[PATCH 0/3] RISC-V tracing support

[Sean Anderson]

On 8/24/20 10:44 AM, Pragnesh Patel wrote:
> This series add a support of tracing for RISC-V arch.
> 
> This series is also available here [1] for testing.
> Series depends on [2].
> 
> [1] https://github.com/pragnesh26992/u-boot/tree/trace
> [2] https://patchwork.ozlabs.org/project/uboot/cover/20200729095636.1077054-1-seanga2@gmail.com/
> 
> How to test this patch:
> 1) Enable tracing in "configs/sifive_fu540_defconfig"
> CONFIG_TRACE=y
> CONFIG_TRACE_BUFFER_SIZE=0x01000000
> CONFIG_TRACE_CALL_DEPTH_LIMIT=15
> CONFIG_CMD_TRACE=y
> 
> 2) make FTRACE=1 sifive_fu540_defconfig
> 3) make FTRACE=1
> 
> Following are the boot messages on FU540 five cores SMP platform:
> 
> U-Boot 2020.10-rc1-02837-g8613dc2e66 (Aug 24 2020 - 20:03:47 +0530)
> 
> CPU:   rv64imac
> Model: SiFive HiFive Unleashed A00
> DRAM:  8 GiB
> trace: enabled
> MMC:   spi at 10050000:mmc at 0: 0
> Loading Environment from SPIFlash... SF: Detected is25wp256 with page size 256 Bytes, erase size 4 KiB, total 32 MiB
> OK
> In:    serial at 10010000
> Out:   serial at 10010000
> Err:   serial at 10010000
> Board serial number should not be 0 !!
> Net:
> Warning: ethernet at 10090000 (eth0) using random MAC address - 92:a1:a7:02:5a:14
> eth0: ethernet at 10090000
> Hit any key to stop autoboot:  0
> => trace stats
>         177,722 function sites
>      37,057,350 function calls
>               1 untracked function calls
>       1,279,612 traced function calls (36015585 dropped due to overflow)
>              19 maximum observed call depth
>              15 call depth limit
>      37,055,565 calls not traced due to depth
> =>
> 
> 
> Pragnesh Patel (3):
>   riscv: Add timer_get_us() for tracing
>   riscv: Mark riscv_timer_get_count() and sifive_clint_get_count() with
>     'notrace'
>   riscv: Mark andes_plmt_get_count() with 'notrace'
> 
>  arch/riscv/lib/Makefile       |  1 +
>  arch/riscv/lib/andes_plmt.c   |  2 +-
>  arch/riscv/lib/sifive_clint.c |  2 +-
>  arch/riscv/lib/timer.c        | 50 +++++++++++++++++++++++++++++++++++
>  drivers/timer/riscv_timer.c   |  2 +-
>  5 files changed, 54 insertions(+), 3 deletions(-)
>  create mode 100644 arch/riscv/lib/timer.c
> 

Tested-by: Sean Anderson <seanga2 at gmail.com>

I tested this on a K210 and had to reduce CONFIG_TRACE_BUFFER_SIZE to
0x100000 (1M) because of its reduced ram. Here is some example output:

U-Boot 2020.10-rc1-00164-gbb14d962f5 (Sep 01 2020 - 16:17:43 -0400)

DRAM:  8 MiB
trace: enabled
In:    serial at 38000000
Out:   serial at 38000000
Err:   serial at 38000000
=> trace stats
         76,948 function sites
     82,375,426 function calls
              1 untracked function calls
         36,075 traced function calls (164135507 dropped due to overflow)
             17 maximum observed call depth
             15 call depth limit
        679,059 calls not traced due to depth
=> 

--Sean