forked from mirrors/linux
		
	soc: qcom: ipa: GSI transactions
This patch implements GSI transactions. A GSI transaction is a structure that represents a single request (consisting of one or more TREs) sent to the GSI hardware. The last TRE in a transaction includes a flag requesting that the GSI interrupt the AP to notify that it has completed. TREs are executed and completed strictly in order. For this reason, the completion of a single TRE implies that all previous TREs (in particular all of those "earlier" in a transaction) have completed. Whenever there is a need to send a request (a set of TREs) to the IPA, a GSI transaction is allocated, specifying the number of TREs that will be required. Details of the request (e.g. transfer offsets and length) are represented by in a Linux scatterlist array that is incorporated in the transaction structure. Once all commands (TREs) are added to a transaction it is committed. When the hardware signals that the request has completed, a callback function allows for cleanup or followup activity to be performed before the transaction is freed. Signed-off-by: Alex Elder <elder@linaro.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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										786
									
								
								drivers/net/ipa/gsi_trans.c
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										786
									
								
								drivers/net/ipa/gsi_trans.c
									
									
									
									
									
										Normal file
									
								
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					// SPDX-License-Identifier: GPL-2.0
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					/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
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					 * Copyright (C) 2019-2020 Linaro Ltd.
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					 */
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					#include <linux/types.h>
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					#include <linux/bits.h>
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					#include <linux/bitfield.h>
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					#include <linux/refcount.h>
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					#include <linux/scatterlist.h>
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					#include <linux/dma-direction.h>
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					#include "gsi.h"
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					#include "gsi_private.h"
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					#include "gsi_trans.h"
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					#include "ipa_gsi.h"
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					#include "ipa_data.h"
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					#include "ipa_cmd.h"
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					/**
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					 * DOC: GSI Transactions
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					 *
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					 * A GSI transaction abstracts the behavior of a GSI channel by representing
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					 * everything about a related group of IPA commands in a single structure.
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					 * (A "command" in this sense is either a data transfer or an IPA immediate
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					 * command.)  Most details of interaction with the GSI hardware are managed
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					 * by the GSI transaction core, allowing users to simply describe commands
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					 * to be performed.  When a transaction has completed a callback function
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					 * (dependent on the type of endpoint associated with the channel) allows
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					 * cleanup of resources associated with the transaction.
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					 *
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					 * To perform a command (or set of them), a user of the GSI transaction
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					 * interface allocates a transaction, indicating the number of TREs required
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					 * (one per command).  If sufficient TREs are available, they are reserved
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					 * for use in the transaction and the allocation succeeds.  This way
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					 * exhaustion of the available TREs in a channel ring is detected
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					 * as early as possible.  All resources required to complete a transaction
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					 * are allocated at transaction allocation time.
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					 *
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					 * Commands performed as part of a transaction are represented in an array
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					 * of Linux scatterlist structures.  This array is allocated with the
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					 * transaction, and its entries are initialized using standard scatterlist
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					 * functions (such as sg_set_buf() or skb_to_sgvec()).
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					 *
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					 * Once a transaction's scatterlist structures have been initialized, the
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					 * transaction is committed.  The caller is responsible for mapping buffers
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					 * for DMA if necessary, and this should be done *before* allocating
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					 * the transaction.  Between a successful allocation and commit of a
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					 * transaction no errors should occur.
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					 *
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					 * Committing transfers ownership of the entire transaction to the GSI
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					 * transaction core.  The GSI transaction code formats the content of
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					 * the scatterlist array into the channel ring buffer and informs the
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					 * hardware that new TREs are available to process.
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					 *
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					 * The last TRE in each transaction is marked to interrupt the AP when the
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					 * GSI hardware has completed it.  Because transfers described by TREs are
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					 * performed strictly in order, signaling the completion of just the last
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					 * TRE in the transaction is sufficient to indicate the full transaction
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					 * is complete.
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					 *
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					 * When a transaction is complete, ipa_gsi_trans_complete() is called by the
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					 * GSI code into the IPA layer, allowing it to perform any final cleanup
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					 * required before the transaction is freed.
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					 */
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					/* Hardware values representing a transfer element type */
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					enum gsi_tre_type {
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						GSI_RE_XFER	= 0x2,
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						GSI_RE_IMMD_CMD	= 0x3,
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					};
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					/* An entry in a channel ring */
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					struct gsi_tre {
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						__le64 addr;		/* DMA address */
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						__le16 len_opcode;	/* length in bytes or enum IPA_CMD_* */
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						__le16 reserved;
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						__le32 flags;		/* TRE_FLAGS_* */
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					};
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					/* gsi_tre->flags mask values (in CPU byte order) */
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					#define TRE_FLAGS_CHAIN_FMASK	GENMASK(0, 0)
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					#define TRE_FLAGS_IEOB_FMASK	GENMASK(8, 8)
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					#define TRE_FLAGS_IEOT_FMASK	GENMASK(9, 9)
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					#define TRE_FLAGS_BEI_FMASK	GENMASK(10, 10)
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					#define TRE_FLAGS_TYPE_FMASK	GENMASK(23, 16)
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					int gsi_trans_pool_init(struct gsi_trans_pool *pool, size_t size, u32 count,
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								u32 max_alloc)
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					{
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						void *virt;
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					#ifdef IPA_VALIDATE
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						if (!size || size % 8)
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							return -EINVAL;
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						if (count < max_alloc)
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							return -EINVAL;
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						if (!max_alloc)
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							return -EINVAL;
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					#endif /* IPA_VALIDATE */
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						/* By allocating a few extra entries in our pool (one less
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						 * than the maximum number that will be requested in a
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						 * single allocation), we can always satisfy requests without
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						 * ever worrying about straddling the end of the pool array.
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						 * If there aren't enough entries starting at the free index,
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						 * we just allocate free entries from the beginning of the pool.
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						 */
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						virt = kcalloc(count + max_alloc - 1, size, GFP_KERNEL);
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						if (!virt)
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							return -ENOMEM;
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						pool->base = virt;
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						/* If the allocator gave us any extra memory, use it */
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						pool->count = ksize(pool->base) / size;
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						pool->free = 0;
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						pool->max_alloc = max_alloc;
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						pool->size = size;
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						pool->addr = 0;		/* Only used for DMA pools */
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						return 0;
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					}
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					void gsi_trans_pool_exit(struct gsi_trans_pool *pool)
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					{
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						kfree(pool->base);
