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[PULL 31/50] target/riscv: Support generic CSR indirect access
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From: |
Alistair Francis |
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Subject: |
[PULL 31/50] target/riscv: Support generic CSR indirect access |
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Date: |
Fri, 17 Jan 2025 15:55:33 +1000 |
From: Kaiwen Xue <kaiwenx@rivosinc.com>
This adds the indirect access registers required by sscsrind/smcsrind
and the operations on them. Note that xiselect and xireg are used for
both AIA and sxcsrind, and the behavior of accessing them depends on
whether each extension is enabled and the value stored in xiselect.
Co-developed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Kaiwen Xue <kaiwenx@rivosinc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-ID: <20250110-counter_delegation-v5-4-e83d797ae294@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
target/riscv/cpu_bits.h | 28 +++++++-
target/riscv/csr.c | 144 ++++++++++++++++++++++++++++++++++++++--
2 files changed, 166 insertions(+), 6 deletions(-)
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index d51f3d8cef..6b1446fb7e 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -173,6 +173,13 @@
#define CSR_MISELECT 0x350
#define CSR_MIREG 0x351
+/* Machine Indirect Register Alias */
+#define CSR_MIREG2 0x352
+#define CSR_MIREG3 0x353
+#define CSR_MIREG4 0x355
+#define CSR_MIREG5 0x356
+#define CSR_MIREG6 0x357
+
/* Machine-Level Interrupts (AIA) */
#define CSR_MTOPEI 0x35c
#define CSR_MTOPI 0xfb0
@@ -222,6 +229,13 @@
#define CSR_SISELECT 0x150
#define CSR_SIREG 0x151
+/* Supervisor Indirect Register Alias */
+#define CSR_SIREG2 0x152
+#define CSR_SIREG3 0x153
+#define CSR_SIREG4 0x155
+#define CSR_SIREG5 0x156
+#define CSR_SIREG6 0x157
+
/* Supervisor-Level Interrupts (AIA) */
#define CSR_STOPEI 0x15c
#define CSR_STOPI 0xdb0
@@ -288,6 +302,13 @@
#define CSR_VSISELECT 0x250
#define CSR_VSIREG 0x251
+/* Virtual Supervisor Indirect Alias */
+#define CSR_VSIREG2 0x252
+#define CSR_VSIREG3 0x253
+#define CSR_VSIREG4 0x255
+#define CSR_VSIREG5 0x256
+#define CSR_VSIREG6 0x257
+
/* VS-Level Interrupts (H-extension with AIA) */
#define CSR_VSTOPEI 0x25c
#define CSR_VSTOPI 0xeb0
@@ -803,10 +824,13 @@ typedef enum RISCVException {
#define ISELECT_IMSIC_EIE63 0xff
#define ISELECT_IMSIC_FIRST ISELECT_IMSIC_EIDELIVERY
#define ISELECT_IMSIC_LAST ISELECT_IMSIC_EIE63
-#define ISELECT_MASK 0x1ff
+#define ISELECT_MASK_AIA 0x1ff
+
+/* MISELECT, SISELECT, and VSISELECT bits (AIA) */
+#define ISELECT_MASK_SXCSRIND 0xfff
/* Dummy [M|S|VS]ISELECT value for emulating [M|S|VS]TOPEI CSRs */
-#define ISELECT_IMSIC_TOPEI (ISELECT_MASK + 1)
+#define ISELECT_IMSIC_TOPEI (ISELECT_MASK_AIA + 1)
/* IMSIC bits (AIA) */
#define IMSIC_TOPEI_IID_SHIFT 16
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 7f4348fe86..49648ddc95 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -306,6 +306,15 @@ static RISCVException aia_any32(CPURISCVState *env, int
csrno)
return any32(env, csrno);
}
+static RISCVException csrind_any(CPURISCVState *env, int csrno)
+{
