From 6db070768733f415fc9bf54582708364ca0e294b Mon Sep 17 00:00:00 2001
From: Andrew Waterman <andrew@sifive.com>
Date: Sat, 25 Feb 2017 15:28:27 -0800
Subject: [PATCH] New counter enable scheme

https://github.com/riscv/riscv-isa-manual/issues/10
---
 riscv/encoding.h   | 28 ++++++++--------------------
 riscv/processor.cc | 21 ++++++++++++---------
 riscv/processor.h  |  4 ++--
 3 files changed, 22 insertions(+), 31 deletions(-)

diff --git a/riscv/encoding.h b/riscv/encoding.h
index 9a87807..a8d4877 100644
--- a/riscv/encoding.h
+++ b/riscv/encoding.h
@@ -184,30 +184,18 @@
   __tmp; })
 
 #define write_csr(reg, val) ({ \
-  if (__builtin_constant_p(val) && (unsigned long)(val) < 32) \
-    asm volatile ("csrw " #reg ", %0" :: "i"(val)); \
-  else \
-    asm volatile ("csrw " #reg ", %0" :: "r"(val)); })
+  asm volatile ("csrw " #reg ", %0" :: "rK"(val)); })
 
 #define swap_csr(reg, val) ({ unsigned long __tmp; \
-  if (__builtin_constant_p(val) && (unsigned long)(val) < 32) \
-    asm volatile ("csrrw %0, " #reg ", %1" : "=r"(__tmp) : "i"(val)); \
-  else \
-    asm volatile ("csrrw %0, " #reg ", %1" : "=r"(__tmp) : "r"(val)); \
+  asm volatile ("csrrw %0, " #reg ", %1" : "=r"(__tmp) : "rK"(val)); \
   __tmp; })
 
 #define set_csr(reg, bit) ({ unsigned long __tmp; \
-  if (__builtin_constant_p(bit) && (unsigned long)(bit) < 32) \
-    asm volatile ("csrrs %0, " #reg ", %1" : "=r"(__tmp) : "i"(bit)); \
-  else \
-    asm volatile ("csrrs %0, " #reg ", %1" : "=r"(__tmp) : "r"(bit)); \
+  asm volatile ("csrrs %0, " #reg ", %1" : "=r"(__tmp) : "rK"(bit)); \
   __tmp; })
 
 #define clear_csr(reg, bit) ({ unsigned long __tmp; \
-  if (__builtin_constant_p(bit) && (unsigned long)(bit) < 32) \
-    asm volatile ("csrrc %0, " #reg ", %1" : "=r"(__tmp) : "i"(bit)); \
-  else \
-    asm volatile ("csrrc %0, " #reg ", %1" : "=r"(__tmp) : "r"(bit)); \
+  asm volatile ("csrrc %0, " #reg ", %1" : "=r"(__tmp) : "rK"(bit)); \
   __tmp; })
 
