From b4b7ff4b08e691656c9d77c758fc355833128ac0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 20 Jan 2016 14:01:31 -0300 Subject: Linux-libre 4.4-gnu --- drivers/net/ethernet/sfc/net_driver.h | 130 +++++++++++++++------------------- 1 file changed, 57 insertions(+), 73 deletions(-) (limited to 'drivers/net/ethernet/sfc/net_driver.h') diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h index 24038ef96..a8ddd122f 100644 --- a/drivers/net/ethernet/sfc/net_driver.h +++ b/drivers/net/ethernet/sfc/net_driver.h @@ -433,21 +433,8 @@ struct efx_channel { struct net_device *napi_dev; struct napi_struct napi_str; #ifdef CONFIG_NET_RX_BUSY_POLL - unsigned int state; - spinlock_t state_lock; -#define EFX_CHANNEL_STATE_IDLE 0 -#define EFX_CHANNEL_STATE_NAPI (1 << 0) /* NAPI owns this channel */ -#define EFX_CHANNEL_STATE_POLL (1 << 1) /* poll owns this channel */ -#define EFX_CHANNEL_STATE_DISABLED (1 << 2) /* channel is disabled */ -#define EFX_CHANNEL_STATE_NAPI_YIELD (1 << 3) /* NAPI yielded this channel */ -#define EFX_CHANNEL_STATE_POLL_YIELD (1 << 4) /* poll yielded this channel */ -#define EFX_CHANNEL_OWNED \ - (EFX_CHANNEL_STATE_NAPI | EFX_CHANNEL_STATE_POLL) -#define EFX_CHANNEL_LOCKED \ - (EFX_CHANNEL_OWNED | EFX_CHANNEL_STATE_DISABLED) -#define EFX_CHANNEL_USER_PEND \ - (EFX_CHANNEL_STATE_POLL | EFX_CHANNEL_STATE_POLL_YIELD) -#endif /* CONFIG_NET_RX_BUSY_POLL */ + unsigned long busy_poll_state; +#endif struct efx_special_buffer eventq; unsigned int eventq_mask; unsigned int eventq_read_ptr; @@ -482,98 +469,94 @@ struct efx_channel { }; #ifdef CONFIG_NET_RX_BUSY_POLL -static inline void efx_channel_init_lock(struct efx_channel *channel) +enum efx_channel_busy_poll_state { + EFX_CHANNEL_STATE_IDLE = 0, + EFX_CHANNEL_STATE_NAPI = BIT(0), + EFX_CHANNEL_STATE_NAPI_REQ_BIT = 1, + EFX_CHANNEL_STATE_NAPI_REQ = BIT(1), + EFX_CHANNEL_STATE_POLL_BIT = 2, + EFX_CHANNEL_STATE_POLL = BIT(2), + EFX_CHANNEL_STATE_DISABLE_BIT = 3, +}; + +static inline void efx_channel_busy_poll_init(struct efx_channel *channel) { - spin_lock_init(&channel->state_lock); + WRITE_ONCE(channel->busy_poll_state, EFX_CHANNEL_STATE_IDLE); } /* Called from the device poll routine to get ownership of a channel. */ static inline bool efx_channel_lock_napi(struct efx_channel *channel) { - bool rc = true; - - spin_lock_bh(&channel->state_lock); - if (channel->state & EFX_CHANNEL_LOCKED) { - WARN_ON(channel->state & EFX_CHANNEL_STATE_NAPI); - channel->state |= EFX_CHANNEL_STATE_NAPI_YIELD; - rc = false; - } else { - /* we don't care if someone yielded */ - channel->state = EFX_CHANNEL_STATE_NAPI; + unsigned long prev, old = READ_ONCE(channel->busy_poll_state); + + while (1) { + switch (old) { + case EFX_CHANNEL_STATE_POLL: + /* Ensure efx_channel_try_lock_poll() wont starve us */ + set_bit(EFX_CHANNEL_STATE_NAPI_REQ_BIT, + &channel->busy_poll_state); + /* fallthrough */ + case EFX_CHANNEL_STATE_POLL | EFX_CHANNEL_STATE_NAPI_REQ: + return false; + default: + break; + } + prev = cmpxchg(&channel->busy_poll_state, old, + EFX_CHANNEL_STATE_NAPI); + if (unlikely(prev != old)) { + /* This is likely to mean we've just entered polling + * state. Go back round to set the REQ bit. + */ + old = prev; + continue; + } + return true; } - spin_unlock_bh(&channel->state_lock); - return rc; } static inline void efx_channel_unlock_napi(struct efx_channel *channel) { - spin_lock_bh(&channel->state_lock); - WARN_ON(channel->state & - (EFX_CHANNEL_STATE_POLL | EFX_CHANNEL_STATE_NAPI_YIELD)); - - channel->state &= EFX_CHANNEL_STATE_DISABLED; - spin_unlock_bh(&channel->state_lock); + /* Make sure write has completed from efx_channel_lock_napi() */ + smp_wmb(); + WRITE_ONCE(channel->busy_poll_state, EFX_CHANNEL_STATE_IDLE); } /* Called from efx_busy_poll(). */ -static inline bool efx_channel_lock_poll(struct efx_channel *channel) +static inline bool efx_channel_try_lock_poll(struct efx_channel *channel) { - bool rc = true; - - spin_lock_bh(&channel->state_lock); - if ((channel->state & EFX_CHANNEL_LOCKED)) { - channel->state |= EFX_CHANNEL_STATE_POLL_YIELD; - rc = false; - } else { - /* preserve yield marks */ - channel->state |= EFX_CHANNEL_STATE_POLL; - } - spin_unlock_bh(&channel->state_lock); - return rc; + return cmpxchg(&channel->busy_poll_state, EFX_CHANNEL_STATE_IDLE, + EFX_CHANNEL_STATE_POLL) == EFX_CHANNEL_STATE_IDLE; } -/* Returns true if NAPI tried to get the channel while it was locked. */ static inline void efx_channel_unlock_poll(struct efx_channel *channel) { - spin_lock_bh(&channel->state_lock); - WARN_ON(channel->state & EFX_CHANNEL_STATE_NAPI); - - /* will reset state to idle, unless channel is disabled */ - channel->state &= EFX_CHANNEL_STATE_DISABLED; - spin_unlock_bh(&channel->state_lock); + clear_bit_unlock(EFX_CHANNEL_STATE_POLL_BIT, &channel->busy_poll_state); } -/* True if a socket is polling, even if it did not get the lock. */ static inline bool efx_channel_busy_polling(struct efx_channel *channel) { - WARN_ON(!(channel->state & EFX_CHANNEL_OWNED)); - return channel->state & EFX_CHANNEL_USER_PEND; + return test_bit(EFX_CHANNEL_STATE_POLL_BIT, &channel->busy_poll_state); } static inline void efx_channel_enable(struct efx_channel *channel) { - spin_lock_bh(&channel->state_lock); - channel->state = EFX_CHANNEL_STATE_IDLE; - spin_unlock_bh(&channel->state_lock); + clear_bit_unlock(EFX_CHANNEL_STATE_DISABLE_BIT, + &channel->busy_poll_state); } -/* False if the channel is currently owned. */ +/* Stop further polling or napi access. + * Returns false if the channel is currently busy polling. + */ static inline bool efx_channel_disable(struct efx_channel *channel) { - bool rc = true; - - spin_lock_bh(&channel->state_lock); - if (channel->state & EFX_CHANNEL_OWNED) - rc = false; - channel->state |= EFX_CHANNEL_STATE_DISABLED; - spin_unlock_bh(&channel->state_lock); - - return rc; + set_bit(EFX_CHANNEL_STATE_DISABLE_BIT, &channel->busy_poll_state); + /* Implicit barrier in efx_channel_busy_polling() */ + return !efx_channel_busy_polling(channel); } #else /* CONFIG_NET_RX_BUSY_POLL */ -static inline void efx_channel_init_lock(struct efx_channel *channel) +static inline void efx_channel_busy_poll_init(struct efx_channel *channel) { } @@ -586,7 +569,7 @@ static inline void efx_channel_unlock_napi(struct efx_channel *channel) { } -static inline bool efx_channel_lock_poll(struct efx_channel *channel) +static inline bool efx_channel_try_lock_poll(struct efx_channel *channel) { return false; } @@ -1279,6 +1262,7 @@ struct efx_nic_type { void (*mcdi_read_response)(struct efx_nic *efx, efx_dword_t *pdu, size_t pdu_offset, size_t pdu_len); int (*mcdi_poll_reboot)(struct efx_nic *efx); + void (*mcdi_reboot_detected)(struct efx_nic *efx); void (*irq_enable_master)(struct efx_nic *efx); void (*irq_test_generate)(struct efx_nic *efx); void (*irq_disable_non_ev)(struct efx_nic *efx); -- cgit v1.2.3-54-g00ecf