| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Dmaengine driver base library for DMA controllers, found on SH-based SoCs |
| * |
| * extracted from shdma.c |
| * |
| * Copyright (C) 2011-2012 Guennadi Liakhovetski <g.liakhovetski@gmx.de> |
| * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com> |
| * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved. |
| * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved. |
| */ |
| |
| #include <linux/delay.h> |
| #include <linux/shdma-base.h> |
| #include <linux/dmaengine.h> |
| #include <linux/init.h> |
| #include <linux/interrupt.h> |
| #include <linux/module.h> |
| #include <linux/pm_runtime.h> |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| |
| #include "../dmaengine.h" |
| |
| /* DMA descriptor control */ |
| enum shdma_desc_status { |
| DESC_IDLE, |
| DESC_PREPARED, |
| DESC_SUBMITTED, |
| DESC_COMPLETED, /* completed, have to call callback */ |
| DESC_WAITING, /* callback called, waiting for ack / re-submit */ |
| }; |
| |
| #define NR_DESCS_PER_CHANNEL 32 |
| |
| #define to_shdma_chan(c) container_of(c, struct shdma_chan, dma_chan) |
| #define to_shdma_dev(d) container_of(d, struct shdma_dev, dma_dev) |
| |
| /* |
| * For slave DMA we assume, that there is a finite number of DMA slaves in the |
| * system, and that each such slave can only use a finite number of channels. |
| * We use slave channel IDs to make sure, that no such slave channel ID is |
| * allocated more than once. |
| */ |
| static unsigned int slave_num = 256; |
| module_param(slave_num, uint, 0444); |
| |
| /* A bitmask with slave_num bits */ |
| static unsigned long *shdma_slave_used; |
| |
| /* Called under spin_lock_irq(&schan->chan_lock") */ |
| static void shdma_chan_xfer_ld_queue(struct shdma_chan *schan) |
| { |
| struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); |
| const struct shdma_ops *ops = sdev->ops; |
| struct shdma_desc *sdesc; |
| |
| /* DMA work check */ |
| if (ops->channel_busy(schan)) |
| return; |
| |
| /* Find the first not transferred descriptor */ |
| list_for_each_entry(sdesc, &schan->ld_queue, node) |
| if (sdesc->mark == DESC_SUBMITTED) { |
| ops->start_xfer(schan, sdesc); |
| break; |
| } |
| } |
| |
| static dma_cookie_t shdma_tx_submit(struct dma_async_tx_descriptor *tx) |
| { |
| struct shdma_desc *chunk, *c, *desc = |
| container_of(tx, struct shdma_desc, async_tx); |
| struct shdma_chan *schan = to_shdma_chan(tx->chan); |
| dma_async_tx_callback callback = tx->callback; |
| dma_cookie_t cookie; |
| bool power_up; |
| |
| spin_lock_irq(&schan->chan_lock); |
| |
| power_up = list_empty(&schan->ld_queue); |
| |
| cookie = dma_cookie_assign(tx); |
| |
| /* Mark all chunks of this descriptor as submitted, move to the queue */ |
| list_for_each_entry_safe(chunk, c, desc->node.prev, node) { |
| /* |
| * All chunks are on the global ld_free, so, we have to find |
| * the end of the chain ourselves |
| */ |
| if (chunk != desc && (chunk->mark == DESC_IDLE || |
| chunk->async_tx.cookie > 0 || |
| chunk->async_tx.cookie == -EBUSY || |
| &chunk->node == &schan->ld_free)) |
| break; |
| chunk->mark = DESC_SUBMITTED; |
| if (chunk->chunks == 1) { |
| chunk->async_tx.callback = callback; |
| chunk->async_tx.callback_param = tx->callback_param; |
| } else { |
| /* Callback goes to the last chunk */ |
| chunk->async_tx.callback = NULL; |
| } |
| chunk->cookie = cookie; |
| list_move_tail(&chunk->node, &schan->ld_queue); |
| |
| dev_dbg(schan->dev, "submit #%d@%p on %d\n", |
| tx->cookie, &chunk->async_tx, schan->id); |
| } |
| |
| if (power_up) { |
| int ret; |
| schan->pm_state = SHDMA_PM_BUSY; |
| |
| ret = pm_runtime_get(schan->dev); |
| |
| spin_unlock_irq(&schan->chan_lock); |
| if (ret < 0) |
| dev_err(schan->dev, "%s(): GET = %d\n", __func__, ret); |
| |
| pm_runtime_barrier(schan->dev); |
| |
| spin_lock_irq(&schan->chan_lock); |
| |
