19dd441e4SAlex Elder // SPDX-License-Identifier: GPL-2.0 29dd441e4SAlex Elder 39dd441e4SAlex Elder /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved. 49dd441e4SAlex Elder * Copyright (C) 2019-2020 Linaro Ltd. 59dd441e4SAlex Elder */ 69dd441e4SAlex Elder 79dd441e4SAlex Elder #include <linux/types.h> 89dd441e4SAlex Elder #include <linux/bits.h> 99dd441e4SAlex Elder #include <linux/bitfield.h> 109dd441e4SAlex Elder #include <linux/refcount.h> 119dd441e4SAlex Elder #include <linux/scatterlist.h> 129dd441e4SAlex Elder #include <linux/dma-direction.h> 139dd441e4SAlex Elder 149dd441e4SAlex Elder #include "gsi.h" 159dd441e4SAlex Elder #include "gsi_private.h" 169dd441e4SAlex Elder #include "gsi_trans.h" 179dd441e4SAlex Elder #include "ipa_gsi.h" 189dd441e4SAlex Elder #include "ipa_data.h" 199dd441e4SAlex Elder #include "ipa_cmd.h" 209dd441e4SAlex Elder 219dd441e4SAlex Elder /** 229dd441e4SAlex Elder * DOC: GSI Transactions 239dd441e4SAlex Elder * 249dd441e4SAlex Elder * A GSI transaction abstracts the behavior of a GSI channel by representing 259dd441e4SAlex Elder * everything about a related group of IPA commands in a single structure. 269dd441e4SAlex Elder * (A "command" in this sense is either a data transfer or an IPA immediate 279dd441e4SAlex Elder * command.) Most details of interaction with the GSI hardware are managed 289dd441e4SAlex Elder * by the GSI transaction core, allowing users to simply describe commands 299dd441e4SAlex Elder * to be performed. When a transaction has completed a callback function 309dd441e4SAlex Elder * (dependent on the type of endpoint associated with the channel) allows 319dd441e4SAlex Elder * cleanup of resources associated with the transaction. 329dd441e4SAlex Elder * 339dd441e4SAlex Elder * To perform a command (or set of them), a user of the GSI transaction 349dd441e4SAlex Elder * interface allocates a transaction, indicating the number of TREs required 359dd441e4SAlex Elder * (one per command). If sufficient TREs are available, they are reserved 369dd441e4SAlex Elder * for use in the transaction and the allocation succeeds. This way 379dd441e4SAlex Elder * exhaustion of the available TREs in a channel ring is detected 389dd441e4SAlex Elder * as early as possible. All resources required to complete a transaction 399dd441e4SAlex Elder * are allocated at transaction allocation time. 409dd441e4SAlex Elder * 419dd441e4SAlex Elder * Commands performed as part of a transaction are represented in an array 429dd441e4SAlex Elder * of Linux scatterlist structures. This array is allocated with the 439dd441e4SAlex Elder * transaction, and its entries are initialized using standard scatterlist 449dd441e4SAlex Elder * functions (such as sg_set_buf() or skb_to_sgvec()). 459dd441e4SAlex Elder * 469dd441e4SAlex Elder * Once a transaction's scatterlist structures have been initialized, the 479dd441e4SAlex Elder * transaction is committed. The caller is responsible for mapping buffers 489dd441e4SAlex Elder * for DMA if necessary, and this should be done *before* allocating 499dd441e4SAlex Elder * the transaction. Between a successful allocation and commit of a 509dd441e4SAlex Elder * transaction no errors should occur. 519dd441e4SAlex Elder * 529dd441e4SAlex Elder * Committing transfers ownership of the entire transaction to the GSI 539dd441e4SAlex Elder * transaction core. The GSI transaction code formats the content of 549dd441e4SAlex Elder * the scatterlist array into the channel ring buffer and informs the 559dd441e4SAlex Elder * hardware that new TREs are available to process. 569dd441e4SAlex Elder * 579dd441e4SAlex Elder * The last TRE in each transaction is marked to interrupt the AP when the 589dd441e4SAlex Elder * GSI hardware has completed it. Because transfers described by TREs are 599dd441e4SAlex Elder * performed strictly in order, signaling the completion of just the last 609dd441e4SAlex Elder * TRE in the transaction is sufficient to indicate the full transaction 619dd441e4SAlex Elder * is complete. 629dd441e4SAlex Elder * 639dd441e4SAlex Elder * When a transaction is complete, ipa_gsi_trans_complete() is called by the 649dd441e4SAlex Elder * GSI code into the IPA layer, allowing it to perform any final cleanup 659dd441e4SAlex Elder * required before the transaction is freed. 669dd441e4SAlex Elder */ 679dd441e4SAlex Elder 689dd441e4SAlex Elder /* Hardware values representing a transfer element type */ 699dd441e4SAlex Elder enum gsi_tre_type { 709dd441e4SAlex Elder GSI_RE_XFER = 0x2, 719dd441e4SAlex Elder GSI_RE_IMMD_CMD = 0x3, 729dd441e4SAlex Elder }; 739dd441e4SAlex Elder 749dd441e4SAlex Elder /* An entry in a channel ring */ 759dd441e4SAlex Elder struct gsi_tre { 769dd441e4SAlex Elder __le64 addr; /* DMA address */ 779dd441e4SAlex Elder __le16 len_opcode; /* length in bytes or enum IPA_CMD_* */ 789dd441e4SAlex Elder __le16 reserved; 799dd441e4SAlex Elder __le32 flags; /* TRE_FLAGS_* */ 809dd441e4SAlex Elder }; 819dd441e4SAlex Elder 829dd441e4SAlex Elder /* gsi_tre->flags mask values (in CPU byte order) */ 839dd441e4SAlex Elder #define TRE_FLAGS_CHAIN_FMASK GENMASK(0, 0) 849dd441e4SAlex Elder #define TRE_FLAGS_IEOT_FMASK GENMASK(9, 9) 859dd441e4SAlex Elder #define TRE_FLAGS_BEI_FMASK GENMASK(10, 10) 869dd441e4SAlex Elder #define TRE_FLAGS_TYPE_FMASK GENMASK(23, 16) 879dd441e4SAlex Elder 889dd441e4SAlex Elder int gsi_trans_pool_init(struct gsi_trans_pool *pool, size_t size, u32 count, 899dd441e4SAlex Elder u32 max_alloc) 909dd441e4SAlex Elder { 919dd441e4SAlex Elder void *virt; 929dd441e4SAlex Elder 937ad3bd52SAlex Elder if (!size) 949dd441e4SAlex Elder return -EINVAL; 959dd441e4SAlex Elder if (count < max_alloc) 969dd441e4SAlex Elder return -EINVAL; 979dd441e4SAlex Elder if (!max_alloc) 989dd441e4SAlex Elder return -EINVAL; 999dd441e4SAlex Elder 1009dd441e4SAlex Elder /* By allocating a few extra entries in our pool (one less 1019dd441e4SAlex Elder * than the maximum number that will be requested in a 1029dd441e4SAlex Elder * single allocation), we can always satisfy requests without 1039dd441e4SAlex Elder * ever worrying about straddling the end of the pool array. 