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						memset(pool, 0, sizeof(*pool));
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					}
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					/* Allocate the requested number of (zeroed) entries from the pool */
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					/* Home-grown DMA pool.  This way we can preallocate and use the tre_count
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					 * to guarantee allocations will succeed.  Even though we specify max_alloc
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					 * (and it can be more than one), we only allow allocation of a single
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					 * element from a DMA pool.
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					 */
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					int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool,
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								    size_t size, u32 count, u32 max_alloc)
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					{
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						size_t total_size;
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						dma_addr_t addr;
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						void *virt;
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					#ifdef IPA_VALIDATE
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						if (!size || size % 8)
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							return -EINVAL;
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						if (count < max_alloc)
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							return -EINVAL;
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						if (!max_alloc)
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							return -EINVAL;
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					#endif /* IPA_VALIDATE */
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						/* Don't let allocations cross a power-of-two boundary */
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						size = __roundup_pow_of_two(size);
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						total_size = (count + max_alloc - 1) * size;
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						/* The allocator will give us a power-of-2 number of pages.  But we
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						 * can't guarantee that, so request it.  That way we won't waste any
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						 * memory that would be available beyond the required space.
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						 */
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						total_size = get_order(total_size) << PAGE_SHIFT;
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						virt = dma_alloc_coherent(dev, total_size, &addr, GFP_KERNEL);
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						if (!virt)
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							return -ENOMEM;
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						pool->base = virt;
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						pool->count = total_size / size;
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						pool->free = 0;
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						pool->size = size;
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						pool->max_alloc = max_alloc;
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						pool->addr = addr;
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						return 0;
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					}
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					void gsi_trans_pool_exit_dma(struct device *dev, struct gsi_trans_pool *pool)
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					{
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						dma_free_coherent(dev, pool->size, pool->base, pool->addr);
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						memset(pool, 0, sizeof(*pool));
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					}
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					/* Return the byte offset of the next free entry in the pool */
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					static u32 gsi_trans_pool_alloc_common(struct gsi_trans_pool *pool, u32 count)
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					{
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						u32 offset;
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						/* assert(count > 0); */
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						/* assert(count <= pool->max_alloc); */
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						/* Allocate from beginning if wrap would occur */
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						if (count > pool->count - pool->free)
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							pool->free = 0;
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						offset = pool->free * pool->size;
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						pool->free += count;
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						memset(pool->base + offset, 0, count * pool->size);
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						return offset;
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					}
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					/* Allocate a contiguous block of zeroed entries from a pool */
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					void *gsi_trans_pool_alloc(struct gsi_trans_pool *pool, u32 count)
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					{
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						return pool->base + gsi_trans_pool_alloc_common(pool, count);
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					}
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					/* Allocate a single zeroed entry from a DMA pool */
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					void *gsi_trans_pool_alloc_dma(struct gsi_trans_pool *pool, dma_addr_t *addr)
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					{
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						u32 offset = gsi_trans_pool_alloc_common(pool, 1);
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						*addr = pool->addr + offset;
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						return pool->base + offset;
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					}
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					/* Return the pool element that immediately follows the one given.
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					 * This only works done if elements are allocated one at a time.
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					 */
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					void *gsi_trans_pool_next(struct gsi_trans_pool *pool, void *element)
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					{
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						void *end = pool->base + pool->count * pool->size;
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						/* assert(element >= pool->base); */
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						/* assert(element < end); */
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						/* assert(pool->max_alloc == 1); */
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						element += pool->size;
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						return element < end ? element : pool->base;
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					}
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					/* Map a given ring entry index to the transaction associated with it */
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					static void gsi_channel_trans_map(struct gsi_channel *channel, u32 index,
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									  struct gsi_trans *trans)
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					{
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						/* Note: index *must* be used modulo the ring count here */
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						channel->trans_info.map[index % channel->tre_ring.count] = trans;
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					}
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					/* Return the transaction mapped to a given ring entry */
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					struct gsi_trans *
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					gsi_channel_trans_mapped(struct gsi_channel *channel, u32 index)
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					{
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						/* Note: index *must* be used modulo the ring count here */
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						return channel->trans_info.map[index % channel->tre_ring.count];
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					}
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					/* Return the oldest completed transaction for a channel (or null) */
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					struct gsi_trans *gsi_channel_trans_complete(struct gsi_channel *channel)
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					{
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						return list_first_entry_or_null(&channel->trans_info.complete,
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										struct gsi_trans, links);
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					}
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					/* Move a transaction from the allocated list to the pending list */
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					static void gsi_trans_move_pending(struct gsi_trans *trans)
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					{
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						struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id];
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						struct gsi_trans_info *trans_info = &channel->trans_info;
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						spin_lock_bh(&trans_info->spinlock);
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						list_move_tail(&trans->links, &trans_info->pending);
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						spin_unlock_bh(&trans_info->spinlock);
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					}
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					/* Move a transaction and all of its predecessors from the pending list
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					 * to the completed list.
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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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						struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id];
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						struct gsi_trans_info *trans_info = &channel->trans_info;
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						struct list_head list;
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						spin_lock_bh(&trans_info->spinlock);
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						/* Move this transaction and all predecessors to completed list */
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						list_cut_position(&list, &trans_info->pending, &trans->links);
 | 
				
			||||||
 | 
						list_splice_tail(&list, &trans_info->complete);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						spin_unlock_bh(&trans_info->spinlock);
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Move a transaction from the completed list to the polled list */
 | 
				
			||||||
 | 
					void gsi_trans_move_polled(struct gsi_trans *trans)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id];
 | 
				
			||||||
 | 
						struct gsi_trans_info *trans_info = &channel->trans_info;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						spin_lock_bh(&trans_info->spinlock);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						list_move_tail(&trans->links, &trans_info->polled);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						spin_unlock_bh(&trans_info->spinlock);
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Reserve some number of TREs on a channel.  Returns true if successful */
 | 
				
			||||||
 | 
					static bool
 | 
				
			||||||
 | 
					gsi_trans_tre_reserve(struct gsi_trans_info *trans_info, u32 tre_count)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						int avail = atomic_read(&trans_info->tre_avail);
 | 
				
