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Diffstat (limited to 'drivers/net/wireless/bcmdhd_1363/include/bcm_ring.h')
| -rw-r--r-- | drivers/net/wireless/bcmdhd_1363/include/bcm_ring.h | 616 |
1 files changed, 616 insertions, 0 deletions
diff --git a/drivers/net/wireless/bcmdhd_1363/include/bcm_ring.h b/drivers/net/wireless/bcmdhd_1363/include/bcm_ring.h new file mode 100644 index 000000000000..3681c9d481e2 --- /dev/null +++ b/drivers/net/wireless/bcmdhd_1363/include/bcm_ring.h @@ -0,0 +1,616 @@ +#ifndef __bcm_ring_included__ +#define __bcm_ring_included__ + +/* + * +---------------------------------------------------------------------------- + * + * bcm_ring.h : Ring context abstraction + * + * The ring context tracks the WRITE and READ indices where elements may be + * produced and consumed respectively. All elements in the ring need to be + * fixed size. + * + * NOTE: A ring of size N, may only hold N-1 elements. + * + * +---------------------------------------------------------------------------- + * + * API Notes: + * + * Ring manipulation API allows for: + * Pending operations: Often before some work can be completed, it may be + * desired that several resources are available, e.g. space for production in + * a ring. Approaches such as, #1) reserve resources one by one and return them + * if another required resource is not available, or #2) employ a two pass + * algorithm of first testing whether all resources are available, have a + * an impact on performance critical code. The approach taken here is more akin + * to approach #2, where a test for resource availability essentially also + * provides the index for production in an un-committed state. + * The same approach is taken for the consumer side. + * + * - Pending production: Fetch the next index where a ring element may be + * produced. The caller may not commit the WRITE of the element. + * - Pending consumption: Fetch the next index where a ring element may be + * consumed. The caller may not commut the READ of the element. + * + * Producer side API: + * - bcm_ring_is_full : Test whether ring is full + * - bcm_ring_prod : Fetch index where an element may be produced (commit) + * - bcm_ring_prod_pend: Fetch index where an element may be produced (pending) + * - bcm_ring_prod_done: Commit a previous pending produce fetch + * - bcm_ring_prod_avail: Fetch total number free slots eligible for production + * + * Consumer side API: + * - bcm_ring_is_empty : Test whether ring is empty + * - bcm_ring_cons : Fetch index where an element may be consumed (commit) + * - bcm_ring_cons_pend: Fetch index where an element may be consumed (pending) + * - bcm_ring_cons_done: Commit a previous pending consume fetch + * - bcm_ring_cons_avail: Fetch total number elements eligible for consumption + * + * - bcm_ring_sync_read: Sync read offset in peer ring, from local ring + * - bcm_ring_sync_write: Sync write offset in peer ring, from local ring + * + * +---------------------------------------------------------------------------- + * + * Design Notes: + * Following items are not tracked in a ring context (design decision) + * - width of a ring element. + * - depth of the ring. + * - base of the buffer, where the elements are stored. + * - count of number of free slots in the ring + * + * Implementation Notes: + * - When BCM_RING_DEBUG is enabled, need explicit bcm_ring_init(). + * - BCM_RING_EMPTY and BCM_RING_FULL are (-1) + * + * +---------------------------------------------------------------------------- + * + * Usage Notes: + * An application may incarnate a ring of some fixed sized elements, by defining + * - a ring data buffer to store the ring elements. + * - depth of the ring (max number of elements managed by ring context). + * Preferrably, depth may be represented as a constant. + * - width of a ring element: to be used in pointer arithmetic with the ring's + * data buffer base and an index to fetch the ring element. + * + * Use bcm_workq_t to instantiate a pair of workq constructs, one for the + * producer and the other for the consumer, both