target/arm: Implement the CPY* instructions

The FEAT_MOPS CPY* instructions implement memory copies. These
come in both "always forwards" (memcpy-style) and "overlap OK"
(memmove-style) flavours.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230912140434.1333369-12-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2023-09-12 15:04:33 +01:00
parent 69c51dc372
commit 5d7b37b5f6
4 changed files with 535 additions and 0 deletions

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@ -575,3 +575,17 @@ SETE 00 011001110 ..... 10 . . 01 ..... ..... @set
SETGP 00 011101110 ..... 00 . . 01 ..... ..... @set
SETGM 00 011101110 ..... 01 . . 01 ..... ..... @set
SETGE 00 011101110 ..... 10 . . 01 ..... ..... @set
# Memmove/Memcopy: the CPY insns allow overlapping src/dest and
# copy in the correct direction; the CPYF insns always copy forwards.
#
# options has the nontemporal and unpriv bits for src and dest
&cpy rs rn rd options
@cpy .. ... . ..... rs:5 options:4 .. rn:5 rd:5 &cpy
CPYFP 00 011 0 01000 ..... .... 01 ..... ..... @cpy
CPYFM 00 011 0 01010 ..... .... 01 ..... ..... @cpy
CPYFE 00 011 0 01100 ..... .... 01 ..... ..... @cpy
CPYP 00 011 1 01000 ..... .... 01 ..... ..... @cpy
CPYM 00 011 1 01010 ..... .... 01 ..... ..... @cpy
CPYE 00 011 1 01100 ..... .... 01 ..... ..... @cpy

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@ -1048,6 +1048,15 @@ static uint64_t page_limit(uint64_t addr)
return TARGET_PAGE_ALIGN(addr + 1) - addr;
}
/*
* Return the number of bytes we can copy starting from addr and working
* backwards without crossing a page boundary.
*/
static uint64_t page_limit_rev(uint64_t addr)
{
return (addr & ~TARGET_PAGE_MASK) + 1;
}
/*
* Perform part of a memory set on an area of guest memory starting at
* toaddr (a dirty address) and extending for setsize bytes.
@ -1392,3 +1401,448 @@ void HELPER(setge)(CPUARMState *env, uint32_t syndrome, uint32_t mtedesc)
{
do_sete(env, syndrome, mtedesc, set_step_tags, true, GETPC());
}
/*
* Perform part of a memory copy from the guest memory at fromaddr
* and extending for copysize bytes, to the guest memory at
* toaddr. Both addreses are dirty.
*
* Returns the number of bytes actually set, which might be less than
* copysize; the caller should loop until the whole copy has been done.
* The caller should ensure that the guest registers are correct
* for the possibility that the first byte of the copy encounters
* an exception or watchpoint. We guarantee not to take any faults
* for bytes other than the first.
*/
static uint64_t copy_step(CPUARMState *env, uint64_t toaddr, uint64_t fromaddr,
uint64_t copysize, int wmemidx, int rmemidx,
uint32_t *wdesc, uint32_t *rdesc, uintptr_t ra)
{
void *rmem;
void *wmem;
/* Don't cross a page boundary on either source or destination */
copysize = MIN(copysize, page_limit(toaddr));
copysize = MIN(copysize, page_limit(fromaddr));
/*
* Handle MTE tag checks: either handle the tag mismatch for byte 0,
* or else copy up to but not including the byte with the mismatch.
*/
if (*rdesc) {
uint64_t mtesize = mte_mops_probe(env, fromaddr, copysize, *rdesc);
if (mtesize == 0) {
mte_check_fail(env, *rdesc, fromaddr, ra);
*rdesc = 0;
} else {
copysize = MIN(copysize, mtesize);
}
}
if (*wdesc) {
uint64_t mtesize = mte_mops_probe(env, toaddr, copysize, *wdesc);
if (mtesize == 0) {
mte_check_fail(env, *wdesc, toaddr, ra);
*wdesc = 0;
} else {
copysize = MIN(copysize, mtesize);
}
}
toaddr = useronly_clean_ptr(toaddr);
fromaddr = useronly_clean_ptr(fromaddr);
/* Trapless lookup of whether we can get a host memory pointer */
wmem = tlb_vaddr_to_host(env, toaddr, MMU_DATA_STORE, wmemidx);
rmem = tlb_vaddr_to_host(env, fromaddr, MMU_DATA_LOAD, rmemidx);
#ifndef CONFIG_USER_ONLY
/*
* If we don't have host memory for both source and dest then just
* do a single byte copy. This will handle watchpoints, invalid pages,
* etc correctly. For clean code pages, the next iteration will see
* the page dirty and will use the fast path.
