Something went wrong. Try again.
(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
Something went wrong. Try again.
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474// SPDX-License-Identifier: GPL-2.0-or-later/* * Isochronous I/O functionality: * - Isochronous DMA context management * - Isochronous bus resource management (channels, bandwidth), client side * * Copyright (C) 2006 Kristian Hoegsberg <krh@bitplanet.net> */
#include <linux/dma-mapping.h>#include <linux/errno.h>#include <linux/firewire.h>#include <linux/firewire-constants.h>#include <linux/kernel.h>#include <linux/mm.h>#include <linux/slab.h>#include <linux/spinlock.h>#include <linux/vmalloc.h>#include <linux/export.h>
#include <asm/byteorder.h>
#include "core.h"
#include <trace/events/firewire.h>
/* * Isochronous DMA context management */
int fw_iso_buffer_alloc(struct fw_iso_buffer *buffer, int page_count){ struct page **page_array __free(kfree) = kzalloc_objs(page_array[0], page_count);
if (!page_array) return -ENOMEM;
// Retrieve noncontiguous pages. The descriptors for 1394 OHCI isochronous DMA contexts // have a set of address and length per each, while the reason to use pages is the // convenience to map them into virtual address space of user process. unsigned long nr_populated = alloc_pages_bulk(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO, page_count, page_array); if (nr_populated != page_count) { // Assuming the above call fills page_array sequentially from the beginning. release_pages(page_array, nr_populated); return -ENOMEM; }
buffer->page_count = page_count; buffer->pages = no_free_ptr(page_array);
return 0;}
int fw_iso_buffer_map_dma(struct fw_iso_buffer *buffer, struct fw_card *card, enum dma_data_direction direction){ dma_addr_t *dma_addrs __free(kfree) = kzalloc_objs(dma_addrs[0], buffer->page_count); int i;
if (!dma_addrs) return -ENOMEM;
// Retrieve DMA mapping addresses for the pages. They are not contiguous. Maintain the cache // coherency for the pages by hand. for (i = 0; i < buffer->page_count; i++) { // The dma_map_phys() with a physical address per page is available here, instead. dma_addr_t dma_addr = dma_map_page(card->device, buffer->pages[i], 0, PAGE_SIZE, direction); if (dma_mapping_error(card->device, dma_addr)) break;
dma_addrs[i] = dma_addr; } if (i < buffer->page_count) { while (i-- > 0) dma_unmap_page(card->device, dma_addrs[i], PAGE_SIZE, buffer->direction); return -ENOMEM; }
buffer->direction = direction; buffer->dma_addrs = no_free_ptr(dma_addrs);
return 0;}
int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card, int page_count, enum dma_data_direction direction){ int ret;
ret = fw_iso_buffer_alloc(buffer, page_count); if (ret < 0) return ret;
ret = fw_iso_buffer_map_dma(buffer, card, direction); if (ret < 0) fw_iso_buffer_destroy(buffer, card);
return ret;}EXPORT_SYMBOL(fw_iso_buffer_init);
void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer, struct fw_card *card){ if (buffer->dma_addrs) { for (int i = 0; i < buffer->page_count; ++i) { dma_addr_t dma_addr = buffer->dma_addrs[i]; dma_unmap_page(card->device, dma_addr, PAGE_SIZE, buffer->direction); } kfree(buffer->dma_addrs); buffer->dma_addrs = NULL; }
if (buffer->pages) { release_pages(buffer->pages, buffer->page_count); kfree(buffer->pages); buffer->pages = NULL; }
buffer->page_count = 0;}EXPORT_SYMBOL(fw_iso_buffer_destroy);
/* Convert DMA address to offset into virtually contiguous buffer. */size_t fw_iso_buffer_lookup(struct fw_iso_buffer *buffer, dma_addr_t completed){ for (int i = 0; i < buffer->page_count; i++) { dma_addr_t dma_addr = buffer->dma_addrs[i]; ssize_t offset = (ssize_t)completed - (ssize_t)dma_addr; if (offset > 0 && offset <= PAGE_SIZE) return (i << PAGE_SHIFT) + offset; }
return 0;}
struct fw_iso_context *__fw_iso_context_create(struct fw_card *card, int type, int channel, int speed, size_t header_size, size_t header_storage_size, union fw_iso_callback callback, void *callback_data){ struct fw_iso_context *ctx;
ctx = smp_load_acquire(&card->driver)->allocate_iso_context(card, type, channel, header_size, header_storage_size); if (IS_ERR(ctx)) return ctx;