| /* Have we been reset, while waiting? */ |
| if (schan->pm_state != SHDMA_PM_ESTABLISHED) { |
| struct shdma_dev *sdev = |
| to_shdma_dev(schan->dma_chan.device); |
| const struct shdma_ops *ops = sdev->ops; |
| dev_dbg(schan->dev, "Bring up channel %d\n", |
| schan->id); |
| /* |
| * TODO: .xfer_setup() might fail on some platforms. |
| * Make it int then, on error remove chunks from the |
| * queue again |
| */ |
| ops->setup_xfer(schan, schan->slave_id); |
| |
| if (schan->pm_state == SHDMA_PM_PENDING) |
| shdma_chan_xfer_ld_queue(schan); |
| schan->pm_state = SHDMA_PM_ESTABLISHED; |
| } |
| } else { |
| /* |
| * Tell .device_issue_pending() not to run the queue, interrupts |
| * will do it anyway |
| */ |
| schan->pm_state = SHDMA_PM_PENDING; |
| } |
| |
| spin_unlock_irq(&schan->chan_lock); |
| |
| return cookie; |
| } |
| |
| /* Called with desc_lock held */ |
| static struct shdma_desc *shdma_get_desc(struct shdma_chan *schan) |
| { |
| struct shdma_desc *sdesc; |
| |
| list_for_each_entry(sdesc, &schan->ld_free, node) |
| if (sdesc->mark != DESC_PREPARED) { |
| BUG_ON(sdesc->mark != DESC_IDLE); |
| list_del(&sdesc->node); |
| return sdesc; |
| } |
| |
| return NULL; |
| } |
| |
| static int shdma_setup_slave(struct shdma_chan *schan, dma_addr_t slave_addr) |
| { |
| struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); |
| const struct shdma_ops *ops = sdev->ops; |
| int ret, match; |
| |
| if (schan->dev->of_node) { |
| match = schan->hw_req; |
| ret = ops->set_slave(schan, match, slave_addr, true); |
| if (ret < 0) |
| return ret; |
| } else { |
| match = schan->real_slave_id; |
| } |
| |
| if (schan->real_slave_id < 0 || schan->real_slave_id >= slave_num) |
| return -EINVAL; |
| |
| if (test_and_set_bit(schan->real_slave_id, shdma_slave_used)) |
| return -EBUSY; |
| |
| ret = ops->set_slave(schan, match, slave_addr, false); |
| if (ret < 0) { |
| clear_bit(schan->real_slave_id, shdma_slave_used); |
| return ret; |
| } |
| |
| schan->slave_id = schan->real_slave_id; |
| |
| return 0; |
| } |
| |
| static int shdma_alloc_chan_resources(struct dma_chan *chan) |
| { |
| struct shdma_chan *schan = to_shdma_chan(chan); |
| struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); |
| const struct shdma_ops *ops = sdev->ops; |
| struct shdma_desc *desc; |
| struct shdma_slave *slave = chan->private; |
| int ret, i; |
| |
| /* |
| * This relies on the guarantee from dmaengine that alloc_chan_resources |
| * never runs concurrently with itself or free_chan_resources. |
| */ |
| if (slave) { |
| /* Legacy mode: .private is set in filter */ |
| schan->real_slave_id = slave->slave_id; |
| ret = shdma_setup_slave(schan, 0); |
| if (ret < 0) |
| goto esetslave; |
| } else { |
| /* Normal mode: real_slave_id was set by filter */ |
| schan->slave_id = -EINVAL; |
| } |
| |
| schan->desc = kcalloc(NR_DESCS_PER_CHANNEL, |
| sdev->desc_size, GFP_KERNEL); |
| if (!schan->desc) { |
| ret = -ENOMEM; |
| goto edescalloc; |
| } |
| schan->desc_num = NR_DESCS_PER_CHANNEL; |
| |
| for (i = 0; i < NR_DESCS_PER_CHANNEL; i++) { |
| desc = ops->embedded_desc(schan->desc, i); |
| dma_async_tx_descriptor_init(&desc->async_tx, |
| &schan->dma_chan); |
| desc->async_tx.tx_submit = shdma_tx_submit; |
| desc->mark = DESC_IDLE; |
| |
| list_add(&desc->node, &schan->ld_free); |
| } |
| |
| return NR_DESCS_PER_CHANNEL; |
| |
| edescalloc: |
| if (slave) |
| esetslave: |
| clear_bit(slave->slave_id, shdma_slave_used); |
| chan->private = NULL; |
| return ret; |
| } |
| |
| /* |
| * This is the standard shdma filter function to be used as a replacement to the |
| * "old" method, using the .private pointer. |
| * You always have to pass a valid slave id as the argument, old drivers that |
| * pass ERR_PTR(-EINVAL) as a filter parameter and set it up in dma_slave_config |
| * need to be updated so we can remove the slave_id field from dma_slave_config. |