*/
if (unlikely(!rmem || !wmem)) {
uint8_t byte;
if (rmem) {
byte = *(uint8_t *)rmem;
} else {
byte = cpu_ldub_mmuidx_ra(env, fromaddr, rmemidx, ra);
}
if (wmem) {
*(uint8_t *)wmem = byte;
} else {
cpu_stb_mmuidx_ra(env, toaddr, byte, wmemidx, ra);
}
return 1;
}
#endif
/* Easy case: just memmove the host memory */
memmove(wmem, rmem, copysize);
return copysize;
}
/*
* Do part of a backwards memory copy. Here toaddr and fromaddr point
* to the *last* byte to be copied.
*/
static uint64_t copy_step_rev(CPUARMState *env, uint64_t toaddr,
uint64_t fromaddr,
uint64_t copysize, int wmemidx, int rmemidx,
uint32_t *wdesc, uint32_t *rdesc, uintptr_t ra)
{
void *rmem;
void *wmem;
/* Don't cross a page boundary on either source or destination */
copysize = MIN(copysize, page_limit_rev(toaddr));
copysize = MIN(copysize, page_limit_rev(fromaddr));
/*
* Handle MTE tag checks: either handle the tag mismatch for byte 0,
* or else copy up to but not including the byte with the mismatch.
*/
if (*rdesc) {
uint64_t mtesize = mte_mops_probe_rev(env, fromaddr, copysize, *rdesc);
if (mtesize == 0) {
mte_check_fail(env, *rdesc, fromaddr, ra);
*rdesc = 0;
} else {
copysize = MIN(copysize, mtesize);
}
}
if (*wdesc) {
uint64_t mtesize = mte_mops_probe_rev(env, toaddr, copysize, *wdesc);
if (mtesize == 0) {
mte_check_fail(env, *wdesc, toaddr, ra);
*wdesc = 0;
} else {
copysize = MIN(copysize, mtesize);
}
}
toaddr = useronly_clean_ptr(toaddr);
fromaddr = useronly_clean_ptr(fromaddr);
/* Trapless lookup of whether we can get a host memory pointer */
wmem = tlb_vaddr_to_host(env, toaddr, MMU_DATA_STORE, wmemidx);
rmem = tlb_vaddr_to_host(env, fromaddr, MMU_DATA_LOAD, rmemidx);
#ifndef CONFIG_USER_ONLY
/*
* If we don't have host memory for both source and dest then just
* do a single byte copy. This will handle watchpoints, invalid pages,
* etc correctly. For clean code pages, the next iteration will see
* the page dirty and will use the fast path.
*/
if (unlikely(!rmem || !wmem)) {
uint8_t byte;
if (rmem) {
byte = *(uint8_t *)rmem;
} else {
byte = cpu_ldub_mmuidx_ra(env, fromaddr, rmemidx, ra);
}
if (wmem) {
*(uint8_t *)wmem = byte;
} else {
cpu_stb_mmuidx_ra(env, toaddr, byte, wmemidx, ra);
}
return 1;
}
#endif
/*
* Easy case: just memmove the host memory. Note that wmem and
* rmem here point to the *last* byte to copy.
*/
memmove(wmem - (copysize - 1), rmem - (copysize - 1), copysize);
return copysize;
}
/*
* for the Memory Copy operation, our implementation chooses always
* to use "option A", where we update Xd and Xs to the final addresses
* in the CPYP insn, and then in CPYM and CPYE only need to update Xn.
*
* @env: CPU
* @syndrome: syndrome value for mismatch exceptions
* (also contains the register numbers we need to use)
* @wdesc: MTE descriptor for the writes (destination)
* @rdesc: MTE descriptor for the reads (source)
* @move: true if this is CPY (memmove), false for CPYF (memcpy forwards)
*/
static void do_cpyp(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
uint32_t rdesc, uint32_t move, uintptr_t ra)
{
int rd = mops_destreg(syndrome);
int rs = mops_srcreg(syndrome);
int rn = mops_sizereg(syndrome);
uint32_t rmemidx = FIELD_EX32(rdesc, MTEDESC, MIDX);
uint32_t wmemidx = FIELD_EX32(wdesc, MTEDESC, MIDX);
bool forwards = true;
uint64_t toaddr = env->xregs[rd];
uint64_t fromaddr = env->xregs[rs];
uint64_t copysize = env->xregs[rn];
uint64_t stagecopysize, step;
check_mops_enabled(env, ra);
if (move) {
/*
* Copy backwards if necessary. The direction for a non-overlapping
* copy is IMPDEF; we choose forwards.
