[PATCH 02/11] target/riscv: Update CSR xintthresh in CLIC mode

[Ian Brockbank]

From: Ian Brockbank <ian.brockbank@cirrus.com>

The interrupt-level threshold (xintthresh) CSR holds an 8-bit field
for the threshold level of the associated privilege mode.

For horizontal interrupts, only the ones with higher interrupt levels
than the threshold level are allowed to preempt.

Signed-off-by: Ian Brockbank <ian.brockbank@cirrus.com>
Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
---
 target/riscv/cpu.h      |  2 ++
 target/riscv/cpu_bits.h |  2 ++
 target/riscv/csr.c      | 28 ++++++++++++++++++++++++++++
 3 files changed, 32 insertions(+)

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 95303f50d3..9b5f36ad0a 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -260,6 +260,7 @@ struct CPUArchState {

     uint64_t miclaim;
     uint64_t mintstatus; /* clic-spec */
+    target_ulong mintthresh; /* clic-spec */

     uint64_t mie;
     uint64_t mideleg;
@@ -283,6 +284,7 @@ struct CPUArchState {
     target_ulong stvec;
     target_ulong sepc;
     target_ulong scause;
+    target_ulong sintthresh; /* clic-spec */

     target_ulong mtvec;
     target_ulong mepc;
diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 2e65495b54..ad45402370 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -166,6 +166,7 @@
 #define CSR_MTVAL           0x343
 #define CSR_MIP             0x344
 #define CSR_MINTSTATUS      0xfb1 /* clic-spec-draft */
+#define CSR_MINTTHRESH      0x347 /* clic-spec-draft */

 /* Machine-Level Window to Indirectly Accessed Registers (AIA) */
 #define CSR_MISELECT        0x350
@@ -208,6 +209,7 @@
 #define CSR_STVAL           0x143
 #define CSR_SIP             0x144
 #define CSR_SINTSTATUS      0xdb1 /* clic-spec-draft */
+#define CSR_SINTTHRESH      0x147 /* clic-spec-draft */

 /* Sstc supervisor CSRs */
 #define CSR_STIMECMP        0x14D
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index f9ed7b9079..9c824c0d8f 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -2903,6 +2903,18 @@ static int read_mintstatus(CPURISCVState *env, int 
csrno, target_ulong *val)
     return RISCV_EXCP_NONE;
 }

+static int read_mintthresh(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->mintthresh;
+    return 0;
+}
+
+static int write_mintthresh(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->mintthresh = val;
+    return 0;
+}
+
 /* Supervisor Trap Setup */
 static RISCVException read_sstatus_i128(CPURISCVState *env, int csrno,
                                         Int128 *val)
@@ -3322,6 +3334,18 @@ static int read_sintstatus(CPURISCVState *env, int 
csrno, target_ulong *val)
     return RISCV_EXCP_NONE;
 }

+static int read_sintthresh(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->sintthresh;
+    return 0;
+}
+
+static int write_sintthresh(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->sintthresh = val;
+    return 0;
+}
+
 /* Supervisor Protection and Translation */
 static RISCVException read_satp(CPURISCVState *env, int csrno,
                                 target_ulong *val)
@@ -5621,9 +5645,13 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {

     /* Machine Mode Core Level Interrupt Controller */
     [CSR_MINTSTATUS]     = { "mintstatus", clic,  read_mintstatus       },
+    [CSR_MINTTHRESH]     = { "mintthresh", clic,  read_mintthresh,
+                             write_mintthresh },

     /* Supervisor Mode Core Level Interrupt Controller */
     [CSR_SINTSTATUS]     = { "sintstatus", clic,  read_sintstatus       },
+    [CSR_SINTTHRESH]     = { "sintthresh", clic,  read_sintthresh,
+                             write_sintthresh },

     [CSR_SCOUNTOVF]      = { "scountovf", sscofpmf,  read_scountovf,
                              .min_priv_ver = PRIV_VERSION_1_12_0 },
--
2.46.0.windows.1
This message and any attachments may contain privileged and confidential 
information that is intended solely for the person(s) to whom it is addressed. 
If you are not an intended recipient you must not: read; copy; distribute; 
discuss; take any action in or make any reliance upon the contents of this 
message; nor open or read any attachment. If you have received this message in 
error, please notify us as soon as possible on the following telephone number 
and destroy this message including any attachments. Thank you. Cirrus Logic 
International (UK) Ltd and Cirrus Logic International Semiconductor Ltd are 
companies registered in Scotland, with registered numbers SC089839 and SC495735 
respectively. Our registered office is at 7B Nightingale Way, Quartermile, 
Edinburgh, EH3 9EG, UK. Tel: +44 (0)131 272 7000. www.cirrus.com