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>

docs/plat/nvidia-tegra.rst

@@ -82,6 +82,8 @@ uint64\_t tzdram\_base;
 int uart\_id;
 /* L2 ECC parity protection disable flag \*/
 int l2\_ecc\_parity\_prot\_dis;
+/* SHMEM base address for storing the boot logs \*/
+uint64\_t boot\_profiler\_shmem\_base;
 } plat\_params\_from\_bl2\_t;
 
 Power Management

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);
+		}
+	}
+}

plat/nvidia/tegra/common/tegra_bl31_setup.c

@@ -26,6 +26,7 @@
 #include <plat/common/platform.h>
 
 #include <memctrl.h>
+#include <profiler.h>
 #include <tegra_def.h>
 #include <tegra_platform.h>
 #include <tegra_private.h>
@@ -125,6 +126,7 @@ void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
 	image_info_t bl32_img_info = { {0} };
 	uint64_t tzdram_start, tzdram_end, bl32_start, bl32_end;
 	uint32_t console_clock;
+	int32_t ret;
 
 	/*
 	 * For RESET_TO_BL31 systems, BL31 is the first bootloader to run so
@@ -194,6 +196,32 @@ void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
 			     TEGRA_CONSOLE_BAUDRATE);
 	}
 
+	/*
+	 * The previous bootloader passes the base address of the shared memory
+	 * location to store the boot profiler logs. Sanity check the
+	 * address and initilise the profiler library, if it looks ok.
+	 */
+	if (plat_params->boot_profiler_shmem_base != 0ULL) {
+
+		ret = bl31_check_ns_address(plat_params->boot_profiler_shmem_base,
+				PROFILER_SIZE_BYTES);
+		if (ret == (int32_t)0) {
+
+			/* store the membase for the profiler lib */
+			plat_bl31_params_from_bl2.boot_profiler_shmem_base =
+				plat_params->boot_profiler_shmem_base;
+
+			/* initialise the profiler library */
+			boot_profiler_init(plat_params->boot_profiler_shmem_base,
+					   TEGRA_TMRUS_BASE);
+		}
+	}
+
+	/*
+	 * Add timestamp for platform early setup entry.
+	 */
+	boot_profiler_add_record("[TF] early setup entry");
+
 	/*
 	 * Initialize delay timer
 	 */
@@ -244,6 +272,11 @@ void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
 	/* Early platform setup for Tegra SoCs */
 	plat_early_platform_setup();
 
+	/*
+	 * Add timestamp for platform early setup exit.
+	 */
+	boot_profiler_add_record("[TF] early setup exit");
+
 	INFO("BL3-1: Boot CPU: %s Processor [%lx]\n",
 	     (((read_midr() >> MIDR_IMPL_SHIFT) & MIDR_IMPL_MASK)
 	      == DENVER_IMPL) ? "Denver" : "ARM", read_mpidr());
@@ -268,6 +301,11 @@ void plat_trusty_set_boot_args(aapcs64_params_t *args)
  ******************************************************************************/
 void bl31_platform_setup(void)
 {
+	/*
+	 * Add timestamp for platform setup entry.
+	 */
+	boot_profiler_add_record("[TF] plat setup entry");
+
 	/* Initialize the gic cpu and distributor interfaces */
 	plat_gic_setup();
 
@@ -287,6 +325,11 @@ void bl31_platform_setup(void)
 	 */
 	tegra_memctrl_tzram_setup(TEGRA_TZRAM_BASE, TEGRA_TZRAM_SIZE);
 
+	/*
+	 * Add timestamp for platform setup exit.
+	 */
+	boot_profiler_add_record("[TF] plat setup exit");
+
 	INFO("BL3-1: Tegra platform setup complete\n");
 }
 
@@ -305,6 +348,12 @@ void bl31_plat_runtime_setup(void)
 	 * disabled before we jump to the non-secure world.
 	 */
 	tegra_memctrl_disable_ahb_redirection();
+
+	/*
+	 * Add final timestamp before exiting BL31.
+	 */
+	boot_profiler_add_record("[TF] bl31 exit");
+	boot_profiler_deinit();
 }
 
 /*******************************************************************************
@@ -325,6 +374,11 @@ void bl31_plat_arch_setup(void)
 #endif
 	const plat_params_from_bl2_t *params_from_bl2 = bl31_get_plat_params();
 
+	/*
+	 * Add timestamp for arch setup entry.
+	 */
+	boot_profiler_add_record("[TF] arch setup entry");
+
 	/* add memory regions */
 	mmap_add_region(rw_start, rw_start,
 			rw_size,
@@ -373,6 +427,11 @@ void bl31_plat_arch_setup(void)
 	/* enable the MMU */
 	enable_mmu_el3(0);
 
+	/*
+	 * Add timestamp for arch setup exit.
+	 */
+	boot_profiler_add_record("[TF] arch setup exit");
+
 	INFO("BL3-1: Tegra: MMU enabled\n");
 }
 

plat/nvidia/tegra/common/tegra_common.mk

@@ -5,6 +5,7 @@
 #
 
 PLAT_INCLUDES		:=	-Iplat/nvidia/tegra/include/drivers \
+				-Iplat/nvidia/tegra/include/lib \
 				-Iplat/nvidia/tegra/include \
 				-Iplat/nvidia/tegra/include/${TARGET_SOC}
 
@@ -25,6 +26,7 @@ BL31_SOURCES		+=	drivers/console/aarch64/console.S		\
 				${TEGRA_GICv2_SOURCES}				\
 				${COMMON_DIR}/aarch64/tegra_helpers.S		\
 				${COMMON_DIR}/drivers/pmc/pmc.c			\
+				${COMMON_DIR}/lib/debug/profiler.c		\
 				${COMMON_DIR}/tegra_bl31_setup.c		\
 				${COMMON_DIR}/tegra_delay_timer.c		\
 				${COMMON_DIR}/tegra_fiq_glue.c			\

plat/nvidia/tegra/include/lib/profiler.h

@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __PROFILER_H__
+#define __PROFILER_H__
+
+/*******************************************************************************
+ * Number of bytes of memory used by the profiler on Tegra
+ ******************************************************************************/
+#define PROFILER_SIZE_BYTES	U(0x1000)
+
+void boot_profiler_init(uint64_t shmem_base, uint32_t tmr_base);
+void boot_profiler_add_record(const char *str);
+void boot_profiler_deinit(void);
+
+#endif /* __PROFILER_H__ */

plat/nvidia/tegra/include/tegra_private.h

@@ -44,6 +44,8 @@ typedef struct plat_params_from_bl2 {
 	int32_t uart_id;
 	/* L2 ECC parity protection disable flag */
 	int32_t l2_ecc_parity_prot_dis;
+	/* SHMEM base address for storing the boot logs */
+	uint64_t boot_profiler_shmem_base;
 } plat_params_from_bl2_t;
 
 /*******************************************************************************