target/arm: Check alignment in helper_mte_check

Fixes a bug in that with SCTLR.A set, we should raise any
alignment fault before raising any MTE check fault.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230530191438.411344-15-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/internals.h

@@ -1242,7 +1242,8 @@ FIELD(MTEDESC, MIDX,  0, 4)
 FIELD(MTEDESC, TBI,   4, 2)
 FIELD(MTEDESC, TCMA,  6, 2)
 FIELD(MTEDESC, WRITE, 8, 1)
-FIELD(MTEDESC, SIZEM1, 9, SIMD_DATA_BITS - 9)  /* size - 1 */
+FIELD(MTEDESC, ALIGN, 9, 3)
+FIELD(MTEDESC, SIZEM1, 12, SIMD_DATA_BITS - 12)  /* size - 1 */
 
 bool mte_probe(CPUARMState *env, uint32_t desc, uint64_t ptr);
 uint64_t mte_check(CPUARMState *env, uint32_t desc, uint64_t ptr, uintptr_t ra);

target/arm/tcg/mte_helper.c

@@ -785,6 +785,24 @@ uint64_t mte_check(CPUARMState *env, uint32_t desc, uint64_t ptr, uintptr_t ra)
 
 uint64_t HELPER(mte_check)(CPUARMState *env, uint32_t desc, uint64_t ptr)
 {
+    /*
+     * R_XCHFJ: Alignment check not caused by memory type is priority 1,
+     * higher than any translation fault.  When MTE is disabled, tcg
+     * performs the alignment check during the code generated for the
+     * memory access.  With MTE enabled, we must check this here before
+     * raising any translation fault in allocation_tag_mem.
+     */
+    unsigned align = FIELD_EX32(desc, MTEDESC, ALIGN);
+    if (unlikely(align)) {
+        align = (1u << align) - 1;
+        if (unlikely(ptr & align)) {
+            int idx = FIELD_EX32(desc, MTEDESC, MIDX);
+            bool w = FIELD_EX32(desc, MTEDESC, WRITE);
+            MMUAccessType type = w ? MMU_DATA_STORE : MMU_DATA_LOAD;
+            arm_cpu_do_unaligned_access(env_cpu(env), ptr, type, idx, GETPC());
+        }
+    }
+
     return mte_check(env, desc, ptr, GETPC());
 }
 

target/arm/tcg/translate-a64.c

@@ -264,6 +264,7 @@ static TCGv_i64 gen_mte_check1_mmuidx(DisasContext *s, TCGv_i64 addr,
         desc = FIELD_DP32(desc, MTEDESC, TBI, s->tbid);
         desc = FIELD_DP32(desc, MTEDESC, TCMA, s->tcma);
         desc = FIELD_DP32(desc, MTEDESC, WRITE, is_write);
+        desc = FIELD_DP32(desc, MTEDESC, ALIGN, get_alignment_bits(memop));
         desc = FIELD_DP32(desc, MTEDESC, SIZEM1, memop_size(memop) - 1);
 
         ret = tcg_temp_new_i64();
@@ -295,6 +296,7 @@ TCGv_i64 gen_mte_checkN(DisasContext *s, TCGv_i64 addr, bool is_write,
         desc = FIELD_DP32(desc, MTEDESC, TBI, s->tbid);
         desc = FIELD_DP32(desc, MTEDESC, TCMA, s->tcma);
         desc = FIELD_DP32(desc, MTEDESC, WRITE, is_write);
+        desc = FIELD_DP32(desc, MTEDESC, ALIGN, get_alignment_bits(single_mop));
         desc = FIELD_DP32(desc, MTEDESC, SIZEM1, total_size - 1);
 
         ret = tcg_temp_new_i64();