#include "trap.h"
#include "common.h"
#include "config.h"
+#include "sim.h"
#include "processor.h"
#include "memtracer.h"
+#include <stdlib.h>
#include <vector>
// virtual memory configuration
-typedef reg_t pte_t;
-const reg_t LEVELS = sizeof(pte_t) == sizeof(uint64_t) ? 3 : 2;
-const reg_t PGSHIFT = 13;
+#define PGSHIFT 12
const reg_t PGSIZE = 1 << PGSHIFT;
-const reg_t PTIDXBITS = PGSHIFT - (sizeof(pte_t) == 8 ? 3 : 2);
-const reg_t VPN_BITS = PTIDXBITS * LEVELS;
-const reg_t PPN_BITS = 8*sizeof(reg_t) - PGSHIFT;
-const reg_t VA_BITS = VPN_BITS + PGSHIFT;
-
-// page table entry (PTE) fields
-#define PTE_T 0x001 // Entry is a page Table descriptor
-#define PTE_E 0x002 // Entry is a page table Entry
-#define PTE_R 0x004 // Referenced
-#define PTE_D 0x008 // Dirty
-#define PTE_UX 0x010 // User eXecute permission
-#define PTE_UW 0x020 // User Read permission
-#define PTE_UR 0x040 // User Write permission
-#define PTE_SX 0x080 // Supervisor eXecute permission
-#define PTE_SW 0x100 // Supervisor Read permission
-#define PTE_SR 0x200 // Supervisor Write permission
-#define PTE_PERM (PTE_SR | PTE_SW | PTE_SX | PTE_UR | PTE_UW | PTE_UX)
-#define PTE_PPN_SHIFT 13 // LSB of physical page number in the PTE
+const reg_t PGMASK = ~(PGSIZE-1);
+
+struct insn_fetch_t
+{
+ insn_func_t func;
+ insn_t insn;
+};
+
+struct icache_entry_t {
+ reg_t tag;
+ struct icache_entry_t* next;
+ insn_fetch_t data;
+};
+
+struct tlb_entry_t {
+ char* host_offset;
+ reg_t target_offset;
+};
+
+class trigger_matched_t
+{
+ public:
+ trigger_matched_t(int index,
+ trigger_operation_t operation, reg_t address, reg_t data) :
+ index(index), operation(operation), address(address), data(data) {}
+
+ int index;
+ trigger_operation_t operation;
+ reg_t address;
+ reg_t data;
+};
// this class implements a processor's port into the virtual memory system.
// an MMU and instruction cache are maintained for simulator performance.
class mmu_t
{
public:
- mmu_t(char* _mem, size_t _memsz);
+ mmu_t(simif_t* sim, processor_t* proc);
~mmu_t();
+ inline reg_t misaligned_load(reg_t addr, size_t size)
+ {
+#ifdef RISCV_ENABLE_MISALIGNED
+ reg_t res = 0;
+ for (size_t i = 0; i < size; i++)
+ res += (reg_t)load_uint8(addr + i) << (i * 8);
+ return res;
+#else
+ throw trap_load_address_misaligned(addr);
+#endif
+ }
+
+ inline void misaligned_store(reg_t addr, reg_t data, size_t size)
+ {
+#ifdef RISCV_ENABLE_MISALIGNED
+ for (size_t i = 0; i < size; i++)
+ store_uint8(addr + i, data >> (i * 8));
+#else
+ throw trap_store_address_misaligned(addr);
+#endif
+ }
+
// template for functions that load an aligned value from memory
#define load_func(type) \
- type##_t load_##type(reg_t addr) { \
- if(unlikely(addr % sizeof(type##_t))) \
- { \
- badvaddr = addr; \
- throw trap_load_address_misaligned; \
+ inline type##_t load_##type(reg_t addr) { \
+ if (unlikely(addr & (sizeof(type##_t)-1))) \
+ return misaligned_load(addr, sizeof(type##_t)); \
+ reg_t vpn = addr >> PGSHIFT; \
+ if (likely(tlb_load_tag[vpn % TLB_ENTRIES] == vpn)) \
+ return *(type##_t*)(tlb_data[vpn % TLB_ENTRIES].host_offset + addr); \
+ if (unlikely(tlb_load_tag[vpn % TLB_ENTRIES] == (vpn | TLB_CHECK_TRIGGERS))) { \
