target/arm: Adjust PAR_EL1.SH for Device and Normal-NC memory types

The PAR_EL1.SH field documents that for the cases of:
 * Device memory
 * Normal memory with both Inner and Outer Non-Cacheable
the field should be 0b10 rather than whatever was in the
translation table descriptor field. (In the pseudocode this
is handled by PAREncodeShareability().) Perform this
adjustment when assembling a PAR value.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230807141514.19075-16-peter.maydell@linaro.org

target/arm/helper.c

@@ -3342,6 +3342,19 @@ static CPAccessResult ats_access(CPUARMState *env, const ARMCPRegInfo *ri,
 }
 
 #ifdef CONFIG_TCG
+static int par_el1_shareability(GetPhysAddrResult *res)
+{
+    /*
+     * The PAR_EL1.SH field must be 0b10 for Device or Normal-NC
+     * memory -- see pseudocode PAREncodeShareability().
+     */
+    if (((res->cacheattrs.attrs & 0xf0) == 0) ||
+        res->cacheattrs.attrs == 0x44 || res->cacheattrs.attrs == 0x40) {
+        return 2;
+    }
+    return res->cacheattrs.shareability;
+}
+
 static uint64_t do_ats_write(CPUARMState *env, uint64_t value,
                              MMUAccessType access_type, ARMMMUIdx mmu_idx,
                              bool is_secure)
@@ -3470,7 +3483,7 @@ static uint64_t do_ats_write(CPUARMState *env, uint64_t value,
                 par64 |= (1 << 9); /* NS */
             }
             par64 |= (uint64_t)res.cacheattrs.attrs << 56; /* ATTR */
-            par64 |= res.cacheattrs.shareability << 7; /* SH */
+            par64 |= par_el1_shareability(&res) << 7; /* SH */
         } else {
             uint32_t fsr = arm_fi_to_lfsc(&fi);