1 // SPDX-License-Identifier: GPL-2.0-or-later
4  *   - Isochronous DMA context management
5  *   - Isochronous bus resource management (channels, bandwidth), client side
10 #include <linux/dma-mapping.h>
13 #include <linux/firewire-constants.h>
35 	buffer->page_count = 0;  in fw_iso_buffer_alloc()
36 	buffer->page_count_mapped = 0;  in fw_iso_buffer_alloc()
37 	buffer->pages = kmalloc_array(page_count, sizeof(buffer->pages[0]),  in fw_iso_buffer_alloc()
39 	if (buffer->pages == NULL)  in fw_iso_buffer_alloc()
40 		return -ENOMEM;  in fw_iso_buffer_alloc()
43 		buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);  in fw_iso_buffer_alloc()
44 		if (buffer->pages[i] == NULL)  in fw_iso_buffer_alloc()
47 	buffer->page_count = i;  in fw_iso_buffer_alloc()
50 		return -ENOMEM;  in fw_iso_buffer_alloc()
62 	buffer->direction = direction;  in fw_iso_buffer_map_dma()
64 	for (i = 0; i < buffer->page_count; i++) {  in fw_iso_buffer_map_dma()
65 		address = dma_map_page(card->device, buffer->pages[i],  in fw_iso_buffer_map_dma()
67 		if (dma_mapping_error(card->device, address))  in fw_iso_buffer_map_dma()
70 		set_page_private(buffer->pages[i], address);  in fw_iso_buffer_map_dma()
72 	buffer->page_count_mapped = i;  in fw_iso_buffer_map_dma()
73 	if (i < buffer->page_count)  in fw_iso_buffer_map_dma()
74 		return -ENOMEM;  in fw_iso_buffer_map_dma()
102 	for (i = 0; i < buffer->page_count_mapped; i++) {  in fw_iso_buffer_destroy()
103 		address = page_private(buffer->pages[i]);  in fw_iso_buffer_destroy()
104 		dma_unmap_page(card->device, address,  in fw_iso_buffer_destroy()
105 			       PAGE_SIZE, buffer->direction);  in fw_iso_buffer_destroy()
107 	for (i = 0; i < buffer->page_count; i++)  in fw_iso_buffer_destroy()
108 		__free_page(buffer->pages[i]);  in fw_iso_buffer_destroy()
110 	kfree(buffer->pages);  in fw_iso_buffer_destroy()
111 	buffer->pages = NULL;  in fw_iso_buffer_destroy()
112 	buffer->page_count = 0;  in fw_iso_buffer_destroy()
113 	buffer->page_count_mapped = 0;  in fw_iso_buffer_destroy()
124 	for (i = 0; i < buffer->page_count; i++) {  in fw_iso_buffer_lookup()
125 		address = page_private(buffer->pages[i]);  in fw_iso_buffer_lookup()
126 		offset = (ssize_t)completed - (ssize_t)address;  in fw_iso_buffer_lookup()
140 	ctx = card->driver->allocate_iso_context(card,  in fw_iso_context_create()
145 	ctx->card = card;  in fw_iso_context_create()
146 	ctx->type = type;  in fw_iso_context_create()
147 	ctx->channel = channel;  in fw_iso_context_create()
148 	ctx->speed = speed;  in fw_iso_context_create()
149 	ctx->header_size = header_size;  in fw_iso_context_create()
150 	ctx->callback.sc = callback;  in fw_iso_context_create()
151 	ctx->callback_data = callback_data;  in fw_iso_context_create()
167 	ctx->card->driver->free_iso_context(ctx);  in fw_iso_context_destroy()
178 	return ctx->card->driver->start_iso(ctx, cycle, sync, tags);  in fw_iso_context_start()
186 	return ctx->card->driver->set_iso_channels(ctx, channels);  in fw_iso_context_set_channels()
198 	return ctx->card->driver->queue_iso(ctx, packet, buffer, payload);  in fw_iso_context_queue()
208 	ctx->card->driver->flush_queue_iso(ctx);  in fw_iso_context_queue_flush()
213  * fw_iso_context_flush_completions() - process isochronous context in current process context.
237 	if (WARN_ON_ONCE(current_work() == &ctx->work))  in fw_iso_context_flush_completions()
240 	disable_work_sync(&ctx->work);  in fw_iso_context_flush_completions()
242 	err = ctx->card->driver->flush_iso_completions(ctx);  in fw_iso_context_flush_completions()
244 	enable_work(&ctx->work);  in fw_iso_context_flush_completions()
261 	if (WARN_ON_ONCE(current_work() == &ctx->work))  in fw_iso_context_stop()
264 	err = ctx->card->driver->stop_iso(ctx);  in fw_iso_context_stop()
266 	cancel_work_sync(&ctx->work);  in fw_iso_context_stop()
273  * Isochronous bus resource management (channels, bandwidth), client side
277 			    int bandwidth, bool allocate)  in manage_bandwidth()  argument
283 	 * On a 1394a IRM with low contention, try < 1 is enough.  in manage_bandwidth()
284 	 * On a 1394-1995 IRM, we need at least try < 2.  in manage_bandwidth()
288 		new = allocate ? old - bandwidth : old + bandwidth;  in manage_bandwidth()
290 			return -EBUSY;  in manage_bandwidth()
299 			/* A generation change frees all bandwidth. */  in manage_bandwidth()
300 			return allocate ? -EAGAIN : bandwidth;  in manage_bandwidth()
304 				return bandwidth;  in manage_bandwidth()
311 	return -EIO;  in manage_bandwidth()
319 	int channel, ret = -EIO, retry = 5;  in manage_channel()
327 		ret = -EBUSY;  in manage_channel()
329 		bit = cpu_to_be32(1 << (31 - channel));  in manage_channel()
340 			return allocate ? -EAGAIN : channel;  in manage_channel()
348 			/* Is the IRM 1394a-2000 compliant? */  in manage_channel()
352 			fallthrough;	/* It's a 1394-1995 IRM, retry */  in manage_channel()
355 				retry--;  in manage_channel()
356 				channel--;  in manage_channel()
358 				ret = -EIO;  in manage_channel()
372 	mask = channel < 32 ? 1 << channel : 1 << (channel - 32);  in deallocate_channel()
380  * fw_iso_resource_manage() - Allocate or deallocate a channel and/or bandwidth
385  * @bandwidth: pointer for returning bandwidth allocation result
388  * In parameters: card, generation, channels_mask, bandwidth, allocate
389  * Out parameters: channel, bandwidth
395  * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for
397  * Allocates or deallocates as many bandwidth allocation units as specified.
400  * Returns bandwidth = 0 if no bandwidth was allocated or deallocated.
403  * channel = -EAGAIN.
405  * If channel allocation fails, no bandwidth will be allocated either.
406  * If bandwidth allocation fails, no channel will be allocated either.
407  * But deallocations of channel and bandwidth are tried independently
411 			    u64 channels_mask, int *channel, int *bandwidth,  in fw_iso_resource_manage()  argument
416 	int irm_id, ret, c = -EINVAL;  in fw_iso_resource_manage()
418 	scoped_guard(spinlock_irq, &card->lock)  in fw_iso_resource_manage()
419 		irm_id = card->irm_node->node_id;  in fw_iso_resource_manage()
435 		*bandwidth = 0;  in fw_iso_resource_manage()
437 	if (*bandwidth == 0)  in fw_iso_resource_manage()
440 	ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate);  in fw_iso_resource_manage()
442 		*bandwidth = 0;  in fw_iso_resource_manage()