+ type##_t data = *(type##_t*)(tlb_data[vpn % TLB_ENTRIES].host_offset + addr); \
+ if (!matched_trigger) { \
+ matched_trigger = trigger_exception(OPERATION_LOAD, addr, data); \
+ if (matched_trigger) \
+ throw *matched_trigger; \
+ } \
+ return data; \
} \
- reg_t paddr = translate(addr, sizeof(type##_t), false, false); \
- return *(type##_t*)(mem + paddr); \
+ type##_t res; \
+ load_slow_path(addr, sizeof(type##_t), (uint8_t*)&res); \
+ return res; \
}
// load value from memory at aligned address; zero extend to register width
// template for functions that store an aligned value to memory
#define store_func(type) \
void store_##type(reg_t addr, type##_t val) { \
- if(unlikely(addr % sizeof(type##_t))) \
- { \
- badvaddr = addr; \
- throw trap_store_address_misaligned; \
+ if (unlikely(addr & (sizeof(type##_t)-1))) \
+ return misaligned_store(addr, val, sizeof(type##_t)); \
+ reg_t vpn = addr >> PGSHIFT; \
+ if (likely(tlb_store_tag[vpn % TLB_ENTRIES] == vpn)) \
+ *(type##_t*)(tlb_data[vpn % TLB_ENTRIES].host_offset + addr) = val; \
+ else if (unlikely(tlb_store_tag[vpn % TLB_ENTRIES] == (vpn | TLB_CHECK_TRIGGERS))) { \
+ if (!matched_trigger) { \
+ matched_trigger = trigger_exception(OPERATION_STORE, addr, val); \
+ if (matched_trigger) \
+ throw *matched_trigger; \
+ } \
+ *(type##_t*)(tlb_data[vpn % TLB_ENTRIES].host_offset + addr) = val; \
+ } \
+ else \
+ store_slow_path(addr, sizeof(type##_t), (const uint8_t*)&val); \
+ }
+
+ // template for functions that perform an atomic memory operation
+ #define amo_func(type) \
+ template<typename op> \
+ type##_t amo_##type(reg_t addr, op f) { \
+ if (addr & (sizeof(type##_t)-1)) \
+ throw trap_store_address_misaligned(addr); \
+ try { \
+ auto lhs = load_##type(addr); \
+ store_##type(addr, f(lhs)); \
+ return lhs; \
+ } catch (trap_load_page_fault& t) { \
+ /* AMO faults should be reported as store faults */ \
+ throw trap_store_page_fault(t.get_tval()); \
+ } catch (trap_load_access_fault& t) { \
+ /* AMO faults should be reported as store faults */ \
+ throw trap_store_access_fault(t.get_tval()); \
} \
- reg_t paddr = translate(addr, sizeof(type##_t), true, false); \
- *(type##_t*)(mem + paddr) = val; \
}
+ void store_float128(reg_t addr, float128_t val)
+ {
+#ifndef RISCV_ENABLE_MISALIGNED
+ if (unlikely(addr & (sizeof(float128_t)-1)))
+ throw trap_store_address_misaligned(addr);
+#endif
+ store_uint64(addr, val.v[0]);
+ store_uint64(addr + 8, val.v[1]);
+ }
+
+ float128_t load_float128(reg_t addr)
+ {
+#ifndef RISCV_ENABLE_MISALIGNED
+ if (unlikely(addr & (sizeof(float128_t)-1)))
+ throw trap_load_address_misaligned(addr);
+#endif
+ return (float128_t){load_uint64(addr), load_uint64(addr + 8)};
+ }
+
// store value to memory at aligned address
store_func(uint8)
store_func(uint16)
store_func(uint32)
store_func(uint64)
- struct insn_fetch_t
+ // perform an atomic memory operation at an aligned address
+ amo_func(uint32)
+ amo_func(uint64)
+
+ static const reg_t ICACHE_ENTRIES = 1024;
+
+ inline size_t icache_index(reg_t addr)
{
- insn_t insn;
- insn_func_t func;
- };
-
- // load instruction from memory at aligned address.