1049dd441e4SAlex Elder * If there aren't enough entries starting at the free index, 1059dd441e4SAlex Elder * we just allocate free entries from the beginning of the pool. 1069dd441e4SAlex Elder */ 1079dd441e4SAlex Elder virt = kcalloc(count + max_alloc - 1, size, GFP_KERNEL); 1089dd441e4SAlex Elder if (!virt) 1099dd441e4SAlex Elder return -ENOMEM; 1109dd441e4SAlex Elder 1119dd441e4SAlex Elder pool->base = virt; 1129dd441e4SAlex Elder /* If the allocator gave us any extra memory, use it */ 1139dd441e4SAlex Elder pool->count = ksize(pool->base) / size; 1149dd441e4SAlex Elder pool->free = 0; 1159dd441e4SAlex Elder pool->max_alloc = max_alloc; 1169dd441e4SAlex Elder pool->size = size; 1179dd441e4SAlex Elder pool->addr = 0; /* Only used for DMA pools */ 1189dd441e4SAlex Elder 1199dd441e4SAlex Elder return 0; 1209dd441e4SAlex Elder } 1219dd441e4SAlex Elder 1229dd441e4SAlex Elder void gsi_trans_pool_exit(struct gsi_trans_pool *pool) 1239dd441e4SAlex Elder { 1249dd441e4SAlex Elder kfree(pool->base); 1259dd441e4SAlex Elder memset(pool, 0, sizeof(*pool)); 1269dd441e4SAlex Elder } 1279dd441e4SAlex Elder 1289dd441e4SAlex Elder /* Allocate the requested number of (zeroed) entries from the pool */ 1299dd441e4SAlex Elder /* Home-grown DMA pool. This way we can preallocate and use the tre_count 1309dd441e4SAlex Elder * to guarantee allocations will succeed. Even though we specify max_alloc 1319dd441e4SAlex Elder * (and it can be more than one), we only allow allocation of a single 1329dd441e4SAlex Elder * element from a DMA pool. 1339dd441e4SAlex Elder */ 1349dd441e4SAlex Elder int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool, 1359dd441e4SAlex Elder size_t size, u32 count, u32 max_alloc) 1369dd441e4SAlex Elder { 1379dd441e4SAlex Elder size_t total_size; 1389dd441e4SAlex Elder dma_addr_t addr; 1399dd441e4SAlex Elder void *virt; 1409dd441e4SAlex Elder 1417ad3bd52SAlex Elder if (!size) 1429dd441e4SAlex Elder return -EINVAL; 1439dd441e4SAlex Elder if (count < max_alloc) 1449dd441e4SAlex Elder return -EINVAL; 1459dd441e4SAlex Elder if (!max_alloc) 1469dd441e4SAlex Elder return -EINVAL; 1479dd441e4SAlex Elder 1489dd441e4SAlex Elder /* Don't let allocations cross a power-of-two boundary */ 1499dd441e4SAlex Elder size = __roundup_pow_of_two(size); 1509dd441e4SAlex Elder total_size = (count + max_alloc - 1) * size; 1519dd441e4SAlex Elder 15219aaf72cSAlex Elder /* The allocator will give us a power-of-2 number of pages 15319aaf72cSAlex Elder * sufficient to satisfy our request. Round up our requested 15419aaf72cSAlex Elder * size to avoid any unused space in the allocation. This way 15519aaf72cSAlex Elder * gsi_trans_pool_exit_dma() can assume the total allocated 1561130b252SAlex Elder * size is exactly (count * size). 1579dd441e4SAlex Elder */ 1589dd441e4SAlex Elder total_size = get_order(total_size) << PAGE_SHIFT; 1599dd441e4SAlex Elder 1609dd441e4SAlex Elder virt = dma_alloc_coherent(dev, total_size, &addr, GFP_KERNEL); 1619dd441e4SAlex Elder if (!virt) 1629dd441e4SAlex Elder return -ENOMEM; 1639dd441e4SAlex Elder 1649dd441e4SAlex Elder pool->base = virt; 1659dd441e4SAlex Elder pool->count = total_size / size; 1669dd441e4SAlex Elder pool->free = 0; 1679dd441e4SAlex Elder pool->size = size; 1689dd441e4SAlex Elder pool->max_alloc = max_alloc; 1699dd441e4SAlex Elder pool->addr = addr; 1709dd441e4SAlex Elder 1719dd441e4SAlex Elder return 0; 1729dd441e4SAlex Elder } 1739dd441e4SAlex Elder 1749dd441e4SAlex Elder void gsi_trans_pool_exit_dma(struct device *dev, struct gsi_trans_pool *pool) 1759dd441e4SAlex Elder { 1761130b252SAlex Elder size_t total_size = pool->count * pool->size; 1771130b252SAlex Elder 1781130b252SAlex Elder dma_free_coherent(dev, total_size, pool->base, pool->addr); 1799dd441e4SAlex Elder memset(pool, 0, sizeof(*pool)); 1809dd441e4SAlex Elder } 1819dd441e4SAlex Elder 1829dd441e4SAlex Elder /* Return the byte offset of the next free entry in the pool */ 1839dd441e4SAlex Elder static u32 gsi_trans_pool_alloc_common(struct gsi_trans_pool *pool, u32 count) 1849dd441e4SAlex Elder { 1859dd441e4SAlex Elder u32 offset; 1869dd441e4SAlex Elder 1875bc55884SAlex Elder WARN_ON(!count); 1885bc55884SAlex Elder WARN_ON(count > pool->max_alloc); 1899dd441e4SAlex Elder 1909dd441e4SAlex Elder /* Allocate from beginning if wrap would occur */ 1919dd441e4SAlex Elder if (count > pool->count - pool->free) 1929dd441e4SAlex Elder pool->free = 0; 1939dd441e4SAlex Elder 1949dd441e4SAlex Elder offset = pool->free * pool->size; 1959dd441e4SAlex Elder pool->free += count; 1969dd441e4SAlex Elder memset(pool->base + offset, 0, count * pool->size); 1979dd441e4SAlex Elder 1989dd441e4SAlex Elder return