adds WT cache functionality as mixin

src/iss/arch/riscv_hart_m_p.h

@@ -422,6 +422,15 @@ protected:
     feature_config cfg;
     unsigned mcause_max_irq{(FEAT&features_e::FEAT_CLIC)?4096:16};
     inline bool debug_mode_active() {return this->reg.PRIV&0x4;}
+    std::pair<std::function<mem_read_f>, std::function<mem_write_f>>
+    replace_mem_access(std::function<mem_read_f> rd, std::function<mem_write_f> wr){
+        std::pair<std::function<mem_read_f>, std::function<mem_write_f>> ret{hart_mem_rd_delegate, hart_mem_wr_delegate};
+        hart_mem_rd_delegate = rd;
+        hart_mem_wr_delegate = wr;
+        return ret;
+    }
+    std::function<mem_read_f> hart_mem_rd_delegate;
+    std::function<mem_write_f> hart_mem_wr_delegate;
 };
 
 template <typename BASE, features_e FEAT>
@@ -543,6 +552,12 @@ riscv_hart_m_p<BASE, FEAT>::riscv_hart_m_p(feature_config cfg)
         csr_wr_cb[dcsr] = &this_class::write_dcsr_dcsr;
         csr_rd_cb[dcsr] = &this_class::read_dcsr_reg;
     }
+    hart_mem_rd_delegate = [this](phys_addr_t a, unsigned l, uint8_t* const d) -> iss::status {
+        return this->read_mem(a, l, d);
+    };
+    hart_mem_wr_delegate = [this](phys_addr_t a, unsigned l, uint8_t const* const d) -> iss::status {
+        return this->write_mem(a, l, d);
+    };
 }
 
 template <typename BASE, features_e FEAT> std::pair<uint64_t, bool> riscv_hart_m_p<BASE, FEAT>::load_file(std::string name, int type) {
@@ -663,9 +678,9 @@ iss::status riscv_hart_m_p<BASE, FEAT>::read(const address_type type, const acce
                         auto idx = std::distance(std::begin(memfn_range), it);
                         res = memfn_read[idx](phys_addr, length, data);
                     } else
-                        res = read_mem( phys_addr, length, data);
+                        res = hart_mem_rd_delegate( phys_addr, length, data);
                 } else {
-                    res = read_mem( phys_addr, length, data);
+                    res = hart_mem_rd_delegate( phys_addr, length, data);
                 }
                 if (unlikely(res != iss::Ok)){
                     this->trap_state = (1UL << 31) | (5 << 16); // issue trap 5 (load access fault

src/iss/arch/riscv_hart_msu_vp.h

@@ -845,7 +845,7 @@ template <typename BASE> iss::status riscv_hart_msu_vp<BASE>::write_reg(unsigned
     return iss::Ok;
 }
 
-template <typename BASE> iss::status riscv_hart_m_p<BASE>::read_cycle(unsigned addr, reg_t &val) {
+template <typename BASE> iss::status riscv_hart_msu_vp<BASE>::read_cycle(unsigned addr, reg_t &val) {
     auto cycle_val = this->icount + cycle_offset;
     if (addr == mcycle) {
         val = static_cast<reg_t>(cycle_val);
@@ -856,7 +856,7 @@ template <typename BASE> iss::status riscv_hart_m_p<BASE>::read_cycle(unsigned a
     return iss::Ok;
 }
 
-template <typename BASE> iss::status riscv_hart_m_p<BASE>::write_cycle(unsigned addr, reg_t val) {
+template <typename BASE> iss::status riscv_hart_msu_vp<BASE>::write_cycle(unsigned addr, reg_t val) {
     if (sizeof(typename traits<BASE>::reg_t) != 4) {
         if (addr == mcycleh)
             return iss::Err;
@@ -872,7 +872,7 @@ template <typename BASE> iss::status riscv_hart_m_p<BASE>::write_cycle(unsigned
     return iss::Ok;
 }
 
-template <typename BASE> iss::status riscv_hart_m_p<BASE>::read_instret(unsigned addr, reg_t &val) {
+template <typename BASE> iss::status riscv_hart_msu_vp<BASE>::read_instret(unsigned addr, reg_t &val) {
     if ((addr&0xff) == (minstret&0xff)) {
         val = static_cast<reg_t>(this->reg.instret);
     } else if ((addr&0xff) == (minstreth&0xff)) {
@@ -882,7 +882,7 @@ template <typename BASE> iss::status riscv_hart_m_p<BASE>::read_instret(unsigned
     return iss::Ok;
 }
 
-template <typename BASE> iss::status riscv_hart_m_p<BASE>::write_instret(unsigned addr, reg_t val) {
+template <typename BASE> iss::status riscv_hart_msu_vp<BASE>::write_instret(unsigned addr, reg_t val) {
     if (sizeof(typename traits<BASE>::reg_t) != 4) {
         if ((addr&0xff) == (minstreth&0xff))
             return iss::Err;
@@ -898,7 +898,7 @@ template <typename BASE> iss::status riscv_hart_m_p<BASE>::write_instret(unsigne
     return iss::Ok;
 }
 