- // (needed because instruction alignment requirement is variable
- // if RVC is supported)
- // returns the instruction at the specified address, given the current
- // RVC mode. func is set to a pointer to a function that knows how to
- // execute the returned instruction.
- inline insn_fetch_t load_insn(reg_t addr, bool rvc)
+ return (addr / PC_ALIGN) % ICACHE_ENTRIES;
+ }
+
+ inline icache_entry_t* refill_icache(reg_t addr, icache_entry_t* entry)
{
- #ifdef RISCV_ENABLE_RVC
- if(addr % 4 == 2 && rvc) // fetch across word boundary
- {
- reg_t addr_lo = translate(addr, 2, false, true);
- insn_fetch_t fetch;
- fetch.insn.bits = *(uint16_t*)(mem + addr_lo);
- fetch.func = get_insn_func(fetch.insn, sr);
-
- if(!INSN_IS_RVC(fetch.insn.bits))
- {
- reg_t addr_hi = translate(addr+2, 2, false, true);
- fetch.insn.bits |= (uint32_t)*(uint16_t*)(mem + addr_hi) << 16;
- }
- return fetch;
+ auto tlb_entry = translate_insn_addr(addr);
+ insn_bits_t insn = *(uint16_t*)(tlb_entry.host_offset + addr);
+ int length = insn_length(insn);
+
+ if (likely(length == 4)) {
+ insn |= (insn_bits_t)*(const int16_t*)translate_insn_addr_to_host(addr + 2) << 16;
+ } else if (length == 2) {
+ insn = (int16_t)insn;
+ } else if (length == 6) {
+ insn |= (insn_bits_t)*(const int16_t*)translate_insn_addr_to_host(addr + 4) << 32;
+ insn |= (insn_bits_t)*(const uint16_t*)translate_insn_addr_to_host(addr + 2) << 16;
+ } else {
+ static_assert(sizeof(insn_bits_t) == 8, "insn_bits_t must be uint64_t");
+ insn |= (insn_bits_t)*(const int16_t*)translate_insn_addr_to_host(addr + 6) << 48;
+ insn |= (insn_bits_t)*(const uint16_t*)translate_insn_addr_to_host(addr + 4) << 32;
+ insn |= (insn_bits_t)*(const uint16_t*)translate_insn_addr_to_host(addr + 2) << 16;
}
- else
- #endif
- {
- reg_t idx = (addr/sizeof(insn_t)) % ICACHE_ENTRIES;
- insn_fetch_t fetch;
- if (unlikely(icache_tag[idx] != addr))
- {
- reg_t paddr = translate(addr, sizeof(insn_t), false, true);
- fetch.insn = *(insn_t*)(mem + paddr);
- fetch.func = get_insn_func(fetch.insn, sr);
-
- reg_t idx = (paddr/sizeof(insn_t)) % ICACHE_ENTRIES;
- icache_tag[idx] = addr;
- icache_data[idx] = fetch.insn;
- icache_func[idx] = fetch.func;
-
- if (tracer.interested_in_range(paddr, paddr + sizeof(insn_t), false, true))
- {
- icache_tag[idx] = -1;
- tracer.trace(paddr, sizeof(insn_t), false, true);
- }
- }
- fetch.insn = icache_data[idx];;
- fetch.func = icache_func[idx];
- return fetch;
+
+ insn_fetch_t fetch = {proc->decode_insn(insn), insn};
+ entry->tag = addr;
+ entry->next = &icache[icache_index(addr + length)];
+ entry->data = fetch;
+
+ reg_t paddr = tlb_entry.target_offset + addr;;
+ if (tracer.interested_in_range(paddr, paddr + 1, FETCH)) {
+ entry->tag = -1;
+ tracer.trace(paddr, length, FETCH);
