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-rw-r--r--machine/emulation.c313
1 files changed, 313 insertions, 0 deletions
diff --git a/machine/emulation.c b/machine/emulation.c
new file mode 100644
index 0000000..5a66997
--- /dev/null
+++ b/machine/emulation.c
@@ -0,0 +1,313 @@
+#include "emulation.h"
+#include "fp_emulation.h"
+#include "config.h"
+#include "unprivileged_memory.h"
+#include "mtrap.h"
+#include <limits.h>
+
+void illegal_insn_trap(uintptr_t* regs, uintptr_t mcause, uintptr_t mepc)
+{
+ asm (".pushsection .rodata\n"
+ "illegal_insn_trap_table:\n"
+ " .word truly_illegal_insn\n"
+#ifdef PK_ENABLE_FP_EMULATION
+ " .word emulate_float_load\n"
+#else
+ " .word truly_illegal_insn\n"
+#endif
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+#ifdef PK_ENABLE_FP_EMULATION
+ " .word emulate_float_store\n"
+#else
+ " .word truly_illegal_insn\n"
+#endif
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word emulate_mul_div\n"
+ " .word truly_illegal_insn\n"
+ " .word emulate_mul_div32\n"
+ " .word truly_illegal_insn\n"
+#ifdef PK_ENABLE_FP_EMULATION
+ " .word emulate_fmadd\n"
+ " .word emulate_fmadd\n"
+ " .word emulate_fmadd\n"
+ " .word emulate_fmadd\n"
+ " .word emulate_fp\n"
+#else
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+#endif
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word emulate_system\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .word truly_illegal_insn\n"
+ " .popsection");
+
+ uintptr_t mstatus;
+ insn_t insn = get_insn(mepc, &mstatus);
+
+ if (unlikely((insn & 3) != 3))
+ return truly_illegal_insn(regs, mcause, mepc, mstatus, insn);
+
+ write_csr(mepc, mepc + 4);
+
+ extern int32_t illegal_insn_trap_table[];
+ int32_t* pf = (void*)illegal_insn_trap_table + (insn & 0x7c);
+ emulation_func f = (emulation_func)(uintptr_t)*pf;
+ f(regs, mcause, mepc, mstatus, insn);
+}
+
+void __attribute__((noinline)) truly_illegal_insn(uintptr_t* regs, uintptr_t mcause, uintptr_t mepc, uintptr_t mstatus, insn_t insn)
+{
+ redirect_trap(mepc, mstatus);
+}
+
+void misaligned_load_trap(uintptr_t* regs, uintptr_t mcause, uintptr_t mepc)
+{
+ union {
+ uint8_t bytes[8];
+ uintptr_t intx;
+ uint64_t int64;
+ } val;
+ uintptr_t mstatus;
+ insn_t insn = get_insn(mepc, &mstatus);
+ uintptr_t addr = GET_RS1(insn, regs) + IMM_I(insn);
+
+ int shift = 0, fp = 0, len;
+ if ((insn & MASK_LW) == MATCH_LW)
+ len = 4, shift = 8*(sizeof(uintptr_t) - len);
+#ifdef __riscv64
+ else if ((insn & MASK_LD) == MATCH_LD)
+ len = 8, shift = 8*(sizeof(uintptr_t) - len);
+ else if ((insn & MASK_LWU) == MATCH_LWU)
+ fp = 0, len = 4, shift = 0;
+#endif
+ else if ((insn & MASK_FLD) == MATCH_FLD)
+ fp = 1, len = 8;
+ else if ((insn & MASK_FLW) == MATCH_FLW)
+ fp = 1, len = 4;
+ else if ((insn & MASK_LH) == MATCH_LH)
+ len = 2, shift = 8*(sizeof(uintptr_t) - len);
+ else if ((insn & MASK_LHU) == MATCH_LHU)
+ len = 2;
+ else
