neorv32/sw/example/demo_hpm/main.c

182 lines
11 KiB
C

// #################################################################################################
// # << NEORV32 - Hardware Performance Monitors (HPMs) Demo Program >> #
// # ********************************************************************************************* #
// # BSD 3-Clause License #
// # #
// # Copyright (c) 2024, Stephan Nolting. All rights reserved. #
// # #
// # Redistribution and use in source and binary forms, with or without modification, are #
// # permitted provided that the following conditions are met: #
// # #
// # 1. Redistributions of source code must retain the above copyright notice, this list of #
// # conditions and the following disclaimer. #
// # #
// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of #
// # conditions and the following disclaimer in the documentation and/or other materials #
// # provided with the distribution. #
// # #
// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to #
// # endorse or promote products derived from this software without specific prior written #
// # permission. #
// # #
// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS #
// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF #
// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE #
// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, #
// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED #
// # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING #
// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED #
// # OF THE POSSIBILITY OF SUCH DAMAGE. #
// # ********************************************************************************************* #
// # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #
// #################################################################################################
/**********************************************************************//**
* @file demo_hpm/main.c
* @author Stephan Nolting
* @brief Hardware performance monitor (HPM) example program.
**************************************************************************/
#include <neorv32.h>
/**********************************************************************//**
* @name User configuration
**************************************************************************/
/**@{*/
/** UART BAUD rate */
#define BAUD_RATE 19200
/**@}*/
/**********************************************************************//**
* Main function
*
* @note This program requires the CPU Zihpm extension (with at least 2 regions) and UART0.
*
* @return 0 if execution was successful
**************************************************************************/
int main() {
// initialize NEORV32 run-time environment
neorv32_rte_setup();
// setup UART at default baud rate, no interrupts
neorv32_uart0_setup(BAUD_RATE, 0);
// check if UART0 is implemented
if (neorv32_uart0_available() == 0) {
return 1; // UART0 not available, exit
}
// check if Zihpm is implemented at all
if ((neorv32_cpu_csr_read(CSR_MXISA) & (1 << CSR_MXISA_ZIHPM)) == 0) {
neorv32_uart0_printf("ERROR! Zihpm CPU extension not implemented!\n");
return 1;
}
// check if at least one HPM counter is implemented
if (neorv32_cpu_hpm_get_num_counters() == 0) {
neorv32_uart0_printf("ERROR! No HPM counters implemented!\n");
return 1;
}
// intro
neorv32_uart0_printf("\n<<< NEORV32 Hardware Performance Monitors (HPMs) Example Program >>>\n\n");
neorv32_uart0_printf("[NOTE] This program will use up to 9 HPM counters (if available).\n\n");
// show HPM hardware configuration
uint32_t hpm_num = neorv32_cpu_hpm_get_num_counters();
uint32_t hpm_width = neorv32_cpu_hpm_get_size();
neorv32_uart0_printf("%u HPM counters detected, each %u bits wide\n", hpm_num, hpm_width);
// stop all CPU counters including HPMs
neorv32_cpu_csr_write(CSR_MCOUNTINHIBIT, -1);
// clear HPM counters (low and high word);
// there will be NO exception if we access a HPM counter register that has not been implemented
// as long as Zihpm is implemented
if (hpm_num > 0) { neorv32_cpu_csr_write(CSR_MHPMCOUNTER3, 0); neorv32_cpu_csr_write(CSR_MHPMCOUNTER3H, 0); }
if (hpm_num > 1) { neorv32_cpu_csr_write(CSR_MHPMCOUNTER4, 0); neorv32_cpu_csr_write(CSR_MHPMCOUNTER4H, 0); }
if (hpm_num > 2) { neorv32_cpu_csr_write(CSR_MHPMCOUNTER5, 0); neorv32_cpu_csr_write(CSR_MHPMCOUNTER5H, 0); }
if (hpm_num > 3) { neorv32_cpu_csr_write(CSR_MHPMCOUNTER6, 0); neorv32_cpu_csr_write(CSR_MHPMCOUNTER6H, 0); }
if (hpm_num > 4) { neorv32_cpu_csr_write(CSR_MHPMCOUNTER7, 0); neorv32_cpu_csr_write(CSR_MHPMCOUNTER7H, 0); }
if (hpm_num > 5) { neorv32_cpu_csr_write(CSR_MHPMCOUNTER8, 0); neorv32_cpu_csr_write(CSR_MHPMCOUNTER8H, 0); }