| * parameter. If this filter is used, the slave driver, after calling |
| * dma_request_channel(), will also have to call dmaengine_slave_config() with |
| * .direction, and either .src_addr or .dst_addr set. |
| * |
| * NOTE: this filter doesn't support multiple DMAC drivers with the DMA_SLAVE |
| * capability! If this becomes a requirement, hardware glue drivers, using this |
| * services would have to provide their own filters, which first would check |
| * the device driver, similar to how other DMAC drivers, e.g., sa11x0-dma.c, do |
| * this, and only then, in case of a match, call this common filter. |
| * NOTE 2: This filter function is also used in the DT case by shdma_of_xlate(). |
| * In that case the MID-RID value is used for slave channel filtering and is |
| * passed to this function in the "arg" parameter. |
| */ |
| bool shdma_chan_filter(struct dma_chan *chan, void *arg) |
| { |
| struct shdma_chan *schan; |
| struct shdma_dev *sdev; |
| int slave_id = (long)arg; |
| int ret; |
| |
| /* Only support channels handled by this driver. */ |
| if (chan->device->device_alloc_chan_resources != |
| shdma_alloc_chan_resources) |
| return false; |
| |
| schan = to_shdma_chan(chan); |
| sdev = to_shdma_dev(chan->device); |
| |
| /* |
| * For DT, the schan->slave_id field is generated by the |
| * set_slave function from the slave ID that is passed in |
| * from xlate. For the non-DT case, the slave ID is |
| * directly passed into the filter function by the driver |
| */ |
| if (schan->dev->of_node) { |
| ret = sdev->ops->set_slave(schan, slave_id, 0, true); |
| if (ret < 0) |
| return false; |
| |
| schan->real_slave_id = schan->slave_id; |
| return true; |
| } |
| |
| if (slave_id < 0) { |
| /* No slave requested - arbitrary channel */ |
| dev_warn(sdev->dma_dev.dev, "invalid slave ID passed to dma_request_slave\n"); |
| return true; |
| } |
| |
| if (slave_id >= slave_num) |
| return false; |
| |
| ret = sdev->ops->set_slave(schan, slave_id, 0, true); |
| if (ret < 0) |
| return false; |
| |
| schan->real_slave_id = slave_id; |
| |
| return true; |
| } |
| EXPORT_SYMBOL(shdma_chan_filter); |
| |
| static dma_async_tx_callback __ld_cleanup(struct shdma_chan *schan, bool all) |
| { |
| struct shdma_desc *desc, *_desc; |
| /* Is the "exposed" head of a chain acked? */ |
| bool head_acked = false; |
| dma_cookie_t cookie = 0; |
| dma_async_tx_callback callback = NULL; |
| struct dmaengine_desc_callback cb; |
| unsigned long flags; |
| LIST_HEAD(cyclic_list); |
| |
| memset(&cb, 0, sizeof(cb)); |
| spin_lock_irqsave(&schan->chan_lock, flags); |
| list_for_each_entry_safe(desc, _desc, &schan->ld_queue, node) { |
| struct dma_async_tx_descriptor *tx = &desc->async_tx; |
| |
| BUG_ON(tx->cookie > 0 && tx->cookie != desc->cookie); |
| BUG_ON(desc->mark != DESC_SUBMITTED && |
| desc->mark != DESC_COMPLETED && |
| desc->mark != DESC_WAITING); |
| |
| /* |
| * queue is ordered, and we use this loop to (1) clean up all |
| * completed descriptors, and to (2) update descriptor flags of |
| * any chunks in a (partially) completed chain |
| */ |
| if (!all && desc->mark == DESC_SUBMITTED && |
| desc->cookie != cookie) |
| break; |
| |
| if (tx->cookie > 0) |
| cookie = tx->cookie; |
| |
| if (desc->mark == DESC_COMPLETED && desc->chunks == 1) { |
| if (schan->dma_chan.completed_cookie != desc->cookie - 1) |
| dev_dbg(schan->dev, |
| "Completing cookie %d, expected %d\n", |
| desc->cookie, |
| schan->dma_chan.completed_cookie + 1); |
| schan->dma_chan.completed_cookie = desc->cookie; |
| } |
| |
| /* Call callback on the last chunk */ |
| if (desc->mark == DESC_COMPLETED && tx->callback) { |
| desc->mark = DESC_WAITING; |
| dmaengine_desc_get_callback(tx, &cb); |
| callback = tx->callback; |
| dev_dbg(schan->dev, "descriptor #%d@%p on %d callback\n", |
| tx->cookie, tx, schan->id); |
| BUG_ON(desc->chunks != 1); |
| break; |
| } |
| |