offset; 1999dd441e4SAlex Elder } 2009dd441e4SAlex Elder 2019dd441e4SAlex Elder /* Allocate a contiguous block of zeroed entries from a pool */ 2029dd441e4SAlex Elder void *gsi_trans_pool_alloc(struct gsi_trans_pool *pool, u32 count) 2039dd441e4SAlex Elder { 2049dd441e4SAlex Elder return pool->base + gsi_trans_pool_alloc_common(pool, count); 2059dd441e4SAlex Elder } 2069dd441e4SAlex Elder 2079dd441e4SAlex Elder /* Allocate a single zeroed entry from a DMA pool */ 2089dd441e4SAlex Elder void *gsi_trans_pool_alloc_dma(struct gsi_trans_pool *pool, dma_addr_t *addr) 2099dd441e4SAlex Elder { 2109dd441e4SAlex Elder u32 offset = gsi_trans_pool_alloc_common(pool, 1); 2119dd441e4SAlex Elder 2129dd441e4SAlex Elder *addr = pool->addr + offset; 2139dd441e4SAlex Elder 2149dd441e4SAlex Elder return pool->base + offset; 2159dd441e4SAlex Elder } 2169dd441e4SAlex Elder 2178eec7831SAlex Elder /* Map a TRE ring entry index to the transaction it is associated with */ 2188eec7831SAlex Elder static void gsi_trans_map(struct gsi_trans *trans, u32 index) 2199dd441e4SAlex Elder { 2208eec7831SAlex Elder struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id]; 2218eec7831SAlex Elder 2228eec7831SAlex Elder /* The completion event will indicate the last TRE used */ 2238eec7831SAlex Elder index += trans->used_count - 1; 2248eec7831SAlex Elder 2259dd441e4SAlex Elder /* Note: index *must* be used modulo the ring count here */ 2269dd441e4SAlex Elder channel->trans_info.map[index % channel->tre_ring.count] = trans; 2279dd441e4SAlex Elder } 2289dd441e4SAlex Elder 2299dd441e4SAlex Elder /* Return the transaction mapped to a given ring entry */ 2309dd441e4SAlex Elder struct gsi_trans * 2319dd441e4SAlex Elder gsi_channel_trans_mapped(struct gsi_channel *channel, u32 index) 2329dd441e4SAlex Elder { 2339dd441e4SAlex Elder /* Note: index *must* be used modulo the ring count here */ 2349dd441e4SAlex Elder return channel->trans_info.map[index % channel->tre_ring.count]; 2359dd441e4SAlex Elder } 2369dd441e4SAlex Elder 2379dd441e4SAlex Elder /* Return the oldest completed transaction for a channel (or null) */ 2389dd441e4SAlex Elder struct gsi_trans *gsi_channel_trans_complete(struct gsi_channel *channel) 2399dd441e4SAlex Elder { 2409dd441e4SAlex Elder return list_first_entry_or_null(&channel->trans_info.complete, 2419dd441e4SAlex Elder struct gsi_trans, links); 2429dd441e4SAlex Elder } 2439dd441e4SAlex Elder 244b63f507cSAlex Elder /* Move a transaction from the allocated list to the committed list */ 245b63f507cSAlex Elder static void gsi_trans_move_committed(struct gsi_trans *trans) 2469dd441e4SAlex Elder { 2479dd441e4SAlex Elder struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id]; 2489dd441e4SAlex Elder struct gsi_trans_info *trans_info = &channel->trans_info; 249*41e2a2c0SAlex Elder u16 trans_index; 2509dd441e4SAlex Elder 2519dd441e4SAlex Elder spin_lock_bh(&trans_info->spinlock); 2529dd441e4SAlex Elder 253b63f507cSAlex Elder list_move_tail(&trans->links, &trans_info->committed); 254b63f507cSAlex Elder 255*41e2a2c0SAlex Elder trans = list_first_entry_or_null(&trans_info->alloc, 256*41e2a2c0SAlex Elder struct gsi_trans, links); 257*41e2a2c0SAlex Elder 258b63f507cSAlex Elder spin_unlock_bh(&trans_info->spinlock); 259*41e2a2c0SAlex Elder 260*41e2a2c0SAlex Elder /* This allocated transaction is now committed */ 261*41e2a2c0SAlex Elder trans_info->allocated_id++; 262*41e2a2c0SAlex Elder 263*41e2a2c0SAlex Elder if (trans) { 264*41e2a2c0SAlex Elder trans_index = trans_info->allocated_id % channel->tre_count; 265*41e2a2c0SAlex Elder WARN_ON(trans != &trans_info->trans[trans_index]); 266*41e2a2c0SAlex Elder } else { 267*41e2a2c0SAlex Elder WARN_ON(trans_info->allocated_id != trans_info->free_id); 268*41e2a2c0SAlex Elder } 269b63f507cSAlex Elder } 270b63f507cSAlex Elder 271b63f507cSAlex Elder /* Move transactions from the committed list to the pending list */ 272b63f507cSAlex Elder static void gsi_trans_move_pending(struct gsi_trans *trans) 273b63f507cSAlex Elder { 274b63f507cSAlex Elder struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id]; 275b63f507cSAlex Elder struct gsi_trans_info *trans_info = &channel->trans_info; 276b63f507cSAlex Elder struct list_head list; 277b63f507cSAlex Elder 278b63f507cSAlex Elder spin_lock_bh(&trans_info->spinlock); 279b63f507cSAlex Elder 280b63f507cSAlex Elder /* Move this transaction and all predecessors to the pending list */ 281b63f507cSAlex Elder list_cut_position(&list, &trans_info->committed, &trans->links); 282b63f507cSAlex Elder list_splice_tail(&list, &trans_info->pending); 2839dd441e4SAlex Elder 2849dd441e4SAlex Elder spin_unlock_bh(&trans_info->spinlock); 2859dd441e4SAlex Elder } 2869dd441e4SAlex Elder 2879dd441e4SAlex Elder /* Move a transaction and all of its predecessors from the pending list 2889dd441e4SAlex Elder * to the completed list. 2899dd441e4SAlex Elder */ 2909dd441e4SAlex Elder void gsi_trans_move_complete(struct gsi_trans *trans) 2919dd441e4SAlex Elder { 2929dd441e4SAlex Elder struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id]; 2939dd441e4SAlex Elder struct gsi_trans_info *trans_info = &channel->trans_info; 2949dd441e4SAlex Elder struct list_head list; 2959dd441e4SAlex Elder 2969dd441e4SAlex Elder spin_lock_bh(&trans_info->spinlock); 2979dd441e4SAlex Elder 2989dd441e4SAlex Elder /* Move this transaction and all predecessors to completed list */ 