			||||||
 | 
						int new;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						do {
 | 
				
			||||||
 | 
							new = avail - (int)tre_count;
 | 
				
			||||||
 | 
							if (unlikely(new < 0))
 | 
				
			||||||
 | 
								return false;
 | 
				
			||||||
 | 
						} while (!atomic_try_cmpxchg(&trans_info->tre_avail, &avail, new));
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return true;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Release previously-reserved TRE entries to a channel */
 | 
				
			||||||
 | 
					static void
 | 
				
			||||||
 | 
					gsi_trans_tre_release(struct gsi_trans_info *trans_info, u32 tre_count)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						atomic_add(tre_count, &trans_info->tre_avail);
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Allocate a GSI transaction on a channel */
 | 
				
			||||||
 | 
					struct gsi_trans *gsi_channel_trans_alloc(struct gsi *gsi, u32 channel_id,
 | 
				
			||||||
 | 
										  u32 tre_count,
 | 
				
			||||||
 | 
										  enum dma_data_direction direction)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						struct gsi_channel *channel = &gsi->channel[channel_id];
 | 
				
			||||||
 | 
						struct gsi_trans_info *trans_info;
 | 
				
			||||||
 | 
						struct gsi_trans *trans;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* assert(tre_count <= gsi_channel_trans_tre_max(gsi, channel_id)); */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						trans_info = &channel->trans_info;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* We reserve the TREs now, but consume them at commit time.
 | 
				
			||||||
 | 
						 * If there aren't enough available, we're done.
 | 
				
			||||||
 | 
						 */
 | 
				
			||||||
 | 
						if (!gsi_trans_tre_reserve(trans_info, tre_count))
 | 
				
			||||||
 | 
							return NULL;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* Allocate and initialize non-zero fields in the the transaction */
 | 
				
			||||||
 | 
						trans = gsi_trans_pool_alloc(&trans_info->pool, 1);
 | 
				
			||||||
 | 
						trans->gsi = gsi;
 | 
				
			||||||
 | 
						trans->channel_id = channel_id;
 | 
				
			||||||
 | 
						trans->tre_count = tre_count;
 | 
				
			||||||
 | 
						init_completion(&trans->completion);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* Allocate the scatterlist and (if requested) info entries. */
 | 
				
			||||||
 | 
						trans->sgl = gsi_trans_pool_alloc(&trans_info->sg_pool, tre_count);
 | 
				
			||||||
 | 
						sg_init_marker(trans->sgl, tre_count);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						trans->direction = direction;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						spin_lock_bh(&trans_info->spinlock);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						list_add_tail(&trans->links, &trans_info->alloc);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						spin_unlock_bh(&trans_info->spinlock);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						refcount_set(&trans->refcount, 1);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return trans;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Free a previously-allocated transaction (used only in case of error) */
 | 
				
			||||||
 | 
					void gsi_trans_free(struct gsi_trans *trans)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						struct gsi_trans_info *trans_info;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						if (!refcount_dec_and_test(&trans->refcount))
 | 
				
			||||||
 | 
							return;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						trans_info = &trans->gsi->channel[trans->channel_id].trans_info;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						spin_lock_bh(&trans_info->spinlock);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						list_del(&trans->links);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						spin_unlock_bh(&trans_info->spinlock);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						ipa_gsi_trans_release(trans);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* Releasing the reserved TREs implicitly frees the sgl[] and
 | 
				
			||||||
 | 
						 * (if present) info[] arrays, plus the transaction itself.
 | 
				
			||||||
 | 
						 */
 | 
				
			||||||
 | 
						gsi_trans_tre_release(trans_info, trans->tre_count);
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Add an immediate command to a transaction */
 | 
				
			||||||
 | 
					void gsi_trans_cmd_add(struct gsi_trans *trans, void *buf, u32 size,
 | 
				
			||||||
 | 
							       dma_addr_t addr, enum dma_data_direction direction,
 | 
				
			||||||
 | 
							       enum ipa_cmd_opcode opcode)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						struct ipa_cmd_info *info;
 | 
				
			||||||
 | 
						u32 which = trans->used++;
 | 
				
			||||||
 | 
						struct scatterlist *sg;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* assert(which < trans->tre_count); */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* Set the page information for the buffer.  We also need to fill in
 | 
				
			||||||
 | 
						 * the DMA address for the buffer (something dma_map_sg() normally
 | 
				
			||||||
 | 
						 * does).
 | 
				
			||||||
 | 
						 */
 | 
				
			||||||
 | 
						sg = &trans->sgl[which];
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						sg_set_buf(sg, buf, size);
 | 
				
			||||||
 | 
						sg_dma_address(sg) = addr;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						info = &trans->info[which];
 | 
				
			||||||
 | 
						info->opcode = opcode;
 | 
				
			||||||
 | 
						info->direction = direction;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Add a page transfer to a transaction.  It will fill the only TRE. */
 | 
				
			||||||
 | 
					int gsi_trans_page_add(struct gsi_trans *trans, struct page *page, u32 size,
 | 
				
			||||||
 | 
							       u32 offset)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						struct scatterlist *sg = &trans->sgl[0];
 | 
				
			||||||
 | 
						int ret;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* assert(trans->tre_count == 1); */
 | 
				
			||||||
 | 
						/* assert(!trans->used); */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						sg_set_page(sg, page, size, offset);
 | 
				
			||||||
 | 
						ret = dma_map_sg(trans->gsi->dev, sg, 1, trans->direction);
 | 
				
			||||||
 | 
						if (!ret)
 | 
				
			||||||
 | 
							return -ENOMEM;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						trans->used++;	/* Transaction now owns the (DMA mapped) page */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return 0;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Add an SKB transfer to a transaction.  No other TREs will be used. */
 | 
				
			||||||
 | 
					int gsi_trans_skb_add(struct gsi_trans *trans, struct sk_buff *skb)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						struct scatterlist *sg = &trans->sgl[0];
 | 
				
			||||||
 | 
						u32 used;
 | 
				
			||||||
 | 
						int ret;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* assert(trans->tre_count == 1); */
 | 
				