 #define rdtime() read_csr(time)
@@ -788,6 +776,7 @@
 #define CSR_SSTATUS 0x100
 #define CSR_SIE 0x104
 #define CSR_STVEC 0x105
+#define CSR_SCOUNTEREN 0x106
 #define CSR_SSCRATCH 0x140
 #define CSR_SEPC 0x141
 #define CSR_SCAUSE 0x142
@@ -800,6 +789,7 @@
 #define CSR_MIDELEG 0x303
 #define CSR_MIE 0x304
 #define CSR_MTVEC 0x305
+#define CSR_MCOUNTEREN 0x306
 #define CSR_MSCRATCH 0x340
 #define CSR_MEPC 0x341
 #define CSR_MCAUSE 0x342
@@ -843,8 +833,6 @@
 #define CSR_MHPMCOUNTER29 0xb1d
 #define CSR_MHPMCOUNTER30 0xb1e
 #define CSR_MHPMCOUNTER31 0xb1f
-#define CSR_MUCOUNTEREN 0x320
-#define CSR_MSCOUNTEREN 0x321
 #define CSR_MHPMEVENT3 0x323
 #define CSR_MHPMEVENT4 0x324
 #define CSR_MHPMEVENT5 0x325
@@ -1258,6 +1246,7 @@ DECLARE_CSR(hpmcounter31, CSR_HPMCOUNTER31)
 DECLARE_CSR(sstatus, CSR_SSTATUS)
 DECLARE_CSR(sie, CSR_SIE)
 DECLARE_CSR(stvec, CSR_STVEC)
+DECLARE_CSR(scounteren, CSR_SCOUNTEREN)
 DECLARE_CSR(sscratch, CSR_SSCRATCH)
 DECLARE_CSR(sepc, CSR_SEPC)
 DECLARE_CSR(scause, CSR_SCAUSE)
@@ -1270,6 +1259,7 @@ DECLARE_CSR(medeleg, CSR_MEDELEG)
 DECLARE_CSR(mideleg, CSR_MIDELEG)
 DECLARE_CSR(mie, CSR_MIE)
 DECLARE_CSR(mtvec, CSR_MTVEC)
+DECLARE_CSR(mcounteren, CSR_MCOUNTEREN)
 DECLARE_CSR(mscratch, CSR_MSCRATCH)
 DECLARE_CSR(mepc, CSR_MEPC)
 DECLARE_CSR(mcause, CSR_MCAUSE)
@@ -1313,8 +1303,6 @@ DECLARE_CSR(mhpmcounter28, CSR_MHPMCOUNTER28)
 DECLARE_CSR(mhpmcounter29, CSR_MHPMCOUNTER29)
 DECLARE_CSR(mhpmcounter30, CSR_MHPMCOUNTER30)
 DECLARE_CSR(mhpmcounter31, CSR_MHPMCOUNTER31)
-DECLARE_CSR(mucounteren, CSR_MUCOUNTEREN)
-DECLARE_CSR(mscounteren, CSR_MSCOUNTEREN)
 DECLARE_CSR(mhpmevent3, CSR_MHPMEVENT3)
 DECLARE_CSR(mhpmevent4, CSR_MHPMEVENT4)
 DECLARE_CSR(mhpmevent5, CSR_MHPMEVENT5)
diff --git a/riscv/processor.cc b/riscv/processor.cc
index 29307fd..d44f870 100644
--- a/riscv/processor.cc
+++ b/riscv/processor.cc
@@ -344,11 +344,11 @@ void processor_t::set_csr(int which, reg_t val)
     case CSR_MCYCLEH:
       state.minstret = (val << 32) | (state.minstret << 32 >> 32);
       break;
-    case CSR_MUCOUNTEREN:
-      state.mucounteren = val;
+    case CSR_SCOUNTEREN:
+      state.scounteren = val;
       break;
-    case CSR_MSCOUNTEREN:
-      state.mscounteren = val;
+    case CSR_MCOUNTEREN:
+      state.mcounteren = val;
       break;
     case CSR_SSTATUS: {
       reg_t mask = SSTATUS_SIE | SSTATUS_SPIE | SSTATUS_SPP | SSTATUS_FS
@@ -456,8 +456,11 @@ void processor_t::set_csr(int which, reg_t val)
 
 reg_t processor_t::get_csr(int which)
 {
-  reg_t ctr_en = state.prv == PRV_U ? state.mucounteren :
-                 state.prv == PRV_S ? state.mscounteren : -1U;
+  uint32_t ctr_en = -1;
+  if (state.prv < PRV_M)
+    ctr_en &= state.mcounteren;
+  if (state.prv < PRV_S)
+    ctr_en &= state.scounteren;
   bool ctr_ok = (ctr_en >> (which & 31)) & 1;
 
   if (ctr_ok) {
@@ -468,7 +471,7 @@ reg_t processor_t::get_csr(int which)
   }
   if (which >= CSR_MHPMCOUNTER3 && which <= CSR_MHPMCOUNTER31)
     return 0;
-  if (xlen == 32 && which >= CSR_MHPMCOUNTER3 && which <= CSR_MHPMCOUNTER31)
+  if (xlen == 32 && which >= CSR_MHPMCOUNTER3H && which <= CSR_MHPMCOUNTER31H)
     return 0;
   if (which >= CSR_MHPMEVENT3 && which <= CSR_MHPMEVENT31)
     return 0;
@@ -503,8 +506,8 @@ reg_t processor_t::get_csr(int which)
       if (xlen == 32)
         return state.minstret >> 32;
       break;
-    case CSR_MUCOUNTEREN: return state.mucounteren;
-    case CSR_MSCOUNTEREN: return state.mscounteren;
+    case CSR_SCOUNTEREN: return state.scounteren;
+    case CSR_MCOUNTEREN: return state.mcounteren;
     case CSR_SSTATUS: {
       reg_t mask = SSTATUS_SIE | SSTATUS_SPIE | SSTATUS_SPP | SSTATUS_FS
                  | SSTATUS_XS | SSTATUS_PUM;
diff --git a/riscv/processor.h b/riscv/processor.h
index 0224f10..c294e57 100644
--- a/riscv/processor.h
+++ b/riscv/processor.h
@@ -105,8 +105,8 @@ struct state_t
   reg_t mip;
   reg_t medeleg;
   reg_t mideleg;
-  uint32_t mucounteren;
-  uint32_t mscounteren;
+  uint32_t mcounteren;
+  uint32_t scounteren;
   reg_t sepc;
   reg_t sbadaddr;
   reg_t sscratch;
-- 
2.30.2