linux/drivers/firewire/core-card.c
Stefan Richter cb7c96da36 firewire: core: optimize Topology Map creation
The Topology Map of the local node was created in CPU byte order,
then a temporary big endian copy was created to compute the CRC,
and when a read request to the Topology Map arrived it had to be
converted to big endian byte order again.

We now generate it in big endian byte order in the first place.
This also rids us of 1000 bytes stack usage in tasklet context.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2009-10-14 23:10:48 +02:00

558 lines
15 KiB
C

/*
* Copyright (C) 2005-2007 Kristian Hoegsberg <krh@bitplanet.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <linux/bug.h>
#include <linux/completion.h>
#include <linux/crc-itu-t.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/firewire.h>
#include <linux/firewire-constants.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <asm/atomic.h>
#include <asm/byteorder.h>
#include "core.h"
int fw_compute_block_crc(__be32 *block)
{
int length;
u16 crc;
length = (be32_to_cpu(block[0]) >> 16) & 0xff;
crc = crc_itu_t(0, (u8 *)&block[1], length * 4);
*block |= cpu_to_be32(crc);
return length;
}
static DEFINE_MUTEX(card_mutex);
static LIST_HEAD(card_list);
static LIST_HEAD(descriptor_list);
static int descriptor_count;
static __be32 tmp_config_rom[256];
#define BIB_CRC(v) ((v) << 0)
#define BIB_CRC_LENGTH(v) ((v) << 16)
#define BIB_INFO_LENGTH(v) ((v) << 24)
#define BIB_LINK_SPEED(v) ((v) << 0)
#define BIB_GENERATION(v) ((v) << 4)
#define BIB_MAX_ROM(v) ((v) << 8)
#define BIB_MAX_RECEIVE(v) ((v) << 12)
#define BIB_CYC_CLK_ACC(v) ((v) << 16)
#define BIB_PMC ((1) << 27)
#define BIB_BMC ((1) << 28)
#define BIB_ISC ((1) << 29)
#define BIB_CMC ((1) << 30)
#define BIB_IMC ((1) << 31)
static size_t generate_config_rom(struct fw_card *card, __be32 *config_rom)
{
struct fw_descriptor *desc;
int i, j, k, length;
/*
* Initialize contents of config rom buffer. On the OHCI
* controller, block reads to the config rom accesses the host
* memory, but quadlet read access the hardware bus info block
* registers. That's just crack, but it means we should make
* sure the contents of bus info block in host memory matches
* the version stored in the OHCI registers.
*/
config_rom[0] = cpu_to_be32(
BIB_CRC_LENGTH(4) | BIB_INFO_LENGTH(4) | BIB_CRC(0));
config_rom[1] = cpu_to_be32(0x31333934);
config_rom[2] = cpu_to_be32(
BIB_LINK_SPEED(card->link_speed) |
BIB_GENERATION(card->config_rom_generation++ % 14 + 2) |
BIB_MAX_ROM(2) |
BIB_MAX_RECEIVE(card->max_receive) |
BIB_BMC | BIB_ISC | BIB_CMC | BIB_IMC);
config_rom[3] = cpu_to_be32(card->guid >> 32);
config_rom[4] = cpu_to_be32(card->guid);
/* Generate root directory. */
config_rom[6] = cpu_to_be32(0x0c0083c0); /* node capabilities */
i = 7;
j = 7 + descriptor_count;
/* Generate root directory entries for descriptors. */
list_for_each_entry (desc, &descriptor_list, link) {
if (desc->immediate > 0)
config_rom[i++] = cpu_to_be32(desc->immediate);
config_rom[i] = cpu_to_be32(desc->key | (j - i));
i++;
j += desc->length;
}
/* Update root directory length. */
config_rom[5] = cpu_to_be32((i - 5 - 1) << 16);
/* End of root directory, now copy in descriptors. */
list_for_each_entry (desc, &descriptor_list, link) {
for (k = 0; k < desc->length; k++)
config_rom[i + k] = cpu_to_be32(desc->data[k]);
i += desc->length;
}
/* Calculate CRCs for all blocks in the config rom. This
* assumes that CRC length and info length are identical for
* the bus info block, which is always the case for this
* implementation. */
for (i = 0; i < j; i += length + 1)
length = fw_compute_block_crc(config_rom + i);
return j;
}
static void update_config_roms(void)
{
struct fw_card *card;
size_t length;
list_for_each_entry (card, &card_list, link) {
length = generate_config_rom(card, tmp_config_rom);
card->driver->set_config_rom(card, tmp_config_rom, length);
}
}
int fw_core_add_descriptor(struct fw_descriptor *desc)
{
size_t i;
/*
* Check descriptor is valid; the length of all blocks in the
* descriptor has to add up to exactly the length of the
* block.
