Re: [PATCH 15/61] target/arm: Add CP_REG_AA32_64BIT_{SHIFT,MASK}

[Manos Pitsidianakis <manos.pitsidianakis@linaro.org>]

On Wed, 27 Aug 2025 04:04, Richard Henderson <richard.henderson@linaro.org> wrote:
>Give a name to the bit we're already using.
>
>Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>---
> target/arm/cpregs.h | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
>diff --git a/target/arm/cpregs.h b/target/arm/cpregs.h
>index b6c8eff0dd..3dc4c9927b 100644
>--- a/target/arm/cpregs.h
>+++ b/target/arm/cpregs.h
>@@ -178,9 +178,14 @@ enum {
> #define CP_REG_NS_SHIFT 29
> #define CP_REG_NS_MASK (1 << CP_REG_NS_SHIFT)
> 
>+/* Distinguish 32-bit and 64-bit views of AArch32 system registers. */
>+#define CP_REG_AA32_64BIT_SHIFT  15
>+#define CP_REG_AA32_64BIT_MASK   (1 << CP_REG_AA32_64BIT_SHIFT)

You could use include/qemu/bitops.h

>+
> #define ENCODE_CP_REG(cp, is64, ns, crn, crm, opc1, opc2)   \
>-    ((ns) << CP_REG_NS_SHIFT | ((cp) << 16) | ((is64) << 15) |   \
>-     ((crn) << 11) | ((crm) << 7) | ((opc1) << 3) | (opc2))
>+    (((ns) << CP_REG_NS_SHIFT) |                            \
>+     ((is64) << CP_REG_AA32_64BIT_SHIFT) |                  \
>+     ((cp) << 16) | ((crn) << 11) | ((crm) << 7) | ((opc1) << 3) | (opc2))
> 
> #define ENCODE_AA64_CP_REG(cp, crn, crm, op0, op1, op2) \
>     (CP_REG_AA64_MASK |                                 \
>@@ -202,7 +207,7 @@ static inline uint32_t kvm_to_cpreg_id(uint64_t kvmid)
>         cpregid |= CP_REG_AA64_MASK;
>     } else {
>         if ((kvmid & CP_REG_SIZE_MASK) == CP_REG_SIZE_U64) {
>-            cpregid |= (1 << 15);
>+            cpregid |= CP_REG_AA32_64BIT_MASK;
>         }
> 
>         /*
>@@ -226,8 +231,8 @@ static inline uint64_t cpreg_to_kvm_id(uint32_t cpregid)
>         kvmid = cpregid & ~CP_REG_AA64_MASK;
>         kvmid |= CP_REG_SIZE_U64 | CP_REG_ARM64;
>     } else {
>-        kvmid = cpregid & ~(1 << 15);
>-        if (cpregid & (1 << 15)) {
>+        kvmid = cpregid & ~CP_REG_AA32_64BIT_MASK;
>+        if (cpregid & CP_REG_AA32_64BIT_MASK) {
>             kvmid |= CP_REG_SIZE_U64 | CP_REG_ARM;
>         } else {
>             kvmid |= CP_REG_SIZE_U32 | CP_REG_ARM;
>-- 

Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>

>2.43.0
>
>