ctx->card = card; ctx->type = type; ctx->channel = channel; ctx->speed = speed; ctx->flags = 0; ctx->header_size = header_size; ctx->header_storage_size = header_storage_size; ctx->callback = callback; ctx->callback_data = callback_data;
trace_isoc_outbound_allocate(ctx, channel, speed); trace_isoc_inbound_single_allocate(ctx, channel, header_size); trace_isoc_inbound_multiple_allocate(ctx);
return ctx;}EXPORT_SYMBOL(__fw_iso_context_create);
void fw_iso_context_destroy(struct fw_iso_context *ctx){ trace_isoc_outbound_destroy(ctx); trace_isoc_inbound_single_destroy(ctx); trace_isoc_inbound_multiple_destroy(ctx);
struct fw_card *card = ctx->card;
smp_load_acquire(&card->driver)->free_iso_context(ctx);}EXPORT_SYMBOL(fw_iso_context_destroy);
int fw_iso_context_start(struct fw_iso_context *ctx, int cycle, int sync, int tags){ trace_isoc_outbound_start(ctx, cycle); trace_isoc_inbound_single_start(ctx, cycle, sync, tags); trace_isoc_inbound_multiple_start(ctx, cycle, sync, tags);
struct fw_card *card = ctx->card;
return smp_load_acquire(&card->driver)->start_iso(ctx, cycle, sync, tags);}EXPORT_SYMBOL(fw_iso_context_start);
int fw_iso_context_set_channels(struct fw_iso_context *ctx, u64 *channels){ trace_isoc_inbound_multiple_channels(ctx, *channels);
struct fw_card *card = ctx->card;
return smp_load_acquire(&card->driver)->set_iso_channels(ctx, channels);}
int fw_iso_context_queue(struct fw_iso_context *ctx, struct fw_iso_packet *packet, struct fw_iso_buffer *buffer, unsigned long payload){ trace_isoc_outbound_queue(ctx, payload, packet); trace_isoc_inbound_single_queue(ctx, payload, packet); trace_isoc_inbound_multiple_queue(ctx, payload, packet);
struct fw_card *card = ctx->card;
return smp_load_acquire(&card->driver)->queue_iso(ctx, packet, buffer, payload);}EXPORT_SYMBOL(fw_iso_context_queue);
void fw_iso_context_queue_flush(struct fw_iso_context *ctx){ trace_isoc_outbound_flush(ctx); trace_isoc_inbound_single_flush(ctx); trace_isoc_inbound_multiple_flush(ctx);
struct fw_card *card = ctx->card;
smp_load_acquire(&card->driver)->flush_queue_iso(ctx);}EXPORT_SYMBOL(fw_iso_context_queue_flush);
/** * fw_iso_context_flush_completions() - process isochronous context in current process context. * @ctx: the isochronous context * * Process the isochronous context in the current process context. The registered callback function * is called when a queued packet buffer with the interrupt flag is completed, either after * transmission in the IT context or after being filled in the IR context. Additionally, the * callback function is also called for the packet buffer completed at last. Furthermore, the * callback function is called as well when the header buffer in the context becomes full. If it is * required to process the context asynchronously, fw_iso_context_schedule_flush_completions() is * available instead. * * Context: Process context. May sleep due to disable_work_sync(). */int fw_iso_context_flush_completions(struct fw_iso_context *ctx){ int err;
trace_isoc_outbound_flush_completions(ctx); trace_isoc_inbound_single_flush_completions(ctx); trace_isoc_inbound_multiple_flush_completions(ctx);
might_sleep();
// Avoid dead lock due to programming mistake. if (WARN_ON_ONCE(current_work() == &ctx->work)) return 0;
disable_work_sync(&ctx->work);
struct fw_card *card = ctx->card;
err = smp_load_acquire(&card->driver)->flush_iso_completions(ctx);
enable_work(&ctx->work);
return err;}EXPORT_SYMBOL(fw_iso_context_flush_completions);
int fw_iso_context_stop(struct fw_iso_context *ctx){ int err;
trace_isoc_outbound_stop(ctx); trace_isoc_inbound_single_stop(ctx); trace_isoc_inbound_multiple_stop(ctx);
might_sleep();
// Avoid dead lock due to programming mistake. if (WARN_ON_ONCE(current_work() == &ctx->work)) return 0;
struct fw_card *card = ctx->card;
err = smp_load_acquire(&card->driver)->stop_iso(ctx);
cancel_work_sync(&ctx->work);
return err;}EXPORT_SYMBOL(fw_iso_context_stop);
/* * Isochronous bus resource management (channels, bandwidth), client side */
static int manage_bandwidth(struct fw_card *card, int irm_id, int generation, int bandwidth, bool allocate){ int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0; __be32 data[2];
/* * On a 1394a IRM with low contention, try < 1 is enough. * On a 1394-1995 IRM, we need at least try < 2. * Let's just do try < 5. */ for (try = 0; try < 5; try++) { new = allocate ? old - bandwidth : old + bandwidth; if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL) return -EBUSY;
