linux-generic: timer: remove dead 128 bit optimizations

Remove totally untested branch with 128 bit optimizations
for timer code.
This also fixes static assert bug:
https://bugs.linaro.org/show_bug.cgi?id=2211

Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>
---
 platform/linux-generic/odp_timer.c | 104 -------------------------------------
 1 file changed, 104 deletions(-)

there is one more place for #define NEED_PAD, will send v2

Maxim.

On 05/16/16 22:11, Maxim Uvarov wrote:
> Remove totally untested branch with 128 bit optimizations
> for timer code.
> This also fixes static assert bug:
> https://bugs.linaro.org/show_bug.cgi?id=2211
>
> Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>
> ---
>   platform/linux-generic/odp_timer.c | 104 -------------------------------------
>   1 file changed, 104 deletions(-)
>
> diff --git a/platform/linux-generic/odp_timer.c b/platform/linux-generic/odp_timer.c
> index 6b84309..bf2405c 100644
> --- a/platform/linux-generic/odp_timer.c
> +++ b/platform/linux-generic/odp_timer.c
> @@ -11,15 +11,7 @@
>    *
>    */
>   
> -/* Check if compiler supports 16-byte atomics. GCC needs -mcx16 flag on x86 */
> -/* Using spin lock actually seems faster on Core2 */
> -#ifdef ODP_ATOMIC_U128
> -/* TB_NEEDS_PAD defined if sizeof(odp_buffer_t) != 8 */
> -#define TB_NEEDS_PAD
> -#define TB_SET_PAD(x) ((x).pad = 0)
> -#else
>   #define TB_SET_PAD(x) (void)(x)
> -#endif
>   
>   #include <odp_posix_extensions.h>
>   
> @@ -70,11 +62,9 @@
>    * Mutual exclusion in the absence of CAS16
>    *****************************************************************************/
>   
> -#ifndef ODP_ATOMIC_U128
>   #define NUM_LOCKS 1024
>   static _odp_atomic_flag_t locks[NUM_LOCKS]; /* Multiple locks per cache line! */
>   #define IDX2LOCK(idx) (&locks[(idx) % NUM_LOCKS])
> -#endif
>   
>   /******************************************************************************
>    * Translation between timeout buffer and timeout header
> @@ -102,13 +92,8 @@ typedef struct tick_buf_s {
>   	uint32_t pad;/* Need to be able to access padding for successful CAS */
>   #endif
>   } tick_buf_t
> -#ifdef ODP_ATOMIC_U128
> -ODP_ALIGNED(16) /* 16-byte atomic operations need properly aligned addresses */
> -#endif
>   ;
>   
> -ODP_STATIC_ASSERT(sizeof(tick_buf_t) == 16, "sizeof(tick_buf_t) == 16");
> -
>   typedef struct odp_timer_s {
>   	void *user_ptr;
>   	odp_queue_t queue;/* Used for free list when timer is free */
> @@ -378,34 +363,6 @@ static bool timer_reset(uint32_t idx,
>   	tick_buf_t *tb = &tp->tick_buf[idx];
>   
>   	if (tmo_buf == NULL || *tmo_buf == ODP_BUFFER_INVALID) {
> -#ifdef ODP_ATOMIC_U128
> -		tick_buf_t new, old;
> -		do {
> -			/* Relaxed and non-atomic read of current values */
> -			old.exp_tck.v = tb->exp_tck.v;
> -			old.tmo_buf = tb->tmo_buf;
> -			TB_SET_PAD(old);
> -			/* Check if there actually is a timeout buffer
> -			 * present */
> -			if (old.tmo_buf == ODP_BUFFER_INVALID) {
> -				/* Cannot reset a timer with neither old nor
> -				 * new timeout buffer */
> -				success = false;
> -				break;
> -			}
> -			/* Set up new values */
> -			new.exp_tck.v = abs_tck;
> -			new.tmo_buf = old.tmo_buf;
> -			TB_SET_PAD(new);
> -			/* Atomic CAS will fail if we experienced torn reads,
> -			 * retry update sequence until CAS succeeds */
> -		} while (!_odp_atomic_u128_cmp_xchg_mm(
> -					(_odp_atomic_u128_t *)tb,
> -					(_uint128_t *)&old,
> -					(_uint128_t *)&new,
> -					_ODP_MEMMODEL_RLS,
> -					_ODP_MEMMODEL_RLX));
> -#else
>   #ifdef __ARM_ARCH
>   		/* Since barriers are not good for C-A15, we take an
>   		 * alternative approach using relaxed memory model */
> @@ -453,7 +410,6 @@ static bool timer_reset(uint32_t idx,
>   		/* Release the lock */
>   		_odp_atomic_flag_clear(IDX2LOCK(idx));
>   #endif
> -#endif
>   	} else {
>   		/* We have a new timeout buffer which replaces any old one */
>   		/* Fill in some (constant) header fields for timeout events */