| if (tx->cookie > 0 || tx->cookie == -EBUSY) { |
| if (desc->mark == DESC_COMPLETED) { |
| BUG_ON(tx->cookie < 0); |
| desc->mark = DESC_WAITING; |
| } |
| head_acked = async_tx_test_ack(tx); |
| } else { |
| switch (desc->mark) { |
| case DESC_COMPLETED: |
| desc->mark = DESC_WAITING; |
| /* Fall through */ |
| case DESC_WAITING: |
| if (head_acked) |
| async_tx_ack(&desc->async_tx); |
| } |
| } |
| |
| dev_dbg(schan->dev, "descriptor %p #%d completed.\n", |
| tx, tx->cookie); |
| |
| if (((desc->mark == DESC_COMPLETED || |
| desc->mark == DESC_WAITING) && |
| async_tx_test_ack(&desc->async_tx)) || all) { |
| |
| if (all || !desc->cyclic) { |
| /* Remove from ld_queue list */ |
| desc->mark = DESC_IDLE; |
| list_move(&desc->node, &schan->ld_free); |
| } else { |
| /* reuse as cyclic */ |
| desc->mark = DESC_SUBMITTED; |
| list_move_tail(&desc->node, &cyclic_list); |
| } |
| |
| if (list_empty(&schan->ld_queue)) { |
| dev_dbg(schan->dev, "Bring down channel %d\n", schan->id); |
| pm_runtime_put(schan->dev); |
| schan->pm_state = SHDMA_PM_ESTABLISHED; |
| } else if (schan->pm_state == SHDMA_PM_PENDING) { |
| shdma_chan_xfer_ld_queue(schan); |
| } |
| } |
| } |
| |
| if (all && !callback) |
| /* |
| * Terminating and the loop completed normally: forgive |
| * uncompleted cookies |
| */ |
| schan->dma_chan.completed_cookie = schan->dma_chan.cookie; |
| |
| list_splice_tail(&cyclic_list, &schan->ld_queue); |
| |
| spin_unlock_irqrestore(&schan->chan_lock, flags); |
| |
| dmaengine_desc_callback_invoke(&cb, NULL); |
| |
| return callback; |
| } |
| |
| /* |
| * shdma_chan_ld_cleanup - Clean up link descriptors |
| * |
| * Clean up the ld_queue of DMA channel. |
| */ |
| static void shdma_chan_ld_cleanup(struct shdma_chan *schan, bool all) |
| { |
| while (__ld_cleanup(schan, all)) |
| ; |
| } |
| |
| /* |
| * shdma_free_chan_resources - Free all resources of the channel. |
| */ |
| static void shdma_free_chan_resources(struct dma_chan *chan) |
| { |
| struct shdma_chan *schan = to_shdma_chan(chan); |
| struct shdma_dev *sdev = to_shdma_dev(chan->device); |
| const struct shdma_ops *ops = sdev->ops; |
| LIST_HEAD(list); |
| |
| /* Protect against ISR */ |
| spin_lock_irq(&schan->chan_lock); |
| ops->halt_channel(schan); |
| spin_unlock_irq(&schan->chan_lock); |
| |
| /* Now no new interrupts will occur */ |
| |
| /* Prepared and not submitted descriptors can still be on the queue */ |
| if (!list_empty(&schan->ld_queue)) |
| shdma_chan_ld_cleanup(schan, true); |
| |
| if (schan->slave_id >= 0) { |
| /* The caller is holding dma_list_mutex */ |
| clear_bit(schan->slave_id, shdma_slave_used); |
| chan->private = NULL; |
| } |
| |
| schan->real_slave_id = 0; |
| |
| spin_lock_irq(&schan->chan_lock); |
| |
| list_splice_init(&schan->ld_free, &list); |
| schan->desc_num = 0; |
| |
| spin_unlock_irq(&schan->chan_lock); |
| |
| kfree(schan->desc); |
| } |
| |
| /** |
| * shdma_add_desc - get, set up and return one transfer descriptor |
| * @schan: DMA channel |
| * @flags: DMA transfer flags |
| * @dst: destination DMA address, incremented when direction equals |
| * DMA_DEV_TO_MEM or DMA_MEM_TO_MEM |
| * @src: source DMA address, incremented when direction equals |
| * DMA_MEM_TO_DEV or DMA_MEM_TO_MEM |
| * @len: DMA transfer length |
| * @first: if NULL, set to the current descriptor and cookie set to -EBUSY |
| * @direction: needed for slave DMA to decide which address to keep constant, |
| * equals DMA_MEM_TO_MEM for MEMCPY |
| * Returns 0 or an error |
| * Locks: called with desc_lock held |
| */ |
| static struct shdma_desc *shdma_add_desc(struct shdma_chan *schan, |
| unsigned long flags, dma_addr_t *dst, dma_addr_t *src, size_t *len, |
| struct shdma_desc **first, enum dma_transfer_direction direction) |
| { |
| struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); |
| const struct shdma_ops *ops = sdev->ops; |
