[RFC PATCH 0/6] riscv: add initial support for hardware breakpoints

[Jesse Taube <jesse@rivosinc.com>]

This patchset adds initial support for hardware breakpoints and
watchpoints to the  RISC-V architecture. The framework is built on
top of perf subsystem and SBI debug trigger extension.

Currently following features are not supported and are in works:
 - Ptrace regset support
 - Virtualization of debug triggers

The SBI debug trigger extension can be found at:
https://github.com/riscv-non-isa/riscv-sbi-doc/blob/master/src/ext-debug-triggers.adoc

The Sdtrig ISA is part of RISC-V debug specification which can be
found at:
https://github.com/riscv/riscv-debug-spec

based off the original RFC by Himanshu Chauhan here:
https://lore.kernel.org/lkml/20240222125059.13331-1-hchauhan@ventanamicro.com/

Himanshu Chauhan (2):
  riscv: Add SBI debug trigger extension and function ids
  riscv: Introduce support for hardware break/watchpoints

Jesse Taube (4):
  riscv: Add insn.c, consolidate instruction decoding
  riscv: insn: __read_insn use copy_from_X_nofault
  riscv: hw_breakpoint: Use icount for single stepping
  riscv: ptrace: Add hw breakpoint support

 arch/riscv/Kconfig                     |  12 +
 arch/riscv/include/asm/bug.h           |  12 -
 arch/riscv/include/asm/hw_breakpoint.h |  60 +++
 arch/riscv/include/asm/insn.h          | 131 ++++-
 arch/riscv/include/asm/kdebug.h        |   3 +-
 arch/riscv/include/asm/processor.h     |   4 +
 arch/riscv/include/asm/sbi.h           |  33 +-
 arch/riscv/include/uapi/asm/ptrace.h   |   3 +-
 arch/riscv/kernel/Makefile             |   2 +
 arch/riscv/kernel/hw_breakpoint.c      | 681 +++++++++++++++++++++++++
 arch/riscv/kernel/insn.c               | 153 ++++++
 arch/riscv/kernel/kgdb.c               | 102 +---
 arch/riscv/kernel/probes/kprobes.c     |   1 +
 arch/riscv/kernel/process.c            |   4 +
 arch/riscv/kernel/ptrace.c             |  93 ++++
 arch/riscv/kernel/traps.c              |  11 +-
 arch/riscv/kernel/traps_misaligned.c   |  93 +---
 17 files changed, 1208 insertions(+), 190 deletions(-)
 create mode 100644 arch/riscv/include/asm/hw_breakpoint.h
 create mode 100644 arch/riscv/kernel/hw_breakpoint.c
 create mode 100644 arch/riscv/kernel/insn.c

-- 
2.43.0