pointing to the same circular + * buffer. The producer may operate on it's own local workq and flush the write + * index to the consumer. Likewise the consumer may use its local workq and + * flush the read index to the producer. This way we do not repeatedly access + * the peer's context. The two peers may reside on different CPU cores with a + * private L1 data cache. + * +---------------------------------------------------------------------------- + * + * Copyright (C) 1999-2017, Broadcom Corporation + * + * Unless you and Broadcom execute a separate written software license + * agreement governing use of this software, this software is licensed to you + * under the terms of the GNU General Public License version 2 (the "GPL"), + * available at http://www.broadcom.com/licenses/GPLv2.php, with the + * following added to such license: + * + * As a special exception, the copyright holders of this software give you + * permission to link this software with independent modules, and to copy and + * distribute the resulting executable under terms of your choice, provided that + * you also meet, for each linked independent module, the terms and conditions of + * the license of that module. An independent module is a module which is not + * derived from this software. The special exception does not apply to any + * modifications of the software. + * + * Notwithstanding the above, under no circumstances may you combine this + * software in any way with any other Broadcom software provided under a license + * other than the GPL, without Broadcom's express prior written consent. + * + * <<Broadcom-WL-IPTag/Open:>> + * + * $Id: bcm_ring.h 591283 2015-10-07 11:52:00Z $ + * + * -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- + * vim: set ts=4 noet sw=4 tw=80: + * + * +---------------------------------------------------------------------------- + */ + +#ifdef ____cacheline_aligned +#define __ring_aligned ____cacheline_aligned +#else +#define __ring_aligned +#endif + +/* Conditional compile for debug */ +/* #define BCM_RING_DEBUG */ + +#define BCM_RING_EMPTY (-1) +#define BCM_RING_FULL (-1) +#define BCM_RING_NULL ((bcm_ring_t *)NULL) + +#if defined(BCM_RING_DEBUG) +#define RING_ASSERT(exp) ASSERT(exp) +#define BCM_RING_IS_VALID(ring) (((ring) != BCM_RING_NULL) && \ + ((ring)->self == (ring))) +#else /* ! BCM_RING_DEBUG */ +#define RING_ASSERT(exp) do {} while (0) +#define BCM_RING_IS_VALID(ring) ((ring) != BCM_RING_NULL) +#endif /* ! BCM_RING_DEBUG */ + +#define BCM_RING_SIZE_IS_VALID(ring_size) ((ring_size) > 0) + +/* + * +---------------------------------------------------------------------------- + * Ring Context + * +---------------------------------------------------------------------------- + */ +typedef struct bcm_ring { /* Ring context */ +#if defined(BCM_RING_DEBUG) + struct bcm_ring *self; /* ptr to self for IS VALID test */ +#endif /* BCM_RING_DEBUG */ + int write __ring_aligned; /* WRITE index in a circular ring */ + int read __ring_aligned; /* READ index in a circular ring */ +} bcm_ring_t; + + +static INLINE void bcm_ring_init(bcm_ring_t *ring); +static INLINE void bcm_ring_copy(bcm_ring_t *to, bcm_ring_t *from); +static INLINE bool bcm_ring_is_empty(bcm_ring_t *ring); + +static INLINE int __bcm_ring_next_write(bcm_ring_t *ring, const int ring_size); + +static INLINE bool __bcm_ring_full(bcm_ring_t *ring, int next_write); +static INLINE bool bcm_ring_is_full(bcm_ring_t *ring, const int ring_size); + +static INLINE void bcm_ring_prod_done(bcm_ring_t *ring, int write); +static INLINE int bcm_ring_prod_pend(bcm_ring_t *ring, int *pend_write, + const int ring_size); +static INLINE int bcm_ring_prod(bcm_ring_t *ring, const int ring_size); + +static INLINE void bcm_ring_cons_done(bcm_ring_t *ring, int read); +static INLINE int bcm_ring_cons_pend(bcm_ring_t *ring, int *pend_read, + const int ring_size); +static INLINE int bcm_ring_cons(bcm_ring_t *ring, const int ring_size); + +static INLINE void bcm_ring_sync_read(bcm_ring_t *peer, const bcm_ring_t *self); +static INLINE void bcm_ring_sync_write(bcm_ring_t *peer, const bcm_ring_t *self); + +static INLINE int bcm_ring_prod_avail(const bcm_ring_t *ring, + const int ring_size); +static INLINE int bcm_ring_cons_avail(const bcm_ring_t *ring, + const int ring_size); +static INLINE void bcm_ring_cons_all(bcm_ring_t *ring); + + +/** + * bcm_ring_init - initialize a ring context. + * @ring: pointer to a ring context + */ +static INLINE void +bcm_ring_init(bcm_ring_t *ring) +{ + ASSERT(ring != (bcm_ring_t *)NULL); +#if defined(BCM_RING_DEBUG) + ring->self = ring; +#endif /* BCM_RING_DEBUG */ + ring->write = 0; + ring->read = 0; +} + +/** + * bcm_ring_copy - copy construct a ring + * @to: pointer to the new ring context + * @from: pointer to orig ring context + */ +static INLINE void +bcm_ring_copy(bcm_ring_t *to, bcm_ring_t *from) +{ + bcm_ring_init(to); + + to->write = from->write; + to->read = from->read; +} + +/** + * bcm_ring_is_empty - "Boolean" test whether ring is empty. + * @ring: pointer to a ring context + * + * PS. does not return BCM_RING_EMPTY value. + */ +static INLINE bool +bcm_ring_is_empty(bcm_ring_t *ring) +{ + RING_ASSERT(BCM_RING_IS_VALID(ring)); + return (ring->read == ring->write); +} + + +/** + * __bcm_ring_next_write - determine the index where the next write may occur + * (with wrap-around). + * @ring: pointer to a ring context + * @ring_size: size of the ring + * + * PRIVATE INTERNAL USE ONLY. + */ +static INLINE int +__bcm_ring_next_write(bcm_ring_t *ring, const int ring_size) +{ + RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size)); + return ((ring->write + 1) % ring_size); +} + + +/** + * __bcm_ring_full - support function for ring full test. + * @ring: pointer to a ring context + * @next_write: next location in ring where an element is to be produced + * + * PRIVATE INTERNAL USE ONLY. + */ +static INLINE bool +__bcm_ring_full(bcm_ring_t *ring, int next_write) +{ + return (next_write == ring->read); +} + + +/** + * bcm_ring_is_full - "Boolean" test whether a ring is full. + * @ring: pointer to a ring context + * @ring_size: size of the ring + * + * PS. does not return BCM_RING_FULL value. + */ +static INLINE bool +bcm_ring_is_full(bcm_ring_t *ring, const int ring_size) +{ + int next_write; + RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size)); + next_write = __bcm_ring_next_write(ring, ring_size); + return __bcm_ring_full(ring, next_write); +} + + +/** + * bcm_ring_prod_done - commit a previously pending index where production + * was requested. + * @ring: pointer to a ring context + * @write: index into ring upto where production was done. + * +---------------------------------------------------------------------------- + */ +static INLINE void +bcm_ring_prod_done(bcm_ring_t *ring, int write) +{ + RING_ASSERT(BCM_RING_IS_VALID(ring)); + ring->write = write; +} + + +/** + * bcm_ring_prod_pend - Fetch in "pend" mode, the index where an element may be + * produced. + * @ring: pointer to a ring context + * @pend_write: next index, after the returned index + * @ring_size: size of the ring + */ +static INLINE int +bcm_ring_prod_pend(bcm_ring_t *ring, int *pend_write, const int ring_size) +{ + int rtn; + RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size)); + *pend_write = __bcm_ring_next_write(ring, ring_size); + if (__bcm_ring_full(ring, *pend_write)) { + *pend_write = BCM_RING_FULL; + rtn = BCM_RING_FULL; + } else { + /* production is not committed, caller needs to explicitly commit */ + rtn = ring->write; + } + return rtn; +} + + +/** + * bcm_ring_prod - Fetch and "commit" the next index where a ring element may + * be produced. + * @ring: pointer to a ring context + * @ring_size: size of the ring + */ +static INLINE int +bcm_ring_prod(bcm_ring_t *ring, const int ring_size) +{ + int next_write, prod_write; + RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size)); + + next_write = __bcm_ring_next_write(ring, ring_size); + if (__bcm_ring_full(ring, next_write)) { + prod_write = BCM_RING_FULL; + } else { + prod_write = ring->write; + bcm_ring_prod_done(ring, next_write); /* "commit" production */ + } + return prod_write; +} + + +/** + * bcm_ring_cons_done - commit a previously pending read + * @ring: pointer to a ring context + * @read: index upto which elements have been consumed. + */ +static INLINE void +bcm_ring_cons_done(bcm_ring_t *ring, int read) +{ + RING_ASSERT(BCM_RING_IS_VALID(ring)); + ring->read = read; +} + + +/** + * bcm_ring_cons_pend - fetch in "pend" mode, the next index where a ring + * element may be consumed. + * @ring: pointer to a ring context + * @pend_read: index into ring upto which elements may be consumed. + * @ring_size: size of the ring + */ +static INLINE int +bcm_ring_cons_pend(bcm_ring_t *ring, int *pend_read, const int ring_size) +{ + int rtn; + RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size)); + if (bcm_ring_is_empty(ring)) { + *pend_read = BCM_RING_EMPTY; + rtn = BCM_RING_EMPTY; + } else { + *pend_read = (ring->read + 1) % ring_size; + /* production is not committed, caller needs to explicitly commit */ + rtn = ring->read; + } + return rtn; +} + + +/** + * bcm_ring_cons - fetch and "commit" the next index where a ring element may + * be consumed. + * @ring: pointer to a ring context + * @ring_size: size of the ring + */ +static INLINE int +bcm_ring_cons(bcm_ring_t *ring, const int ring_size) +{ + int cons_read; + RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size)); + if (bcm_ring_is_empty(ring)) { + cons_read = BCM_RING_EMPTY; + } else { + cons_read = ring->read; + ring->read = (ring->read + 1) % ring_size; /* read is committed */ + } + return cons_read; +} + + +/** + * bcm_ring_sync_read - on consumption, update peer's read index. + * @peer: pointer to peer's producer ring context + * @self: pointer to consumer's ring context + */ +static INLINE void +bcm_ring_sync_read(bcm_ring_t *peer, const bcm_ring_t *self) +{ + RING_ASSERT(BCM_RING_IS_VALID(peer)); + RING_ASSERT(BCM_RING_IS_VALID(self)); + peer->read = self->read; /* flush read update to peer producer */ +} + + +/** + * bcm_ring_sync_write - on consumption, update peer's write index. + * @peer: pointer to peer's consumer ring context + * @self: pointer to producer's ring context + */ +static INLINE void +bcm_ring_sync_write(bcm_ring_t *peer, const bcm_ring_t *self) +{ + RING_ASSERT(BCM_RING_IS_VALID(peer)); + RING_ASSERT(BCM_RING_IS_VALID(self)); + peer->write = self->write; /* flush write update to peer consumer */ +} + + +/** + * bcm_ring_prod_avail - fetch total number of available empty slots in the + * ring for production. + * @ring: pointer to a ring context + * @ring_size: size of the ring + */ +static INLINE int +bcm_ring_prod_avail(const bcm_ring_t *ring, const int ring_size) +{ + int prod_avail; + RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size)); + if (ring->write >= ring->read) { + prod_avail = (ring_size - (ring->write - ring->read) - 1); + } else { + prod_avail = (ring->read - (ring->write + 1)); + } + ASSERT(prod_avail < ring_size); + return prod_avail; +} + + +/** + * bcm_ring_cons_avail - fetch total number of available elements for consumption. + * @ring: pointer to a ring context + * @ring_size: size of the ring + */ +static INLINE int +bcm_ring_cons_avail(const bcm_ring_t *ring, const int ring_size) +{ + int cons_avail; + RING_ASSERT(BCM_RING_IS_VALID(ring) && BCM_RING_SIZE_IS_VALID(ring_size)); + if (ring->read == ring->write) { + cons_avail = 0; + } else if (ring->read > ring->write) { + cons_avail = ((ring_size - ring->read) + ring->write); + } else { + cons_avail = ring->write - ring->read; + } + ASSERT(cons_avail < ring_size); + return cons_avail; +} + + +/** + * bcm_ring_cons_all - set ring in state where all elements are consumed. + * @ring: pointer to a ring context + */ +static INLINE void +bcm_ring_cons_all(bcm_ring_t *ring) +{ + ring->read = ring->write; +} + + +/** + * Work Queue + * A work Queue is composed of a ring of work items, of a specified depth. + * It HAS-A bcm_ring object, comprising of a RD and WR offset, to implement a + * producer/consumer circular ring. + */ + +struct bcm_workq { + bcm_ring_t ring; /* Ring context