Re: [Qemu-devel] [RFC 17/38] aie: add target helpers

["Alex Bennée" <alex.bennee@linaro.org>]

Emilio G. Cota <cota@braap.org> writes:

> Signed-off-by: Emilio G. Cota <cota@braap.org>
> ---
>  aie-helper.c              | 112 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/exec/cpu-defs.h   |   5 +++
>  include/qemu/aie-helper.h |   6 +++
>  3 files changed, 123 insertions(+)
>  create mode 100644 aie-helper.c
>  create mode 100644 include/qemu/aie-helper.h
>
> diff --git a/aie-helper.c b/aie-helper.c
> new file mode 100644
> index 0000000..7521150
> --- /dev/null
> +++ b/aie-helper.c
> @@ -0,0 +1,112 @@
> +/*
> + * To be included directly from the target's helper.c
> + */
> +#include "qemu/aie.h"
> +
> +#ifdef CONFIG_USER_ONLY
> +static inline
> +hwaddr h_get_ld_phys(CPUArchState *env, target_ulong vaddr, uintptr_t retaddr)
> +{
> +    return vaddr;
> +}
> +
> +static inline
> +hwaddr h_get_st_phys(CPUArchState *env, target_ulong vaddr, uintptr_t retaddr)
> +{
> +    return vaddr;
> +}
> +#else
> +static inline
> +hwaddr h_get_ld_phys(CPUArchState *env, target_ulong vaddr, uintptr_t retaddr)
> +{
> +    return helper_ret_get_ld_phys(env, vaddr, cpu_mmu_index(env), retaddr);
> +}
> +
> +static inline
> +hwaddr h_get_st_phys(CPUArchState *env, target_ulong vaddr, uintptr_t retaddr)
> +{
> +    return helper_ret_get_st_phys(env, vaddr, cpu_mmu_index(env), retaddr);
> +}
> +#endif /* CONFIG_USER_ONLY */
> +
> +static inline void h_aie_lock(CPUArchState *env, hwaddr paddr)
> +{
> +    AIEEntry *entry = aie_entry_get_lock(paddr);
> +
> +    env->aie_entry = entry;
> +    env->aie_locked = true;
> +}
> +
> +static inline void h_aie_unlock(CPUArchState *env)
> +{
> +    assert(env->aie_entry && env->aie_locked);
> +    qemu_spin_unlock(&env->aie_entry->lock);
> +    env->aie_locked = false;
> +}

This is a little unbalanced as aie_entry_get_lock() returns the entry
with the lock grabbed but we free it in h_aie_unlock. Should we either
grab the lock in the helper or have a helper to free the lock that can
be kept in the aie utils?

> +
> +static inline void h_aie_unlock__done(CPUArchState *env)
> +{
> +    h_aie_unlock(env);
> +    env->aie_entry = NULL;
> +}
> +
> +static inline
> +void aie_ld_lock_ret(CPUArchState *env, target_ulong vaddr, uintptr_t retaddr)
> +{
> +    hwaddr paddr;
> +
> +    assert(!env->aie_locked);
> +    paddr = h_get_ld_phys(env, vaddr, retaddr);
> +    h_aie_lock(env, paddr);
> +}
> +
> +void HELPER(aie_ld_lock)(CPUArchState *env, target_ulong vaddr)
> +{
> +    aie_ld_lock_ret(env, vaddr, GETRA());
> +}
> +
> +static inline
> +void aie_st_lock_ret(CPUArchState *env, target_ulong vaddr, uintptr_t retaddr)
> +{
> +    hwaddr paddr;
> +
> +    assert(!env->aie_locked);
> +    paddr = h_get_st_phys(env, vaddr, retaddr);
> +    h_aie_lock(env, paddr);
> +}
> +
> +void HELPER(aie_unlock__done)(CPUArchState *env)
> +{
> +    h_aie_unlock__done(env);
> +}
> +
> +void HELPER(aie_ld_pre)(CPUArchState *env, target_ulong vaddr)
> +{
> +    if (likely(!env->aie_lock_enabled) || env->aie_locked) {
> +        return;
> +    }
> +    aie_ld_lock_ret(env, vaddr, GETRA());
> +}
> +
> +void HELPER(aie_st_pre)(CPUArchState *env, target_ulong vaddr)
> +{
> +    if (unlikely(env->aie_lock_enabled)) {
> +        if (env->aie_locked) {
> +            return;
> +        }
> +        aie_st_lock_ret(env, vaddr, GETRA());
> +    } else {
> +        hwaddr paddr = h_get_st_phys(env, vaddr, GETRA());
> +
> +        if (unlikely(aie_entry_exists(paddr))) {
> +            h_aie_lock(env, paddr);
> +        }
> +    }
> +}
> +
> +void HELPER(aie_st_post)(CPUArchState *env, target_ulong vaddr)
> +{
> +    if (unlikely(!env->aie_lock_enabled && env->aie_locked)) {
> +        h_aie_unlock__done(env);
> +    }
> +}
> diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h
> index ca9c85c..e6e4568 100644
> --- a/include/exec/cpu-defs.h
> +++ b/include/exec/cpu-defs.h
> @@ -28,6 +28,7 @@
>  #include "qemu/osdep.h"
>  #include "qemu/queue.h"
>  #include "tcg-target.h"
> +#include "qemu/aie.h"
>  #ifndef CONFIG_USER_ONLY
>  #include "exec/hwaddr.h"
>  #endif
> @@ -152,5 +153,9 @@ typedef struct CPUIOTLBEntry {
>  #define CPU_COMMON                                                      \
>      /* soft mmu support */                                              \
>      CPU_COMMON_TLB                                                      \
> +    AIEEntry *aie_entry;                                                \
> +    bool aie_locked;                                                    \
> +    bool aie_lock_enabled;                                              \
> +    bool aie_llsc_st_tracking;                                          \
>  
>  #endif
> diff --git a/include/qemu/aie-helper.h b/include/qemu/aie-helper.h
> new file mode 100644
> index 0000000..86a786a
> --- /dev/null
> +++ b/include/qemu/aie-helper.h
> @@ -0,0 +1,6 @@
> +DEF_HELPER_2(aie_ld_pre, void, env, tl)
> +DEF_HELPER_2(aie_st_pre, void, env, tl)
> +DEF_HELPER_2(aie_st_post, void, env, tl)
> +
> +DEF_HELPER_2(aie_ld_lock, void, env, tl)
> +DEF_HELPER_1(aie_unlock__done, void, env)

-- 
Alex Bennée