*/
if (copysize > 0x007FFFFFFFFFFFFFULL) {
copysize = 0x007FFFFFFFFFFFFFULL;
}
uint64_t fs = extract64(fromaddr, 0, 56);
uint64_t ts = extract64(toaddr, 0, 56);
uint64_t fe = extract64(fromaddr + copysize, 0, 56);
if (fs < ts && fe > ts) {
forwards = false;
}
} else {
if (copysize > INT64_MAX) {
copysize = INT64_MAX;
}
}
if (!mte_checks_needed(fromaddr, rdesc)) {
rdesc = 0;
}
if (!mte_checks_needed(toaddr, wdesc)) {
wdesc = 0;
}
if (forwards) {
stagecopysize = MIN(copysize, page_limit(toaddr));
stagecopysize = MIN(stagecopysize, page_limit(fromaddr));
while (stagecopysize) {
env->xregs[rd] = toaddr;
env->xregs[rs] = fromaddr;
env->xregs[rn] = copysize;
step = copy_step(env, toaddr, fromaddr, stagecopysize,
wmemidx, rmemidx, &wdesc, &rdesc, ra);
toaddr += step;
fromaddr += step;
copysize -= step;
stagecopysize -= step;
}
/* Insn completed, so update registers to the Option A format */
env->xregs[rd] = toaddr + copysize;
env->xregs[rs] = fromaddr + copysize;
env->xregs[rn] = -copysize;
} else {
/*
* In a reverse copy the to and from addrs in Xs and Xd are the start
* of the range, but it's more convenient for us to work with pointers
* to the last byte being copied.
*/
toaddr += copysize - 1;
fromaddr += copysize - 1;
stagecopysize = MIN(copysize, page_limit_rev(toaddr));
stagecopysize = MIN(stagecopysize, page_limit_rev(fromaddr));
while (stagecopysize) {
env->xregs[rn] = copysize;
step = copy_step_rev(env, toaddr, fromaddr, stagecopysize,
wmemidx, rmemidx, &wdesc, &rdesc, ra);
copysize -= step;
stagecopysize -= step;
toaddr -= step;
fromaddr -= step;
}
/*
* Insn completed, so update registers to the Option A format.
* For a reverse copy this is no different to the CPYP input format.
*/
env->xregs[rn] = copysize;
}
/* Set NZCV = 0000 to indicate we are an Option A implementation */
env->NF = 0;
env->ZF = 1; /* our env->ZF encoding is inverted */
env->CF = 0;
env->VF = 0;
return;
}
void HELPER(cpyp)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
uint32_t rdesc)
{
do_cpyp(env, syndrome, wdesc, rdesc, true, GETPC());
}
void HELPER(cpyfp)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
uint32_t rdesc)
{
do_cpyp(env, syndrome, wdesc, rdesc, false, GETPC());
}
static void do_cpym(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
uint32_t rdesc, uint32_t move, uintptr_t ra)
{
/* Main: we choose to copy until less than a page remaining */
CPUState *cs = env_cpu(env);
int rd = mops_destreg(syndrome);
int rs = mops_srcreg(syndrome);
int rn = mops_sizereg(syndrome);
uint32_t rmemidx = FIELD_EX32(rdesc, MTEDESC, MIDX);
uint32_t wmemidx = FIELD_EX32(wdesc, MTEDESC, MIDX);
bool forwards = true;
uint64_t toaddr, fromaddr, copysize, step;
check_mops_enabled(env, ra);
/* We choose to NOP out "no data to copy" before consistency checks */
if (env->xregs[rn] == 0) {
return;
}
check_mops_wrong_option(env, syndrome, ra);
if (move) {
forwards = (int64_t)env->xregs[rn] < 0;
}
if (forwards) {
toaddr = env->xregs[rd] + env->xregs[rn];
fromaddr = env->xregs[rs] + env->xregs[rn];
copysize = -env->xregs[rn];
} else {
copysize = env->xregs[rn];
/* This toaddr and fromaddr point to the *last* byte to copy */