+ if (!riscv_cpu_cfg(env)->ext_smcsrind) {
+ return RISCV_EXCP_ILLEGAL_INST;
+ }
+
+ return RISCV_EXCP_NONE;
+}
+
static RISCVException csrind_or_aia_any(CPURISCVState *env, int csrno)
{
if (!riscv_cpu_cfg(env)->ext_smaia && !riscv_cpu_cfg(env)->ext_smcsrind) {
@@ -389,6 +398,15 @@ static bool csrind_or_aia_extensions_present(CPURISCVState
*env)
return csrind_extensions_present(env) || aia_extensions_present(env);
}
+static RISCVException csrind_smode(CPURISCVState *env, int csrno)
+{
+ if (!csrind_extensions_present(env)) {
+ return RISCV_EXCP_ILLEGAL_INST;
+ }
+
+ return smode(env, csrno);
+}
+
static RISCVException csrind_or_aia_smode(CPURISCVState *env, int csrno)
{
if (!csrind_or_aia_extensions_present(env)) {
@@ -417,6 +435,15 @@ static RISCVException hmode32(CPURISCVState *env, int
csrno)
}
+static RISCVException csrind_hmode(CPURISCVState *env, int csrno)
+{
+ if (!csrind_extensions_present(env)) {
+ return RISCV_EXCP_ILLEGAL_INST;
+ }
+
+ return hmode(env, csrno);
+}
+
static RISCVException csrind_or_aia_hmode(CPURISCVState *env, int csrno)
{
if (!csrind_or_aia_extensions_present(env)) {
@@ -2068,7 +2095,12 @@ static int csrind_xlate_vs_csrno(CPURISCVState *env, int
csrno)
case CSR_SISELECT:
return CSR_VSISELECT;
case CSR_SIREG:
- return CSR_VSIREG;
+ case CSR_SIREG2:
+ case CSR_SIREG3:
+ case CSR_SIREG4:
+ case CSR_SIREG5:
+ case CSR_SIREG6:
+ return CSR_VSIREG + (csrno - CSR_SIREG);
default:
return csrno;
};
@@ -2108,7 +2140,12 @@ static RISCVException rmw_xiselect(CPURISCVState *env,
int csrno,
*val = *iselect;
}
- wr_mask &= ISELECT_MASK;
+ if (riscv_cpu_cfg(env)->ext_smcsrind || riscv_cpu_cfg(env)->ext_sscsrind) {
+ wr_mask &= ISELECT_MASK_SXCSRIND;
+ } else {
+ wr_mask &= ISELECT_MASK_AIA;
+ }
+
if (wr_mask) {
*iselect = (*iselect & ~wr_mask) | (new_val & wr_mask);
}
@@ -2247,6 +2284,56 @@ done:
return RISCV_EXCP_NONE;
}
+/*
+ * rmw_xireg_csrind: Perform indirect access to xireg and xireg2-xireg6
+ *
+ * Perform indirect access to xireg and xireg2-xireg6.
+ * This is a generic interface for all xireg CSRs. Apart from AIA, all other
+ * extension using csrind should be implemented here.
+ */
+static int rmw_xireg_csrind(CPURISCVState *env, int csrno,
+ target_ulong isel, target_ulong *val,
+ target_ulong new_val, target_ulong wr_mask)
+{
+ return -EINVAL;
+}
+
+static int rmw_xiregi(CPURISCVState *env, int csrno, target_ulong *val,
+ target_ulong new_val, target_ulong wr_mask)
+{
+ bool virt = false;
+ int ret = -EINVAL;
+ target_ulong isel;
+
+ ret = smstateen_acc_ok(env, 0, SMSTATEEN0_SVSLCT);
+ if (ret != RISCV_EXCP_NONE) {
+ return ret;
+ }
+
+ /* Translate CSR number for VS-mode */
+ csrno = csrind_xlate_vs_csrno(env, csrno);
+
+ if (CSR_MIREG <= csrno && csrno <= CSR_MIREG6 &&
+ csrno != CSR_MIREG4 - 1) {
+ isel = env->miselect;
+ } else if (CSR_SIREG <= csrno && csrno <= CSR_SIREG6 &&
+ csrno != CSR_SIREG4 - 1) {
+ isel = env->siselect;
+ } else if (CSR_VSIREG <= csrno && csrno <= CSR_VSIREG6 &&
+ csrno != CSR_VSIREG4 - 1) {
+ isel = env->vsiselect;
+ virt = true;
+ } else {
+ goto done;
+ }
+
+ return rmw_xireg_csrind(env, csrno, isel, val, new_val, wr_mask);
+
+done:
+ return (env->virt_enabled && virt) ?