abstraction */ + struct bcm_workq *peer; /* Peer workq context */ + void *buffer; /* Buffer storage for work items in workQ */ + int ring_size; /* Depth of workQ */ +} __ring_aligned; + +typedef struct bcm_workq bcm_workq_t; + + +/* #define BCM_WORKQ_DEBUG */ +#if defined(BCM_WORKQ_DEBUG) +#define WORKQ_ASSERT(exp) ASSERT(exp) +#else /* ! BCM_WORKQ_DEBUG */ +#define WORKQ_ASSERT(exp) do {} while (0) +#endif /* ! BCM_WORKQ_DEBUG */ + +#define WORKQ_AUDIT(workq) \ + WORKQ_ASSERT((workq) != BCM_WORKQ_NULL); \ + WORKQ_ASSERT(WORKQ_PEER(workq) != BCM_WORKQ_NULL); \ + WORKQ_ASSERT((workq)->buffer == WORKQ_PEER(workq)->buffer); \ + WORKQ_ASSERT((workq)->ring_size == WORKQ_PEER(workq)->ring_size); + +#define BCM_WORKQ_NULL ((bcm_workq_t *)NULL) + +#define WORKQ_PEER(workq) ((workq)->peer) +#define WORKQ_RING(workq) (&((workq)->ring)) +#define WORKQ_PEER_RING(workq) (&((workq)->peer->ring)) + +#define WORKQ_ELEMENT(__elem_type, __workq, __index) ({ \ + WORKQ_ASSERT((__workq) != BCM_WORKQ_NULL); \ + WORKQ_ASSERT((__index) < ((__workq)->ring_size)); \ + ((__elem_type *)((__workq)->buffer)) + (__index); \ +}) + + +static INLINE void bcm_workq_init(bcm_workq_t *workq, bcm_workq_t *workq_peer, + void *buffer, int ring_size); + +static INLINE bool bcm_workq_is_empty(bcm_workq_t *workq_prod); + +static INLINE void bcm_workq_prod_sync(bcm_workq_t *workq_prod); +static INLINE void bcm_workq_cons_sync(bcm_workq_t *workq_cons); + +static INLINE void bcm_workq_prod_refresh(bcm_workq_t *workq_prod); +static INLINE void bcm_workq_cons_refresh(bcm_workq_t *workq_cons); + +/** + * bcm_workq_init - initialize a workq + * @workq: pointer to a workq context + * @buffer: pointer to a pre-allocated circular buffer to serve as a ring + * @ring_size: size of the ring in terms of max number of elements. + */ +static INLINE void +bcm_workq_init(bcm_workq_t *workq, bcm_workq_t *workq_peer, + void *buffer, int ring_size) +{ + ASSERT(workq != BCM_WORKQ_NULL); + ASSERT(workq_peer != BCM_WORKQ_NULL); + ASSERT(buffer != NULL); + ASSERT(ring_size > 0); + + WORKQ_PEER(workq) = workq_peer; + WORKQ_PEER(workq_peer) = workq; + + bcm_ring_init(WORKQ_RING(workq)); + bcm_ring_init(WORKQ_RING(workq_peer)); + + workq->buffer = workq_peer->buffer = buffer; + workq->ring_size = workq_peer->ring_size = ring_size; +} + +/** + * bcm_workq_empty - test whether there is work + * @workq_prod: producer's workq + */ +static INLINE bool +bcm_workq_is_empty(bcm_workq_t *workq_prod) +{ + return bcm_ring_is_empty(WORKQ_RING(workq_prod)); +} + +/** + * bcm_workq_prod_sync - Commit the producer write index to peer workq's ring + * @workq_prod: producer's workq whose write index must be synced to peer + */ +static INLINE void +bcm_workq_prod_sync(bcm_workq_t *workq_prod) +{ + WORKQ_AUDIT(workq_prod); + + /* cons::write <--- prod::write */ + bcm_ring_sync_write(WORKQ_PEER_RING(workq_prod), WORKQ_RING(workq_prod)); +} + +/** + * bcm_workq_cons_sync - Commit the consumer read index to the peer workq's ring + * @workq_cons: consumer's workq whose read index must be synced to peer + */ +static INLINE void +bcm_workq_cons_sync(bcm_workq_t *workq_cons) +{ + WORKQ_AUDIT(workq_cons); + + /* prod::read <--- cons::read */ + bcm_ring_sync_read(WORKQ_PEER_RING(workq_cons), WORKQ_RING(workq_cons)); +} + + +/** + * bcm_workq_prod_refresh - Fetch the updated consumer's read index + * @workq_prod: producer's workq whose read index must be refreshed from peer + */ +static INLINE void +bcm_workq_prod_refresh(bcm_workq_t *workq_prod) +{ + WORKQ_AUDIT(workq_prod); + + /* prod::read <--- cons::read */ + bcm_ring_sync_read(WORKQ_RING(workq_prod), WORKQ_PEER_RING(workq_prod)); +} + +/** + * bcm_workq_cons_refresh - Fetch the updated producer's write index + * @workq_cons: consumer's workq whose write index must be refreshed from peer + */ +static INLINE void +bcm_workq_cons_refresh(bcm_workq_t *workq_cons) +{ + WORKQ_AUDIT(workq_cons); + + /* cons::write <--- prod::write */ + bcm_ring_sync_write(WORKQ_RING(workq_cons), WORKQ_PEER_RING(workq_cons)); +} + + +#endif /* ! __bcm_ring_h_included__ */ |