*/
i = 0;
while (i < desc->length)
i += (desc->data[i] >> 16) + 1;
if (i != desc->length)
return -EINVAL;
mutex_lock(&card_mutex);
list_add_tail(&desc->link, &descriptor_list);
descriptor_count++;
if (desc->immediate > 0)
descriptor_count++;
update_config_roms();
mutex_unlock(&card_mutex);
return 0;
}
EXPORT_SYMBOL(fw_core_add_descriptor);
void fw_core_remove_descriptor(struct fw_descriptor *desc)
{
mutex_lock(&card_mutex);
list_del(&desc->link);
descriptor_count--;
if (desc->immediate > 0)
descriptor_count--;
update_config_roms();
mutex_unlock(&card_mutex);
}
EXPORT_SYMBOL(fw_core_remove_descriptor);
static void allocate_broadcast_channel(struct fw_card *card, int generation)
{
int channel, bandwidth = 0;
fw_iso_resource_manage(card, generation, 1ULL << 31, &channel,
&bandwidth, true, card->bm_transaction_data);
if (channel == 31) {
card->broadcast_channel_allocated = true;
device_for_each_child(card->device, (void *)(long)generation,
fw_device_set_broadcast_channel);
}
}
static const char gap_count_table[] = {
63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40
};
void fw_schedule_bm_work(struct fw_card *card, unsigned long delay)
{
fw_card_get(card);
if (!schedule_delayed_work(&card->work, delay))
fw_card_put(card);
}
static void fw_card_bm_work(struct work_struct *work)
{
struct fw_card *card = container_of(work, struct fw_card, work.work);
struct fw_device *root_device;
struct fw_node *root_node;
unsigned long flags;
int root_id, new_root_id, irm_id, local_id;
int gap_count, generation, grace, rcode;
bool do_reset = false;
bool root_device_is_running;
bool root_device_is_cmc;
spin_lock_irqsave(&card->lock, flags);
if (card->local_node == NULL) {
spin_unlock_irqrestore(&card->lock, flags);
goto out_put_card;
}
generation = card->generation;
root_node = card->root_node;
fw_node_get(root_node);
root_device = root_node->data;
root_device_is_running = root_device &&
atomic_read(&root_device->state) == FW_DEVICE_RUNNING;
root_device_is_cmc = root_device && root_device->cmc;
root_id = root_node->node_id;
irm_id = card->irm_node->node_id;
local_id = card->local_node->node_id;
grace = time_after(jiffies, card->reset_jiffies + DIV_ROUND_UP(HZ, 8));
if (is_next_generation(generation, card->bm_generation) ||
(card->bm_generation != generation && grace)) {
/*
* This first step is to figure out who is IRM and
* then try to become bus manager. If the IRM is not
* well defined (e.g. does not have an active link
* layer or does not responds to our lock request, we
* will have to do a little vigilante bus management.
* In that case, we do a goto into the gap count logic
* so that when we do the reset, we still optimize the
* gap count. That could well save a reset in the
* next generation.
