Commit Graph

27 Commits

Author SHA1 Message Date
Chao-ying Fu
8a3071222a lib: Emulate AMO instructions when Zaamo is not available
The AMO instructions are very critical for Linux so allow low-end
RISC-V implementations without Zaamo to boot Linux by emulating AMO
instructions using Zalrsc when OpenSBI is compiled without Zaamo.

Signed-off-by: Chao-ying Fu <cfu@mips.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Link: https://lore.kernel.org/r/20250519121207.976949-1-apatel@ventanamicro.com
Signed-off-by: Anup Patel <anup@brainfault.org>
2025-05-20 09:18:03 +05:30
Clément Léger
80656bdb1d lib: sbi: factorize previous mode computation
Previous privilege mode retrieval from mstatus is done at different
places, factorize it rather than copy/pasting it again.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
2024-10-25 23:53:18 +05:30
Dongdong Zhang
d4322eebd0 lib: sbi: Enhance CSR Handling in system_opcode_insn
- Completed TODO in `system_opcode_insn` to ensure CSR read/write
  instruction handling.
- Refactored to use new macros `GET_RS1_NUM` and `GET_CSR_NUM`.
- Updated `GET_RM` macro and replaced hardcoded funct3 values with
  constants (`CSRRW`, `CSRRS`, `CSRRC`, etc.).
- Removed redundant `GET_RM` from `riscv_fp.h`.
- Improved validation and error handling for CSR instructions.

This patch enhances the clarity and correctness of CSR handling
in `system_opcode_insn`.

Signed-off-by: Dongdong Zhang <zhangdongdong@eswincomputing.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-08-23 13:36:49 +05:30
Anup Patel
f414cf931e lib: sbi: Simplify parameters of sbi_illegal_insn_handler()
The struct sbi_trap_context already has the information needed by
sbi_illegal_insn_handler() so directly pass struct sbi_trap_context
pointer to this function.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
2024-03-19 11:31:31 +05:30
Samuel Holland
2e8517865a lib: sbi: Remove epc from struct sbi_trap_info
In the only places this value is used, it duplicates mepc from
struct sbi_trap_regs.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2024-03-19 11:31:16 +05:30
Xiang W
4e3353057a lib: sbi: Remove unnecessary semicolon
We have redundant semicolon at quite a few places so let's remove it.

Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2023-05-11 12:31:34 +05:30
Rahul Pathak
111afc1230 lib: sbi_illegal_insn: Fix FENCE.TSO emulation infinite trap loop
In case of missing "FENCE.TSO" instruction implementation,
opensbi can emulate the "FENCE.TSO" with "FENCE RW,RW", but
mepc was not incremented to continue from the next instruction
causing infinite trap.

Fixes: cb8271c8 ("lib: sbi_illegal_insn: Add emulation for fence.tso")
Signed-off-by: Rahul Pathak <rpathak@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Samuel Holland <samuel@sholland.org>
2022-08-22 08:57:23 +05:30
Vivian Wang
1c4ce74f51 lib: sbi: Set gva when creating sbi_trap_info
In some cases the sbi_trap_info argument passed to sbi_trap_redirect is
created from scratch by filling its fields. Since we previously added a
gva field to struct sbi_trap_info, initialize gva in these cases also.

Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Vivian Wang <dramforever@live.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2022-08-22 08:49:49 +05:30
Samuel Holland
cb8271c8e4 lib: sbi_illegal_insn: Add emulation for fence.tso
While OpenC906 appears to properly decode `fence.tso` as a fence
instruction[1], the version of the C906 taped out in the Allwinner D1
does not, and raises illegal instruction.

Handle this errata by emulating `fence.tso` as `fence rw, rw`.

[1]: https://github.com/T-head-Semi/openc906/blob/30827e7f/C906_RTL_FACTORY/gen_rtl/idu/rtl/aq_idu_id_decd.v#L2097

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
2022-06-01 17:20:20 +05:30
Samuel Holland
ff65bfec4e lib: sbi_illegal_insn: Constify illegal_insn_table
This table does not need to be modified at runtime.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
2022-05-30 10:54:31 +05:30
Xiang W
f067bb84cf lib: sbi: fix system_opcode_insn
If the csr's operation comes from M mode, it should not be forwarded
to low-privilege processing, this patch fixes this problem.

Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2022-05-30 10:22:13 +05:30
Atish Patra
764a17d852 lib: sbi: Implement firmware counters
RISC-V SBI v0.3 specification defines a set of firmware events that can
provide additional information about the current firmware context. All
of the firmware event monitoring are enabled now. The firmware
events must be defined as raw perf event with MSB set as specified in the
specification.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:38:23 +05:30
Anup Patel
4f3bad6e43 lib: sbi: Handle the case where MTVAL has illegal instruction address
The Kendryte K210 follows RISC-V v1.9 spec so MTVAL has instruction
address (instead of instruction encoding) on illegal instruction trap.