+ RISCV_EXCP_VIRT_INSTRUCTION_FAULT : RISCV_EXCP_ILLEGAL_INST;
+}
+
static RISCVException rmw_xireg(CPURISCVState *env, int csrno,
target_ulong *val, target_ulong new_val,
target_ulong wr_mask)
@@ -2279,8 +2366,21 @@ static RISCVException rmw_xireg(CPURISCVState *env, int
csrno,
goto done;
};
+ /*
+ * Use the xiselect range to determine actual op on xireg.
+ *
+ * Since we only checked the existence of AIA or Indirect Access in the
+ * predicate, we should check the existence of the exact extension when
+ * we get to a specific range and return illegal instruction exception even
+ * in VS-mode.
+ */
if (xiselect_aia_range(isel)) {
return rmw_xireg_aia(env, csrno, isel, val, new_val, wr_mask);
+ } else if (riscv_cpu_cfg(env)->ext_smcsrind ||
+ riscv_cpu_cfg(env)->ext_sscsrind) {
+ return rmw_xireg_csrind(env, csrno, isel, val, new_val, wr_mask);
+ } else {
+ return RISCV_EXCP_ILLEGAL_INST;
}
done:
@@ -2760,7 +2860,7 @@ static RISCVException write_mstateen0(CPURISCVState *env,
int csrno,
wr_mask |= SMSTATEEN0_P1P13;
}
- if (riscv_cpu_cfg(env)->ext_smaia) {
+ if (riscv_cpu_cfg(env)->ext_smaia || riscv_cpu_cfg(env)->ext_smcsrind) {
wr_mask |= SMSTATEEN0_SVSLCT;
}
@@ -2853,7 +2953,7 @@ static RISCVException write_hstateen0(CPURISCVState *env,
int csrno,
wr_mask |= SMSTATEEN0_FCSR;
}
- if (riscv_cpu_cfg(env)->ext_ssaia) {
+ if (riscv_cpu_cfg(env)->ext_ssaia || riscv_cpu_cfg(env)->ext_sscsrind) {
wr_mask |= SMSTATEEN0_SVSLCT;
}
@@ -5062,6 +5162,18 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
[CSR_MIREG] = { "mireg", csrind_or_aia_any, NULL, NULL,
rmw_xireg },
+ /* Machine Indirect Register Alias */
+ [CSR_MIREG2] = { "mireg2", csrind_any, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+ [CSR_MIREG3] = { "mireg3", csrind_any, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+ [CSR_MIREG4] = { "mireg4", csrind_any, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+ [CSR_MIREG5] = { "mireg5", csrind_any, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+ [CSR_MIREG6] = { "mireg6", csrind_any, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+
/* Machine-Level Interrupts (AIA) */
[CSR_MTOPEI] = { "mtopei", aia_any, NULL, NULL, rmw_xtopei },
[CSR_MTOPI] = { "mtopi", aia_any, read_mtopi },
@@ -5193,6 +5305,18 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
[CSR_SIREG] = { "sireg", csrind_or_aia_smode, NULL, NULL,
rmw_xireg },
+ /* Supervisor Indirect Register Alias */
+ [CSR_SIREG2] = { "sireg2", csrind_smode, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+ [CSR_SIREG3] = { "sireg3", csrind_smode, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+ [CSR_SIREG4] = { "sireg4", csrind_smode, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+ [CSR_SIREG5] = { "sireg5", csrind_smode, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+ [CSR_SIREG6] = { "sireg6", csrind_smode, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+
/* Supervisor-Level Interrupts (AIA) */
[CSR_STOPEI] = { "stopei", aia_smode, NULL, NULL, rmw_xtopei },
[CSR_STOPI] = { "stopi", aia_smode, read_stopi },