| struct shdma_desc *new; |
| size_t copy_size = *len; |
| |
| if (!copy_size) |
| return NULL; |
| |
| /* Allocate the link descriptor from the free list */ |
| new = shdma_get_desc(schan); |
| if (!new) { |
| dev_err(schan->dev, "No free link descriptor available\n"); |
| return NULL; |
| } |
| |
| ops->desc_setup(schan, new, *src, *dst, ©_size); |
| |
| if (!*first) { |
| /* First desc */ |
| new->async_tx.cookie = -EBUSY; |
| *first = new; |
| } else { |
| /* Other desc - invisible to the user */ |
| new->async_tx.cookie = -EINVAL; |
| } |
| |
| dev_dbg(schan->dev, |
| "chaining (%zu/%zu)@%pad -> %pad with %p, cookie %d\n", |
| copy_size, *len, src, dst, &new->async_tx, |
| new->async_tx.cookie); |
| |
| new->mark = DESC_PREPARED; |
| new->async_tx.flags = flags; |
| new->direction = direction; |
| new->partial = 0; |
| |
| *len -= copy_size; |
| if (direction == DMA_MEM_TO_MEM || direction == DMA_MEM_TO_DEV) |
| *src += copy_size; |
| if (direction == DMA_MEM_TO_MEM || direction == DMA_DEV_TO_MEM) |
| *dst += copy_size; |
| |
| return new; |
| } |
| |
| /* |
| * shdma_prep_sg - prepare transfer descriptors from an SG list |
| * |
| * Common routine for public (MEMCPY) and slave DMA. The MEMCPY case is also |
| * converted to scatter-gather to guarantee consistent locking and a correct |
| * list manipulation. For slave DMA direction carries the usual meaning, and, |
| * logically, the SG list is RAM and the addr variable contains slave address, |
| * e.g., the FIFO I/O register. For MEMCPY direction equals DMA_MEM_TO_MEM |
| * and the SG list contains only one element and points at the source buffer. |
| */ |
| static struct dma_async_tx_descriptor *shdma_prep_sg(struct shdma_chan *schan, |
| struct scatterlist *sgl, unsigned int sg_len, dma_addr_t *addr, |
| enum dma_transfer_direction direction, unsigned long flags, bool cyclic) |
| { |
| struct scatterlist *sg; |
| struct shdma_desc *first = NULL, *new = NULL /* compiler... */; |
| LIST_HEAD(tx_list); |
| int chunks = 0; |
| unsigned long irq_flags; |
| int i; |
| |
| for_each_sg(sgl, sg, sg_len, i) |
| chunks += DIV_ROUND_UP(sg_dma_len(sg), schan->max_xfer_len); |
| |
| /* Have to lock the whole loop to protect against concurrent release */ |
| spin_lock_irqsave(&schan->chan_lock, irq_flags); |
| |
| /* |
| * Chaining: |
| * first descriptor is what user is dealing with in all API calls, its |
| * cookie is at first set to -EBUSY, at tx-submit to a positive |
| * number |
| * if more than one chunk is needed further chunks have cookie = -EINVAL |
| * the last chunk, if not equal to the first, has cookie = -ENOSPC |
| * all chunks are linked onto the tx_list head with their .node heads |
| * only during this function, then they are immediately spliced |
| * back onto the free list in form of a chain |
| */ |
| for_each_sg(sgl, sg, sg_len, i) { |
| dma_addr_t sg_addr = sg_dma_address(sg); |
| size_t len = sg_dma_len(sg); |
| |
| if (!len) |
| goto err_get_desc; |
| |
| do { |
| dev_dbg(schan->dev, "Add SG #%d@%p[%zu], dma %pad\n", |
| i, sg, len, &sg_addr); |
| |
| if (direction == DMA_DEV_TO_MEM) |
| new = shdma_add_desc(schan, flags, |
| &sg_addr, addr, &len, &first, |
| direction); |
| else |
| new = shdma_add_desc(schan, flags, |
| addr, &sg_addr, &len, &first, |
| direction); |
| if (!new) |
| goto err_get_desc; |
| |
| new->cyclic = cyclic; |
| if (cyclic) |
| new->chunks = 1; |
| else |
| new->chunks = chunks--; |
| list_add_tail(&new->node, &tx_list); |
| } while (len); |
| } |
| |
| if (new != first) |
| new->async_tx.cookie = -ENOSPC; |
| |
| /* Put them back on the free list, so, they don't get lost */ |
| list_splice_tail(&tx_list, &schan->ld_free); |
| |
| spin_unlock_irqrestore(&schan->chan_lock, irq_flags); |
| |
| return &first->async_tx; |
| |
| err_get_desc: |
| list_for_each_entry(new, &tx_list, node) |
| new->mark = DESC_IDLE; |
| list_splice(&tx_list, &schan->ld_free); |