			||||||
 | 
						/* assert(!trans->used); */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* skb->len will not be 0 (checked early) */
 | 
				
			||||||
 | 
						ret = skb_to_sgvec(skb, sg, 0, skb->len);
 | 
				
			||||||
 | 
						if (ret < 0)
 | 
				
			||||||
 | 
							return ret;
 | 
				
			||||||
 | 
						used = ret;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						ret = dma_map_sg(trans->gsi->dev, sg, used, trans->direction);
 | 
				
			||||||
 | 
						if (!ret)
 | 
				
			||||||
 | 
							return -ENOMEM;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						trans->used += used;	/* Transaction now owns the (DMA mapped) skb */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return 0;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Compute the length/opcode value to use for a TRE */
 | 
				
			||||||
 | 
					static __le16 gsi_tre_len_opcode(enum ipa_cmd_opcode opcode, u32 len)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						return opcode == IPA_CMD_NONE ? cpu_to_le16((u16)len)
 | 
				
			||||||
 | 
									      : cpu_to_le16((u16)opcode);
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Compute the flags value to use for a given TRE */
 | 
				
			||||||
 | 
					static __le32 gsi_tre_flags(bool last_tre, bool bei, enum ipa_cmd_opcode opcode)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						enum gsi_tre_type tre_type;
 | 
				
			||||||
 | 
						u32 tre_flags;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						tre_type = opcode == IPA_CMD_NONE ? GSI_RE_XFER : GSI_RE_IMMD_CMD;
 | 
				
			||||||
 | 
						tre_flags = u32_encode_bits(tre_type, TRE_FLAGS_TYPE_FMASK);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* Last TRE contains interrupt flags */
 | 
				
			||||||
 | 
						if (last_tre) {
 | 
				
			||||||
 | 
							/* All transactions end in a transfer completion interrupt */
 | 
				
			||||||
 | 
							tre_flags |= TRE_FLAGS_IEOT_FMASK;
 | 
				
			||||||
 | 
							/* Don't interrupt when outbound commands are acknowledged */
 | 
				
			||||||
 | 
							if (bei)
 | 
				
			||||||
 | 
								tre_flags |= TRE_FLAGS_BEI_FMASK;
 | 
				
			||||||
 | 
						} else {	/* All others indicate there's more to come */
 | 
				
			||||||
 | 
							tre_flags |= TRE_FLAGS_CHAIN_FMASK;
 | 
				
			||||||
 | 
						}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return cpu_to_le32(tre_flags);
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					static void gsi_trans_tre_fill(struct gsi_tre *dest_tre, dma_addr_t addr,
 | 
				
			||||||
 | 
								       u32 len, bool last_tre, bool bei,
 | 
				
			||||||
 | 
								       enum ipa_cmd_opcode opcode)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						struct gsi_tre tre;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						tre.addr = cpu_to_le64(addr);
 | 
				
			||||||
 | 
						tre.len_opcode = gsi_tre_len_opcode(opcode, len);
 | 
				
			||||||
 | 
						tre.reserved = 0;
 | 
				
			||||||
 | 
						tre.flags = gsi_tre_flags(last_tre, bei, opcode);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* ARM64 can write 16 bytes as a unit with a single instruction.
 | 
				
			||||||
 | 
						 * Doing the assignment this way is an attempt to make that happen.
 | 
				
			||||||
 | 
						 */
 | 
				
			||||||
 | 
						*dest_tre = tre;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * __gsi_trans_commit() - Common GSI transaction commit code
 | 
				
			||||||
 | 
					 * @trans:	Transaction to commit
 | 
				
			||||||
 | 
					 * @ring_db:	Whether to tell the hardware about these queued transfers
 | 
				
			||||||
 | 
					 *
 | 
				
			||||||
 | 
					 * Formats channel ring TRE entries based on the content of the scatterlist.
 | 
				
			||||||
 | 
					 * Maps a transaction pointer to the last ring entry used for the transaction,
 | 
				
			||||||
 | 
					 * so it can be recovered when it completes.  Moves the transaction to the
 | 
				
			||||||
 | 
					 * pending list.  Finally, updates the channel ring pointer and optionally
 | 
				
			||||||
 | 
					 * rings the doorbell.
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					static void __gsi_trans_commit(struct gsi_trans *trans, bool ring_db)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id];
 | 
				
			||||||
 | 
						struct gsi_ring *ring = &channel->tre_ring;
 | 
				
			||||||
 | 
						enum ipa_cmd_opcode opcode = IPA_CMD_NONE;
 | 
				
			||||||
 | 
						bool bei = channel->toward_ipa;
 | 
				
			||||||
 | 
						struct ipa_cmd_info *info;
 | 
				
			||||||
 | 
						struct gsi_tre *dest_tre;
 | 
				
			||||||
 | 
						struct scatterlist *sg;
 | 
				
			||||||
 | 
						u32 byte_count = 0;
 | 
				
			||||||
 | 
						u32 avail;
 | 
				
			||||||
 | 
						u32 i;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* assert(trans->used > 0); */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* Consume the entries.  If we cross the end of the ring while
 | 
				
			||||||
 | 
						 * filling them we'll switch to the beginning to finish.
 | 
				
			||||||
 | 
						 * If there is no info array we're doing a simple data
 | 
				
			||||||
 | 
						 * transfer request, whose opcode is IPA_CMD_NONE.
 | 
				
			||||||
 | 
						 */
 | 
				
			||||||
 | 
						info = trans->info ? &trans->info[0] : NULL;
 | 
				
			||||||
 | 
						avail = ring->count - ring->index % ring->count;
 | 
				
			||||||
 | 
						dest_tre = gsi_ring_virt(ring, ring->index);
 | 
				
			||||||
 | 
						for_each_sg(trans->sgl, sg, trans->used, i) {
 | 
				
			||||||
 | 
							bool last_tre = i == trans->used - 1;
 | 
				
			||||||
 | 
							dma_addr_t addr = sg_dma_address(sg);
 | 
				
			||||||
 | 
							u32 len = sg_dma_len(sg);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
							byte_count += len;
 | 
				
			||||||
 | 
							if (!avail--)
 | 
				
			||||||
 | 
								dest_tre = gsi_ring_virt(ring, 0);
 | 
				
			||||||
 | 
							if (info)
 | 
				
			||||||
 | 
								opcode = info++->opcode;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
							gsi_trans_tre_fill(dest_tre, addr, len, last_tre, bei, opcode);
 | 
				