-template <typename BASE> iss::status riscv_hart_m_p<BASE>::read_time(unsigned addr, reg_t &val) {
+template <typename BASE> iss::status riscv_hart_msu_vp<BASE>::read_time(unsigned addr, reg_t &val) {
     uint64_t time_val = this->icount / (100000000 / 32768 - 1); //-> ~3052;
     if (addr == time) {
         val = static_cast<reg_t>(time_val);
@@ -909,7 +909,7 @@ template <typename BASE> iss::status riscv_hart_m_p<BASE>::read_time(unsigned ad
     return iss::Ok;
 }
 
-template <typename BASE> iss::status riscv_hart_m_p<BASE>::read_tvec(unsigned addr, reg_t &val) {
+template <typename BASE> iss::status riscv_hart_msu_vp<BASE>::read_tvec(unsigned addr, reg_t &val) {
     val = csr[addr] & ~2;
     return iss::Ok;
 }

src/iss/arch/riscv_hart_mu_p.h

@@ -449,6 +449,16 @@ protected:
     feature_config cfg;
     unsigned mcause_max_irq{(FEAT&features_e::FEAT_CLIC)?4096:16};
     inline bool debug_mode_active() {return this->reg.PRIV&0x4;}
+
+    std::pair<std::function<mem_read_f>, std::function<mem_write_f>>
+    replace_mem_access(std::function<mem_read_f> rd, std::function<mem_write_f> wr){
+        std::pair<std::function<mem_read_f>, std::function<mem_write_f>> ret{hart_mem_rd_delegate, hart_mem_wr_delegate};
+        hart_mem_rd_delegate = rd;
+        hart_mem_wr_delegate = wr;
+        return ret;
+    }
+    std::function<mem_read_f> hart_mem_rd_delegate;
+    std::function<mem_write_f> hart_mem_wr_delegate;
 };
 
 template <typename BASE, features_e FEAT>
@@ -612,6 +622,12 @@ riscv_hart_mu_p<BASE, FEAT>::riscv_hart_mu_p(feature_config cfg)
         csr_wr_cb[dcsr] = &this_class::write_dcsr_dcsr;
         csr_rd_cb[dcsr] = &this_class::read_dcsr_reg;
     }
+    hart_mem_rd_delegate = [this](phys_addr_t a, unsigned l, uint8_t* const d) -> iss::status {
+        return this->read_mem(a, l, d);
+    };
+    hart_mem_wr_delegate = [this](phys_addr_t a, unsigned l, uint8_t const* const d) -> iss::status {
+        return this->write_mem(a, l, d);
+    };
 }
 
 template <typename BASE, features_e FEAT> std::pair<uint64_t, bool> riscv_hart_mu_p<BASE, FEAT>::load_file(std::string name, int type) {
@@ -829,9 +845,9 @@ iss::status riscv_hart_mu_p<BASE, FEAT>::read(const address_type type, const acc
                         auto idx = std::distance(std::begin(memfn_range), it);
                         res = memfn_read[idx](phys_addr, length, data);
                     } else
-                        res = read_mem( phys_addr, length, data);
+                        res = hart_mem_rd_delegate( phys_addr, length, data);
                 } else {
-                    res = read_mem( phys_addr, length, data);
+                    res = hart_mem_rd_delegate( phys_addr, length, data);
                 }
                 if (unlikely(res != iss::Ok)){
                     this->trap_state = (1UL << 31) | (5 << 16); // issue trap 5 (load access fault
@@ -930,9 +946,9 @@ iss::status riscv_hart_mu_p<BASE, FEAT>::write(const address_type type, const ac
                         auto idx = std::distance(std::begin(memfn_range), it);
                         res = memfn_write[idx]( phys_addr, length, data);
                     } else
-                        res = write_mem( phys_addr, length, data);
+                        res = hart_mem_wr_delegate( phys_addr, length, data);
                 } else {
-                    res = write_mem( phys_addr, length, data);
+                    res = hart_mem_wr_delegate( phys_addr, length, data);
                 }
                 if (unlikely(res != iss::Ok)) {
                     this->trap_state = (1UL << 31) | (7 << 16); // issue trap 7 (Store/AMO access fault)

