target/arm: Define and use new regime_tcr_value() function

The regime_tcr() function returns a pointer to a struct TCR
corresponding to the TCR controlling a translation regime.  The
struct TCR has the raw value of the register, plus two fields mask
and base_mask which are used as a small optimization in the case of
32-bit short-descriptor lookups.  Almost all callers of regime_tcr()
only want the raw register value.  Define and use a new
regime_tcr_value() function which returns only the raw 64-bit
register value.

This is a preliminary to removing the 32-bit short descriptor
optimization -- it only saves a handful of bit operations, which is
tiny compared to the overhead of doing a page table walk at all, and
the TCR struct is awkward and makes fixing
https://gitlab.com/qemu-project/qemu/-/issues/1103 unnecessarily
difficult.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220714132303.1287193-2-peter.maydell@linaro.org

target/arm/tlb_helper.c

@@ -20,7 +20,7 @@ bool regime_using_lpae_format(CPUARMState *env, ARMMMUIdx mmu_idx)
         return true;
     }
     if (arm_feature(env, ARM_FEATURE_LPAE)
-        && (regime_tcr(env, mmu_idx)->raw_tcr & TTBCR_EAE)) {
+        && (regime_tcr_value(env, mmu_idx) & TTBCR_EAE)) {
         return true;
     }
     return false;