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19aaf72c0c
A recent patch avoided doing 64-bit modulo operations by checking the alignment of some DMA allocations using only the lower 32 bits of the address. David Laight pointed out (after the fix was committed) that DMA allocations might already satisfy the alignment requirements. And he was right. Remove the alignment checks that occur after DMA allocation requests, and update comments to explain why the constraint is satisfied. The only place IPA_TABLE_ALIGN was used was to check the alignment; it is therefore no longer needed, so get rid of it. Add comments where GSI_RING_ELEMENT_SIZE and the tre_count and event_count channel data fields are defined to make explicit they are required to be powers of 2. Revise a comment in gsi_trans_pool_init_dma(), taking into account that dma_alloc_coherent() guarantees its result is aligned to a page size (or order thereof). Don't bother printing an error if a DMA allocation fails. Suggested-by: David Laight <David.Laight@ACULAB.COM> Signed-off-by: Alex Elder <elder@linaro.org> Signed-off-by: David S. Miller <davem@davemloft.net>
119 lines
3.7 KiB
C
119 lines
3.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
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* Copyright (C) 2018-2020 Linaro Ltd.
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*/
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#ifndef _GSI_PRIVATE_H_
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#define _GSI_PRIVATE_H_
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/* === Only "gsi.c" and "gsi_trans.c" should include this file === */
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#include <linux/types.h>
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struct gsi_trans;
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struct gsi_ring;
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struct gsi_channel;
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#define GSI_RING_ELEMENT_SIZE 16 /* bytes; must be a power of 2 */
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/* Return the entry that follows one provided in a transaction pool */
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void *gsi_trans_pool_next(struct gsi_trans_pool *pool, void *element);
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/**
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* gsi_trans_move_complete() - Mark a GSI transaction completed
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* @trans: Transaction to commit
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*/
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void gsi_trans_move_complete(struct gsi_trans *trans);
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/**
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* gsi_trans_move_polled() - Mark a transaction polled
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* @trans: Transaction to update
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*/
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void gsi_trans_move_polled(struct gsi_trans *trans);
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/**
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* gsi_trans_complete() - Complete a GSI transaction
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* @trans: Transaction to complete
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*
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* Marks a transaction complete (including freeing it).
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*/
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void gsi_trans_complete(struct gsi_trans *trans);
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/**
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* gsi_channel_trans_mapped() - Return a transaction mapped to a TRE index
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* @channel: Channel associated with the transaction
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* @index: Index of the TRE having a transaction
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*
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* Return: The GSI transaction pointer associated with the TRE index
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*/
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struct gsi_trans *gsi_channel_trans_mapped(struct gsi_channel *channel,
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u32 index);
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/**
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* gsi_channel_trans_complete() - Return a channel's next completed transaction
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* @channel: Channel whose next transaction is to be returned
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*
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* Return: The next completed transaction, or NULL if nothing new
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*/
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struct gsi_trans *gsi_channel_trans_complete(struct gsi_channel *channel);
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/**
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* gsi_channel_trans_cancel_pending() - Cancel pending transactions
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* @channel: Channel whose pending transactions should be cancelled
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*
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* Cancel all pending transactions on a channel. These are transactions
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* that have been committed but not yet completed. This is required when
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* the channel gets reset. At that time all pending transactions will be
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* marked as cancelled.
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*
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* NOTE: Transactions already complete at the time of this call are
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* unaffected.
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*/
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void gsi_channel_trans_cancel_pending(struct gsi_channel *channel);
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/**
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* gsi_channel_trans_init() - Initialize a channel's GSI transaction info
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* @gsi: GSI pointer
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* @channel_id: Channel number
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*
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* Return: 0 if successful, or -ENOMEM on allocation failure
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*
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* Creates and sets up information for managing transactions on a channel
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*/
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int gsi_channel_trans_init(struct gsi *gsi, u32 channel_id);
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/**
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* gsi_channel_trans_exit() - Inverse of gsi_channel_trans_init()
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* @channel: Channel whose transaction information is to be cleaned up
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*/
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void gsi_channel_trans_exit(struct gsi_channel *channel);
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/**
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* gsi_channel_doorbell() - Ring a channel's doorbell
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* @channel: Channel whose doorbell should be rung
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*
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* Rings a channel's doorbell to inform the GSI hardware that new
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* transactions (TREs, really) are available for it to process.
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*/
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void gsi_channel_doorbell(struct gsi_channel *channel);
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/**
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* gsi_ring_virt() - Return virtual address for a ring entry
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* @ring: Ring whose address is to be translated
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* @index: Index (slot number) of entry
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*/
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void *gsi_ring_virt(struct gsi_ring *ring, u32 index);
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/**
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* gsi_channel_tx_queued() - Report the number of bytes queued to hardware
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* @channel: Channel whose bytes have been queued
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*
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* This arranges for the the number of transactions and bytes for
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* transfer that have been queued to hardware to be reported. It
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* passes this information up the network stack so it can be used to
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* throttle transmissions.
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*/
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void gsi_channel_tx_queued(struct gsi_channel *channel);
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#endif /* _GSI_PRIVATE_H_ */
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