src/iss/arch/wt_cache.h

@@ -0,0 +1,172 @@
+/*******************************************************************************
+ * Copyright (C) 2023 MINRES Technologies GmbH
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Contributors:
+ *       eyck@minres.com - initial implementation
+ ******************************************************************************/
+
+#ifndef _RISCV_HART_M_P_WT_CACHE_H
+#define _RISCV_HART_M_P_WT_CACHE_H
+
+#include <iss/vm_types.h>
+#include <util/ities.h>
+#include <vector>
+#include <map>
+#include <memory>
+
+namespace iss {
+namespace arch {
+namespace cache {
+
+enum class state { INVALID, VALID};
+struct line {
+    uint64_t tag_addr{0};
+    state st{state::INVALID};
+    std::vector<uint8_t> data;
+    line(unsigned line_sz):  data(line_sz) {}
+};
+struct set {
+    std::vector<line> ways;
+    set(unsigned ways_count, line const& l): ways(ways_count, l) {}
+};
+struct cache {
+    std::vector<set> sets;
+
+    cache(unsigned size, unsigned line_sz, unsigned ways) {
+        line const ref_line{line_sz};
+        set const ref_set{ways, ref_line};
+        sets.resize(size/(ways*line_sz), ref_set);
+    }
+};
+
+struct wt_policy {
+    bool is_cacheline_hit(cache& c );
+};
+}
+
+// write thru, allocate on read, direct mapped or set-associative with round-robin replacement policy
+template <typename BASE> class wt_cache : public BASE {
+public:
+    using base_class = BASE;
+    using this_class = wt_cache<BASE>;
+    using reg_t = typename BASE::reg_t;
+    using mem_read_f = typename BASE::mem_read_f;
+    using mem_write_f = typename BASE::mem_write_f;
+    using phys_addr_t = typename BASE::phys_addr_t;
+
+    wt_cache();
+    virtual ~wt_cache() = default;
+
+    unsigned size{4096};
+    unsigned line_sz{32};
+    unsigned ways{1};
+    uint64_t io_address{0xf0000000};
+    uint64_t io_addr_mask{0xf0000000};
+protected:
+    iss::status read_cache(phys_addr_t addr, unsigned, uint8_t *const);
+    iss::status write_cache(phys_addr_t addr, unsigned, uint8_t const *const);
+    std::function<mem_read_f> cache_mem_rd_delegate;
+    std::function<mem_write_f> cache_mem_wr_delegate;
+    std::unique_ptr<cache::cache> dcache_ptr;
+    std::unique_ptr<cache::cache> icache_ptr;
+    size_t get_way_select() {
+        return 0;
+    }
+};
+
+
+template<typename BASE>
+inline wt_cache<BASE>::wt_cache() {
+    auto cb = base_class::replace_mem_access(
+            [this](phys_addr_t a, unsigned l, uint8_t* const d) -> iss::status { return read_cache(a, l,d);},
+            [this](phys_addr_t a, unsigned l, uint8_t const* const d) -> iss::status { return write_cache(a, l,d);});
+    cache_mem_rd_delegate = cb.first;
+    cache_mem_wr_delegate = cb.second;
+}
+
+template<typename BASE>
+iss::status iss::arch::wt_cache<BASE>::read_cache(phys_addr_t a, unsigned l, uint8_t* const d) {
+    if(!icache_ptr) {
+        icache_ptr.reset(new cache::cache(size, line_sz, ways));
+        dcache_ptr.reset(new cache::cache(size, line_sz, ways));
+    }
+    if((a.val&io_addr_mask) != io_address) {
+        auto set_addr=(a.val&(size-1))>>util::ilog2(line_sz*ways);
+        auto tag_addr=a.val>>util::ilog2(line_sz);
+        auto& set = (a.access==access_type::FETCH?icache_ptr:dcache_ptr)->sets[set_addr];
+        for(auto& cl: set.ways) {
+            if(cl.st==cache::state::VALID && cl.tag_addr==tag_addr) {
+                auto start_addr = a.val&(line_sz-1);
+                for(auto i = 0U; i<l; ++i)
+                    d[i] = cl.data[start_addr+i];
+                return iss::Ok;
+            }
+        }
+        auto& cl = set.ways[get_way_select()];
+        phys_addr_t cl_addr{a};
+        cl_addr.val=tag_addr<<util::ilog2(line_sz);
+        cache_mem_rd_delegate(cl_addr, line_sz, cl.data.data());
+        cl.tag_addr=tag_addr;
+        cl.st=cache::state::VALID;
+        auto start_addr = a.val&(line_sz-1);
+        for(auto i = 0U; i<l; ++i)
+            d[i] = cl.data[start_addr+i];
+        return iss::Ok;
+    } else
+        return cache_mem_rd_delegate(a, l, d);
+}
+
+template<typename BASE>
+iss::status iss::arch::wt_cache<BASE>::write_cache(phys_addr_t a, unsigned l, const uint8_t* const d) {
+    if(!dcache_ptr)
+        dcache_ptr.reset(new cache::cache(size, line_sz, ways));
+    auto res = cache_mem_wr_delegate(a, l, d);
+    if(res == iss::Ok && ((a.val&io_addr_mask) != io_address)) {
+        auto set_addr=(a.val&(size-1))>>util::ilog2(line_sz*ways);
+        auto tag_addr=a.val>>util::ilog2(line_sz);
+        auto& set = dcache_ptr->sets[set_addr];
+        for(auto& cl: set.ways) {
+            if(cl.st==cache::state::VALID && cl.tag_addr==tag_addr) {
+                auto start_addr = a.val&(line_sz-1);
+                for(auto i = 0U; i<l; ++i)
+                    cl.data[start_addr+1] = d[i];
+                break;
+            }
+        }
+    }
+    return res;
+}
+
+
+
+} // namespace arch
+} // namespace iss
+
+#endif /* _RISCV_HART_M_P_H */