RISC-V: Add kexec/kdump support

This patch series adds kexec/kdump and crash kernel support on RISC-V. For testing the patches a patched version of kexec-tools is needed (still a work in progress) which can be found at:

https://riscv.ics.forth.gr/kexec-tools-patched.tar.xz

v4:
* Rebase on top of "fixes" branch
* Resolve Alex's comments

v3:
* Rebase on newer kernel tree
* Minor cleanups
* Split UAPI changes to a separate patch
* Improve / cleanup init_resources
* Resolve Palmer's comments

v2:
* Rebase on newer kernel tree
* Minor cleanups
* Properly populate the ioresources tre, so that it can be used later on for implementing strict /dev/mem
* Use linux,usable-memory on /memory instead of a new binding
* USe a reserved-memory node for ELF core header

Nick Kossifidis (5):
RISC-V: Add EM_RISCV to kexec UAPI header
RISC-V: Add kexec support
RISC-V: Improve init_resources
RISC-V: Add kdump support
RISC-V: Add crash kernel support

 arch/riscv/Kconfig                  |  25 ++++
 arch/riscv/include/asm/elf.h        |   6 +
 arch/riscv/include/asm/kexec.h      |  56 +++++++
 arch/riscv/kernel/Makefile          |   6 +
 arch/riscv/kernel/crash_dump.c      |  46 ++++++
 arch/riscv/kernel/crash_save_regs.S |  56 +++++++
 arch/riscv/kernel/kexec_relocate.S  | 223 ++++++++++++++++++++++++++++
 arch/riscv/kernel/machine_kexec.c   | 193 ++++++++++++++++++++++++
 arch/riscv/kernel/setup.c           | 114 ++++++++------
 arch/riscv/mm/init.c                | 104 +++++++++++++
 include/uapi/linux/kexec.h          |   1 +
 11 files changed, 784 insertions(+), 46 deletions(-)
 create mode 100644 arch/riscv/include/asm/kexec.h
 create mode 100644 arch/riscv/kernel/crash_dump.c
 create mode 100644 arch/riscv/kernel/crash_save_regs.S
 create mode 100644 arch/riscv/kernel/kexec_relocate.S
 create mode 100644 arch/riscv/kernel/machine_kexec.c

2.26.2