			||||||
 | 
							dest_tre++;
 | 
				
			||||||
 | 
						}
 | 
				
			||||||
 | 
						ring->index += trans->used;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						if (channel->toward_ipa) {
 | 
				
			||||||
 | 
							/* We record TX bytes when they are sent */
 | 
				
			||||||
 | 
							trans->len = byte_count;
 | 
				
			||||||
 | 
							trans->trans_count = channel->trans_count;
 | 
				
			||||||
 | 
							trans->byte_count = channel->byte_count;
 | 
				
			||||||
 | 
							channel->trans_count++;
 | 
				
			||||||
 | 
							channel->byte_count += byte_count;
 | 
				
			||||||
 | 
						}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* Associate the last TRE with the transaction */
 | 
				
			||||||
 | 
						gsi_channel_trans_map(channel, ring->index - 1, trans);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						gsi_trans_move_pending(trans);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* Ring doorbell if requested, or if all TREs are allocated */
 | 
				
			||||||
 | 
						if (ring_db || !atomic_read(&channel->trans_info.tre_avail)) {
 | 
				
			||||||
 | 
							/* Report what we're handing off to hardware for TX channels */
 | 
				
			||||||
 | 
							if (channel->toward_ipa)
 | 
				
			||||||
 | 
								gsi_channel_tx_queued(channel);
 | 
				
			||||||
 | 
							gsi_channel_doorbell(channel);
 | 
				
			||||||
 | 
						}
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Commit a GSI transaction */
 | 
				
			||||||
 | 
					void gsi_trans_commit(struct gsi_trans *trans, bool ring_db)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						if (trans->used)
 | 
				
			||||||
 | 
							__gsi_trans_commit(trans, ring_db);
 | 
				
			||||||
 | 
						else
 | 
				
			||||||
 | 
							gsi_trans_free(trans);
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Commit a GSI transaction and wait for it to complete */
 | 
				
			||||||
 | 
					void gsi_trans_commit_wait(struct gsi_trans *trans)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						if (!trans->used)
 | 
				
			||||||
 | 
							goto out_trans_free;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						refcount_inc(&trans->refcount);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						__gsi_trans_commit(trans, true);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						wait_for_completion(&trans->completion);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					out_trans_free:
 | 
				
			||||||
 | 
						gsi_trans_free(trans);
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Commit a GSI transaction and wait for it to complete, with timeout */
 | 
				
			||||||
 | 
					int gsi_trans_commit_wait_timeout(struct gsi_trans *trans,
 | 
				
			||||||
 | 
									  unsigned long timeout)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						unsigned long timeout_jiffies = msecs_to_jiffies(timeout);
 | 
				
			||||||
 | 
						unsigned long remaining = 1;	/* In case of empty transaction */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						if (!trans->used)
 | 
				
			||||||
 | 
							goto out_trans_free;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						refcount_inc(&trans->refcount);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						__gsi_trans_commit(trans, true);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						remaining = wait_for_completion_timeout(&trans->completion,
 | 
				
			||||||
 | 
											timeout_jiffies);
 | 
				
			||||||
 | 
					out_trans_free:
 | 
				
			||||||
 | 
						gsi_trans_free(trans);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return remaining ? 0 : -ETIMEDOUT;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Process the completion of a transaction; called while polling */
 | 
				
			||||||
 | 
					void gsi_trans_complete(struct gsi_trans *trans)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						/* If the entire SGL was mapped when added, unmap it now */
 | 
				
			||||||
 | 
						if (trans->direction != DMA_NONE)
 | 
				
			||||||
 | 
							dma_unmap_sg(trans->gsi->dev, trans->sgl, trans->used,
 | 
				
			||||||
 | 
								     trans->direction);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						ipa_gsi_trans_complete(trans);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						complete(&trans->completion);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						gsi_trans_free(trans);
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Cancel a channel's pending transactions */
 | 
				
			||||||
 | 
					void gsi_channel_trans_cancel_pending(struct gsi_channel *channel)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						struct gsi_trans_info *trans_info = &channel->trans_info;
 | 
				
			||||||
 | 
						struct gsi_trans *trans;
 | 
				
			||||||
 | 
						bool cancelled;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* channel->gsi->mutex is held by caller */
 | 
				
			||||||
 | 
						spin_lock_bh(&trans_info->spinlock);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						cancelled = !list_empty(&trans_info->pending);
 | 
				
			||||||
 | 
						list_for_each_entry(trans, &trans_info->pending, links)
 | 
				
			||||||
 | 
							trans->cancelled = true;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						list_splice_tail_init(&trans_info->pending, &trans_info->complete);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						spin_unlock_bh(&trans_info->spinlock);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* Schedule NAPI polling to complete the cancelled transactions */
 | 
				
			||||||
 | 
						if (cancelled)
 | 
				
			||||||
 | 
							napi_schedule(&channel->napi);
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Issue a command to read a single byte from a channel */
 | 
				
			||||||
 | 
					int gsi_trans_read_byte(struct gsi *gsi, u32 channel_id, dma_addr_t addr)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						struct gsi_channel *channel = &gsi->channel[channel_id];
 | 
				
			||||||
 | 
						struct gsi_ring *ring = &channel->tre_ring;
 | 
				
			||||||
 | 
						struct gsi_trans_info *trans_info;
 | 
				
			||||||
 | 
						struct gsi_tre *dest_tre;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						trans_info = &channel->trans_info;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* First reserve the TRE, if possible */
 | 
				
			||||||
 | 
						if (!gsi_trans_tre_reserve(trans_info, 1))
 | 
				
			||||||
 | 
							return -EBUSY;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* Now fill the the reserved TRE and tell the hardware */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						dest_tre = gsi_ring_virt(ring, ring->index);
 | 
				
			||||||
 | 
						gsi_trans_tre_fill(dest_tre, addr, 1, true, false, IPA_CMD_NONE);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						ring->index++;
 | 
				
			||||||
 | 
						gsi_channel_doorbell(channel);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return 0;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Mark a gsi_trans_read_byte() request done */
 | 
				