}
+ return entry;
}
- // get the virtual address that caused a fault
- reg_t get_badvaddr() { return badvaddr; }
+ inline icache_entry_t* access_icache(reg_t addr)
+ {
+ icache_entry_t* entry = &icache[icache_index(addr)];
+ if (likely(entry->tag == addr))
+ return entry;
+ return refill_icache(addr, entry);
+ }
- // get/set the page table base register
- reg_t get_ptbr() { return ptbr; }
- void set_ptbr(reg_t addr) { ptbr = addr & ~(PGSIZE-1); flush_tlb(); }
- // keep the MMU in sync with processor mode
- void set_sr(uint32_t _sr) { sr = _sr; }
+ inline insn_fetch_t load_insn(reg_t addr)
+ {
+ icache_entry_t entry;
+ return refill_icache(addr, &entry)->data;
+ }
- // flush the TLB and instruction cache
void flush_tlb();
void flush_icache();
void register_memtracer(memtracer_t*);
+ int is_dirty_enabled()
+ {
+#ifdef RISCV_ENABLE_DIRTY
+ return 1;
+#else
+ return 0;
+#endif
+ }
+
+ int is_misaligned_enabled()
+ {
+#ifdef RISCV_ENABLE_MISALIGNED
+ return 1;
+#else
+ return 0;
+#endif
+ }
+
private:
- char* mem;
- size_t memsz;
- reg_t badvaddr;
- reg_t ptbr;
- uint32_t sr;
+ simif_t* sim;
+ processor_t* proc;
memtracer_list_t tracer;
+ uint16_t fetch_temp;
+
+ // implement an instruction cache for simulator performance
+ icache_entry_t icache[ICACHE_ENTRIES];
// implement a TLB for simulator performance
static const reg_t TLB_ENTRIES = 256;
- reg_t tlb_data[TLB_ENTRIES];
+ // If a TLB tag has TLB_CHECK_TRIGGERS set, then the MMU must check for a
+ // trigger match before completing an access.
+ static const reg_t TLB_CHECK_TRIGGERS = reg_t(1) << 63;
+ tlb_entry_t tlb_data[TLB_ENTRIES];
reg_t tlb_insn_tag[TLB_ENTRIES];
reg_t tlb_load_tag[TLB_ENTRIES];
reg_t tlb_store_tag[TLB_ENTRIES];
- // implement an instruction cache for simulator performance
- static const reg_t ICACHE_ENTRIES = 256;
- insn_t icache_data[ICACHE_ENTRIES];
- insn_func_t icache_func[ICACHE_ENTRIES];
- reg_t icache_tag[ICACHE_ENTRIES];
+ // finish translation on a TLB miss and update the TLB
+ tlb_entry_t refill_tlb(reg_t vaddr, reg_t paddr, char* host_addr, access_type type);
+ const char* fill_from_mmio(reg_t vaddr, reg_t paddr);
- // finish translation on a TLB miss and upate the TLB
- reg_t refill_tlb(reg_t addr, reg_t bytes, bool store, bool fetch);
+ // perform a page table walk for a given VA; set referenced/dirty bits
+ reg_t walk(reg_t addr, access_type type, reg_t prv);
- // perform a page table walk for a given virtual address
- pte_t walk(reg_t addr);
+ // handle uncommon cases: TLB misses, page faults, MMIO
+ tlb_entry_t fetch_slow_path(reg_t addr);
+ void load_slow_path(reg_t addr, reg_t len, uint8_t* bytes);
+ void store_slow_path(reg_t addr, reg_t len, const uint8_t* bytes);
+ reg_t translate(reg_t addr, access_type type);
