buffer */
+ (void)snprintf((char *)cur->tag, len, "%s", str);
+ cur->timestamp = mmio_read_32(tmr);
+
+ /* start from head if we reached the end */
+ if (cur == tail) {
+ cur = head;
+ } else {
+ cur++;
+ }
+ }
+}
+
+/*******************************************************************************
+ * Deinint the profiler
+ ******************************************************************************/
+void boot_profiler_deinit(void)
+{
+ if (shmem_base_addr != ULL(0)) {
+
+ /* clean up resources */
+ cur = NULL;
+ head = NULL;
+ tail = NULL;
+
+ /* flush the shmem for it to be visible to the NS world */
+ flush_dcache_range(shmem_base_addr, PROFILER_SIZE_BYTES);
+
+ /* unmap the shmem buffer */
+ if (is_shmem_buf_mapped) {
+ (void)mmap_remove_dynamic_region(shmem_base_addr,
+ PROFILER_SIZE_BYTES);
+ }
+ }
+}