			||||||
 | 
					void gsi_trans_read_byte_done(struct gsi *gsi, u32 channel_id)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						struct gsi_channel *channel = &gsi->channel[channel_id];
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						gsi_trans_tre_release(&channel->trans_info, 1);
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Initialize a channel's GSI transaction info */
 | 
				
			||||||
 | 
					int gsi_channel_trans_init(struct gsi *gsi, u32 channel_id)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						struct gsi_channel *channel = &gsi->channel[channel_id];
 | 
				
			||||||
 | 
						struct gsi_trans_info *trans_info;
 | 
				
			||||||
 | 
						u32 tre_max;
 | 
				
			||||||
 | 
						int ret;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* Ensure the size of a channel element is what's expected */
 | 
				
			||||||
 | 
						BUILD_BUG_ON(sizeof(struct gsi_tre) != GSI_RING_ELEMENT_SIZE);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* The map array is used to determine what transaction is associated
 | 
				
			||||||
 | 
						 * with a TRE that the hardware reports has completed.  We need one
 | 
				
			||||||
 | 
						 * map entry per TRE.
 | 
				
			||||||
 | 
						 */
 | 
				
			||||||
 | 
						trans_info = &channel->trans_info;
 | 
				
			||||||
 | 
						trans_info->map = kcalloc(channel->tre_count, sizeof(*trans_info->map),
 | 
				
			||||||
 | 
									  GFP_KERNEL);
 | 
				
			||||||
 | 
						if (!trans_info->map)
 | 
				
			||||||
 | 
							return -ENOMEM;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* We can't use more TREs than there are available in the ring.
 | 
				
			||||||
 | 
						 * This limits the number of transactions that can be oustanding.
 | 
				
			||||||
 | 
						 * Worst case is one TRE per transaction (but we actually limit
 | 
				
			||||||
 | 
						 * it to something a little less than that).  We allocate resources
 | 
				
			||||||
 | 
						 * for transactions (including transaction structures) based on
 | 
				
			||||||
 | 
						 * this maximum number.
 | 
				
			||||||
 | 
						 */
 | 
				
			||||||
 | 
						tre_max = gsi_channel_tre_max(channel->gsi, channel_id);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* Transactions are allocated one at a time. */
 | 
				
			||||||
 | 
						ret = gsi_trans_pool_init(&trans_info->pool, sizeof(struct gsi_trans),
 | 
				
			||||||
 | 
									  tre_max, 1);
 | 
				
			||||||
 | 
						if (ret)
 | 
				
			||||||
 | 
							goto err_kfree;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* A transaction uses a scatterlist array to represent the data
 | 
				
			||||||
 | 
						 * transfers implemented by the transaction.  Each scatterlist
 | 
				
			||||||
 | 
						 * element is used to fill a single TRE when the transaction is
 | 
				
			||||||
 | 
						 * committed.  So we need as many scatterlist elements as the
 | 
				
			||||||
 | 
						 * maximum number of TREs that can be outstanding.
 | 
				
			||||||
 | 
						 *
 | 
				
			||||||
 | 
						 * All TREs in a transaction must fit within the channel's TLV FIFO.
 | 
				
			||||||
 | 
						 * A transaction on a channel can allocate as many TREs as that but
 | 
				
			||||||
 | 
						 * no more.
 | 
				
			||||||
 | 
						 */
 | 
				
			||||||
 | 
						ret = gsi_trans_pool_init(&trans_info->sg_pool,
 | 
				
			||||||
 | 
									  sizeof(struct scatterlist),
 | 
				
			||||||
 | 
									  tre_max, channel->tlv_count);
 | 
				
			||||||
 | 
						if (ret)
 | 
				
			||||||
 | 
							goto err_trans_pool_exit;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						/* Finally, the tre_avail field is what ultimately limits the number
 | 
				
			||||||
 | 
						 * of outstanding transactions and their resources.  A transaction
 | 
				
			||||||
 | 
						 * allocation succeeds only if the TREs available are sufficient for
 | 
				
			||||||
 | 
						 * what the transaction might need.  Transaction resource pools are
 | 
				
			||||||
 | 
						 * sized based on the maximum number of outstanding TREs, so there
 | 
				
			||||||
 | 
						 * will always be resources available if there are TREs available.
 | 
				
			||||||
 | 
						 */
 | 
				
			||||||
 | 
						atomic_set(&trans_info->tre_avail, tre_max);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						spin_lock_init(&trans_info->spinlock);
 | 
				
			||||||
 | 
						INIT_LIST_HEAD(&trans_info->alloc);
 | 
				
			||||||
 | 
						INIT_LIST_HEAD(&trans_info->pending);
 | 
				
			||||||
 | 
						INIT_LIST_HEAD(&trans_info->complete);
 | 
				
			||||||
 | 
						INIT_LIST_HEAD(&trans_info->polled);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return 0;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					err_trans_pool_exit:
 | 
				
			||||||
 | 
						gsi_trans_pool_exit(&trans_info->pool);
 | 
				
			||||||
 | 
					err_kfree:
 | 
				
			||||||
 | 
						kfree(trans_info->map);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						dev_err(gsi->dev, "error %d initializing channel %u transactions\n",
 | 
				
			||||||
 | 
							ret, channel_id);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						return ret;
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Inverse of gsi_channel_trans_init() */
 | 
				
			||||||
 | 
					void gsi_channel_trans_exit(struct gsi_channel *channel)
 | 
				
			||||||
 | 
					{
 | 
				
			||||||
 | 
						struct gsi_trans_info *trans_info = &channel->trans_info;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						gsi_trans_pool_exit(&trans_info->sg_pool);
 | 
				
			||||||
 | 
						gsi_trans_pool_exit(&trans_info->pool);
 | 
				
			||||||
 | 
						kfree(trans_info->map);
 | 
				
			||||||
 | 
					}
 | 
				
			||||||
							
								
								
									
										226
									
								
								drivers/net/ipa/gsi_trans.h
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										226
									
								
								drivers/net/ipa/gsi_trans.h
									
									
									
									
									