toaddr = env->xregs[rd] + copysize - 1;
fromaddr = env->xregs[rs] + copysize - 1;
}
if (!mte_checks_needed(fromaddr, rdesc)) {
rdesc = 0;
}
if (!mte_checks_needed(toaddr, wdesc)) {
wdesc = 0;
}
/* Our implementation has no particular parameter requirements for CPYM */
/* Do the actual memmove */
if (forwards) {
while (copysize >= TARGET_PAGE_SIZE) {
step = copy_step(env, toaddr, fromaddr, copysize,
wmemidx, rmemidx, &wdesc, &rdesc, ra);
toaddr += step;
fromaddr += step;
copysize -= step;
env->xregs[rn] = -copysize;
if (copysize >= TARGET_PAGE_SIZE &&
unlikely(cpu_loop_exit_requested(cs))) {
cpu_loop_exit_restore(cs, ra);
}
}
} else {
while (copysize >= TARGET_PAGE_SIZE) {
step = copy_step_rev(env, toaddr, fromaddr, copysize,
wmemidx, rmemidx, &wdesc, &rdesc, ra);
toaddr -= step;
fromaddr -= step;
copysize -= step;
env->xregs[rn] = copysize;
if (copysize >= TARGET_PAGE_SIZE &&
unlikely(cpu_loop_exit_requested(cs))) {
cpu_loop_exit_restore(cs, ra);
}
}
}
}
void HELPER(cpym)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
uint32_t rdesc)
{
do_cpym(env, syndrome, wdesc, rdesc, true, GETPC());
}
void HELPER(cpyfm)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
uint32_t rdesc)
{
do_cpym(env, syndrome, wdesc, rdesc, false, GETPC());
}
static void do_cpye(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
uint32_t rdesc, uint32_t move, uintptr_t ra)
{
/* Epilogue: do the last partial page */
int rd = mops_destreg(syndrome);
int rs = mops_srcreg(syndrome);
int rn = mops_sizereg(syndrome);
uint32_t rmemidx = FIELD_EX32(rdesc, MTEDESC, MIDX);
uint32_t wmemidx = FIELD_EX32(wdesc, MTEDESC, MIDX);
bool forwards = true;
uint64_t toaddr, fromaddr, copysize, step;
check_mops_enabled(env, ra);
/* We choose to NOP out "no data to copy" before consistency checks */
if (env->xregs[rn] == 0) {
return;
}
check_mops_wrong_option(env, syndrome, ra);
if (move) {
forwards = (int64_t)env->xregs[rn] < 0;
}
if (forwards) {
toaddr = env->xregs[rd] + env->xregs[rn];
fromaddr = env->xregs[rs] + env->xregs[rn];
copysize = -env->xregs[rn];
} else {
copysize = env->xregs[rn];
/* This toaddr and fromaddr point to the *last* byte to copy */
toaddr = env->xregs[rd] + copysize - 1;
fromaddr = env->xregs[rs] + copysize - 1;
}
if (!mte_checks_needed(fromaddr, rdesc)) {
rdesc = 0;
}
if (!mte_checks_needed(toaddr, wdesc)) {
wdesc = 0;
}
/* Check the size; we don't want to have do a check-for-interrupts */
if (copysize >= TARGET_PAGE_SIZE) {
raise_exception_ra(env, EXCP_UDEF, syndrome,
mops_mismatch_exception_target_el(env), ra);
}
/* Do the actual memmove */
if (forwards) {
while (copysize > 0) {
step = copy_step(env, toaddr, fromaddr, copysize,
wmemidx, rmemidx, &wdesc, &rdesc, ra);
toaddr += step;
fromaddr += step;
copysize -= step;
env->xregs[rn] = -copysize;
}
} else {
while (copysize > 0) {
step = copy_step_rev(env, toaddr, fromaddr, copysize,
wmemidx, rmemidx, &wdesc, &rdesc, ra);
toaddr -= step;
fromaddr -= step;
copysize -= step;
env->xregs[rn] = copysize;
}
}
}
void HELPER(cpye)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
uint32_t rdesc)
{
do_cpye(env, syndrome, wdesc, rdesc, true, GETPC());
}