| |
| spin_unlock_irqrestore(&schan->chan_lock, irq_flags); |
| |
| return NULL; |
| } |
| |
| static struct dma_async_tx_descriptor *shdma_prep_memcpy( |
| struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src, |
| size_t len, unsigned long flags) |
| { |
| struct shdma_chan *schan = to_shdma_chan(chan); |
| struct scatterlist sg; |
| |
| if (!chan || !len) |
| return NULL; |
| |
| BUG_ON(!schan->desc_num); |
| |
| sg_init_table(&sg, 1); |
| sg_set_page(&sg, pfn_to_page(PFN_DOWN(dma_src)), len, |
| offset_in_page(dma_src)); |
| sg_dma_address(&sg) = dma_src; |
| sg_dma_len(&sg) = len; |
| |
| return shdma_prep_sg(schan, &sg, 1, &dma_dest, DMA_MEM_TO_MEM, |
| flags, false); |
| } |
| |
| static struct dma_async_tx_descriptor *shdma_prep_slave_sg( |
| struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, |
| enum dma_transfer_direction direction, unsigned long flags, void *context) |
| { |
| struct shdma_chan *schan = to_shdma_chan(chan); |
| struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); |
| const struct shdma_ops *ops = sdev->ops; |
| int slave_id = schan->slave_id; |
| dma_addr_t slave_addr; |
| |
| if (!chan) |
| return NULL; |
| |
| BUG_ON(!schan->desc_num); |
| |
| /* Someone calling slave DMA on a generic channel? */ |
| if (slave_id < 0 || !sg_len) { |
| dev_warn(schan->dev, "%s: bad parameter: len=%d, id=%d\n", |
| __func__, sg_len, slave_id); |
| return NULL; |
| } |
| |
| slave_addr = ops->slave_addr(schan); |
| |
| return shdma_prep_sg(schan, sgl, sg_len, &slave_addr, |
| direction, flags, false); |
| } |
| |
| #define SHDMA_MAX_SG_LEN 32 |
| |
| static struct dma_async_tx_descriptor *shdma_prep_dma_cyclic( |
| struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, |
| size_t period_len, enum dma_transfer_direction direction, |
| unsigned long flags) |
| { |
| struct shdma_chan *schan = to_shdma_chan(chan); |
| struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); |
| struct dma_async_tx_descriptor *desc; |
| const struct shdma_ops *ops = sdev->ops; |
| unsigned int sg_len = buf_len / period_len; |
| int slave_id = schan->slave_id; |
| dma_addr_t slave_addr; |
| struct scatterlist *sgl; |
| int i; |
| |
| if (!chan) |
| return NULL; |
| |
| BUG_ON(!schan->desc_num); |
| |
| if (sg_len > SHDMA_MAX_SG_LEN) { |
| dev_err(schan->dev, "sg length %d exceeds limit %d", |
| sg_len, SHDMA_MAX_SG_LEN); |
| return NULL; |
| } |
| |
| /* Someone calling slave DMA on a generic channel? */ |
| if (slave_id < 0 || (buf_len < period_len)) { |
| dev_warn(schan->dev, |
| "%s: bad parameter: buf_len=%zu, period_len=%zu, id=%d\n", |
| __func__, buf_len, period_len, slave_id); |
| return NULL; |
| } |
| |
| slave_addr = ops->slave_addr(schan); |
| |
| /* |
| * Allocate the sg list dynamically as it would consumer too much stack |
| * space. |
| */ |
| sgl = kcalloc(sg_len, sizeof(*sgl), GFP_KERNEL); |
| if (!sgl) |
| return NULL; |
| |
| sg_init_table(sgl, sg_len); |
| |
| for (i = 0; i < sg_len; i++) { |
| dma_addr_t src = buf_addr + (period_len * i); |
| |
| sg_set_page(&sgl[i], pfn_to_page(PFN_DOWN(src)), period_len, |
| offset_in_page(src)); |
| sg_dma_address(&sgl[i]) = src; |
| sg_dma_len(&sgl[i]) = period_len; |
| } |
| |
| desc = shdma_prep_sg(schan, sgl, sg_len, &slave_addr, |
| direction, flags, true); |
| |
| kfree(sgl); |
| return desc; |
| } |
| |
| static int shdma_terminate_all(struct dma_chan *chan) |
| { |
| struct shdma_chan *schan = to_shdma_chan(chan); |
| struct shdma_dev *sdev = to_shdma_dev(chan->device); |
| const struct shdma_ops *ops = sdev->ops; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&schan->chan_lock, flags); |
| ops->halt_channel(schan); |
| |
| if (ops->get_partial && !list_empty(&schan->ld_queue)) { |
| /* Record partial transfer */ |
| struct shdma_desc *desc = list_first_entry(&schan->ld_queue, |
| struct shdma_desc, node); |
