diff options
| author | Michael Clark <mjc@sifive.com> | 2019-03-16 01:21:03 +0000 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@sifive.com> | 2019-03-19 05:14:39 -0700 |
| commit | acbbb94e5730c9808830938e869d243014e2923a (patch) | |
| tree | 3398a36b64ab9b9e50e6b7907e81d5b49dbf6595 /target/riscv/csr.c | |
| parent | d26f5a423438e579d3ff0ca35e44edb966a36233 (diff) | |
RISC-V: Add support for vectored interrupts
If vectored interrupts are enabled (bits[1:0]
of mtvec/stvec == 1) then use the following
logic for trap entry address calculation:
pc = mtvec + cause * 4
In addition to adding support for vectored interrupts
this patch simplifies the interrupt delivery logic
by making sync/async cause decoding and encoding
steps distinct.
The cause code and the sign bit indicating sync/async
is split at the beginning of the function and fixed
cause is renamed to cause. The MSB setting for async
traps is delayed until setting mcause/scause to allow
redundant variables to be eliminated. Some variables
are renamed for conciseness and moved so that decls
are at the start of the block.
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Alistair Francis <Alistair.Francis@wdc.com>
Signed-off-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Diffstat (limited to 'target/riscv/csr.c')
| -rw-r--r-- | target/riscv/csr.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/target/riscv/csr.c b/target/riscv/csr.c index 385bb38768..e1d91b6c60 100644 --- a/target/riscv/csr.c +++ b/target/riscv/csr.c @@ -435,10 +435,10 @@ static int read_mtvec(CPURISCVState *env, int csrno, target_ulong *val) static int write_mtvec(CPURISCVState *env, int csrno, target_ulong val) { /* bits [1:0] encode mode; 0 = direct, 1 = vectored, 2 >= reserved */ - if ((val & 3) == 0) { - env->mtvec = val >> 2 << 2; + if ((val & 3) < 2) { + env->mtvec = val; } else { - qemu_log_mask(LOG_UNIMP, "CSR_MTVEC: vectored traps not supported"); + qemu_log_mask(LOG_UNIMP, "CSR_MTVEC: reserved mode not supported\n"); } return 0; } @@ -607,10 +607,10 @@ static int read_stvec(CPURISCVState *env, int csrno, target_ulong *val) static int write_stvec(CPURISCVState *env, int csrno, target_ulong val) { /* bits [1:0] encode mode; 0 = direct, 1 = vectored, 2 >= reserved */ - if ((val & 3) == 0) { - env->stvec = val >> 2 << 2; + if ((val & 3) < 2) { + env->stvec = val; } else { - qemu_log_mask(LOG_UNIMP, "CSR_STVEC: vectored traps not supported"); + qemu_log_mask(LOG_UNIMP, "CSR_STVEC: reserved mode not supported\n"); } return 0; } |