										Normal file
									
								
							| 
						 | 
					@ -0,0 +1,226 @@
 | 
				
			||||||
 | 
					/* SPDX-License-Identifier: GPL-2.0 */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
 | 
				
			||||||
 | 
					 * Copyright (C) 2019-2020 Linaro Ltd.
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					#ifndef _GSI_TRANS_H_
 | 
				
			||||||
 | 
					#define _GSI_TRANS_H_
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					#include <linux/types.h>
 | 
				
			||||||
 | 
					#include <linux/refcount.h>
 | 
				
			||||||
 | 
					#include <linux/completion.h>
 | 
				
			||||||
 | 
					#include <linux/dma-direction.h>
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					#include "ipa_cmd.h"
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					struct scatterlist;
 | 
				
			||||||
 | 
					struct device;
 | 
				
			||||||
 | 
					struct sk_buff;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					struct gsi;
 | 
				
			||||||
 | 
					struct gsi_trans;
 | 
				
			||||||
 | 
					struct gsi_trans_pool;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * struct gsi_trans - a GSI transaction
 | 
				
			||||||
 | 
					 *
 | 
				
			||||||
 | 
					 * Most fields in this structure for internal use by the transaction core code:
 | 
				
			||||||
 | 
					 * @links:	Links for channel transaction lists by state
 | 
				
			||||||
 | 
					 * @gsi:	GSI pointer
 | 
				
			||||||
 | 
					 * @channel_id: Channel number transaction is associated with
 | 
				
			||||||
 | 
					 * @cancelled:	If set by the core code, transaction was cancelled
 | 
				
			||||||
 | 
					 * @tre_count:	Number of TREs reserved for this transaction
 | 
				
			||||||
 | 
					 * @used:	Number of TREs *used* (could be less than tre_count)
 | 
				
			||||||
 | 
					 * @len:	Total # of transfer bytes represented in sgl[] (set by core)
 | 
				
			||||||
 | 
					 * @data:	Preserved but not touched by the core transaction code
 | 
				
			||||||
 | 
					 * @sgl:	An array of scatter/gather entries managed by core code
 | 
				
			||||||
 | 
					 * @info:	Array of command information structures (command channel)
 | 
				
			||||||
 | 
					 * @direction:	DMA transfer direction (DMA_NONE for commands)
 | 
				
			||||||
 | 
					 * @refcount:	Reference count used for destruction
 | 
				
			||||||
 | 
					 * @completion:	Completed when the transaction completes
 | 
				
			||||||
 | 
					 * @byte_count:	TX channel byte count recorded when transaction committed
 | 
				
			||||||
 | 
					 * @trans_count: Channel transaction count when committed (for BQL accounting)
 | 
				
			||||||
 | 
					 *
 | 
				
			||||||
 | 
					 * The size used for some fields in this structure were chosen to ensure
 | 
				
			||||||
 | 
					 * the full structure size is no larger than 128 bytes.
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					struct gsi_trans {
 | 
				
			||||||
 | 
						struct list_head links;		/* gsi_channel lists */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						struct gsi *gsi;
 | 
				
			||||||
 | 
						u8 channel_id;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						bool cancelled;			/* true if transaction was cancelled */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						u8 tre_count;			/* # TREs requested */
 | 
				
			||||||
 | 
						u8 used;			/* # entries used in sgl[] */
 | 
				
			||||||
 | 
						u32 len;			/* total # bytes across sgl[] */
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						void *data;
 | 
				
			||||||
 | 
						struct scatterlist *sgl;
 | 
				
			||||||
 | 
						struct ipa_cmd_info *info;	/* array of entries, or null */
 | 
				
			||||||
 | 
						enum dma_data_direction direction;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						refcount_t refcount;
 | 
				
			||||||
 | 
						struct completion completion;
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
						u64 byte_count;			/* channel byte_count when committed */
 | 
				
			||||||
 | 
						u64 trans_count;		/* channel trans_count when committed */
 | 
				
			||||||
 | 
					};
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_pool_init() - Initialize a pool of structures for transactions
 | 
				
			||||||
 | 
					 * @gsi:	GSI pointer
 | 
				
			||||||
 | 
					 * @size:	Size of elements in the pool
 | 
				
			||||||
 | 
					 * @count:	Minimum number of elements in the pool
 | 
				
			||||||
 | 
					 * @max_alloc:	Maximum number of elements allocated at a time from pool
 | 
				
			||||||
 | 
					 *
 | 
				
			||||||
 | 
					 * @Return:	0 if successful, or a negative error code
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					int gsi_trans_pool_init(struct gsi_trans_pool *pool, size_t size, u32 count,
 | 
				
			||||||
 | 
								u32 max_alloc);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_pool_alloc() - Allocate one or more elements from a pool
 | 
				
			||||||
 | 
					 * @pool:	Pool pointer
 | 
				
			||||||
 | 
					 * @count:	Number of elements to allocate from the pool
 | 
				
			||||||
 | 
					 *
 | 
				
			||||||
 | 
					 * @Return:	Virtual address of element(s) allocated from the pool
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					void *gsi_trans_pool_alloc(struct gsi_trans_pool *pool, u32 count);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_pool_exit() - Inverse of gsi_trans_pool_init()
 | 
				
			||||||
 | 
					 * @pool:	Pool pointer
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					void gsi_trans_pool_exit(struct gsi_trans_pool *pool);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_pool_init_dma() - Initialize a pool of DMA-able structures
 | 
				
			||||||
 | 
					 * @dev:	Device used for DMA
 | 
				
			||||||
 | 
					 * @pool:	Pool pointer
 | 
				
			||||||
 | 
					 * @size:	Size of elements in the pool
 | 
				
			||||||
 | 
					 * @count:	Minimum number of elements in the pool
 | 
				
			||||||
 | 
					 * @max_alloc:	Maximum number of elements allocated at a time from pool
 | 
				
			||||||
 | 
					 *
 | 
				
			||||||
 | 
					 * @Return:	0 if successful, or a negative error code
 | 
				
			||||||
 | 
					 *
 | 
				
			||||||
 | 
					 * Structures in this pool reside in DMA-coherent memory.
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool,
 | 
				
			||||||
 | 
								    size_t size, u32 count, u32 max_alloc);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_pool_alloc_dma() - Allocate an element from a DMA pool
 | 
				