*/
if (!card->irm_node->link_on) {
new_root_id = local_id;
fw_notify("IRM has link off, making local node (%02x) root.\n",
new_root_id);
goto pick_me;
}
card->bm_transaction_data[0] = cpu_to_be32(0x3f);
card->bm_transaction_data[1] = cpu_to_be32(local_id);
spin_unlock_irqrestore(&card->lock, flags);
rcode = fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
irm_id, generation, SCODE_100,
CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID,
card->bm_transaction_data,
sizeof(card->bm_transaction_data));
if (rcode == RCODE_GENERATION)
/* Another bus reset, BM work has been rescheduled. */
goto out;
if (rcode == RCODE_COMPLETE &&
card->bm_transaction_data[0] != cpu_to_be32(0x3f)) {
/* Somebody else is BM. Only act as IRM. */
if (local_id == irm_id)
allocate_broadcast_channel(card, generation);
goto out;
}
spin_lock_irqsave(&card->lock, flags);
if (rcode != RCODE_COMPLETE) {
/*
* The lock request failed, maybe the IRM
* isn't really IRM capable after all. Let's
* do a bus reset and pick the local node as
* root, and thus, IRM.
*/
new_root_id = local_id;
fw_notify("BM lock failed, making local node (%02x) root.\n",
new_root_id);
goto pick_me;
}
} else if (card->bm_generation != generation) {
/*
* We weren't BM in the last generation, and the last
* bus reset is less than 125ms ago. Reschedule this job.
*/
spin_unlock_irqrestore(&card->lock, flags);
fw_schedule_bm_work(card, DIV_ROUND_UP(HZ, 8));
goto out;
}
/*
* We're bus manager for this generation, so next step is to
* make sure we have an active cycle master and do gap count
* optimization.
*/
card->bm_generation = generation;
if (root_device == NULL) {
/*
* Either link_on is false, or we failed to read the
* config rom. In either case, pick another root.
*/
new_root_id = local_id;
} else if (!root_device_is_running) {
/*
* If we haven't probed this device yet, bail out now
* and let's try again once that's done.
*/
spin_unlock_irqrestore(&card->lock, flags);
goto out;
} else if (root_device_is_cmc) {
/*
* FIXME: I suppose we should set the cmstr bit in the
* STATE_CLEAR register of this node, as described in
* 1394-1995, 8.4.2.6. Also, send out a force root
* packet for this node.
*/
new_root_id = root_id;
} else {
/*
* Current root has an active link layer and we
* successfully read the config rom, but it's not
* cycle master capable.
*/
new_root_id = local_id;
}
pick_me:
/*
* Pick a gap count from 1394a table E-1. The table doesn't cover
* the typically much larger 1394b beta repeater delays though.
*/
if (!card->beta_repeaters_present &&
root_node->max_hops < ARRAY_SIZE(gap_count_table))
gap_count = gap_count_table[root_node->max_hops];
else
gap_count = 63;
/*
* Finally, figure out if we should do a reset or not. If we have
* done less than 5 resets with the same physical topology and we
* have either a new root or a new gap count setting, let's do it.
*/
if (card->bm_retries++ < 5 &&
(card->gap_count != gap_count || new_root_id != root_id))
do_reset = true;
spin_unlock_irqrestore(&card->lock, flags);
if (do_reset) {
fw_notify("phy config: card %d, new root=%x, gap_count=%d\n",
card->index, new_root_id, gap_count);
fw_send_phy_config(card, new_root_id, generation, gap_count);
fw_core_initiate_bus_reset(card, 1);
/* Will allocate broadcast channel after the reset. */
} else {
if (local_id == irm_id)
allocate_broadcast_channel(card, generation);
}
out:
fw_node_put(root_node);
out_put_card:
fw_card_put(card);
}
static void flush_timer_callback(unsigned long data)
{
struct fw_card *card = (struct fw_card *)data;
fw_flush_transactions(card);
}
void fw_card_initialize(struct fw_card *card,
const struct fw_card_driver *driver,
struct device *device)
{
static atomic_t index = ATOMIC_INIT(-1);
card->index = atomic_inc_return(&index);
card->driver = driver;
card->device = device;
card->current_tlabel = 0;
card->tlabel_mask = 0;
card->color = 0;
card->broadcast_channel = BROADCAST_CHANNEL_INITIAL;
kref_init(&card->kref);
init_completion(&card->done);
INIT_LIST_HEAD(&card->transaction_list);
spin_lock_init(&card->lock);
setup_timer(&card->flush_timer,
flush_timer_callback, (unsigned long)card);
card->local_node = NULL;
INIT_DELAYED_WORK(&card->work, fw_card_bm_work);
}
EXPORT_SYMBOL(fw_card_initialize);
int fw_card_add(struct fw_card *card,
u32 max_receive, u32 link_speed, u64 guid)
{
size_t length;
int ret;
card->max_receive = max_receive;
card->link_speed = link_speed;
card->guid = guid;
mutex_lock(&card_mutex);
length = generate_config_rom(card, tmp_config_rom);
ret = card->driver->enable(card, tmp_config_rom, length);
if (ret == 0)
list_add_tail(&card->link, &card_list);
mutex_unlock(&card_mutex);
return ret;
}
EXPORT_SYMBOL(fw_card_add);
/*
* The next few functions implement a dummy driver that is used once a card
* driver shuts down an fw_card. This allows the driver to cleanly unload,
* as all IO to the card will be handled (and failed) by the dummy driver
* instead of calling into the module. Only functions for iso context
* shutdown still need to be provided by the card driver.