- // translate a virtual address to a physical address
- reg_t translate(reg_t addr, reg_t bytes, bool store, bool fetch)
- {
- reg_t idx = (addr >> PGSHIFT) % TLB_ENTRIES;
+ // ITLB lookup
+ inline tlb_entry_t translate_insn_addr(reg_t addr) {
+ reg_t vpn = addr >> PGSHIFT;
+ if (likely(tlb_insn_tag[vpn % TLB_ENTRIES] == vpn))
+ return tlb_data[vpn % TLB_ENTRIES];
+ if (unlikely(tlb_insn_tag[vpn % TLB_ENTRIES] == (vpn | TLB_CHECK_TRIGGERS))) {
+ uint16_t* ptr = (uint16_t*)(tlb_data[vpn % TLB_ENTRIES].host_offset + addr);
+ int match = proc->trigger_match(OPERATION_EXECUTE, addr, *ptr);
+ if (match >= 0)
+ throw trigger_matched_t(match, OPERATION_EXECUTE, addr, *ptr);
+ return tlb_data[vpn % TLB_ENTRIES];
+ }
+ return fetch_slow_path(addr);
+ }
- reg_t* tlb_tag = fetch ? tlb_insn_tag : store ? tlb_store_tag :tlb_load_tag;
- reg_t expected_tag = addr & ~(PGSIZE-1);
- if(likely(tlb_tag[idx] == expected_tag))
- return ((uintptr_t)addr & (PGSIZE-1)) + tlb_data[idx];
+ inline const uint16_t* translate_insn_addr_to_host(reg_t addr) {
+ return (uint16_t*)(translate_insn_addr(addr).host_offset + addr);
+ }
- return refill_tlb(addr, bytes, store, fetch);
+ inline trigger_matched_t *trigger_exception(trigger_operation_t operation,
+ reg_t address, reg_t data)
+ {
+ if (!proc) {
+ return NULL;
+ }
+ int match = proc->trigger_match(operation, address, data);
+ if (match == -1)
+ return NULL;
+ if (proc->state.mcontrol[match].timing == 0) {
+ throw trigger_matched_t(match, operation, address, data);
+ }
+ return new trigger_matched_t(match, operation, address, data);
}
-
+
+ bool check_triggers_fetch;
+ bool check_triggers_load;
+ bool check_triggers_store;
+ // The exception describing a matched trigger, or NULL.
+ trigger_matched_t *matched_trigger;
+
friend class processor_t;
};
+struct vm_info {
+ int levels;
+ int idxbits;
+ int ptesize;
+ reg_t ptbase;
+};
+
+inline vm_info decode_vm_info(int xlen, reg_t prv, reg_t satp)
+{
+ if (prv == PRV_M) {
+ return {0, 0, 0, 0};
+ } else if (prv <= PRV_S && xlen == 32) {
+ switch (get_field(satp, SATP32_MODE)) {
+ case SATP_MODE_OFF: return {0, 0, 0, 0};
+ case SATP_MODE_SV32: return {2, 10, 4, (satp & SATP32_PPN) << PGSHIFT};
+ default: abort();
+ }
+ } else if (prv <= PRV_S && xlen == 64) {
+ switch (get_field(satp, SATP64_MODE)) {
+ case SATP_MODE_OFF: return {0, 0, 0, 0};
+ case SATP_MODE_SV39: return {3, 9, 8, (satp & SATP64_PPN) << PGSHIFT};
+ case SATP_MODE_SV48: return {4, 9, 8, (satp & SATP64_PPN) << PGSHIFT};
+ case SATP_MODE_SV57: return {5, 9, 8, (satp & SATP64_PPN) << PGSHIFT};
+ case SATP_MODE_SV64: return {6, 9, 8, (satp & SATP64_PPN) << PGSHIFT};
+ default: abort();
+ }
+ } else {
+ abort();
+ }
+}
+
#endif
projects / riscv-isa-sim.git / blobdiff