This allows hardware and/or derived cpu instances to override or implement new CSR operations.
Cc: Sagar Karandikar <sag...@eecs.berkeley.edu> Cc: Bastian Koppelmann <kbast...@mail.uni-paderborn.de> Cc: Palmer Dabbelt <pal...@sifive.com> Cc: Alistair Francis <alistair.fran...@wdc.com> Signed-off-by: Michael Clark <m...@sifive.com> --- target/riscv/cpu.h | 18 ++++++++++++++++++ target/riscv/csr.c | 35 ++++++++++++++++++----------------- 2 files changed, 36 insertions(+), 17 deletions(-) diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h index 6fb0014..4030530 100644 --- a/target/riscv/cpu.h +++ b/target/riscv/cpu.h @@ -301,6 +301,24 @@ static inline target_ulong csr_read_helper(CPURISCVState *env, int csrno) return val; } +typedef int (*riscv_csr_predicate_fn)(CPURISCVState *env, int csrno); +typedef int (*riscv_csr_read_fn)(CPURISCVState *env, int csrno, + target_ulong *ret_value); +typedef int (*riscv_csr_write_fn)(CPURISCVState *env, int csrno, + target_ulong new_value); +typedef int (*riscv_csr_op_fn)(CPURISCVState *env, int csrno, + target_ulong *ret_value, target_ulong new_value, target_ulong write_mask); + +typedef struct { + riscv_csr_predicate_fn predicate; + riscv_csr_read_fn read; + riscv_csr_write_fn write; + riscv_csr_op_fn op; +} riscv_csr_operations; + +void riscv_get_csr_ops(int csrno, riscv_csr_operations *ops); +void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops); + #include "exec/cpu-all.h" #endif /* RISCV_CPU_H */ diff --git a/target/riscv/csr.c b/target/riscv/csr.c index da66908..25a7e26 100644 --- a/target/riscv/csr.c +++ b/target/riscv/csr.c @@ -23,28 +23,29 @@ #include "qemu/main-loop.h" #include "exec/exec-all.h" +/* CSR function table */ -/* Control and Status Register function table forward declaration */ +static riscv_csr_operations csr_ops[]; -typedef int (*riscv_csr_predicate_fn)(CPURISCVState *env, int csrno); -typedef int (*riscv_csr_read_fn)(CPURISCVState *env, int csrno, - target_ulong *ret_value); -typedef int (*riscv_csr_write_fn)(CPURISCVState *env, int csrno, - target_ulong new_value); -typedef int (*riscv_csr_op_fn)(CPURISCVState *env, int csrno, - target_ulong *ret_value, target_ulong new_value, target_ulong write_mask); +/* CSR function table constants */ -typedef struct { - riscv_csr_predicate_fn predicate; - riscv_csr_read_fn read; - riscv_csr_write_fn write; - riscv_csr_op_fn op; -} riscv_csr_operations; +enum { + CSR_TABLE_SIZE = 0xfff +}; + +/* CSR function table public API */ -static const riscv_csr_operations csr_ops[]; +void riscv_get_csr_ops(int csrno, riscv_csr_operations *ops) +{ + *ops = csr_ops[csrno & CSR_TABLE_SIZE]; +} +void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops) +{ + csr_ops[csrno & CSR_TABLE_SIZE] = *ops; +} -/* Predicates */ +/* CSR function table predicates (private) */ static int fs(CPURISCVState *env, int csrno) { @@ -780,7 +781,7 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value, /* Control and Status Register function table */ -static const riscv_csr_operations csr_ops[0xfff] = { +static riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = { /* User Floating-Point CSRs */ [CSR_FFLAGS] = { fs, read_fflags, write_fflags }, [CSR_FRM] = { fs, read_frm, write_frm }, -- 2.7.0