+ return truly_illegal_insn(regs, mcause, mepc, mstatus, insn);
+
+ val.int64 = 0;
+ for (intptr_t i = len-1; i >= 0; i--)
+ val.bytes[i] = load_uint8_t((void *)(addr + i), mepc);
+
+ if (!fp)
+ SET_RD(insn, regs, (intptr_t)val.intx << shift >> shift);
+ else if (len == 8)
+ SET_F64_RD(insn, regs, val.int64);
+ else
+ SET_F32_RD(insn, regs, val.intx);
+
+ write_csr(mepc, mepc + 4);
+}
+
+void misaligned_store_trap(uintptr_t* regs, uintptr_t mcause, uintptr_t mepc)
+{
+ union {
+ uint8_t bytes[8];
+ uintptr_t intx;
+ uint64_t int64;
+ } val;
+ uintptr_t mstatus;
+ insn_t insn = get_insn(mepc, &mstatus);
+ int len;
+
+ val.intx = GET_RS2(insn, regs);
+ if ((insn & MASK_SW) == MATCH_SW)
+ len = 4;
+#ifdef __riscv64
+ else if ((insn & MASK_SD) == MATCH_SD)
+ len = 8;
+#endif
+ else if ((insn & MASK_FSD) == MATCH_FSD)
+ len = 8, val.int64 = GET_F64_RS2(insn, regs);
+ else if ((insn & MASK_FSW) == MATCH_FSW)
+ len = 4, val.intx = GET_F32_RS2(insn, regs);
+ else if ((insn & MASK_SH) == MATCH_SH)
+ len = 2;
+ else
+ return truly_illegal_insn(regs, mcause, mepc, mstatus, insn);
+
+ uintptr_t addr = GET_RS1(insn, regs) + IMM_S(insn);
+ for (int i = 0; i < len; i++)
+ store_uint8_t((void *)(addr + i), val.bytes[i], mepc);
+
+ write_csr(mepc, mepc + 4);
+}
+
+#ifdef __riscv64
+typedef __int128 double_int;
+#else
+typedef int64_t double_int;
+#endif
+
+DECLARE_EMULATION_FUNC(emulate_mul_div)
+{
+ uintptr_t rs1 = GET_RS1(insn, regs), rs2 = GET_RS2(insn, regs), val;
+
+#ifndef __riscv_muldiv
+ // If compiled with -mno-multiply, GCC will expand these out
+ if ((insn & MASK_MUL) == MATCH_MUL)
+ val = rs1 * rs2;
+ else if ((insn & MASK_DIV) == MATCH_DIV)
+ val = (intptr_t)rs1 / (intptr_t)rs2;
+ else if ((insn & MASK_DIVU) == MATCH_DIVU)
+ val = rs1 / rs2;
+ else if ((insn & MASK_REM) == MATCH_REM)
+ val = (intptr_t)rs1 % (intptr_t)rs2;
+ else if ((insn & MASK_REMU) == MATCH_REMU)
+ val = rs1 % rs2;
+ else if ((insn & MASK_MULH) == MATCH_MULH)
+ val = ((double_int)(intptr_t)rs1 * (double_int)(intptr_t)rs2) >> (8 * sizeof(rs1));
+ else if ((insn & MASK_MULHU) == MATCH_MULHU)
+ val = ((double_int)rs1 * (double_int)rs2) >> (8 * sizeof(rs1));
+ else if ((insn & MASK_MULHSU) == MATCH_MULHSU)
+ val = ((double_int)(intptr_t)rs1 * (double_int)rs2) >> (8 * sizeof(rs1));
+ else
+#endif
+ return truly_illegal_insn(regs, mcause, mepc, mstatus, insn);
+
+ SET_RD(insn, regs, val);
+}
+
+DECLARE_EMULATION_FUNC(emulate_mul_div32)
+{
+ uint32_t rs1 = GET_RS1(insn, regs), rs2 = GET_RS2(insn, regs);
+ int32_t val;
+
+#if defined(__riscv64) && !defined(__riscv_muldiv)
+ // If compiled with -mno-multiply, GCC will expand these out
+ if ((insn & MASK_MULW) == MATCH_MULW)
+ val = rs1 * rs2;
+ else if ((insn & MASK_DIVW) == MATCH_DIVW)
+ val = (int32_t)rs1 / (int32_t)rs2;
+ else if ((insn & MASK_DIVUW) == MATCH_DIVUW)
+ val = rs1 / rs2;
+ else if ((insn & MASK_REMW) == MATCH_REMW)
+ val = (int32_t)rs1 % (int32_t)rs2;