> @@ -468,19 +424,6 @@ static bool timer_reset(uint32_t idx,
>   		}
>   		/* Else ignore buffers of other types */
>   		odp_buffer_t old_buf = ODP_BUFFER_INVALID;
> -#ifdef ODP_ATOMIC_U128
> -		tick_buf_t new, old;
> -		new.exp_tck.v = abs_tck;
> -		new.tmo_buf = *tmo_buf;
> -		TB_SET_PAD(new);
> -		/* We are releasing the new timeout buffer to some other
> -		 * thread */
> -		_odp_atomic_u128_xchg_mm((_odp_atomic_u128_t *)tb,
> -					 (_uint128_t *)&new,
> -					 (_uint128_t *)&old,
> -					 _ODP_MEMMODEL_ACQ_RLS);
> -		old_buf = old.tmo_buf;
> -#else
>   		/* Take a related lock */
>   		while (_odp_atomic_flag_tas(IDX2LOCK(idx)))
>   			/* While lock is taken, spin using relaxed loads */
> @@ -496,7 +439,6 @@ static bool timer_reset(uint32_t idx,
>   
>   		/* Release the lock */
>   		_odp_atomic_flag_clear(IDX2LOCK(idx));
> -#endif
>   		/* Return old timeout buffer */
>   		*tmo_buf = old_buf;
>   	}
> @@ -510,18 +452,6 @@ static odp_buffer_t timer_cancel(odp_timer_pool *tp,
>   	tick_buf_t *tb = &tp->tick_buf[idx];
>   	odp_buffer_t old_buf;
>   
> -#ifdef ODP_ATOMIC_U128
> -	tick_buf_t new, old;
> -	/* Update the timer state (e.g. cancel the current timeout) */
> -	new.exp_tck.v = new_state;
> -	/* Swap out the old buffer */
> -	new.tmo_buf = ODP_BUFFER_INVALID;
> -	TB_SET_PAD(new);
> -	_odp_atomic_u128_xchg_mm((_odp_atomic_u128_t *)tb,
> -				 (_uint128_t *)&new, (_uint128_t *)&old,
> -				 _ODP_MEMMODEL_RLX);
> -	old_buf = old.tmo_buf;
> -#else
>   	/* Take a related lock */
>   	while (_odp_atomic_flag_tas(IDX2LOCK(idx)))
>   		/* While lock is taken, spin using relaxed loads */
> @@ -537,7 +467,6 @@ static odp_buffer_t timer_cancel(odp_timer_pool *tp,
>   
>   	/* Release the lock */
>   	_odp_atomic_flag_clear(IDX2LOCK(idx));
> -#endif
>   	/* Return the old buffer */
>   	return old_buf;
>   }
> @@ -548,34 +477,6 @@ static unsigned timer_expire(odp_timer_pool *tp, uint32_t idx, uint64_t tick)
>   	tick_buf_t *tb = &tp->tick_buf[idx];
>   	odp_buffer_t tmo_buf = ODP_BUFFER_INVALID;
>   	uint64_t exp_tck;
> -#ifdef ODP_ATOMIC_U128
> -	/* Atomic re-read for correctness */
> -	exp_tck = _odp_atomic_u64_load_mm(&tb->exp_tck, _ODP_MEMMODEL_RLX);
> -	/* Re-check exp_tck */
> -	if (odp_likely(exp_tck <= tick)) {
> -		/* Attempt to grab timeout buffer, replace with inactive timer
> -		 * and invalid buffer */
> -		tick_buf_t new, old;
> -		old.exp_tck.v = exp_tck;
> -		old.tmo_buf = tb->tmo_buf;
> -		TB_SET_PAD(old);
> -		/* Set the inactive/expired bit keeping the expiration tick so
> -		 * that we can check against the expiration tick of the timeout
> -		 * when it is received */
> -		new.exp_tck.v = exp_tck | TMO_INACTIVE;
> -		new.tmo_buf = ODP_BUFFER_INVALID;
> -		TB_SET_PAD(new);
> -		int succ = _odp_atomic_u128_cmp_xchg_mm(
> -				(_odp_atomic_u128_t *)tb,
> -				(_uint128_t *)&old, (_uint128_t *)&new,
> -				_ODP_MEMMODEL_RLS, _ODP_MEMMODEL_RLX);
> -		if (succ)
> -			tmo_buf = old.tmo_buf;
> -		/* Else CAS failed, something changed => skip timer
> -		 * this tick, it will be checked again next tick */
> -	}
> -	/* Else false positive, ignore */
> -#else
>   	/* Take a related lock */
>   	while (_odp_atomic_flag_tas(IDX2LOCK(idx)))
>   		/* While lock is taken, spin using relaxed loads */
> @@ -600,7 +501,6 @@ static unsigned timer_expire(odp_timer_pool *tp, uint32_t idx, uint64_t tick)
>   	/* Else false positive, ignore */
>   	/* Release the lock */
>   	_odp_atomic_flag_clear(IDX2LOCK(idx));
> -#endif
>   	if (odp_likely(tmo_buf != ODP_BUFFER_INVALID)) {
>   		/* Fill in expiration tick for timeout events */
>   		if (odp_event_type(odp_buffer_to_event(tmo_buf)) ==
> @@ -974,13 +874,9 @@ void odp_timeout_free(odp_timeout_t tmo)
>   
>   int odp_timer_init_global(void)
>   {
> -#ifndef ODP_ATOMIC_U128
>   	uint32_t i;
>   	for (i = 0; i < NUM_LOCKS; i++)
>   		_odp_atomic_flag_clear(&locks[i]);
> -#else
> -	ODP_DBG("Using lock-less timer implementation\n");
> -#endif
>   	odp_atomic_init_u32(&num_timer_pools, 0);
>   
>   	block_sigalarm();