On 30 September 2014 22:49, Greg Bellows <greg.bell...@linaro.org> wrote:
> From: Fabian Aggeler <aggel...@ethz.ch>
>
> If EL3 is in Aarch32 state certain cp registers are banked (secure and
> non-secure instance). When reading or writing to coprocessor registers
> the following macros can be used.
>
> - A32_BANKED macros are used for choosing the banked register based on
> provided
> input security argument. This macro is used to choose the bank during
> translation of MRC/MCR instructions that are dependent on something other
> than the current secure state.
> - A32_BANKED_CURRENT macros are used for choosing the banked register based on
> current secure state. This is NOT to be used for choosing the bank used
> during translation as it breaks monitor mode.
>
> If EL3 is operating in Aarch64 state coprocessor registers are not
> banked anymore. The macros use the non-secure instance (_ns) in this
> case, which is architecturally mapped to the Aarch64 EL register.
>
> Signed-off-by: Sergey Fedorov <s.fedo...@samsung.com>
> Signed-off-by: Fabian Aggeler <aggel...@ethz.ch>
> Signed-off-by: Greg Bellows <greg.bell...@linaro.org>
>
> ----------
> v4 -> v5
> - Cleaned-up macros to try and alleviate misuse. Made A32_BANKED macros take
> secure arg indicator rather than relying on USE_SECURE_REG. Incorporated
> the
> A32_BANKED macros into the A32_BANKED_CURRENT. CURRENT is now the only one
> that automatically chooses based on current secure state.
> ---
> target-arm/cpu.h | 36 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 36 insertions(+)
>
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index 601f8fe..c58fdf5 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -807,6 +807,42 @@ static inline bool arm_el_is_aa64(CPUARMState *env, int
> el)
> return arm_feature(env, ARM_FEATURE_AARCH64);
> }
>
> +/* Macro for determing whether to use the secure or non-secure bank of a CP
> + * register. When EL3 is operating in Aarch32 state, the NS-bit determines
> + * whether the secure instance of a cp-register should be used.
> + */
> +#define USE_SECURE_REG(_env) ( \
> + arm_feature((_env), ARM_FEATURE_EL3) && \
> + !arm_el_is_aa64((_env), 3) && \
> + !((_env)->cp15.scr_el3 & SCR_NS))
Better to use an inline function for this rather than a macro,
I think.
> +
> +/* Macros for accessing a specified CP register bank */
> +#define A32_BANKED_REG_GET(_env, _regname, _secure) \
> + ((_secure) ? (_env)->cp15._regname##_s : (_env)->cp15._regname##_ns)
> +
> +#define A32_BANKED_REG_SET(_env, _regname, _secure, _val) \
> + do { \
> + if (_secure) { \
> + (_env)->cp15._regname##_s = (_val); \
> + } else { \
> + (_env)->cp15._regname##_ns = (_val); \
> + } \
> + } while (0)
> +
> +/* Macros for automatically accessing a specific CP register bank depending
> on
> + * the current secure state of the system. These macros are not intended for
> + * supporting instruction translation reads/writes as these are dependent
> + * solely on the SCR.NS bit and not the mode.
> + */
> +#define A32_BANKED_CURRENT_REG_GET(_env, _regname) \
> + A32_BANKED_REG_GET((_env), _regname, \
> + ((!arm_el_is_aa64((_env), 3) && arm_is_secure(_env))))
> +
> +#define A32_BANKED_CURRENT_REG_SET(_env, _regname, _val)
> \
> + A32_BANKED_REG_SET((_env), _regname, \
> + ((!arm_el_is_aa64((_env), 3) &&
> arm_is_secure(_env))), \
> + (_val))
> +
...though these all have to be macros because of the regname handling.
(Do we use "!arm_el_is_aa64((env), 3) && arm_is_secure(env)"
often enough to make it worth a utility function? I can't
think of a good name though, so maybe not...)
thanks
-- PMM