data[0] = cpu_to_be32(old); data[1] = cpu_to_be32(new); switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, irm_id, generation, SCODE_100, CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE, data, 8)) { case RCODE_GENERATION: /* A generation change frees all bandwidth. */ return allocate ? -EAGAIN : bandwidth;
case RCODE_COMPLETE: if (be32_to_cpup(data) == old) return bandwidth;
old = be32_to_cpup(data); /* Fall through. */ } }
return -EIO;}
static int manage_channel(struct fw_card *card, int irm_id, int generation, u32 channels_mask, u64 offset, bool allocate){ __be32 bit, all, old; __be32 data[2]; int channel, ret = -EIO, retry = 5;
old = all = allocate ? cpu_to_be32(~0) : 0;
for (channel = 0; channel < 32; channel++) { if (!(channels_mask & 1 << channel)) continue;
ret = -EBUSY;
bit = cpu_to_be32(1 << (31 - channel)); if ((old & bit) != (all & bit)) continue;
data[0] = old; data[1] = old ^ bit; switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, irm_id, generation, SCODE_100, offset, data, 8)) { case RCODE_GENERATION: /* A generation change frees all channels. */ return allocate ? -EAGAIN : channel;
case RCODE_COMPLETE: if (data[0] == old) return channel;
old = data[0];
/* Is the IRM 1394a-2000 compliant? */ if ((data[0] & bit) == (data[1] & bit)) continue;
fallthrough; /* It's a 1394-1995 IRM, retry */ default: if (retry) { retry--; channel--; } else { ret = -EIO; } } }
return ret;}
static void deallocate_channel(struct fw_card *card, int irm_id, int generation, int channel){ u32 mask; u64 offset;
mask = channel < 32 ? 1 << channel : 1 << (channel - 32); offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI : CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;
manage_channel(card, irm_id, generation, mask, offset, false);}
/** * fw_iso_resource_manage() - Allocate or deallocate a channel and/or bandwidth * @card: card interface for this action * @generation: bus generation * @channels_mask: bitmask for channel allocation * @channel: pointer for returning channel allocation result * @bandwidth: pointer for returning bandwidth allocation result * @allocate: whether to allocate (true) or deallocate (false) * * In parameters: card, generation, channels_mask, bandwidth, allocate * Out parameters: channel, bandwidth * * This function blocks (sleeps) during communication with the IRM. * * Allocates or deallocates at most one channel out of channels_mask. * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0. * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for * channel 0 and LSB for channel 63.) * Allocates or deallocates as many bandwidth allocation units as specified. * * Returns channel < 0 if no channel was allocated or deallocated. * Returns bandwidth = 0 if no bandwidth was allocated or deallocated. * * If generation is stale, deallocations succeed but allocations fail with * channel = -EAGAIN. * * If channel allocation fails, no bandwidth will be allocated either. * If bandwidth allocation fails, no channel will be allocated either. * But deallocations of channel and bandwidth are tried independently * of each other's success. */void fw_iso_resource_manage(struct fw_card *card, int generation, u64 channels_mask, int *channel, int *bandwidth, bool allocate){ u32 channels_hi = channels_mask; /* channels 31...0 */ u32 channels_lo = channels_mask >> 32; /* channels 63...32 */ int irm_id, ret, c = -EINVAL;
scoped_guard(spinlock_irq, &card->lock) irm_id = card->irm_node->node_id;
if (channels_hi) c = manage_channel(card, irm_id, generation, channels_hi, CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI, allocate); if (channels_lo && c < 0) { c = manage_channel(card, irm_id, generation, channels_lo, CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO, allocate); if (c >= 0) c += 32; } *channel = c;
if (allocate && channels_mask != 0 && c < 0) *bandwidth = 0;
if (*bandwidth == 0) return;
ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate); if (ret < 0) *bandwidth = 0;
if (allocate && ret < 0) { if (c >= 0) deallocate_channel(card, irm_id, generation, c); *channel = ret; }}EXPORT_SYMBOL(fw_iso_resource_manage);