/*
* 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];
/* ROM header, bus info block, root dir header, capabilities = 7 quadlets */
static size_t config_rom_length = 1 + 4 + 1 + 1;
#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 void 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);
WARN_ON(j != config_rom_length);
}
static void update_config_roms(void)
{
struct fw_card *card;
list_for_each_entry (card, &card_list, link) {
generate_config_rom(card, tmp_config_rom);
card->driver->set_config_rom(card, tmp_config_rom,
config_rom_length);
}
}
static size_t required_space(struct fw_descriptor *desc)
{
/* descriptor + entry into root dir + optional immediate entry */
return desc->length + 1 + (desc->immediate > 0 ? 1 : 0);
}
int fw_core_add_descriptor(struct fw_descriptor *desc)
{
size_t i;
int ret;
/*
* 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);
if (config_rom_length + required_space(desc) > 256) {
ret = -EBUSY;
} else {
list_add_tail(&desc->link, &descriptor_list);
config_rom_length += required_space(desc);
descriptor_count++;
if (desc->immediate > 0)
descriptor_count++;
update_config_roms();
ret = 0;
}
mutex_unlock(&card_mutex);
return ret;
}
EXPORT_SYMBOL(fw_core_add_descriptor);
void fw_core_remove_descriptor(struct fw_descriptor *desc)
{
mutex_lock(&card_mutex);
list_del(&desc->link);
config_rom_length -= required_space(desc);
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)
{
int ret;
card->max_receive = max_receive;
card->link_speed = link_speed;
card->guid = guid;
mutex_lock(&card_mutex);
generate_config_rom(card, tmp_config_rom);
ret = card->driver->enable(card, tmp_config_rom, 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);