*/
static int dummy_enable(struct fw_card *card,
const __be32 *config_rom, size_t length)
{
BUG();
return -1;
}
static int dummy_update_phy_reg(struct fw_card *card, int address,
int clear_bits, int set_bits)
{
return -ENODEV;
}
static int dummy_set_config_rom(struct fw_card *card,
const __be32 *config_rom, size_t length)
{
/*
* We take the card out of card_list before setting the dummy
* driver, so this should never get called.
*/
BUG();
return -1;
}
static void dummy_send_request(struct fw_card *card, struct fw_packet *packet)
{
packet->callback(packet, card, -ENODEV);
}
static void dummy_send_response(struct fw_card *card, struct fw_packet *packet)
{
packet->callback(packet, card, -ENODEV);
}
static int dummy_cancel_packet(struct fw_card *card, struct fw_packet *packet)
{
return -ENOENT;
}
static int dummy_enable_phys_dma(struct fw_card *card,
int node_id, int generation)
{
return -ENODEV;
}
static const struct fw_card_driver dummy_driver_template = {
.enable = dummy_enable,
.update_phy_reg = dummy_update_phy_reg,
.set_config_rom = dummy_set_config_rom,
.send_request = dummy_send_request,
.cancel_packet = dummy_cancel_packet,
.send_response = dummy_send_response,
.enable_phys_dma = dummy_enable_phys_dma,
};
void fw_card_release(struct kref *kref)
{
struct fw_card *card = container_of(kref, struct fw_card, kref);
complete(&card->done);
}
void fw_core_remove_card(struct fw_card *card)
{
struct fw_card_driver dummy_driver = dummy_driver_template;
card->driver->update_phy_reg(card, 4,
PHY_LINK_ACTIVE | PHY_CONTENDER, 0);
fw_core_initiate_bus_reset(card, 1);
mutex_lock(&card_mutex);
list_del_init(&card->link);
mutex_unlock(&card_mutex);
/* Switch off most of the card driver interface. */
dummy_driver.free_iso_context = card->driver->free_iso_context;
dummy_driver.stop_iso = card->driver->stop_iso;
card->driver = &dummy_driver;
fw_destroy_nodes(card);
/* Wait for all users, especially device workqueue jobs, to finish. */
fw_card_put(card);
wait_for_completion(&card->done);
WARN_ON(!list_empty(&card->transaction_list));
del_timer_sync(&card->flush_timer);
}
EXPORT_SYMBOL(fw_core_remove_card);
int fw_core_initiate_bus_reset(struct fw_card *card, int short_reset)
{
int reg = short_reset ? 5 : 1;
int bit = short_reset ? PHY_BUS_SHORT_RESET : PHY_BUS_RESET;
return card->driver->update_phy_reg(card, reg, 0, bit);
}
EXPORT_SYMBOL(fw_core_initiate_bus_reset);