| desc->partial = ops->get_partial(schan, desc); |
| } |
| |
| spin_unlock_irqrestore(&schan->chan_lock, flags); |
| |
| shdma_chan_ld_cleanup(schan, true); |
| |
| return 0; |
| } |
| |
| static int shdma_config(struct dma_chan *chan, |
| struct dma_slave_config *config) |
| { |
| struct shdma_chan *schan = to_shdma_chan(chan); |
| |
| /* |
| * So far only .slave_id is used, but the slave drivers are |
| * encouraged to also set a transfer direction and an address. |
| */ |
| if (!config) |
| return -EINVAL; |
| |
| /* |
| * overriding the slave_id through dma_slave_config is deprecated, |
| * but possibly some out-of-tree drivers still do it. |
| */ |
| if (WARN_ON_ONCE(config->slave_id && |
| config->slave_id != schan->real_slave_id)) |
| schan->real_slave_id = config->slave_id; |
| |
| /* |
| * We could lock this, but you shouldn't be configuring the |
| * channel, while using it... |
| */ |
| return shdma_setup_slave(schan, |
| config->direction == DMA_DEV_TO_MEM ? |
| config->src_addr : config->dst_addr); |
| } |
| |
| static void shdma_issue_pending(struct dma_chan *chan) |
| { |
| struct shdma_chan *schan = to_shdma_chan(chan); |
| |
| spin_lock_irq(&schan->chan_lock); |
| if (schan->pm_state == SHDMA_PM_ESTABLISHED) |
| shdma_chan_xfer_ld_queue(schan); |
| else |
| schan->pm_state = SHDMA_PM_PENDING; |
| spin_unlock_irq(&schan->chan_lock); |
| } |
| |
| static enum dma_status shdma_tx_status(struct dma_chan *chan, |
| dma_cookie_t cookie, |
| struct dma_tx_state *txstate) |
| { |
| struct shdma_chan *schan = to_shdma_chan(chan); |
| enum dma_status status; |
| unsigned long flags; |
| |
| shdma_chan_ld_cleanup(schan, false); |
| |
| spin_lock_irqsave(&schan->chan_lock, flags); |
| |
| status = dma_cookie_status(chan, cookie, txstate); |
| |
| /* |
| * If we don't find cookie on the queue, it has been aborted and we have |
| * to report error |
| */ |
| if (status != DMA_COMPLETE) { |
| struct shdma_desc *sdesc; |
| status = DMA_ERROR; |
| list_for_each_entry(sdesc, &schan->ld_queue, node) |
| if (sdesc->cookie == cookie) { |
| status = DMA_IN_PROGRESS; |
| break; |
| } |
| } |
| |
| spin_unlock_irqrestore(&schan->chan_lock, flags); |
| |
| return status; |
| } |
| |
| /* Called from error IRQ or NMI */ |
| bool shdma_reset(struct shdma_dev *sdev) |
| { |
| const struct shdma_ops *ops = sdev->ops; |
| struct shdma_chan *schan; |
| unsigned int handled = 0; |
| int i; |
| |
| /* Reset all channels */ |
| shdma_for_each_chan(schan, sdev, i) { |
| struct shdma_desc *sdesc; |
| LIST_HEAD(dl); |
| |
| if (!schan) |
| continue; |
| |
| spin_lock(&schan->chan_lock); |
| |
| /* Stop the channel */ |
| ops->halt_channel(schan); |
| |
| list_splice_init(&schan->ld_queue, &dl); |
| |
| if (!list_empty(&dl)) { |
| dev_dbg(schan->dev, "Bring down channel %d\n", schan->id); |
| pm_runtime_put(schan->dev); |
| } |
| schan->pm_state = SHDMA_PM_ESTABLISHED; |
| |
| spin_unlock(&schan->chan_lock); |
| |
| /* Complete all */ |
| list_for_each_entry(sdesc, &dl, node) { |
| struct dma_async_tx_descriptor *tx = &sdesc->async_tx; |
| |
| sdesc->mark = DESC_IDLE; |
| dmaengine_desc_get_callback_invoke(tx, NULL); |
| } |
| |
| spin_lock(&schan->chan_lock); |
| list_splice(&dl, &schan->ld_free); |
| spin_unlock(&schan->chan_lock); |
| |
| handled++; |
| } |
| |
| return !!handled; |
| } |
| EXPORT_SYMBOL(shdma_reset); |
| |
| static irqreturn_t chan_irq(int irq, void *dev) |
| { |
| struct shdma_chan *schan = dev; |
| const struct shdma_ops *ops = |
| to_shdma_dev(schan->dma_chan.device)->ops; |
| irqreturn_t ret; |
| |
| spin_lock(&schan->chan_lock); |
| |
| ret = ops->chan_irq(schan, irq) ? IRQ_WAKE_THREAD : IRQ_NONE; |
| |
| spin_unlock(&schan->chan_lock); |
| |
| return ret; |
| } |
| |
| static irqreturn_t chan_irqt(int irq, void *dev) |
| { |
| struct shdma_chan *schan = dev; |
| const struct shdma_ops *ops = |
| to_shdma_dev(schan->dma_chan.device)->ops; |
