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authorHou Weiying <weiying_hou@outlook.com>2020-08-08 16:56:40 +0800
committerAlistair Francis <alistair.francis@wdc.com>2020-08-21 22:37:55 -0700
commitfdd33b86b20d153b131fc6259aea7a0084ab14b8 (patch)
treec3ecddf0a9345ff6fd25ed8b79869dfdffc8f193 /target/riscv/pmp.c
parent6eaf9cf56f0f6e3faf73273f93cfe3e2e9fd0786 (diff)
riscv: Fix bug in setting pmpcfg CSR for RISCV64
First, sizeof(target_ulong) equals to 4 on riscv32, so this change does not change the function on riscv32. Second, sizeof(target_ulong) equals to 8 on riscv64, and 'reg_index * 8 + i' is not a legal pmp_index (we will explain later), which should be 'reg_index * 4 + i'. If the parameter reg_index equals to 2 (means that we will change the value of pmpcfg2, or the second pmpcfg on riscv64), then pmpcfg_csr_write(env, 2, val) will map write tasks to pmp_write_cfg(env, 2 * 8 + [0...7], val). However, no cfg csr is indexed by value 16 or 23 on riscv64, so we consider it as a bug. We are looking for constant (e.g., define a new constant named RISCV_WORD_SIZE) in QEMU to help others understand code better, but none was found. A possible good explanation of this literal is it is the minimum word length on riscv is 4 bytes (32 bit). Signed-off-by: Hongzheng-Li <Ethan.Lee.QNL@gmail.com> Signed-off-by: Hou Weiying <weiying_hou@outlook.com> Signed-off-by: Myriad-Dreamin <camiyoru@gmail.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-Id: <SG2PR02MB263420036254AC8841F66CE393460@SG2PR02MB2634.apcprd02.prod.outlook.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Diffstat (limited to 'target/riscv/pmp.c')
-rw-r--r--target/riscv/pmp.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c
index 2a2b9f5363..b14feeb7da 100644
--- a/target/riscv/pmp.c
+++ b/target/riscv/pmp.c
@@ -320,8 +320,7 @@ void pmpcfg_csr_write(CPURISCVState *env, uint32_t reg_index,
for (i = 0; i < sizeof(target_ulong); i++) {
cfg_val = (val >> 8 * i) & 0xff;
- pmp_write_cfg(env, (reg_index * sizeof(target_ulong)) + i,
- cfg_val);
+ pmp_write_cfg(env, (reg_index * 4) + i, cfg_val);
}
}
@@ -336,7 +335,7 @@ target_ulong pmpcfg_csr_read(CPURISCVState *env, uint32_t reg_index)
target_ulong val = 0;
for (i = 0; i < sizeof(target_ulong); i++) {
- val = pmp_read_cfg(env, (reg_index * sizeof(target_ulong)) + i);
+ val = pmp_read_cfg(env, (reg_index * 4) + i);
cfg_val |= (val << (i * 8));
}
trace_pmpcfg_csr_read(env->mhartid, reg_index, cfg_val);