diff options
Diffstat (limited to 'drivers/net/ipa/gsi_trans.c')
| -rw-r--r-- | drivers/net/ipa/gsi_trans.c | 786 |
1 files changed, 786 insertions, 0 deletions
diff --git a/drivers/net/ipa/gsi_trans.c b/drivers/net/ipa/gsi_trans.c new file mode 100644 index 000000000000..2fd21d75367d --- /dev/null +++ b/drivers/net/ipa/gsi_trans.c @@ -0,0 +1,786 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved. + * Copyright (C) 2019-2020 Linaro Ltd. + */ + +#include <linux/types.h> +#include <linux/bits.h> +#include <linux/bitfield.h> +#include <linux/refcount.h> +#include <linux/scatterlist.h> +#include <linux/dma-direction.h> + +#include "gsi.h" +#include "gsi_private.h" +#include "gsi_trans.h" +#include "ipa_gsi.h" +#include "ipa_data.h" +#include "ipa_cmd.h" + +/** + * DOC: GSI Transactions + * + * A GSI transaction abstracts the behavior of a GSI channel by representing + * everything about a related group of IPA commands in a single structure. + * (A "command" in this sense is either a data transfer or an IPA immediate + * command.) Most details of interaction with the GSI hardware are managed + * by the GSI transaction core, allowing users to simply describe commands + * to be performed. When a transaction has completed a callback function + * (dependent on the type of endpoint associated with the channel) allows + * cleanup of resources associated with the transaction. + * + * To perform a command (or set of them), a user of the GSI transaction + * interface allocates a transaction, indicating the number of TREs required + * (one per command). If sufficient TREs are available, they are reserved + * for use in the transaction and the allocation succeeds. This way + * exhaustion of the available TREs in a channel ring is detected + * as early as possible. All resources required to complete a transaction + * are allocated at transaction allocation time. + * + * Commands performed as part of a transaction are represented in an array + * of Linux scatterlist structures. This array is allocated with the + * transaction, and its entries are initialized using standard scatterlist + * functions (such as sg_set_buf() or skb_to_sgvec()). + * + * Once a transaction's scatterlist structures have been initialized, the + * transaction is committed. The caller is responsible for mapping buffers + * for DMA if necessary, and this should be done *before* allocating + * the transaction. Between a successful allocation and commit of a + * transaction no errors should occur. + * + * Committing transfers ownership of the entire transaction to the GSI + * transaction core. The GSI transaction code formats the content of + * the scatterlist array into the channel ring buffer and informs the + * hardware that new TREs are available to process. + * + * The last TRE in each transaction is marked to interrupt the AP when the + * GSI hardware has completed it. Because transfers described by TREs are + * performed strictly in order, signaling the completion of just the last + * TRE in the transaction is sufficient to indicate the full transaction + * is complete. + * + * When a transaction is complete, ipa_gsi_trans_complete() is called by the + * GSI code into the IPA layer, allowing it to perform any final cleanup + * required before the transaction is freed. + */ + +/* Hardware values representing a transfer element type */ +enum gsi_tre_type { + GSI_RE_XFER = 0x2, + GSI_RE_IMMD_CMD = 0x3, +}; + +/* An entry in a channel ring */ +struct gsi_tre { + __le64 addr; /* DMA address */ + __le16 len_opcode; /* length in bytes or enum IPA_CMD_* */ + __le16 reserved; + __le32 flags; /* TRE_FLAGS_* */ +}; + +/* gsi_tre->flags mask values (in CPU byte order) */ +#define TRE_FLAGS_CHAIN_FMASK GENMASK(0, 0) +#define TRE_FLAGS_IEOB_FMASK GENMASK(8, 8) +#define TRE_FLAGS_IEOT_FMASK GENMASK(9, 9) +#define TRE_FLAGS_BEI_FMASK GENMASK(10, 10) +#define TRE_FLAGS_TYPE_FMASK GENMASK(23, 16) + +int gsi_trans_pool_init(struct gsi_trans_pool *pool, size_t size, u32 count, + u32 max_alloc) +{ + void *virt; + +#ifdef IPA_VALIDATE + if (!size || size % 8) + return -EINVAL; + if (count < max_alloc) + return -EINVAL; + if (!max_alloc) + return -EINVAL; +#endif /* IPA_VALIDATE */ + + /* By allocating a few extra entries in our pool (one less + * than the maximum number that will be requested in a + * single allocation), we can always satisfy requests without + * ever worrying about straddling the end of the pool array. + * If there aren't enough entries starting at the free index, + * we just allocate free entries from the beginning of the pool. + */ + virt = kcalloc(count + max_alloc - 1, size, GFP_KERNEL); + if (!virt) + return -ENOMEM; + + pool->base = virt; + /* If the allocator gave us any extra memory, use it */ + pool->count = ksize(pool->base) / size; + pool->free = 0; + pool->max_alloc = max_alloc; + pool->size = size; + pool->addr = 0; /* Only used for DMA pools */ + + return 0; +} + +void gsi_trans_pool_exit(struct gsi_trans_pool *pool) +{ + kfree(pool->base); + memset(pool, 0, sizeof(*pool)); +} + +/* Allocate the requested number of (zeroed) entries from the pool */ +/* Home-grown DMA pool. This way we can preallocate and use the tre_count + * to guarantee allocations will succeed. Even though we specify max_alloc + * (and it can be more than one), we only allow allocation of a single + * element from a DMA pool. + */ +int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool, + size_t size, u32 count, u32 max_alloc) +{ + size_t total_size; + dma_addr_t addr; + void *virt; + +#ifdef IPA_VALIDATE + if (!size || size % 8) + return -EINVAL; + if (count < max_alloc) + return -EINVAL; + if (!max_alloc) + return -EINVAL; +#endif /* IPA_VALIDATE */ + + /* Don't let allocations cross a power-of-two boundary */ + size = __roundup_pow_of_two(size); + total_size = (count + max_alloc - 1) * size; + + /* The allocator will give us a power-of-2 number of pages. But we + * can't guarantee that, so request it. That way we won't waste any + * memory that would be available beyond the required space. + */ + total_size = get_order(total_size) << PAGE_SHIFT; + + virt = dma_alloc_coherent(dev, total_size, &addr, GFP_KERNEL); + if (!virt) + return -ENOMEM; + + pool->base = virt; + pool->count = total_size / size; + pool->free = 0; + pool->size = size; + pool->max_alloc = max_alloc; + pool->addr = addr; + + return 0; +} + +void gsi_trans_pool_exit_dma(struct device *dev, struct gsi_trans_pool *pool) +{ + dma_free_coherent(dev, pool->size, pool->base, pool->addr); + memset(pool, 0, sizeof(*pool)); +} + +/* Return the byte offset of the next free entry in the pool */ +static u32 gsi_trans_pool_alloc_common(struct gsi_trans_pool *pool, u32 count) +{ + u32 offset; + + /* assert(count > 0); */ + /* assert(count <= pool->max_alloc); */ + + /* Allocate from beginning if wrap would occur */ + if (count > pool->count - pool->free) + pool->free = 0; + + offset = pool->free * pool->size; + pool->free += count; + memset(pool->base + offset, 0, count * pool->size); + + return offset; +} + +/* Allocate a contiguous block of zeroed entries from a pool */ +void *gsi_trans_pool_alloc(struct gsi_trans_pool *pool, u32 count) +{ + return pool->base + gsi_trans_pool_alloc_common(pool, count); +} + +/* Allocate a single zeroed entry from a DMA pool */ +void *gsi_trans_pool_alloc_dma(struct gsi_trans_pool *pool, dma_addr_t *addr) +{ + u32 offset = gsi_trans_pool_alloc_common(pool, 1); + + *addr = pool->addr + offset; + + return pool->base + offset; +} + +/* Return the pool element that immediately follows the one given. + * This only works done if elements are allocated one at a time. + */ +void *gsi_trans_pool_next(struct gsi_trans_pool *pool, void *element) +{ + void *end = pool->base + pool->count * pool->size; + + /* assert(element >= pool->base); */ + /* assert(element < end); */ + /* assert(pool->max_alloc == 1); */ + element += pool->size; + + return element < end ? element : pool->base; +} + +/* Map a given ring entry index to the transaction associated with it */ +static void gsi_channel_trans_map(struct gsi_channel *channel, u32 index, + struct gsi_trans *trans) +{ + /* Note: index *must* be used modulo the ring count here */ + channel->trans_info.map[index % channel->tre_ring.count] = trans; +} + +/* Return the transaction mapped to a given ring entry */ +struct gsi_trans * +gsi_channel_trans_mapped(struct gsi_channel *channel, u32 index) +{ + /* Note: index *must* be used modulo the ring count here */ + return channel->trans_info.map[index % channel->tre_ring.count]; +} + +/* Return the oldest completed transaction for a channel (or null) */ +struct gsi_trans *gsi_channel_trans_complete(struct gsi_channel *channel) +{ + return list_first_entry_or_null(&channel->trans_info.complete, + struct gsi_trans, links); +} + +/* Move a transaction from the allocated list to the pending list */ +static void gsi_trans_move_pending(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->pending); + + spin_unlock_bh(&trans_info->spinlock); +} + +/* Move a transaction and all of its predecessors from the pending list + * to the completed list. + */ +void gsi_trans_move_complete(struct gsi_trans *trans) +{ + struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id]; + struct gsi_trans_info *trans_info = &channel->trans_info; + struct list_head list; + + spin_lock_bh(&trans_info->spinlock); + + /* Move this transaction and all predecessors to completed list */ + 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); +} |