| struct shdma_desc *sdesc; |
| |
| spin_lock_irq(&schan->chan_lock); |
| list_for_each_entry(sdesc, &schan->ld_queue, node) { |
| if (sdesc->mark == DESC_SUBMITTED && |
| ops->desc_completed(schan, sdesc)) { |
| dev_dbg(schan->dev, "done #%d@%p\n", |
| sdesc->async_tx.cookie, &sdesc->async_tx); |
| sdesc->mark = DESC_COMPLETED; |
| break; |
| } |
| } |
| /* Next desc */ |
| shdma_chan_xfer_ld_queue(schan); |
| spin_unlock_irq(&schan->chan_lock); |
| |
| shdma_chan_ld_cleanup(schan, false); |
| |
| return IRQ_HANDLED; |
| } |
| |
| int shdma_request_irq(struct shdma_chan *schan, int irq, |
| unsigned long flags, const char *name) |
| { |
| int ret = devm_request_threaded_irq(schan->dev, irq, chan_irq, |
| chan_irqt, flags, name, schan); |
| |
| schan->irq = ret < 0 ? ret : irq; |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(shdma_request_irq); |
| |
| void shdma_chan_probe(struct shdma_dev *sdev, |
| struct shdma_chan *schan, int id) |
| { |
| schan->pm_state = SHDMA_PM_ESTABLISHED; |
| |
| /* reference struct dma_device */ |
| schan->dma_chan.device = &sdev->dma_dev; |
| dma_cookie_init(&schan->dma_chan); |
| |
| schan->dev = sdev->dma_dev.dev; |
| schan->id = id; |
| |
| if (!schan->max_xfer_len) |
| schan->max_xfer_len = PAGE_SIZE; |
| |
| spin_lock_init(&schan->chan_lock); |
| |
| /* Init descripter manage list */ |
| INIT_LIST_HEAD(&schan->ld_queue); |
| INIT_LIST_HEAD(&schan->ld_free); |
| |
| /* Add the channel to DMA device channel list */ |
| list_add_tail(&schan->dma_chan.device_node, |
| &sdev->dma_dev.channels); |
| sdev->schan[id] = schan; |
| } |
| EXPORT_SYMBOL(shdma_chan_probe); |
| |
| void shdma_chan_remove(struct shdma_chan *schan) |
| { |
| list_del(&schan->dma_chan.device_node); |
| } |
| EXPORT_SYMBOL(shdma_chan_remove); |
| |
| int shdma_init(struct device *dev, struct shdma_dev *sdev, |
| int chan_num) |
| { |
| struct dma_device *dma_dev = &sdev->dma_dev; |
| |
| /* |
| * Require all call-backs for now, they can trivially be made optional |
| * later as required |
| */ |
| if (!sdev->ops || |
| !sdev->desc_size || |
| !sdev->ops->embedded_desc || |
| !sdev->ops->start_xfer || |
| !sdev->ops->setup_xfer || |
| !sdev->ops->set_slave || |
| !sdev->ops->desc_setup || |
| !sdev->ops->slave_addr || |
| !sdev->ops->channel_busy || |
| !sdev->ops->halt_channel || |
| !sdev->ops->desc_completed) |
| return -EINVAL; |
| |
| sdev->schan = kcalloc(chan_num, sizeof(*sdev->schan), GFP_KERNEL); |
| if (!sdev->schan) |
| return -ENOMEM; |
| |
| INIT_LIST_HEAD(&dma_dev->channels); |
| |
| /* Common and MEMCPY operations */ |
| dma_dev->device_alloc_chan_resources |
| = shdma_alloc_chan_resources; |
| dma_dev->device_free_chan_resources = shdma_free_chan_resources; |
| dma_dev->device_prep_dma_memcpy = shdma_prep_memcpy; |
| dma_dev->device_tx_status = shdma_tx_status; |
| dma_dev->device_issue_pending = shdma_issue_pending; |
| |
| /* Compulsory for DMA_SLAVE fields */ |
| dma_dev->device_prep_slave_sg = shdma_prep_slave_sg; |
| dma_dev->device_prep_dma_cyclic = shdma_prep_dma_cyclic; |
| dma_dev->device_config = shdma_config; |
| dma_dev->device_terminate_all = shdma_terminate_all; |
| |
| dma_dev->dev = dev; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(shdma_init); |
| |
| void shdma_cleanup(struct shdma_dev *sdev) |
| { |
| kfree(sdev->schan); |
| } |
| EXPORT_SYMBOL(shdma_cleanup); |
| |
| static int __init shdma_enter(void) |
| { |
| shdma_slave_used = kcalloc(DIV_ROUND_UP(slave_num, BITS_PER_LONG), |
| sizeof(long), |
| GFP_KERNEL); |
| if (!shdma_slave_used) |
| return -ENOMEM; |
| return 0; |
| } |
| module_init(shdma_enter); |
| |
| static void __exit shdma_exit(void) |
| { |
| kfree(shdma_slave_used); |
| } |
| module_exit(shdma_exit); |
| |
| MODULE_LICENSE("GPL v2"); |
| MODULE_DESCRIPTION("SH-DMA driver base library"); |
| MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>"); |