			||||||
 | 
					 * @pool:	DMA pool pointer
 | 
				
			||||||
 | 
					 * @addr:	DMA address "handle" associated with the allocation
 | 
				
			||||||
 | 
					 *
 | 
				
			||||||
 | 
					 * @Return:	Virtual address of element allocated from the pool
 | 
				
			||||||
 | 
					 *
 | 
				
			||||||
 | 
					 * Only one element at a time may be allocated from a DMA pool.
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					void *gsi_trans_pool_alloc_dma(struct gsi_trans_pool *pool, dma_addr_t *addr);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_pool_exit() - Inverse of gsi_trans_pool_init()
 | 
				
			||||||
 | 
					 * @pool:	Pool pointer
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					void gsi_trans_pool_exit_dma(struct device *dev, struct gsi_trans_pool *pool);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_channel_trans_alloc() - Allocate a GSI transaction on a channel
 | 
				
			||||||
 | 
					 * @gsi:	GSI pointer
 | 
				
			||||||
 | 
					 * @channel_id:	Channel the transaction is associated with
 | 
				
			||||||
 | 
					 * @tre_count:	Number of elements in the transaction
 | 
				
			||||||
 | 
					 * @direction:	DMA direction for entire SGL (or DMA_NONE)
 | 
				
			||||||
 | 
					 *
 | 
				
			||||||
 | 
					 * @Return:	A GSI transaction structure, or a null pointer if all
 | 
				
			||||||
 | 
					 *		available transactions are in use
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					struct gsi_trans *gsi_channel_trans_alloc(struct gsi *gsi, u32 channel_id,
 | 
				
			||||||
 | 
										  u32 tre_count,
 | 
				
			||||||
 | 
										  enum dma_data_direction direction);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_free() - Free a previously-allocated GSI transaction
 | 
				
			||||||
 | 
					 * @trans:	Transaction to be freed
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					void gsi_trans_free(struct gsi_trans *trans);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_cmd_add() - Add an immediate command to a transaction
 | 
				
			||||||
 | 
					 * @trans:	Transaction
 | 
				
			||||||
 | 
					 * @buf:	Buffer pointer for command payload
 | 
				
			||||||
 | 
					 * @size:	Number of bytes in buffer
 | 
				
			||||||
 | 
					 * @addr:	DMA address for payload
 | 
				
			||||||
 | 
					 * @direction:	Direction of DMA transfer (or DMA_NONE if none required)
 | 
				
			||||||
 | 
					 * @opcode:	IPA immediate command opcode
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					void gsi_trans_cmd_add(struct gsi_trans *trans, void *buf, u32 size,
 | 
				
			||||||
 | 
							       dma_addr_t addr, enum dma_data_direction direction,
 | 
				
			||||||
 | 
							       enum ipa_cmd_opcode opcode);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_page_add() - Add a page transfer to a transaction
 | 
				
			||||||
 | 
					 * @trans:	Transaction
 | 
				
			||||||
 | 
					 * @page:	Page pointer
 | 
				
			||||||
 | 
					 * @size:	Number of bytes (starting at offset) to transfer
 | 
				
			||||||
 | 
					 * @offset:	Offset within page for start of transfer
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					int gsi_trans_page_add(struct gsi_trans *trans, struct page *page, u32 size,
 | 
				
			||||||
 | 
							       u32 offset);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_skb_add() - Add a socket transfer to a transaction
 | 
				
			||||||
 | 
					 * @trans:	Transaction
 | 
				
			||||||
 | 
					 * @skb:	Socket buffer for transfer (outbound)
 | 
				
			||||||
 | 
					 *
 | 
				
			||||||
 | 
					 * @Return:	0, or -EMSGSIZE if socket data won't fit in transaction.
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					int gsi_trans_skb_add(struct gsi_trans *trans, struct sk_buff *skb);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_commit() - Commit a GSI transaction
 | 
				
			||||||
 | 
					 * @trans:	Transaction to commit
 | 
				
			||||||
 | 
					 * @ring_db:	Whether to tell the hardware about these queued transfers
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					void gsi_trans_commit(struct gsi_trans *trans, bool ring_db);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_commit_wait() - Commit a GSI transaction and wait for it
 | 
				
			||||||
 | 
					 *			     to complete
 | 
				
			||||||
 | 
					 * @trans:	Transaction to commit
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					void gsi_trans_commit_wait(struct gsi_trans *trans);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_commit_wait_timeout() - Commit a GSI transaction and wait for
 | 
				
			||||||
 | 
					 *				     it to complete, with timeout
 | 
				
			||||||
 | 
					 * @trans:	Transaction to commit
 | 
				
			||||||
 | 
					 * @timeout:	Timeout period (in milliseconds)
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					int gsi_trans_commit_wait_timeout(struct gsi_trans *trans,
 | 
				
			||||||
 | 
									  unsigned long timeout);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_read_byte() - Issue a single byte read TRE on a channel
 | 
				
			||||||
 | 
					 * @gsi:	GSI pointer
 | 
				
			||||||
 | 
					 * @channel_id:	Channel on which to read a byte
 | 
				
			||||||
 | 
					 * @addr:	DMA address into which to transfer the one byte
 | 
				
			||||||
 | 
					 *
 | 
				
			||||||
 | 
					 * This is not a transaction operation at all.  It's defined here because
 | 
				
			||||||
 | 
					 * it needs to be done in coordination with other transaction activity.
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					int gsi_trans_read_byte(struct gsi *gsi, u32 channel_id, dma_addr_t addr);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					/**
 | 
				
			||||||
 | 
					 * gsi_trans_read_byte_done() - Clean up after a single byte read TRE
 | 
				
			||||||
 | 
					 * @gsi:	GSI pointer
 | 
				
			||||||
 | 
					 * @channel_id:	Channel on which byte was read
 | 
				
			||||||
 | 
					 *
 | 
				
			||||||
 | 
					 * This function needs to be called to signal that the work related
 | 
				
			||||||
 | 
					 * to reading a byte initiated by gsi_trans_read_byte() is complete.
 | 
				
			||||||
 | 
					 */
 | 
				
			||||||
 | 
					void gsi_trans_read_byte_done(struct gsi *gsi, u32 channel_id);
 | 
				
			||||||
 | 
					
 | 
				
			||||||
 | 
					#endif /* _GSI_TRANS_H_ */
 | 
				
			||||||
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		Reference in a new issue