Zicbom is the Cache-Block Management extension defined in the already
ratified RISC-V Base Cache Management Operation (CBO) ISA extension [1].
The extension contains three instructions: cbo.clean, cbo.flush and
cbo.inval. All of them must be implemented in the same group as LQ and
cbo.zero due to overlapping patterns.
All these instructions can throw a Illegal Instruction/Virtual
Instruction exception, similar to the existing cbo.zero. The same
check_zicbo_envcfg() is used to handle these exceptions.
Aside from that, these instructions also need to handle page faults and
guest page faults. This is done in a new check_zicbom_access() helper.
As with Zicboz, the cache block size for Zicbom is also configurable.
Note that the spec determines that Zicbo[mp] and Zicboz can have
different cache sizes (Section 2.7 of [1]), so we also include a
'cbom_blocksize' to go along with the existing 'cboz_blocksize'. They
are set to the same size, so unless users want to play around with the
settings both sizes will be the same.
[1] https://github.com/riscv/riscv-CMOs/blob/master/specifications/cmobase-v1.0.1.pdf
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Co-developed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Signed-off-by: Christoph Muellner <cmuellner@linux.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20230224132536.552293-4-dbarboza@ventanamicro.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The RISC-V base cache management operation (CBO) ISA extension has been
ratified. It defines three extensions: Cache-Block Management, Cache-Block
Prefetch and Cache-Block Zero. More information about the spec can be
found at [1].
Let's start by implementing the Cache-Block Zero extension, Zicboz. It
uses the cbo.zero instruction that, as with all CBO instructions that
will be added later, needs to be implemented in an overlap group with
the LQ instruction due to overlapping patterns.
cbo.zero throws a Illegal Instruction/Virtual Instruction exception
depending on CSR state. This is also the case for the remaining cbo
instructions we're going to add next, so create a check_zicbo_envcfg()
that will be used by all Zicbo[mz] instructions.
[1] https://github.com/riscv/riscv-CMOs/blob/master/specifications/cmobase-v1.0.1.pdf
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Co-developed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Signed-off-by: Christoph Muellner <cmuellner@linux.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Message-ID: <20230224132536.552293-3-dbarboza@ventanamicro.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
