RISC-V Proxy Kernel
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// See LICENSE for license details.
#include "emulation.h"
#include "fp_emulation.h"
#include "unprivileged_memory.h"
#include "mtrap.h"
#include "config.h"
#include "pk.h"
#ifdef __riscv_vector
static inline void set_vreg(uintptr_t vlenb, uintptr_t which, uintptr_t pos, uintptr_t size, const uint8_t* bytes)
{
pos += (which % 8) * vlenb;
bytes -= pos;
asm volatile ("vsetvli x0, %0, e8, m8, tu, ma" :: "r" (pos + size));
write_csr(vstart, pos);
switch (which / 8) {
case 0: asm volatile ("vle8.v v0, (%0)" :: "r" (bytes) : "memory"); break;
case 1: asm volatile ("vle8.v v8, (%0)" :: "r" (bytes) : "memory"); break;
case 2: asm volatile ("vle8.v v16, (%0)" :: "r" (bytes) : "memory"); break;
case 3: asm volatile ("vle8.v v24, (%0)" :: "r" (bytes) : "memory"); break;
default:
}
}
static inline void get_vreg(uintptr_t vlenb, uintptr_t which, uintptr_t pos, uintptr_t size, uint8_t* bytes)
{
pos += (which % 8) * vlenb;
bytes -= pos;
asm volatile ("vsetvli x0, %0, e8, m8, tu, ma" :: "r" (pos + size));
write_csr(vstart, pos);
switch (which / 8) {
case 0: asm volatile ("vse8.v v0, (%0)" :: "r" (bytes) : "memory"); break;
case 1: asm volatile ("vse8.v v8, (%0)" :: "r" (bytes) : "memory"); break;
case 2: asm volatile ("vse8.v v16, (%0)" :: "r" (bytes) : "memory"); break;
case 3: asm volatile ("vse8.v v24, (%0)" :: "r" (bytes) : "memory"); break;
default:
}
}
static inline void vsetvl(uintptr_t vl, uintptr_t vtype)
{
asm volatile ("vsetvl x0, %0, %1" :: "r" (vl), "r" (vtype));
}
#define VLEN_MAX 4096
DECLARE_EMULATION_FUNC(misaligned_vec_ldst)
{
uintptr_t vl = read_csr(vl);
uintptr_t vtype = read_csr(vtype);
uintptr_t vlenb = read_csr(vlenb);
uintptr_t vstart = read_csr(vstart);
_Bool masked = ((insn >> 25) & 1) == 0;
_Bool unit = ((insn >> 26) & 3) == 0;
_Bool strided = ((insn >> 26) & 3) == 2;
_Bool indexed = !strided && !unit;
_Bool mew = (insn >> 28) & 1;
_Bool lumop_simple = ((insn >> 20) & 0x1f) == 0;
_Bool lumop_whole = ((insn >> 20) & 0x1f) == 8;
_Bool lumop_fof = ((insn >> 20) & 0x1f) == 16;
_Bool load = ((insn >> 5) & 1) == 0;
_Bool illegal = mew || (unit && !(lumop_simple || lumop_whole || (load && lumop_fof)));
_Bool fof = unit && lumop_fof;
_Bool whole_reg = unit && lumop_whole;
uintptr_t vd = (insn >> 7) & 0x1f;
uintptr_t vs2 = (insn >> 20) & 0x1f;
uintptr_t vsew = (vtype >> 3) & 3;
uintptr_t vlmul = vtype & 7;
uintptr_t view = (insn >> 12) & 3;
uintptr_t veew = indexed ? vsew : view;
uintptr_t len = 1 << veew;
uintptr_t nf0 = 1 + ((insn >> 29) & 7);
uintptr_t nf = whole_reg ? 1 : nf0;
uintptr_t evl = whole_reg ? (nf0 * vlenb) >> veew : vl;
uintptr_t vemul = whole_reg ? 0 : (vlmul + veew - vsew) & 7;
uintptr_t emul = 1 << ((vemul & 4) ? 0 : vemul);
uintptr_t base = GET_RS1(insn, regs);
uintptr_t stride = strided ? GET_RS2(insn, regs) : nf * len;
if (illegal || vlenb > VLEN_MAX / 8)
return truly_illegal_insn(regs, mcause, mepc, mstatus, insn);
uint8_t mask[VLEN_MAX / 8];
if (masked)
get_vreg(vlenb, 0, 0, vlenb, mask);
do {
if (!masked || ((mask[vstart / 8] >> (vstart % 8)) & 1)) {
// compute element address
uintptr_t addr = base + vstart * stride;
if (indexed) {
uintptr_t offset = 0;
get_vreg(vlenb, vs2, vstart << view, 1 << view, (uint8_t *)&offset);
addr = base + offset;
}
uint8_t bytes[8 /* max segments */ * sizeof(uint64_t)];
if (!load) {
// obtain store data from regfile
for (uintptr_t seg = 0; seg < nf; seg++)
get_vreg(vlenb, vd + seg * emul, vstart * len, len, &bytes[seg * len]);
}
// restore clobbered vl/vtype/vstart in case we trap
vsetvl(vl, vtype);
write_csr(vstart, vstart);
if (load) {
// obtain load data from memory
for (uintptr_t seg = 0; seg < nf; seg++)
for (uintptr_t i = 0; i < len; i++)
bytes[seg * len + i] = load_uint8_t((void *)(addr + seg * len + i), mepc);
// write load data to regfile
for (uintptr_t seg = 0; seg < nf; seg++)
set_vreg(vlenb, vd + seg * emul, vstart * len, len, &bytes[seg * len]);
} else {
// write store data to memory
for (uintptr_t seg = 0; seg < nf; seg++)
for (uintptr_t i = 0; i < len; i++)
store_uint8_t((void *)(addr + seg * len + i), bytes[seg * len + i], mepc);
}
}
} while (++vstart < evl && !fof);
// restore clobbered vl/vtype; vstart=0; advance pc
vsetvl(fof ? 1 : vl, vtype);
write_csr(mepc, mepc + 4);
}
#endif