2999dd441e4SAlex Elder list_cut_position(&list, &trans_info->pending, &trans->links); 3009dd441e4SAlex Elder list_splice_tail(&list, &trans_info->complete); 3019dd441e4SAlex Elder 3029dd441e4SAlex Elder spin_unlock_bh(&trans_info->spinlock); 3039dd441e4SAlex Elder } 3049dd441e4SAlex Elder 3059dd441e4SAlex Elder /* Move a transaction from the completed list to the polled list */ 3069dd441e4SAlex Elder void gsi_trans_move_polled(struct gsi_trans *trans) 3079dd441e4SAlex Elder { 3089dd441e4SAlex Elder struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id]; 3099dd441e4SAlex Elder struct gsi_trans_info *trans_info = &channel->trans_info; 3109dd441e4SAlex Elder 3119dd441e4SAlex Elder spin_lock_bh(&trans_info->spinlock); 3129dd441e4SAlex Elder 3139dd441e4SAlex Elder list_move_tail(&trans->links, &trans_info->polled); 3149dd441e4SAlex Elder 3159dd441e4SAlex Elder spin_unlock_bh(&trans_info->spinlock); 3169dd441e4SAlex Elder } 3179dd441e4SAlex Elder 3189dd441e4SAlex Elder /* Reserve some number of TREs on a channel. Returns true if successful */ 3199dd441e4SAlex Elder static bool 3209dd441e4SAlex Elder gsi_trans_tre_reserve(struct gsi_trans_info *trans_info, u32 tre_count) 3219dd441e4SAlex Elder { 3229dd441e4SAlex Elder int avail = atomic_read(&trans_info->tre_avail); 3239dd441e4SAlex Elder int new; 3249dd441e4SAlex Elder 3259dd441e4SAlex Elder do { 3269dd441e4SAlex Elder new = avail - (int)tre_count; 3279dd441e4SAlex Elder if (unlikely(new < 0)) 3289dd441e4SAlex Elder return false; 3299dd441e4SAlex Elder } while (!atomic_try_cmpxchg(&trans_info->tre_avail, &avail, new)); 3309dd441e4SAlex Elder 3319dd441e4SAlex Elder return true; 3329dd441e4SAlex Elder } 3339dd441e4SAlex Elder 3349dd441e4SAlex Elder /* Release previously-reserved TRE entries to a channel */ 3359dd441e4SAlex Elder static void 3369dd441e4SAlex Elder gsi_trans_tre_release(struct gsi_trans_info *trans_info, u32 tre_count) 3379dd441e4SAlex Elder { 3389dd441e4SAlex Elder atomic_add(tre_count, &trans_info->tre_avail); 3399dd441e4SAlex Elder } 3409dd441e4SAlex Elder 3415fc7f9baSAlex Elder /* Return true if no transactions are allocated, false otherwise */ 3425fc7f9baSAlex Elder bool gsi_channel_trans_idle(struct gsi *gsi, u32 channel_id) 3435fc7f9baSAlex Elder { 3445fc7f9baSAlex Elder u32 tre_max = gsi_channel_tre_max(gsi, channel_id); 3455fc7f9baSAlex Elder struct gsi_trans_info *trans_info; 3465fc7f9baSAlex Elder 3475fc7f9baSAlex Elder trans_info = &gsi->channel[channel_id].trans_info; 3485fc7f9baSAlex Elder 3495fc7f9baSAlex Elder return atomic_read(&trans_info->tre_avail) == tre_max; 3505fc7f9baSAlex Elder } 3515fc7f9baSAlex Elder 3529dd441e4SAlex Elder /* Allocate a GSI transaction on a channel */ 3539dd441e4SAlex Elder struct gsi_trans *gsi_channel_trans_alloc(struct gsi *gsi, u32 channel_id, 3549dd441e4SAlex Elder u32 tre_count, 3559dd441e4SAlex Elder enum dma_data_direction direction) 3569dd441e4SAlex Elder { 3579dd441e4SAlex Elder struct gsi_channel *channel = &gsi->channel[channel_id]; 3589dd441e4SAlex Elder struct gsi_trans_info *trans_info; 3599dd441e4SAlex Elder struct gsi_trans *trans; 36012382d11SAlex Elder u16 trans_index; 3619dd441e4SAlex Elder 36288e03057SAlex Elder if (WARN_ON(tre_count > channel->trans_tre_max)) 3635bc55884SAlex Elder return NULL; 3649dd441e4SAlex Elder 3659dd441e4SAlex Elder trans_info = &channel->trans_info; 3669dd441e4SAlex Elder 36712382d11SAlex Elder /* If we can't reserve the TREs for the transaction, we're done */ 3689dd441e4SAlex Elder if (!gsi_trans_tre_reserve(trans_info, tre_count)) 3699dd441e4SAlex Elder return NULL; 3709dd441e4SAlex Elder 37112382d11SAlex Elder trans_index = trans_info->free_id % channel->tre_count; 37212382d11SAlex Elder trans = &trans_info->trans[trans_index]; 37312382d11SAlex Elder memset(trans, 0, sizeof(*trans)); 37412382d11SAlex Elder 37512382d11SAlex Elder /* Initialize non-zero fields in the transaction */ 3769dd441e4SAlex Elder trans->gsi = gsi; 3779dd441e4SAlex Elder trans->channel_id = channel_id; 3783eeabea6SAlex Elder trans->rsvd_count = tre_count; 3799dd441e4SAlex Elder init_completion(&trans->completion); 3809dd441e4SAlex Elder 381616c4a83SAlex Elder /* Allocate the scatterlist */ 3829dd441e4SAlex Elder trans->sgl = gsi_trans_pool_alloc(&trans_info->sg_pool, tre_count); 3839dd441e4SAlex Elder sg_init_marker(trans->sgl, tre_count); 3849dd441e4SAlex Elder 3859dd441e4SAlex Elder trans->direction = direction; 38612382d11SAlex Elder refcount_set(&trans->refcount, 1); 38712382d11SAlex Elder 38812382d11SAlex Elder /* This free transaction will now be allocated */ 38912382d11SAlex Elder trans_info->free_id++; 3909dd441e4SAlex Elder 3919dd441e4SAlex Elder spin_lock_bh(&trans_info->spinlock); 3929dd441e4SAlex Elder 3939dd441e4SAlex Elder list_add_tail(&trans->links, &trans_info->alloc); 3949dd441e4SAlex Elder 395*41e2a2c0SAlex Elder trans = list_first_entry(&trans_info->alloc, struct gsi_trans, links); 396*41e2a2c0SAlex Elder 3979dd441e4SAlex Elder spin_unlock_bh(&trans_info->spinlock); 3989dd441e4SAlex Elder 399*41e2a2c0SAlex Elder WARN_ON(trans_info->allocated_id == trans_info->free_id); 400*41e2a2c0SAlex Elder trans_index = trans_info->allocated_id % channel->tre_count; 401*41e2a2c0SAlex Elder WARN_ON(trans != &trans_info->trans[trans_index]); 402*41e2a2c0SAlex Elder 4039dd441e4SAlex Elder return trans; 4049dd441e4SAlex Elder } 4059dd441e4SAlex Elder 406064c9c32SAlex