+ else if ((insn & MASK_REMUW) == MATCH_REMUW)
+ val = rs1 % rs2;
+ else
+#endif
+ return truly_illegal_insn(regs, mcause, mepc, mstatus, insn);
+
+ SET_RD(insn, regs, val);
+}
+
+static inline int emulate_read_csr(int num, uintptr_t mstatus, uintptr_t* result)
+{
+ switch (num)
+ {
+ case CSR_TIME:
+ *result = read_csr(mtime) + HLS()->utime_delta;
+ return 0;
+ case CSR_CYCLE:
+ *result = read_csr(mcycle) + HLS()->ucycle_delta;
+ return 0;
+ case CSR_INSTRET:
+ *result = read_csr(minstret) + HLS()->uinstret_delta;
+ return 0;
+ case CSR_STIME:
+ *result = read_csr(mtime) + HLS()->stime_delta;
+ return 0;
+ case CSR_SCYCLE:
+ *result = read_csr(mcycle) + HLS()->scycle_delta;
+ return 0;
+ case CSR_SINSTRET:
+ *result = read_csr(minstret) + HLS()->sinstret_delta;
+ return 0;
+#ifdef __riscv32
+ case CSR_TIMEH:
+ *result = (((uint64_t)read_csr(mtimeh) << 32) + read_csr(mtime)
+ + HLS()->stime_delta) >> 32;
+ return 0;
+ case CSR_CYCLEH:
+ *result = (((uint64_t)read_csr(mcycleh) << 32) + read_csr(mcycle)
+ + HLS()->scycle_delta) >> 32;
+ return 0;
+ case CSR_INSTRETH:
+ *result = (((uint64_t)read_csr(minstreth) << 32) + read_csr(minstret)
+ + HLS()->sinstret_delta) >> 32;
+ return 0;
+#endif
+#ifdef PK_ENABLE_FP_EMULATION
+ case CSR_FRM:
+ if ((mstatus & MSTATUS_FS) == 0) break;
+ *result = GET_FRM();
+ return 0;
+ case CSR_FFLAGS:
+ if ((mstatus & MSTATUS_FS) == 0) break;
+ *result = GET_FFLAGS();
+ return 0;
+ case CSR_FCSR:
+ if ((mstatus & MSTATUS_FS) == 0) break;
+ *result = GET_FCSR();
+ return 0;
+#endif
+ }
+ return -1;
+}
+
+static inline int emulate_write_csr(int num, uintptr_t value, uintptr_t mstatus)
+{
+ switch (num)
+ {
+#ifdef PK_ENABLE_FP_EMULATION
+ case CSR_FRM: SET_FRM(value); return 0;
+ case CSR_FFLAGS: SET_FFLAGS(value); return 0;
+ case CSR_FCSR: SET_FCSR(value); return 0;
+#endif
+ }
+ return -1;
+}
+
+DECLARE_EMULATION_FUNC(emulate_system)
+{
+ int rs1_num = (insn >> 15) & 0x1f;
+ uintptr_t rs1_val = GET_RS1(insn, regs);
+ int csr_num = (uint32_t)insn >> 20;
+ uintptr_t csr_val, new_csr_val;
+
+ if (emulate_read_csr(csr_num, mstatus, &csr_val))
+ return truly_illegal_insn(regs, mcause, mepc, mstatus, insn);
+
+ int do_write = rs1_num;
+ switch (GET_RM(insn))
+ {
+ case 0: return truly_illegal_insn(regs, mcause, mepc, mstatus, insn);
+ case 1: new_csr_val = rs1_val; do_write = 1; break;
+ case 2: new_csr_val = csr_val | rs1_val; break;
+ case 3: new_csr_val = csr_val & ~rs1_val; break;
+ case 4: return truly_illegal_insn(regs, mcause, mepc, mstatus, insn);
+ case 5: new_csr_val = rs1_num; do_write = 1; break;
+ case 6: new_csr_val = csr_val | rs1_num; break;
+ case 7: new_csr_val = csr_val & ~rs1_num; break;
+ }
+
+ if (do_write && emulate_write_csr(csr_num, new_csr_val, mstatus))
+ return truly_illegal_insn(regs, mcause, mepc, mstatus, insn);
+
+ SET_RD(insn, regs, csr_val);
+}
generated by cgit v1.1 at 2024-10-18 14:27:48 +0000