if (hpm_num > 6) { neorv32_cpu_csr_write(CSR_MHPMCOUNTER9, 0); neorv32_cpu_csr_write(CSR_MHPMCOUNTER9H, 0); }
if (hpm_num > 7) { neorv32_cpu_csr_write(CSR_MHPMCOUNTER10, 0); neorv32_cpu_csr_write(CSR_MHPMCOUNTER10H, 0); }
if (hpm_num > 8) { neorv32_cpu_csr_write(CSR_MHPMCOUNTER11, 0); neorv32_cpu_csr_write(CSR_MHPMCOUNTER11H, 0); }
// NOTE regarding HPMs 0..2, which are not "actual" HPMs
// - HPM 0 is the machine cycle counter
// - HPM 1 is the machine system timer
// - HPM 2 is the machine instret counter
// these counters have fixed event configurations; however, these according events can also be used for any other "real" HPM
// setup base counters if available
if ((neorv32_cpu_csr_read(CSR_MXISA) & (1 << CSR_MXISA_ZICNTR))) {
neorv32_cpu_csr_write(CSR_MCYCLE, 0); neorv32_cpu_csr_write(CSR_MCYCLEH, 0);
neorv32_cpu_csr_write(CSR_MINSTRET, 0); neorv32_cpu_csr_write(CSR_MINSTRETH, 0);
}
// configure events - one event per counter;
// we can also configure more than one event; the HPM will increment if _any_ event triggers (logical OR);
// there will be NO exception if we access a HPM event register that has not been implemented
// as long as Zihpm is implemented
if (hpm_num > 0) { neorv32_cpu_csr_write(CSR_MHPMEVENT3, 1 << HPMCNT_EVENT_COMPR); } // executed compressed instruction
if (hpm_num > 1) { neorv32_cpu_csr_write(CSR_MHPMEVENT4, 1 << HPMCNT_EVENT_WAIT_DIS); } // instruction dispatch wait cycle
if (hpm_num > 2) { neorv32_cpu_csr_write(CSR_MHPMEVENT5, 1 << HPMCNT_EVENT_WAIT_ALU); } // multi-cycle ALU co-processor wait cycle
if (hpm_num > 3) { neorv32_cpu_csr_write(CSR_MHPMEVENT6, 1 << HPMCNT_EVENT_BRANCH); } // executed branch instruction
if (hpm_num > 4) { neorv32_cpu_csr_write(CSR_MHPMEVENT7, 1 << HPMCNT_EVENT_BRANCHED); } // control flow transfer
if (hpm_num > 5) { neorv32_cpu_csr_write(CSR_MHPMEVENT8, 1 << HPMCNT_EVENT_LOAD); } // executed load operation
if (hpm_num > 6) { neorv32_cpu_csr_write(CSR_MHPMEVENT9, 1 << HPMCNT_EVENT_STORE); } // executed store operation
if (hpm_num > 7) { neorv32_cpu_csr_write(CSR_MHPMEVENT10, 1 << HPMCNT_EVENT_WAIT_LSU); } // load-store unit memory wait cycle
if (hpm_num > 8) { neorv32_cpu_csr_write(CSR_MHPMEVENT11, 1 << HPMCNT_EVENT_TRAP); } // entered trap
// enable all CPU counters including HPMs
neorv32_cpu_csr_write(CSR_MCOUNTINHIBIT, 0);
// this is the part of the the program that is going to be "benchmarked" using the HPMs
// here we are just doing some pointless stuff that will trigger the configured HPM events;
// note that ALL code being executed will be benchmarked - including traps
{
neorv32_uart0_printf("\n > Doing dummy operations...\n");
neorv32_uart0_printf(" > Print some number: %u\n", 52983740);
neorv32_uart0_printf(" > An exception (environment call) handled by the RTE: ");
asm volatile ("ecall"); // environment call
neorv32_uart0_printf(" > An invalid instruction handled by the RTE: ");
asm volatile ("csrwi marchid, 1"); // illegal instruction (writing to read-only CSR)
}
// stop all CPU counters including HPMs
neorv32_cpu_csr_write(CSR_MCOUNTINHIBIT, -1);
// print HPM counter values (low word only)
neorv32_uart0_printf("\nHPM results (low-words only):\n");
if ((neorv32_cpu_csr_read(CSR_MXISA) & (1 << CSR_MXISA_ZICNTR))) {
neorv32_uart0_printf(" cycle (active clock cycles) : %u\n", (uint32_t)neorv32_cpu_csr_read(CSR_MCYCLE));
neorv32_uart0_printf(" instret (retired instructions) : %u\n", (uint32_t)neorv32_cpu_csr_read(CSR_MINSTRET));
}
if (hpm_num > 0) { neorv32_uart0_printf(" HPM03 (compressed instructions) : %u\n", (uint32_t)neorv32_cpu_csr_read(CSR_MHPMCOUNTER3)); }
if (hpm_num > 1) { neorv32_uart0_printf(" HPM04 (instr. dispatch wait cycles) : %u\n", (uint32_t)neorv32_cpu_csr_read(CSR_MHPMCOUNTER4)); }
if (hpm_num > 2) { neorv32_uart0_printf(" HPM05 (ALU wait cycles) : %u\n", (uint32_t)neorv32_cpu_csr_read(CSR_MHPMCOUNTER5)); }
if (hpm_num > 3) { neorv32_uart0_printf(" HPM06 (branch instructions) : %u\n", (uint32_t)neorv32_cpu_csr_read(CSR_MHPMCOUNTER6)); }
if (hpm_num > 4) { neorv32_uart0_printf(" HPM07 (control flow transfers) : %u\n", (uint32_t)neorv32_cpu_csr_read(CSR_MHPMCOUNTER7)); }
if (hpm_num > 5) { neorv32_uart0_printf(" HPM08 (load instructions) : %u\n", (uint32_t)neorv32_cpu_csr_read(CSR_MHPMCOUNTER8)); }
if (hpm_num > 6) { neorv32_uart0_printf(" HPM09 (store instructions) : %u\n", (uint32_t)neorv32_cpu_csr_read(CSR_MHPMCOUNTER9)); }
if (hpm_num > 7) { neorv32_uart0_printf(" HPM10 (load/store wait cycles) : %u\n", (uint32_t)neorv32_cpu_csr_read(CSR_MHPMCOUNTER10)); }
if (hpm_num > 8) { neorv32_uart0_printf(" HPM11 (entered traps) : %u\n", (uint32_t)neorv32_cpu_csr_read(CSR_MHPMCOUNTER11)); }
neorv32_uart0_printf("\nProgram completed.\n");
return 0;
}