Elder /* Free a previously-allocated transaction */ 4079dd441e4SAlex Elder void gsi_trans_free(struct gsi_trans *trans) 4089dd441e4SAlex Elder { 409064c9c32SAlex Elder refcount_t *refcount = &trans->refcount; 4109dd441e4SAlex Elder struct gsi_trans_info *trans_info; 411064c9c32SAlex Elder bool last; 4129dd441e4SAlex Elder 413064c9c32SAlex Elder /* We must hold the lock to release the last reference */ 414064c9c32SAlex Elder if (refcount_dec_not_one(refcount)) 4159dd441e4SAlex Elder return; 4169dd441e4SAlex Elder 4179dd441e4SAlex Elder trans_info = &trans->gsi->channel[trans->channel_id].trans_info; 4189dd441e4SAlex Elder 4199dd441e4SAlex Elder spin_lock_bh(&trans_info->spinlock); 4209dd441e4SAlex Elder 421064c9c32SAlex Elder /* Reference might have been added before we got the lock */ 422064c9c32SAlex Elder last = refcount_dec_and_test(refcount); 423064c9c32SAlex Elder if (last) 4249dd441e4SAlex Elder list_del(&trans->links); 4259dd441e4SAlex Elder 4269dd441e4SAlex Elder spin_unlock_bh(&trans_info->spinlock); 4279dd441e4SAlex Elder 428064c9c32SAlex Elder if (!last) 429064c9c32SAlex Elder return; 430064c9c32SAlex Elder 431*41e2a2c0SAlex Elder /* Unused transactions are allocated but never committed */ 432*41e2a2c0SAlex Elder if (!trans->used_count) 433*41e2a2c0SAlex Elder trans_info->allocated_id++; 434*41e2a2c0SAlex Elder else 4359dd441e4SAlex Elder ipa_gsi_trans_release(trans); 4369dd441e4SAlex Elder 4379dd441e4SAlex Elder /* Releasing the reserved TREs implicitly frees the sgl[] and 4389dd441e4SAlex Elder * (if present) info[] arrays, plus the transaction itself. 4399dd441e4SAlex Elder */ 4403eeabea6SAlex Elder gsi_trans_tre_release(trans_info, trans->rsvd_count); 4419dd441e4SAlex Elder } 4429dd441e4SAlex Elder 4439dd441e4SAlex Elder /* Add an immediate command to a transaction */ 4449dd441e4SAlex Elder void gsi_trans_cmd_add(struct gsi_trans *trans, void *buf, u32 size, 4454de284b7SAlex Elder dma_addr_t addr, enum ipa_cmd_opcode opcode) 4469dd441e4SAlex Elder { 4473eeabea6SAlex Elder u32 which = trans->used_count++; 4489dd441e4SAlex Elder struct scatterlist *sg; 4499dd441e4SAlex Elder 4503eeabea6SAlex Elder WARN_ON(which >= trans->rsvd_count); 4519dd441e4SAlex Elder 452df833050SAlex Elder /* Commands are quite different from data transfer requests. 453df833050SAlex Elder * Their payloads come from a pool whose memory is allocated 454df833050SAlex Elder * using dma_alloc_coherent(). We therefore do *not* map them 455df833050SAlex Elder * for DMA (unlike what we do for pages and skbs). 456df833050SAlex Elder * 457df833050SAlex Elder * When a transaction completes, the SGL is normally unmapped. 458df833050SAlex Elder * A command transaction has direction DMA_NONE, which tells 459df833050SAlex Elder * gsi_trans_complete() to skip the unmapping step. 460df833050SAlex Elder * 461df833050SAlex Elder * The only things we use directly in a command scatter/gather 462df833050SAlex Elder * entry are the DMA address and length. We still need the SG 463df833050SAlex Elder * table flags to be maintained though, so assign a NULL page 464df833050SAlex Elder * pointer for that purpose. 4659dd441e4SAlex Elder */ 4669dd441e4SAlex Elder sg = &trans->sgl[which]; 467df833050SAlex Elder sg_assign_page(sg, NULL); 4689dd441e4SAlex Elder sg_dma_address(sg) = addr; 469df833050SAlex Elder sg_dma_len(sg) = size; 4709dd441e4SAlex Elder 4718797972aSAlex Elder trans->cmd_opcode[which] = opcode; 4729dd441e4SAlex Elder } 4739dd441e4SAlex Elder 4749dd441e4SAlex Elder /* Add a page transfer to a transaction. It will fill the only TRE. */ 4759dd441e4SAlex Elder int gsi_trans_page_add(struct gsi_trans *trans, struct page *page, u32 size, 4769dd441e4SAlex Elder u32 offset) 4779dd441e4SAlex Elder { 4789dd441e4SAlex Elder struct scatterlist *sg = &trans->sgl[0]; 4799dd441e4SAlex Elder int ret; 4809dd441e4SAlex Elder 4813eeabea6SAlex Elder if (WARN_ON(trans->rsvd_count != 1)) 4825bc55884SAlex Elder return -EINVAL; 4833eeabea6SAlex Elder if (WARN_ON(trans->used_count)) 4845bc55884SAlex Elder return -EINVAL; 4859dd441e4SAlex Elder 4869dd441e4SAlex Elder sg_set_page(sg, page, size, offset); 4879dd441e4SAlex Elder ret = dma_map_sg(trans->gsi->dev, sg, 1, trans->direction); 4889dd441e4SAlex Elder if (!ret) 4899dd441e4SAlex Elder return -ENOMEM; 4909dd441e4SAlex Elder 4913eeabea6SAlex Elder trans->used_count++; /* Transaction now owns the (DMA mapped) page */ 4929dd441e4SAlex Elder 4939dd441e4SAlex Elder return 0; 4949dd441e4SAlex Elder } 4959dd441e4SAlex Elder 4969dd441e4SAlex Elder /* Add an SKB transfer to a transaction. No other TREs will be used. */ 4979dd441e4SAlex Elder int gsi_trans_skb_add(struct gsi_trans *trans, struct sk_buff *skb) 4989dd441e4SAlex Elder { 4999dd441e4SAlex Elder struct scatterlist *sg = &trans->sgl[0]; 5003eeabea6SAlex Elder u32 used_count; 5019dd441e4SAlex Elder int ret; 5029dd441e4SAlex Elder 5033eeabea6SAlex Elder if (WARN_ON(trans->rsvd_count != 1)) 5045bc55884SAlex Elder return -EINVAL; 5053eeabea6SAlex Elder if (WARN_ON(trans->used_count)) 5065bc55884SAlex Elder return -EINVAL; 5079dd441e4SAlex Elder 5089dd441e4SAlex Elder /* skb->len will not be 0 (checked early) */ 5099dd441e4SAlex Elder ret = skb_to_sgvec(skb, sg, 0, skb->len); 5109dd441e4SAlex Elder if (ret < 0) 5119dd441e4SAlex Elder return ret; 5123eeabea6SAlex Elder used_count = ret; 5139dd441e4SAlex Elder 5143eeabea6SAlex Elder ret = dma_map_sg(trans->gsi->dev, sg, used_count, trans->direction); 5159dd441e4SAlex Elder if (!ret) 5169dd441e4SAlex Elder return -ENOMEM; 5179dd441e4SAlex Elder 5183eeabea6SAlex Elder /* Transaction now owns the (DMA mapped) skb */ 5193eeabea6SAlex Elder trans->used_count += used_count; 5209dd441e4SAlex Elder 5219dd441e4SAlex Elder return 0; 5229dd441e4SAlex Elder } 5239dd441e4SAlex Elder 5249dd441e4SAlex Elder /* Compute the length/opcode value to use for a TRE */ 5259dd441e4SAlex Elder static __le16 gsi_tre_len_opcode(enum ipa_cmd_opcode opcode, u32 len) 5269dd441e4SAlex Elder { 5279dd441e4SAlex Elder return opcode == IPA_CMD_NONE ? cpu_to_le16((u16)len) 5289dd441e4SAlex Elder : cpu_to_le16((u16)opcode); 5299dd441e4SAlex Elder } 5309dd441e4SAlex Elder 5319dd441e4SAlex Elder /* Compute the flags value to use for a given TRE */ 5329dd441e4SAlex Elder static __le32 gsi_tre_flags(bool last_tre, bool bei, enum ipa_cmd_opcode opcode) 5339dd441e4SAlex Elder { 5349dd441e4SAlex Elder enum gsi_tre_type tre_type; 5359dd441e4SAlex Elder u32 tre_flags; 5369dd441e4SAlex Elder 5379dd441e4SAlex Elder tre_type = opcode == IPA_CMD_NONE ? GSI_RE_XFER : GSI_RE_IMMD_CMD; 5389dd441e4SAlex Elder tre_flags = u32_encode_bits(tre_type, TRE_FLAGS_TYPE_FMASK); 5399dd441e4SAlex Elder 5409dd441e4SAlex Elder /* Last TRE contains interrupt flags */ 5419dd441e4SAlex Elder if (last_tre) { 5429dd441e4SAlex Elder /* All transactions end in a transfer completion interrupt */ 5439dd441e4SAlex Elder tre_flags |= TRE_FLAGS_IEOT_FMASK; 5449dd441e4SAlex Elder /* Don't interrupt when outbound commands are acknowledged */ 5459dd441e4SAlex Elder if (bei) 5469dd441e4SAlex Elder tre_flags |= TRE_FLAGS_BEI_FMASK; 5479dd441e4SAlex Elder } else { /* All others indicate there's more to come */ 5489dd441e4SAlex Elder tre_flags |= TRE_FLAGS_CHAIN_FMASK; 5499dd441e4SAlex Elder } 5509dd441e4SAlex Elder 5519dd441e4SAlex Elder return cpu_to_le32(tre_flags); 5529dd441e4SAlex Elder } 5539dd441e4SAlex Elder 5549dd441e4SAlex Elder static void gsi_trans_tre_fill(struct gsi_tre *dest_tre, dma_addr_t addr, 5559dd441e4SAlex Elder u32 len, bool last_tre, bool bei, 5569dd441e4SAlex Elder enum ipa_cmd_opcode opcode) 5579dd441e4SAlex Elder { 5589dd441e4SAlex Elder struct gsi_tre tre; 5599dd441e4SAlex Elder 5609dd441e4SAlex Elder tre.addr = cpu_to_le64(addr); 5619dd441e4SAlex Elder tre.len_opcode = gsi_tre_len_opcode(opcode, len); 5629dd441e4SAlex Elder tre.reserved = 0; 5639dd441e4SAlex Elder tre.flags = gsi_tre_flags(last_tre, bei, opcode); 5649dd441e4SAlex Elder 5659dd441e4SAlex Elder /* ARM64 can write 16 bytes as a unit with a single instruction. 5669dd441e4SAlex Elder * Doing the assignment this way is an attempt to make that happen. 5679dd441e4SAlex Elder */ 5689dd441e4SAlex Elder *dest_tre = tre; 5699dd441e4SAlex Elder } 5709dd441e4SAlex Elder 5719dd441e4SAlex Elder /** 5729dd441e4SAlex Elder * __gsi_trans_commit() - Common GSI transaction commit code 5739dd441e4SAlex Elder * @trans: Transaction to commit 5749dd441e4SAlex Elder * @ring_db: Whether to tell the hardware about these queued transfers 5759dd441e4SAlex Elder * 5769dd441e4SAlex Elder * Formats channel ring TRE entries based on the content of the scatterlist. 5779dd441e4SAlex Elder * Maps a transaction pointer to the last ring entry used for the transaction, 5789dd441e4SAlex Elder * so it can be recovered when it completes. Moves the transaction to the 5799dd441e4SAlex Elder * pending list. Finally, updates the channel ring pointer and optionally 5809dd441e4SAlex Elder * rings the doorbell. 5819dd441e4SAlex Elder */ 5829dd441e4SAlex Elder static void __gsi_trans_commit(struct gsi_trans *trans, bool ring_db) 5839dd441e4SAlex Elder { 5849dd441e4SAlex Elder struct gsi_channel *channel = &trans->gsi->channel[trans->channel_id]; 5852295947bSAlex Elder struct gsi_ring *tre_ring = &channel->tre_ring; 5869dd441e4SAlex Elder enum ipa_cmd_opcode opcode = IPA_CMD_NONE; 5879dd441e4SAlex Elder bool bei = channel->toward_ipa; 5889dd441e4SAlex Elder struct gsi_tre *dest_tre; 5899dd441e4SAlex Elder struct scatterlist *sg; 5909dd441e4SAlex Elder u32 byte_count = 0; 5918797972aSAlex Elder u8 *cmd_opcode; 5929dd441e4SAlex Elder u32 avail; 5939dd441e4SAlex Elder u32 i; 5949dd441e4SAlex Elder 5953eeabea6SAlex Elder WARN_ON(!trans->used_count); 5969dd441e4SAlex Elder 5979dd441e4SAlex Elder /* Consume the entries. If we cross the end of the ring while 5989dd441e4SAlex Elder * filling them we'll switch to the beginning to finish. 5999dd441e4SAlex Elder * If there is no info array we're doing a simple data 6009dd441e4SAlex Elder * transfer request, whose opcode is IPA_CMD_NONE. 6019dd441e4SAlex Elder */ 6028797972aSAlex Elder cmd_opcode = channel->command ? &trans->cmd_opcode[0] : NULL; 6032295947bSAlex Elder avail = tre_ring->count - tre_ring->index % tre_ring->count; 6042295947bSAlex Elder dest_tre = gsi_ring_virt(tre_ring, tre_ring->index); 6053eeabea6SAlex Elder for_each_sg(trans->sgl, sg, trans->used_count, i) { 6063eeabea6SAlex Elder bool last_tre = i == trans->used_count - 1; 6079dd441e4SAlex Elder dma_addr_t addr = sg_dma_address(sg); 6089dd441e4SAlex Elder u32 len = sg_dma_len(sg); 6099dd441e4SAlex Elder 6109dd441e4SAlex Elder byte_count += len; 6119dd441e4SAlex Elder if (!avail--) 6122295947bSAlex Elder dest_tre = gsi_ring_virt(tre_ring, 0); 6138797972aSAlex Elder if (cmd_opcode) 6148797972aSAlex Elder