The patch series is based on:
enable MMU for RISC-V [1]
which haven't been commited yet.
The patch series provides a basic implementation of exception handling.
It can do only basic things such as decode a cause of an exception,
save/restore registers and execute "wfi" instruction if an exception
can not be handled.
To verify that exception handling works well it was implemented macros
from <asm/bug.h> such as BUG/WARN/run_in_exception/assert_failed.
The implementation of macros is used "ebreak" instruction and set up bug
frame tables for each type of macros.
Also it was implemented register save/restore to return and continue work
after WARN/run_in_exception.
Not all functionality of the macros was implemented as some of them
require hard-panic the system which is not available now. Instead of
hard-panic 'wfi' instruction is used but it should be definitely changed
in the neareset future.
It wasn't implemented show_execution_state() and stack trace discovering
as it's not necessary now.
[1] https://lore.kernel.org/xen-devel/cover.1685027257.git.oleksii.kurochko@gmail.com/T/#t
---
Changes in V6:
- Update the cover letter message: the patch set is based on MMU patch series.
- Introduce new patch with temporary printk functionality. ( it will be
removed when Xen common code will be ready )
- Change early_printk() to printk().
- Remove usage of LINK_TO_LOAD() due to the MMU being enabled first.
- Add additional explanatory comments.
- Remove patch "xen/riscv: initialize boot_info structure" from the patch
series.
---
Changes in V5:
- Rebase on top of [1] and [2]
- Add new patch which introduces stub for <asm/bug.h> to keep Xen compilable
as in the patch [xen/riscv: introduce decode_cause() stuff] is used
header <xen/lib.h> which requires <asm/bug.h>.
- Remove <xen/error.h> from riscv/traps/c as nothing would require
inclusion.
- decode_reserved_interrupt_cause(), decode_interrupt_cause(),
decode_cause, do_unexpected_trap() were made as static they are expected
to be used only in traps.c
- Remove "#include <xen/types.h>" from <asm/bug.h> as there is no any need in it anymore
- Update macros GET_INSN_LENGTH: remove UL and 'unsigned int len;' from it
- Remove " include <xen/bug.h>" from risc/setup.c. it is not needed in the current version of
the patch
- change an argument type from vaddr_t to uint32_t for is_valid_bugaddr and introduce
read_instr() to read instruction properly as the length of qinstruction can be
either 32 or 16 bits.
- Code style fixes
- update the comments before do_bug_frame() in riscv/trap.c
- [[PATCH v4 5/5] automation: modify RISC-V smoke test ] was dropped as it was provided
more simple solution by Andrew. CI: Simplify RISCV smoke testing
- Refactor is_valid_bugaddr() function.
- 2 new patches ([PATCH v5 {1-2}/7]) were introduced, the goal of which is to recalculate
addresses used in traps.c, which can be linker time relative. It is needed as we don't
have enabled MMU yet.
---
Changes in V4:
- Rebase the patch series on top of new version of [introduce generic
implementation of macros from bug.h] patch series.
- Update the cover letter message as 'Early printk' was merged and
the current one patch series is based only on [introduce generic
implementation of macros from bug.h] which hasn't been commited yet.
- The following patches of the patch series were merged to staging:
[PATCH v3 01/14] xen/riscv: change ISA to r64G
[PATCH v3 02/14] xen/riscv: add <asm/asm.h> header
[PATCH v3 03/14] xen/riscv: add <asm/riscv_encoding.h header
[PATCH v3 04/14] xen/riscv: add <asm/csr.h> header
[PATCH v3 05/14] xen/riscv: introduce empty <asm/string.h>
[PATCH v3 06/14] xen/riscv: introduce empty <asm/cache.h>
[PATCH v3 07/14] xen/riscv: introduce exception context
[PATCH v3 08/14] xen/riscv: introduce exception handlers implementation
[PATCH v3 10/14] xen/riscv: mask all interrupts
- Fix addressed comments in xen-devel mailing list.
---
Changes in V3:
- Change the name of config RISCV_ISA_RV64IMA to RISCV_ISA_RV64G
as instructions from Zicsr and Zifencei extensions aren't part of
I extension any more.
- Rebase the patch "xen/riscv: introduce an implementation of macros
from <asm/bug.h>" on top of patch series [introduce generic implementation
of macros from bug.h]
- Update commit messages
---
Changes in V2:
- take the latest riscv_encoding.h from OpenSBI, update it with Xen
related changes, and update the commit message with "Origin:"
tag and the commit message itself.
- add "Origin:" tag to the commit messag of the patch
[xen/riscv: add <asm/csr.h> header].
- Remove the patch [xen/riscv: add early_printk_hnum() function] as the
functionality provided by the patch isn't used now.
- Refactor prcoess.h: move structure offset defines to asm-offsets.c,
change register_t to unsigned long.
- Refactor entry.S to use offsets defined in asm-offsets.C
- Rename {__,}handle_exception to handle_trap() and do_trap() to be more
consistent with RISC-V spec.
- Merge the pathc which introduces do_unexpected_trap() with the patch
[xen/riscv: introduce exception handlers implementation].
- Rename setup_trap_handler() to trap_init() and update correspondingly
the patches in the patch series.
- Refactor bug.h, remove bug_instr_t type from it.
- Refactor decode_trap_cause() function to be more optimization-friendly.
- Add two new empty headers: <cache.h> and <string.h> as they are needed to
include <xen/lib.h> which provides ARRAY_SIZE and other macros.
- Code style fixes.
---
Oleksii Kurochko (6):
xen/riscv: introduce temporary printk stuff
xen/riscv: introduce dummy <asm/bug.h>
xen/riscv: introduce decode_cause() stuff
xen/riscv: introduce trap_init()
xen/riscv: introduce an implementation of macros from <asm/bug.h>
xen/riscv: test basic handling stuff
xen/arch/riscv/early_printk.c | 168 ++++++++++++++++++++
xen/arch/riscv/include/asm/bug.h | 38 +++++
xen/arch/riscv/include/asm/traps.h | 1 +
xen/arch/riscv/setup.c | 20 +++
xen/arch/riscv/traps.c | 238 ++++++++++++++++++++++++++++-
xen/arch/riscv/xen.lds.S | 10 ++
6 files changed, 474 insertions(+), 1 deletion(-)
create mode 100644 xen/arch/riscv/include/asm/bug.h
--
2.40.1