On 10/19/21 2:48 AM, Frédéric Pétrot wrote:
The csrs are accessed through function pointers: we set-up the table
for the 128-bit accesses, make the stub a function that does what it
should, and implement basic accesses on read-only csrs.
Signed-off-by: Frédéric Pétrot <frederic.pet...@univ-grenoble-alpes.fr>
Co-authored-by: Fabien Portas <fabien.por...@grenoble-inp.org>
---
target/riscv/cpu.h | 16 +++++
target/riscv/csr.c | 152 ++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 165 insertions(+), 3 deletions(-)
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index eb4f63fcbf..253e87cd92 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -474,6 +474,15 @@ RISCVException riscv_csrrw_i128(CPURISCVState *env, int
csrno,
Int128 *ret_value,
Int128 new_value, Int128 write_mask);
+typedef RISCVException (*riscv_csr_read128_fn)(CPURISCVState *env, int csrno,
+ Int128 *ret_value);
+typedef RISCVException (*riscv_csr_write128_fn)(CPURISCVState *env, int csrno,
+ Int128 new_value);
+typedef RISCVException (*riscv_csr_op128_fn)(CPURISCVState *env, int csrno,
+ Int128 *ret_value,
+ Int128 new_value,
+ Int128 write_mask);
Do we really want all 3, or just the single rmw function?
Although I guess it's clearest to match the existing code...
+
typedef struct {
const char *name;
riscv_csr_predicate_fn predicate;
@@ -482,6 +491,12 @@ typedef struct {
riscv_csr_op_fn op;
} riscv_csr_operations;
+typedef struct {
+ riscv_csr_read128_fn read128;
+ riscv_csr_write128_fn write128;
+ riscv_csr_op128_fn op128;
+} riscv_csr_operations128;
Eh. I think better to extend the one riscv_csr_operations structure.
+static inline RISCVException riscv_csrrw_check_i128(CPURISCVState *env,
+ int csrno,
+ Int128 write_mask,
+ RISCVCPU *cpu)
Change "Int128 write_mask" to "bool write" and you can share this entire function with
riscv_csrrw.
Indeed, you could split them like so:
riscv_csrrw(...)
{
ret = csrrw_check(...);
if (ret != RISCV_EXCP_NONE) {
return ret;
}
return csrrw_do64(...);
}
riscv_csrrw_128(...)
{
ret = csrrw_check(...);
if (ret != RISCV_EXCP_NONE) {
return ret;
}
if (csr128) {
return csrrw_do128(...);
}
ret = csrrw_do64(..., old64, ...);
if (ret == RISCV_EXCP_NONE) {
*old_val = int128_make64(old64);
}
return ret;
}
+ RISCVException ret = csr_ops[csrno].predicate(env, csrno);
+ if (ret != RISCV_EXCP_NONE) {
+ return ret;
+ }
+
+ return RISCV_EXCP_NONE;
BTW, just
return csr_ops[csrno].predicate(env, csrno);
r~