opcode = *cmd_opcode++; 6159dd441e4SAlex Elder 6169dd441e4SAlex Elder gsi_trans_tre_fill(dest_tre, addr, len, last_tre, bei, opcode); 6179dd441e4SAlex Elder dest_tre++; 6189dd441e4SAlex Elder } 6198eec7831SAlex Elder /* Associate the TRE with the transaction */ 6208eec7831SAlex Elder gsi_trans_map(trans, tre_ring->index); 6218eec7831SAlex Elder 6223eeabea6SAlex Elder tre_ring->index += trans->used_count; 6239dd441e4SAlex Elder 6249dd441e4SAlex Elder trans->len = byte_count; 6254e0f28e9SAlex Elder if (channel->toward_ipa) 6264e0f28e9SAlex Elder gsi_trans_tx_committed(trans); 6279dd441e4SAlex Elder 628b63f507cSAlex Elder gsi_trans_move_committed(trans); 6299dd441e4SAlex Elder 6309dd441e4SAlex Elder /* Ring doorbell if requested, or if all TREs are allocated */ 6319dd441e4SAlex Elder if (ring_db || !atomic_read(&channel->trans_info.tre_avail)) { 6329dd441e4SAlex Elder /* Report what we're handing off to hardware for TX channels */ 6339dd441e4SAlex Elder if (channel->toward_ipa) 634bcec9ecbSAlex Elder gsi_trans_tx_queued(trans); 635b63f507cSAlex Elder gsi_trans_move_pending(trans); 6369dd441e4SAlex Elder gsi_channel_doorbell(channel); 6379dd441e4SAlex Elder } 6389dd441e4SAlex Elder } 6399dd441e4SAlex Elder 6409dd441e4SAlex Elder /* Commit a GSI transaction */ 6419dd441e4SAlex Elder void gsi_trans_commit(struct gsi_trans *trans, bool ring_db) 6429dd441e4SAlex Elder { 6433eeabea6SAlex Elder if (trans->used_count) 6449dd441e4SAlex Elder __gsi_trans_commit(trans, ring_db); 6459dd441e4SAlex Elder else 6469dd441e4SAlex Elder gsi_trans_free(trans); 6479dd441e4SAlex Elder } 6489dd441e4SAlex Elder 6499dd441e4SAlex Elder /* Commit a GSI transaction and wait for it to complete */ 6509dd441e4SAlex Elder void gsi_trans_commit_wait(struct gsi_trans *trans) 6519dd441e4SAlex Elder { 6523eeabea6SAlex Elder if (!trans->used_count) 6539dd441e4SAlex Elder goto out_trans_free; 6549dd441e4SAlex Elder 6559dd441e4SAlex Elder refcount_inc(&trans->refcount); 6569dd441e4SAlex Elder 6579dd441e4SAlex Elder __gsi_trans_commit(trans, true); 6589dd441e4SAlex Elder 6599dd441e4SAlex Elder wait_for_completion(&trans->completion); 6609dd441e4SAlex Elder 6619dd441e4SAlex Elder out_trans_free: 6629dd441e4SAlex Elder gsi_trans_free(trans); 6639dd441e4SAlex Elder } 6649dd441e4SAlex Elder 6659dd441e4SAlex Elder /* Process the completion of a transaction; called while polling */ 6669dd441e4SAlex Elder void gsi_trans_complete(struct gsi_trans *trans) 6679dd441e4SAlex Elder { 6689dd441e4SAlex Elder /* If the entire SGL was mapped when added, unmap it now */ 6699dd441e4SAlex Elder if (trans->direction != DMA_NONE) 6703eeabea6SAlex Elder dma_unmap_sg(trans->gsi->dev, trans->sgl, trans->used_count, 6719dd441e4SAlex Elder trans->direction); 6729dd441e4SAlex Elder 6739dd441e4SAlex Elder ipa_gsi_trans_complete(trans); 6749dd441e4SAlex Elder 6759dd441e4SAlex Elder complete(&trans->completion); 6769dd441e4SAlex Elder 6779dd441e4SAlex Elder gsi_trans_free(trans); 6789dd441e4SAlex Elder } 6799dd441e4SAlex Elder 6809dd441e4SAlex Elder /* Cancel a channel's pending transactions */ 6819dd441e4SAlex Elder void gsi_channel_trans_cancel_pending(struct gsi_channel *channel) 6829dd441e4SAlex Elder { 6839dd441e4SAlex Elder struct gsi_trans_info *trans_info = &channel->trans_info; 6849dd441e4SAlex Elder struct gsi_trans *trans; 6859dd441e4SAlex Elder bool cancelled; 6869dd441e4SAlex Elder 6879dd441e4SAlex Elder /* channel->gsi->mutex is held by caller */ 6889dd441e4SAlex Elder spin_lock_bh(&trans_info->spinlock); 6899dd441e4SAlex Elder 6909dd441e4SAlex Elder cancelled = !list_empty(&trans_info->pending); 6919dd441e4SAlex Elder list_for_each_entry(trans, &trans_info->pending, links) 6929dd441e4SAlex Elder trans->cancelled = true; 6939dd441e4SAlex Elder 6949dd441e4SAlex Elder list_splice_tail_init(&trans_info->pending, &trans_info->complete); 6959dd441e4SAlex Elder 6969dd441e4SAlex Elder spin_unlock_bh(&trans_info->spinlock); 6979dd441e4SAlex Elder 6989dd441e4SAlex Elder /* Schedule NAPI polling to complete the cancelled transactions */ 6999dd441e4SAlex Elder if (cancelled) 7009dd441e4SAlex Elder napi_schedule(&channel->napi); 7019dd441e4SAlex Elder } 7029dd441e4SAlex Elder 7039dd441e4SAlex Elder /* Issue a command to read a single byte from a channel */ 7049dd441e4SAlex Elder int gsi_trans_read_byte(struct gsi *gsi, u32 channel_id, dma_addr_t addr) 7059dd441e4SAlex Elder { 7069dd441e4SAlex Elder struct gsi_channel *channel = &gsi->channel[channel_id]; 7072295947bSAlex Elder struct gsi_ring *tre_ring = &channel->tre_ring; 7089dd441e4SAlex Elder struct gsi_trans_info *trans_info; 7099dd441e4SAlex Elder struct gsi_tre *dest_tre; 7109dd441e4SAlex Elder 7119dd441e4SAlex Elder trans_info = &channel->trans_info; 7129dd441e4SAlex Elder 7139dd441e4SAlex Elder /* First reserve the TRE, if possible */ 7149dd441e4SAlex Elder if (!gsi_trans_tre_reserve(trans_info, 1)) 7159dd441e4SAlex Elder return -EBUSY; 7169dd441e4SAlex Elder 7177c0d97e4SJiang Jian /* Now fill the reserved TRE and tell the hardware */ 7189dd441e4SAlex Elder 7192295947bSAlex Elder dest_tre = gsi_ring_virt(tre_ring, tre_ring->index); 7209dd441e4SAlex Elder gsi_trans_tre_fill(dest_tre, addr, 1, true, false, IPA_CMD_NONE); 7219dd441e4SAlex Elder 7222295947bSAlex Elder tre_ring->index++; 7239dd441e4SAlex Elder gsi_channel_doorbell(channel); 7249dd441e4SAlex Elder 7259dd441e4SAlex Elder return 0; 