@@ -5275,6 +5399,18 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
[CSR_VSIREG] = { "vsireg", csrind_or_aia_hmode, NULL, NULL,
rmw_xireg },
+ /* Virtual Supervisor Indirect Alias */
+ [CSR_VSIREG2] = { "vsireg2", csrind_hmode, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+ [CSR_VSIREG3] = { "vsireg3", csrind_hmode, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+ [CSR_VSIREG4] = { "vsireg4", csrind_hmode, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+ [CSR_VSIREG5] = { "vsireg5", csrind_hmode, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+ [CSR_VSIREG6] = { "vsireg6", csrind_hmode, NULL, NULL, rmw_xiregi,
+ .min_priv_ver = PRIV_VERSION_1_12_0 },
+
/* VS-Level Interrupts (H-extension with AIA) */
[CSR_VSTOPEI] = { "vstopei", aia_hmode, NULL, NULL, rmw_xtopei },
[CSR_VSTOPI] = { "vstopi", aia_hmode, read_vstopi },
--
2.47.1
- [PULL 19/50] target/riscv: Enable updates for pointer masking variables and thus enable pointer masking extension, (continued)
- [PULL 19/50] target/riscv: Enable updates for pointer masking variables and thus enable pointer masking extension, Alistair Francis, 2025/01/17
- [PULL 20/50] target/riscv: Add 'ext_smrnmi' in the RISCVCPUConfig, Alistair Francis, 2025/01/17
- [PULL 21/50] target/riscv: Add Smrnmi CSRs, Alistair Francis, 2025/01/17
- [PULL 22/50] target/riscv: Handle Smrnmi interrupt and exception, Alistair Francis, 2025/01/17
- [PULL 23/50] target/riscv: Add Smrnmi mnret instruction, Alistair Francis, 2025/01/17
- [PULL 24/50] target/riscv: Add Smrnmi cpu extension, Alistair Francis, 2025/01/17
- [PULL 25/50] target/riscv: Add Zicfilp support for Smrnmi, Alistair Francis, 2025/01/17
- [PULL 26/50] target/riscv: Have kvm_riscv_get_timebase_frequency() take RISCVCPU cpu, Alistair Francis, 2025/01/17
- [PULL 27/50] hw/riscv/virt: Remove unnecessary use of &first_cpu, Alistair Francis, 2025/01/17
- [PULL 28/50] target/riscv: Add properties for Indirect CSR Access extension, Alistair Francis, 2025/01/17
- [PULL 31/50] target/riscv: Support generic CSR indirect access,
Alistair Francis <=
- [PULL 35/50] target/riscv: Add counter delegation/configuration support, Alistair Francis, 2025/01/17
- [PULL 30/50] target/riscv: Enable S*stateen bits for AIA, Alistair Francis, 2025/01/17
- [PULL 42/50] target/riscv: Implement Ssdbltrp exception handling, Alistair Francis, 2025/01/17
- [PULL 38/50] target/riscv: Add configuration for S[m|s]csrind, Smcdeleg/Ssccfg, Alistair Francis, 2025/01/17
- [PULL 29/50] target/riscv: Decouple AIA processing from xiselect and xireg, Alistair Francis, 2025/01/17
- [PULL 37/50] target/riscv: Add implied rule for counter delegation extensions, Alistair Francis, 2025/01/17
- [PULL 34/50] target/riscv: Add select value range check for counter delegation, Alistair Francis, 2025/01/17
- [PULL 39/50] target/riscv: Fix henvcfg potentially containing stale bits, Alistair Francis, 2025/01/17
- [PULL 40/50] target/riscv: Add Ssdbltrp CSRs handling, Alistair Francis, 2025/01/17
- [PULL 41/50] target/riscv: Implement Ssdbltrp sret, mret and mnret behavior, Alistair Francis, 2025/01/17