Richard Henderson <richard.hender...@linaro.org> writes:
> Split out a helper function from mte_checkN to perform
> all of the checking and address manpulation. So far,
> just use this in mte_checkN itself.
>
> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
> ---
> target/arm/mte_helper.c | 52 +++++++++++++++++++++++++++++++----------
> 1 file changed, 40 insertions(+), 12 deletions(-)
>
> diff --git a/target/arm/mte_helper.c b/target/arm/mte_helper.c
> index c87717127c..144bfa4a51 100644
> --- a/target/arm/mte_helper.c
> +++ b/target/arm/mte_helper.c
> @@ -753,33 +753,45 @@ static int checkN(uint8_t *mem, int odd, int cmp, int
> count)
> return n;
> }
>
> -uint64_t mte_checkN(CPUARMState *env, uint32_t desc,
> - uint64_t ptr, uintptr_t ra)
> +/*
> + * mte_probe_int:
nit: you might as well go full kernel-doc here as you are documenting
the helper:
/**
* mte_probe_int() - helper for mte_probe and mte_check
> + * @env: CPU environment
> + * @desc: MTEDESC descriptor
> + * @ptr: virtual address of the base of the access
> + * @fault: return virtual address of the first check failure
> + *
> + * Internal routine for both mte_probe and mte_check.
> + * Return zero on failure, filling in *fault.
> + * Return negative on trivial success for tbi disabled.
> + * Return positive on success with tbi enabled.
> + */
> +static int mte_probe_int(CPUARMState *env, uint32_t desc, uint64_t ptr,
> + uintptr_t ra, uint32_t total, uint64_t *fault)
> {
> int mmu_idx, ptr_tag, bit55;
> uint64_t ptr_last, prev_page, next_page;
> uint64_t tag_first, tag_last;
> uint64_t tag_byte_first, tag_byte_last;
> - uint32_t total, tag_count, tag_size, n, c;
> + uint32_t tag_count, tag_size, n, c;
> uint8_t *mem1, *mem2;
> MMUAccessType type;
>
> bit55 = extract64(ptr, 55, 1);
> + *fault = ptr;
>
> /* If TBI is disabled, the access is unchecked, and ptr is not dirty. */
> if (unlikely(!tbi_check(desc, bit55))) {
> - return ptr;
> + return -1;
> }
>
> ptr_tag = allocation_tag_from_addr(ptr);
>
> if (tcma_check(desc, bit55, ptr_tag)) {
> - goto done;
> + return 1;
> }
>
> mmu_idx = FIELD_EX32(desc, MTEDESC, MIDX);
> type = FIELD_EX32(desc, MTEDESC, WRITE) ? MMU_DATA_STORE : MMU_DATA_LOAD;
> - total = FIELD_EX32(desc, MTEDESC, TSIZE);
>
> /* Find the addr of the end of the access, and of the last element. */
> ptr_last = ptr + total - 1;
> @@ -803,7 +815,7 @@ uint64_t mte_checkN(CPUARMState *env, uint32_t desc,
> mem1 = allocation_tag_mem(env, mmu_idx, ptr, type, total,
> MMU_DATA_LOAD, tag_size, ra);
> if (!mem1) {
> - goto done;
> + return 1;
> }
> /* Perform all of the comparisons. */
> n = checkN(mem1, ptr & TAG_GRANULE, ptr_tag, tag_count);
> @@ -829,23 +841,39 @@ uint64_t mte_checkN(CPUARMState *env, uint32_t desc,
> }
> if (n == c) {
> if (!mem2) {
> - goto done;
> + return 1;
> }
> n += checkN(mem2, 0, ptr_tag, tag_count - c);
> }
> }
>
> + if (likely(n == tag_count)) {
> + return 1;
> + }
> +
> /*
> * If we failed, we know which granule. For the first granule, the
> * failure address is @ptr, the first byte accessed. Otherwise the
> * failure address is the first byte of the nth granule.
> */
> - if (unlikely(n < tag_count)) {
> - uint64_t fault = (n == 0 ? ptr : tag_first + n * TAG_GRANULE);
> - mte_check_fail(env, desc, fault, ra);
> + if (n > 0) {
> + *fault = tag_first + n * TAG_GRANULE;
> }
> + return 0;
> +}
>
> - done:
> +uint64_t mte_checkN(CPUARMState *env, uint32_t desc,
> + uint64_t ptr, uintptr_t ra)
> +{
> + uint64_t fault;
> + uint32_t total = FIELD_EX32(desc, MTEDESC, TSIZE);
> + int ret = mte_probe_int(env, desc, ptr, ra, total, &fault);
> +
> + if (unlikely(ret == 0)) {
> + mte_check_fail(env, desc, fault, ra);
> + } else if (ret < 0) {
> + return ptr;
> + }
> return useronly_clean_ptr(ptr);
> }
Otherwise:
Reviewed-by: Alex Bennée <alex.ben...@linaro.org>
--
Alex Bennée
