[PATCH v3 0/1] RISC-V tracing support

[Pragnesh Patel <pragnesh.patel@sifive.com>]

This series add a support of tracing for RISC-V arch.

This series is also available here [1] for testing.
[1] https://github.com/pragnesh26992/u-boot/tree/trace

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

Changes in v3:
- Added gd->arch.plmt in global data
- For timer_get_us(), use readq() instead of andes_plmt_get_count()
  and sifive_clint_get_count()

Changes in v2:
- Remove newly added timer file (arch/riscv/lib/timer.c)
- Added timer_get_us() in riscv_timer.c, sifive_clint_timer.c
  and andes_plmt_timer.c.


Following are the boot messages on FU540 five cores SMP platform:

U-Boot SPL 2021.01-rc1-00244-g88b5af756c-dirty (Nov 11 2020 - 14:57:25 +0530)
Trying to boot from MMC1


U-Boot 2021.01-rc1-00244-g88b5af756c-dirty (Nov 11 2020 - 14:57:25 +0530)

CPU:   rv64imafdc
Model: SiFive HiFive Unleashed A00
DRAM:  8 GiB
trace: enabled
MMC:   spi at 10050000:mmc at 0: 0
*** Warning - bad CRC, using default environment

In:    serial at 10010000
Out:   serial at 10010000
Err:   serial at 10010000
Board serial number should not be 0 !!
Net:
Error: ethernet at 10090000 address not set.
No ethernet found.

Hit any key to stop autoboot:  0
=> trace stats
        178,556 function sites
     15,443,168 function calls
              1 untracked function calls
      1,279,056 traced function calls (14135744 dropped due to overflow)
             19 maximum observed call depth
             15 call depth limit
     15,633,052 calls not traced due to depth
=>


Pragnesh Patel (1):
  riscv: Add timer_get_us() for tracing

 arch/riscv/include/asm/global_data.h |  3 +++
 drivers/timer/andes_plmt_timer.c     | 19 ++++++++++++++++++-
 drivers/timer/riscv_timer.c          | 14 +++++++++++++-
 drivers/timer/sifive_clint_timer.c   | 19 ++++++++++++++++++-
 4 files changed, 52 insertions(+), 3 deletions(-)

-- 
2.17.1