// 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 = 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); ctx->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); return ctx->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); return ctx->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); return ctx->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); ctx->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); err = ctx->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; err = ctx->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);
// 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 = 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);
ctx->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);
return ctx->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);
return ctx->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);
return ctx->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);
ctx->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);
err = ctx->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;
err = ctx->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);