The original sbi_strchr implementation did not conform to the C standard
behavior. According to the C standard and POSIX specification, strchr(s, 0)
should return a pointer to the null terminator at the end of string s.
The previous implementation used a while loop that would terminate when
either reaching the end of string or finding the character, but it would
return NULL when searching for the null terminator instead of returning
a pointer to the null terminator itself.
The fixed implementation uses a do-while loop that ensures even when
searching for the null terminator, the function correctly returns a
pointer to the null terminator position rather than NULL.
This fix ensures sbi_strchr behavior aligns with standard library
function semantics, making it more predictable and safe for users
expecting standard C library behavior.
Signed-off-by: Chen Pei <cp0613@linux.alibaba.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260306094425.1918-3-cp0613@linux.alibaba.com
Signed-off-by: Anup Patel <anup@brainfault.org>
The QoS Identifiers extension (Ssqosid) introduces the srmcfg register,
which configures a hart with two identifiers: a Resource Control ID
(RCID) and a Monitoring Counter ID (MCID). These identifiers accompany
each request issued by the hart to shared resource controllers.
If extension Smstateen is implemented together with Ssqosid, then
Ssqosid also requires the SRMCFG bit in mstateen0 to be implemented. If
mstateen0.SRMCFG is 0, attempts to access srmcfg in privilege modes less
privileged than M-mode raise an illegal-instruction exception. If
mstateen0.SRMCFG is 1 or if extension Smstateen is not implemented,
attempts to access srmcfg when V=1 raise a virtual-instruction exception.
This extension can be found in the RISC-V Instruction Set Manual:
https://github.com/riscv/riscv-isa-manual
Changes in v5:
- Remove SBI_HART_EXT_SSQOSID dependency SBI_HART_PRIV_VER_1_12
Changes in v4:
- Remove extraneous parentheses around SMSTATEEN0_SRMCFG
Changes in v3:
- Check SBI_HART_EXT_SSQOSID when swapping SRMCFG
Changes in v2:
- Remove trap-n-detect
- Context switch CSR_SRMCFG
Signed-off-by: Chen Pei <cp0613@linux.alibaba.com>
Reviewed-by: Radim Krčmář <rkrcmar@ventanamicro.com>
Link: https://lore.kernel.org/r/20251114115722.1831-1-cp0613@linux.alibaba.com
Signed-off-by: Anup Patel <anup@brainfault.org>
For some debuggers that do not implement SYSWRITEC and SYSREADC
operations, we can use SYSWRITE and SYSREAD instead like the
implementation of semihosting_getc().
Signed-off-by: Chen Pei <cp0613@linux.alibaba.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