7269dd441e4SAlex Elder } 7279dd441e4SAlex Elder 7289dd441e4SAlex Elder /* Mark a gsi_trans_read_byte() request done */ 7299dd441e4SAlex Elder void gsi_trans_read_byte_done(struct gsi *gsi, u32 channel_id) 7309dd441e4SAlex Elder { 7319dd441e4SAlex Elder struct gsi_channel *channel = &gsi->channel[channel_id]; 7329dd441e4SAlex Elder 7339dd441e4SAlex Elder gsi_trans_tre_release(&channel->trans_info, 1); 7349dd441e4SAlex Elder } 7359dd441e4SAlex Elder 7369dd441e4SAlex Elder /* Initialize a channel's GSI transaction info */ 7379dd441e4SAlex Elder int gsi_channel_trans_init(struct gsi *gsi, u32 channel_id) 7389dd441e4SAlex Elder { 7399dd441e4SAlex Elder struct gsi_channel *channel = &gsi->channel[channel_id]; 74049200658SAlex Elder u32 tre_count = channel->tre_count; 7419dd441e4SAlex Elder struct gsi_trans_info *trans_info; 7429dd441e4SAlex Elder u32 tre_max; 7439dd441e4SAlex Elder int ret; 7449dd441e4SAlex Elder 7459dd441e4SAlex Elder /* Ensure the size of a channel element is what's expected */ 7469dd441e4SAlex Elder BUILD_BUG_ON(sizeof(struct gsi_tre) != GSI_RING_ELEMENT_SIZE); 7479dd441e4SAlex Elder 7489dd441e4SAlex Elder trans_info = &channel->trans_info; 7499dd441e4SAlex Elder 75049200658SAlex Elder /* The tre_avail field is what ultimately limits the number of 75149200658SAlex Elder * outstanding transactions and their resources. A transaction 75249200658SAlex Elder * allocation succeeds only if the TREs available are sufficient 75349200658SAlex Elder * for what the transaction might need. 7549dd441e4SAlex Elder */ 7559dd441e4SAlex Elder tre_max = gsi_channel_tre_max(channel->gsi, channel_id); 75649200658SAlex Elder atomic_set(&trans_info->tre_avail, tre_max); 7579dd441e4SAlex Elder 75849200658SAlex Elder /* We can't use more TREs than the number available in the ring. 75949200658SAlex Elder * This limits the number of transactions that can be outstanding. 76049200658SAlex Elder * Worst case is one TRE per transaction (but we actually limit 76149200658SAlex Elder * it to something a little less than that). By allocating a 76249200658SAlex Elder * power-of-two number of transactions we can use an index 76349200658SAlex Elder * modulo that number to determine the next one that's free. 76449200658SAlex Elder * Transactions are allocated one at a time. 76549200658SAlex Elder */ 76612382d11SAlex Elder trans_info->trans = kcalloc(tre_count, sizeof(*trans_info->trans), 76712382d11SAlex Elder GFP_KERNEL); 76812382d11SAlex Elder if (!trans_info->trans) 76949200658SAlex Elder return -ENOMEM; 770*41e2a2c0SAlex Elder trans_info->free_id = 0; /* all modulo channel->tre_count */ 771*41e2a2c0SAlex Elder trans_info->allocated_id = 0; 77249200658SAlex Elder 77349200658SAlex Elder /* A completion event contains a pointer to the TRE that caused 77449200658SAlex Elder * the event (which will be the last one used by the transaction). 77549200658SAlex Elder * Each entry in this map records the transaction associated 77649200658SAlex Elder * with a corresponding completed TRE. 77749200658SAlex Elder */ 77849200658SAlex Elder trans_info->map = kcalloc(tre_count, sizeof(*trans_info->map), 77949200658SAlex Elder GFP_KERNEL); 78049200658SAlex Elder if (!trans_info->map) { 78149200658SAlex Elder ret = -ENOMEM; 78249200658SAlex Elder goto err_trans_free; 78349200658SAlex Elder } 7849dd441e4SAlex Elder 7859dd441e4SAlex Elder /* A transaction uses a scatterlist array to represent the data 7869dd441e4SAlex Elder * transfers implemented by the transaction. Each scatterlist 7879dd441e4SAlex Elder * element is used to fill a single TRE when the transaction is 7889dd441e4SAlex Elder * committed. So we need as many scatterlist elements as the 7899dd441e4SAlex Elder * maximum number of TREs that can be outstanding. 7909dd441e4SAlex Elder */ 7919dd441e4SAlex Elder ret = gsi_trans_pool_init(&trans_info->sg_pool, 7929dd441e4SAlex Elder sizeof(struct scatterlist), 79388e03057SAlex Elder tre_max, channel->trans_tre_max); 7949dd441e4SAlex Elder if (ret) 79549200658SAlex Elder goto err_map_free; 7969dd441e4SAlex Elder 7979dd441e4SAlex Elder spin_lock_init(&trans_info->spinlock); 7989dd441e4SAlex Elder INIT_LIST_HEAD(&trans_info->alloc); 799b63f507cSAlex Elder INIT_LIST_HEAD(&trans_info->committed); 8009dd441e4SAlex Elder INIT_LIST_HEAD(&trans_info->pending); 8019dd441e4SAlex Elder INIT_LIST_HEAD(&trans_info->complete); 8029dd441e4SAlex Elder INIT_LIST_HEAD(&trans_info->polled); 8039dd441e4SAlex Elder 8049dd441e4SAlex Elder return 0; 8059dd441e4SAlex Elder 80649200658SAlex Elder err_map_free: 8079dd441e4SAlex Elder kfree(trans_info->map); 80849200658SAlex Elder err_trans_free: 80912382d11SAlex Elder kfree(trans_info->trans); 8109dd441e4SAlex Elder 8119dd441e4SAlex Elder dev_err(gsi->dev, "error %d initializing channel %u transactions\n", 8129dd441e4SAlex Elder ret, channel_id); 8139dd441e4SAlex Elder 8149dd441e4SAlex Elder return ret; 8159dd441e4SAlex Elder } 8169dd441e4SAlex Elder 8179dd441e4SAlex Elder /* Inverse of gsi_channel_trans_init() */ 8189dd441e4SAlex Elder void gsi_channel_trans_exit(struct gsi_channel *channel) 8199dd441e4SAlex Elder { 8209dd441e4SAlex Elder struct gsi_trans_info *trans_info = &channel->trans_info; 8219dd441e4SAlex Elder 8229dd441e4SAlex Elder gsi_trans_pool_exit(&trans_info->sg_pool); 82312382d11SAlex Elder kfree(trans_info->trans); 8249dd441e4SAlex Elder kfree(trans_info->map); 8259dd441e4SAlex Elder } 826