CSR predicate functions are added to the CSR table.
mstatus.FS and counter enable checks are moved
to predicate functions and two new predicates are
added to check misa.S for s* CSRs and a new PMP
CPU feature for pmp* CSRs.
Processors that don't implement S-mode will trap
on access to s* CSRs and processors that don't
implement PMP will trap on accesses to pmp* CSRs.
PMP checks are disabled in riscv_cpu_handle_mmu_fault
when the PMP CPU feature is not present.
Signed-off-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Previous CSR code uses csr_read_helper and csr_write_helper
to update CSR registers however this interface prevents
atomic read/modify/write CSR operations; in addition
there is no trap-free method to access to CSRs due
to the monolithic CSR functions call longjmp.
The current iCSR interface is not safe to be called by
target/riscv/gdbstub.c as privilege checks or missing CSRs
may call longjmp to generate exceptions. It needs to
indicate existence so traps can be generated in the
CSR instruction helpers.
This commit moves CSR access from the monolithic switch
statements in target/riscv/op_helper.c into modular
read/write functions in target/riscv/csr.c using a new
function pointer table for dispatch (which can later
be used to allow CPUs to hook up model specific CSRs).
A read/modify/write interface is added to support atomic
CSR operations and a non-trapping interface is added
to allow exception-free access to CSRs by the debugger.
The CSR functions and CSR dispatch table are ordered
to match The RISC-V Instruction Set Manual, Volume II:
Privileged Architecture Version 1.10, 2.2 CSR Listing.
An API is added to allow derived cpu instances to modify
or implement new CSR operations.
Signed-off-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Change the API of riscv_set_local_interrupt to take a
write mask and value to allow setting and clearing of
multiple local interrupts atomically in a single call.
Rename the new function to riscv_cpu_update_mip.
Signed-off-by: Michael Clark <mjc@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
cpu_init() was removed since 2.12, so drop the define that is now unused.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Privileged ISA v1.9.1 defines mscounteren and mucounteren:
* mscounteren contains a mask of counters available to S-mode
* mucounteren contains a mask of counters available to U-mode
Privileged ISA v1.10 defines mcounteren and scounteren:
* mcounteren contains a mask of counters available to S-mode
* scounteren contains a mask of counters available to U-mode
mcounteren and scounteren CSR registers were implemented
however they were not honoured for counter accesses when
the privilege ISA was >= v1.10. This fix solves the issue
by coalescing the counter enable registers. In addition
the code now generates illegal instruction exceptions
for accesses to the counter enabled registers depending
on the privileged ISA version.
- Coalesce mscounteren and mcounteren into one variable
- Coalesce mucounteren and scounteren into one variable
- Makes mcounteren and scounteren CSR accesses generate
illegal instructions when the privileged ISA <= v1.9.1
- Makes mscounteren and mucounteren CSR accesses generate
illegal instructions when the privileged ISA >= v1.10
Cc: Sagar Karandikar <sagark@eecs.berkeley.edu>
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Alistair Francis <Alistair.Francis@wdc.com>
Signed-off-by: Michael Clark <mjc@sifive.com>
Section 22.8 Subset Naming Convention of the RISC-V ISA Specification
defines the canonical order for extensions in the ISA string. It is
silent on the position of the E extension however E is a substitute
for I so it must come early in the extension list order. A comment
is added to state E and I are mutually exclusive, as the E extension
will be added to the RISC-V port in the future.
Cc: Sagar Karandikar <sagark@eecs.berkeley.edu>
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Alistair Francis <Alistair.Francis@wdc.com>
Signed-off-by: Michael Clark <mjc@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
it will be used for providing to cpu name resolving class for
parsing cpu model for system and user emulation code.
Along with change add target to null-machine tests, so
that when switch to CPU_RESOLVING_TYPE happens,
it would ensure that null-machine usecase still works.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu> (m68k)
Acked-by: David Gibson <david@gibson.dropbear.id.au> (ppc)
Acked-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> (tricore)
Message-Id: <1518000027-274608-4-git-send-email-imammedo@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
[ehabkost: Added macro to riscv too]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Add CPU state header, CPU definitions and initialization routines
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Sagar Karandikar <sagark@eecs.berkeley.edu>
Signed-off-by: Michael Clark <mjc@sifive.com>
