On 9/7/23 09:03, Peter Maydell wrote:
The FEAT_MOPS SETG* instructions are very similar to the SET* instructions, but as well as setting memory contents they also set the MTE tags. They are architecturally required to operate on tag-granule aligned regions only.Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> --- target/arm/internals.h | 10 ++++ target/arm/tcg/a64.decode | 5 ++ target/arm/tcg/helper-a64.c | 92 +++++++++++++++++++++++++++++++--- target/arm/tcg/mte_helper.c | 40 +++++++++++++++ target/arm/tcg/translate-a64.c | 20 +++++--- 5 files changed, 155 insertions(+), 12 deletions(-) diff --git a/target/arm/internals.h b/target/arm/internals.h index a70a7fd50f6..642f77df29b 100644 --- a/target/arm/internals.h +++ b/target/arm/internals.h @@ -1300,6 +1300,16 @@ uint64_t mte_mops_probe(CPUARMState *env, uint64_t ptr, uint64_t size, void mte_check_fail(CPUARMState *env, uint32_t desc, uint64_t dirty_ptr, uintptr_t ra);+/**+ * mte_mops_set_tags: Set MTE tags for a portion of a FEAT_MOPS operation + * @env: CPU env + * @dirty_ptr: Start address of memory region (dirty pointer) + * @size: length of region (guaranteed not to cross page boundary) + * @desc: MTEDESC descriptor word + */ +void mte_mops_set_tags(CPUARMState *env, uint64_t dirty_ptr, uint64_t size, + uint32_t desc); + static inline int allocation_tag_from_addr(uint64_t ptr) { return extract64(ptr, 56, 4); diff --git a/target/arm/tcg/a64.decode b/target/arm/tcg/a64.decode index 8cddc207a6f..46caeb59fe5 100644 --- a/target/arm/tcg/a64.decode +++ b/target/arm/tcg/a64.decode @@ -569,3 +569,8 @@ STZ2G 11011001 11 1 ......... 11 ..... ..... @ldst_tag p=0 w=1 SETP 00 011001110 ..... 00 . . 01 ..... ..... @set SETM 00 011001110 ..... 01 . . 01 ..... ..... @set SETE 00 011001110 ..... 10 . . 01 ..... ..... @set + +# Like SET, but also setting MTE tags +SETGP 00 011101110 ..... 00 . . 01 ..... ..... @set +SETGM 00 011101110 ..... 01 . . 01 ..... ..... @set +SETGE 00 011101110 ..... 10 . . 01 ..... ..... @set diff --git a/target/arm/tcg/helper-a64.c b/target/arm/tcg/helper-a64.c index 73169eb0b56..96780067262 100644 --- a/target/arm/tcg/helper-a64.c +++ b/target/arm/tcg/helper-a64.c @@ -1103,6 +1103,54 @@ static uint64_t set_step(CPUARMState *env, uint64_t toaddr, return setsize; }+/*+ * Similar, but setting tags. The architecture requires us to do this + * in 16-byte chunks. SETP accesses are not tag checked; they set + * the tags. + */ +static uint64_t set_step_tags(CPUARMState *env, uint64_t toaddr, + uint64_t setsize, uint32_t data, int memidx, + uint32_t *mtedesc, uintptr_t ra) +{ + void *mem; + uint64_t cleanaddr; + + setsize = MIN(setsize, page_limit(toaddr)); + + cleanaddr = useronly_clean_ptr(toaddr); + /* + * Trapless lookup: returns NULL for invalid page, I/O, + * watchpoints, clean pages, etc. + */ + mem = tlb_vaddr_to_host(env, cleanaddr, MMU_DATA_STORE, memidx); + +#ifndef CONFIG_USER_ONLY + if (unlikely(!mem)) { + /* + * Slow-path: just do one write. This will handle the + * watchpoint, invalid page, etc handling correctly. + * The architecture requires that we do 16 bytes at a time, + * and we know both ptr and size are 16 byte aligned. + * For clean code pages, the next iteration will see + * the page dirty and will use the fast path. + */ + uint64_t repldata = data * 0x0101010101010101ULL; + cpu_stq_mmuidx_ra(env, toaddr, repldata, memidx, ra); + cpu_stq_mmuidx_ra(env, toaddr + 8, repldata, memidx, ra); + mte_mops_set_tags(env, toaddr, 16, *mtedesc); + return 16;
You can use cpu_st16_mmu for one store.
@@ -1154,20 +1219,27 @@ void HELPER(setp)(CPUARMState *env, uint32_t syndrome, uint32_t mtedesc) int rd = mops_destreg(syndrome); int rs = mops_srcreg(syndrome); int rn = mops_sizereg(syndrome); + bool set_tags = mops_is_setg(syndrome); uint8_t data = env->xregs[rs]; uint32_t memidx = FIELD_EX32(mtedesc, MTEDESC, MIDX); uint64_t toaddr = env->xregs[rd]; uint64_t setsize = env->xregs[rn]; uint64_t stagesetsize, step; uintptr_t ra = GETPC(); + StepFn *stepfn = set_tags ? set_step_tags : set_step;check_mops_enabled(env, ra); if (setsize > INT64_MAX) {setsize = INT64_MAX; + if (set_tags) { + setsize &= ~0xf; + } }
I think it would be a little better if set_tags was visible to the compiler, via inlining, so that all of the conditions can be folded away.
That said, all of the above is optimization not bugs. Reviewed-by: Richard Henderson <richard.hender...@linaro.org> r~
