Re: [PATCH 43/61] target/arm: Add read_raw_cp_reg128, write_raw_cp_reg128

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

On Wed, 27 Aug 2025 04:04, Richard Henderson <richard.henderson@linaro.org> wrote:
>Add the functions and update raw_accessors_invalid to match.
>Add assertions for !ARM_CP_128BIT in read_raw_cp_reg and
>write_raw_cp_reg.
>
>Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>---

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

> target/arm/cpregs.h |  1 +
> target/arm/helper.c | 43 +++++++++++++++++++++++++++++++++++++++----
> 2 files changed, 40 insertions(+), 4 deletions(-)
>
>diff --git a/target/arm/cpregs.h b/target/arm/cpregs.h
>index 0d8c45b60c..bd26a4a260 100644
>--- a/target/arm/cpregs.h
>+++ b/target/arm/cpregs.h
>@@ -1097,6 +1097,7 @@ static inline bool cp_access_ok(int current_el,
> 
> /* Raw read of a coprocessor register (as needed for migration, etc) */
> uint64_t read_raw_cp_reg(CPUARMState *env, const ARMCPRegInfo *ri);
>+Int128 read_raw_cp_reg128(CPUARMState *env, const ARMCPRegInfo *ri);
> 
> /*
>  * Return true if the cp register encoding is in the "feature ID space" as
>diff --git a/target/arm/helper.c b/target/arm/helper.c
>index 7568b78c49..3efc14da3a 100644
>--- a/target/arm/helper.c
>+++ b/target/arm/helper.c
>@@ -115,6 +115,7 @@ static void *raw_ptr(CPUARMState *env, const ARMCPRegInfo *ri)
> 
> uint64_t read_raw_cp_reg(CPUARMState *env, const ARMCPRegInfo *ri)
> {
>+    assert(!(ri->type & ARM_CP_128BIT));
>     /* Raw read of a coprocessor register (as needed for migration, etc). */
>     if (ri->type & ARM_CP_CONST) {
>         return ri->resetvalue;
>@@ -130,6 +131,7 @@ uint64_t read_raw_cp_reg(CPUARMState *env, const ARMCPRegInfo *ri)
> static void write_raw_cp_reg(CPUARMState *env, const ARMCPRegInfo *ri,
>                              uint64_t v)
> {
>+    assert(!(ri->type & ARM_CP_128BIT));
>     /*
>      * Raw write of a coprocessor register (as needed for migration, etc).
>      * Note that constant registers are treated as write-ignored; the
>@@ -147,6 +149,32 @@ static void write_raw_cp_reg(CPUARMState *env, const ARMCPRegInfo *ri,
>     }
> }
> 
>+Int128 read_raw_cp_reg128(CPUARMState *env, const ARMCPRegInfo *ri)
>+{
>+    assert(ri->type & ARM_CP_128BIT);
>+    if (ri->raw_read128fn) {
>+        return ri->raw_read128fn(env, ri);
>+    } else if (ri->read128fn) {
>+        return ri->read128fn(env, ri);
>+    } else {
>+        return raw_read128(env, ri);
>+    }
>+}
>+
>+__attribute__((unused))
>+static void write_raw_cp_reg128(CPUARMState *env, const ARMCPRegInfo *ri,
>+                                Int128 v)
>+{
>+    assert(ri->type & ARM_CP_128BIT);
>+    if (ri->raw_write128fn) {
>+        ri->raw_write128fn(env, ri, v);
>+    } else if (ri->write128fn) {
>+        ri->write128fn(env, ri, v);
>+    } else {
>+        raw_write128(env, ri, v);
>+    }
>+}
>+
> static bool raw_accessors_invalid(const ARMCPRegInfo *ri)
> {
>    /*
>@@ -161,12 +189,19 @@ static bool raw_accessors_invalid(const ARMCPRegInfo *ri)
>     * The tests here line up with the conditions in read/write_raw_cp_reg()
>     * and assertions in raw_read()/raw_write().
>     */
>-    if ((ri->type & ARM_CP_CONST) ||
>-        ri->fieldoffset ||
>-        ((ri->raw_writefn || ri->writefn) && (ri->raw_readfn || ri->readfn))) {
>+    if (ri->type & ARM_CP_CONST) {
>+        return ri->type & ARM_CP_128BIT;
>+    }
>+    if (ri->fieldoffset) {
>         return false;
>     }
>-    return true;
>+    if (ri->type & ARM_CP_128BIT) {
>+        return !((ri->raw_write128fn || ri->write128fn) &&
>+                 (ri->raw_read128fn || ri->read128fn));
>+    } else {
>+        return !((ri->raw_writefn || ri->writefn) &&
>+                 (ri->raw_readfn || ri->readfn));
>+    }
> }
> 
> bool write_cpustate_to_list(ARMCPU *cpu, bool kvm_sync)
>-- 
>2.43.0
>
>