void HELPER(cpyfe)(CPUARMState *env, uint32_t syndrome, uint32_t wdesc,
uint32_t rdesc)
{
do_cpye(env, syndrome, wdesc, rdesc, false, GETPC());
}

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@ -124,3 +124,10 @@ DEF_HELPER_3(sete, void, env, i32, i32)
DEF_HELPER_3(setgp, void, env, i32, i32)
DEF_HELPER_3(setgm, void, env, i32, i32)
DEF_HELPER_3(setge, void, env, i32, i32)
DEF_HELPER_4(cpyp, void, env, i32, i32, i32)
DEF_HELPER_4(cpym, void, env, i32, i32, i32)
DEF_HELPER_4(cpye, void, env, i32, i32, i32)
DEF_HELPER_4(cpyfp, void, env, i32, i32, i32)
DEF_HELPER_4(cpyfm, void, env, i32, i32, i32)
DEF_HELPER_4(cpyfe, void, env, i32, i32, i32)

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@ -4019,6 +4019,66 @@ TRANS_FEAT(SETGP, aa64_mops, do_SET, a, false, true, gen_helper_setgp)
TRANS_FEAT(SETGM, aa64_mops, do_SET, a, false, true, gen_helper_setgm)
TRANS_FEAT(SETGE, aa64_mops, do_SET, a, true, true, gen_helper_setge)
typedef void CpyFn(TCGv_env, TCGv_i32, TCGv_i32, TCGv_i32);
static bool do_CPY(DisasContext *s, arg_cpy *a, bool is_epilogue, CpyFn fn)
{
int rmemidx, wmemidx;
uint32_t syndrome, rdesc = 0, wdesc = 0;
bool wunpriv = extract32(a->options, 0, 1);
bool runpriv = extract32(a->options, 1, 1);
/*
* UNPREDICTABLE cases: we choose to UNDEF, which allows
* us to pull this check before the CheckMOPSEnabled() test
* (which we do in the helper function)
*/
if (a->rs == a->rn || a->rs == a->rd || a->rn == a->rd ||
a->rd == 31 || a->rs == 31 || a->rn == 31) {
return false;
}
rmemidx = get_a64_user_mem_index(s, runpriv);
wmemidx = get_a64_user_mem_index(s, wunpriv);
/*
* We pass option_a == true, matching our implementation;
* we pass wrong_option == false: helper function may set that bit.
*/
syndrome = syn_mop(false, false, a->options, is_epilogue,
false, true, a->rd, a->rs, a->rn);
/* If we need to do MTE tag checking, assemble the descriptors */
if (s->mte_active[runpriv]) {
rdesc = FIELD_DP32(rdesc, MTEDESC, TBI, s->tbid);
rdesc = FIELD_DP32(rdesc, MTEDESC, TCMA, s->tcma);
}
if (s->mte_active[wunpriv]) {
wdesc = FIELD_DP32(wdesc, MTEDESC, TBI, s->tbid);
wdesc = FIELD_DP32(wdesc, MTEDESC, TCMA, s->tcma);
wdesc = FIELD_DP32(wdesc, MTEDESC, WRITE, true);
}
/* The helper function needs these parts of the descriptor regardless */
rdesc = FIELD_DP32(rdesc, MTEDESC, MIDX, rmemidx);
wdesc = FIELD_DP32(wdesc, MTEDESC, MIDX, wmemidx);
/*
* The helper needs the register numbers, but since they're in
* the syndrome anyway, we let it extract them from there rather
* than passing in an extra three integer arguments.
*/
fn(cpu_env, tcg_constant_i32(syndrome), tcg_constant_i32(wdesc),
tcg_constant_i32(rdesc));
return true;
}
TRANS_FEAT(CPYP, aa64_mops, do_CPY, a, false, gen_helper_cpyp)
TRANS_FEAT(CPYM, aa64_mops, do_CPY, a, false, gen_helper_cpym)
TRANS_FEAT(CPYE, aa64_mops, do_CPY, a, true, gen_helper_cpye)
TRANS_FEAT(CPYFP, aa64_mops, do_CPY, a, false, gen_helper_cpyfp)
TRANS_FEAT(CPYFM, aa64_mops, do_CPY, a, false, gen_helper_cpyfm)
TRANS_FEAT(CPYFE, aa64_mops, do_CPY, a, true, gen_helper_cpyfe)
typedef void ArithTwoOp(TCGv_i64, TCGv_i64, TCGv_i64);
static bool gen_rri(DisasContext *s, arg_rri_sf *a,