To handle above case, we fix sbi_illegal_insn_handler() without any
impact on RISC-V v1.10 (or higher) systems. This achieved by exploiting
the fact that program counter (and instruction address) is always 2-byte
aligned in RISC-V world.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-08-21 19:35:31 +05:30
Anup Patel
1b8c0128f1 lib: Add RISC-V hypervisor v0.6.1 support
To support RISC-V hypervisor v0.6.1, we:
1. Don't need to explicitly forward WFI traps from VS/VU-mode
2. Have to delegate virtual instruction trap to HS-mode
3. Have to update trap redirection for changes in HSTATUS CSR

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-06-08 15:41:23 +05:30
Anup Patel
5a7bd0c88d lib: sbi_illegal_insn: Remove mcause, scratch and hartid parameters
We remove mcause, scratch and hartid parameters from various
functions for illegal instruction handling because we can always
get current HART id and current scratch pointer using just one
CSR access.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-03-28 13:32:11 +05:30
Anup Patel
d11c79cd97 lib: sbi_emulate_csr: Remove scratch and hartid parameter
We remove scratch and hartid parameter from various functions
for CSR emulation because we can always get current HART id
and current scratch pointer using just one CSR access.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-03-28 13:32:07 +05:30
Anup Patel
cb78a48231 lib: sbi_trap: Remove scratch parameter from sbi_trap_redirect()
The scratch parameter of sbi_trap_redirect() is not used hence we
remove it.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-03-28 13:32:04 +05:30
Anup Patel
626467cfd9 lib: Remove scratch parameter from unpriv load/store functions
The scratch parameter of unpriv load/store functions is now redundant
hence we remove it.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-03-28 13:32:01 +05:30
Anup Patel
00d332bbe7 include: Move bits related defines and macros to sbi_bitops.h
The right location for all bits related defines and macros is
sbi_bitops.h hence this patch. With this patch, the sbi_bits.h
is redundant so we remove it.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-03-08 11:06:18 +05:30
Anup Patel
2be424bd28 lib: Extend trap redirection for hypervisor v0.5 spec
The hypervisor v0.5 spec introduces two new CSRs for both M-mode
and HS-mode which need to be considered when redirecting traps
hence this patch.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-12-16 14:48:26 +05:30
Anup Patel
0e1322bacb lib: Better naming of unpriv APIs for wider use
The unpriv APIs can be useful to external firmware and out-of-tree
platform support code.

This patch adds "sbi_" prefix to unpriv load/store APIs and rename
struct riscv_unpriv to struct sbi_trap_info everywhere. We also
place struct sbi_trap_info in sbi/sbi_trap.h so that we can use
it for sbi_trap_redirect() as well.

Overall, this patch will make naming of unpriv APIs consistent
with other OpenSBI APIs.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-11-21 13:57:33 +05:30
Anup Patel
b1d8c988bc lib: No need to set VSSTATUS.MXR bit in get_insn()
We don't need to set VSSTATUS.MXR bit in get_insn() for
unpriv instruction read because MSTATUS.MXR bit applies
to both "Stage1" and "Stage2" page tables.

This also allows us to remove the "virt" parameter of
get_insn() function.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-11-21 13:56:03 +05:30
Anup Patel
1e9f88889f lib: Emulate HTIMEDELTA CSR for platforms not having TIME CSR
For platforms not having TIME CSR, we trap-n-emulate TIME CSR
read/write in OpenSBI. Same rationale applies to HTIMEDELTA CSR
as well so we trap-n-emulate HTIMEDELTA CSR for platforms not
having TIME CSR.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-09-30 15:36:14 +05:30
Anup Patel
7d4420bd69 include: Extend get_insn() to read instruction from VS/VU mode
Current implementation of get_insn() is not suitable for reading
instruction from VS/VU mode because we have to set SSTATUS_MXR bit
in VSSTATUS CSR for reading instruction from VS/VU mode.

This patch extends get_insn() to read instruction from VS/VU mode.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2019-09-30 15:35:43 +05:30
Anup Patel
a14e7ee82c lib: Redirect WFI trapped from VS/VU mode to HS-mode
The WFI will trap as illegal instruction trap when executed
in VS/VU mode so we just forward/redirect it to HS-mode so
that hypervisor can deal with it appropriately.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-09-30 15:32:00 +05:30
Anup Patel
a88e424f6c lib: Handle traps when doing unpriv load/store in get_insn()
We can get a page/access trap when doing unpriv load/store in
get_insn() function because on a SMP system Linux swapper running
on HART A can unmap pages from page table used by HART B.

To tackle this we extend get_insn() implementation so that if
we get trap in get_insn() then we redirect it to S-mode as fetch
page/access fault.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-08-13 09:48:40 +05:30
Atish Patra
749b0b0932 lib: Move sbi core library to lib/sbi
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-19 09:48:51 +05:30