/* -*- c-basic-offset: 8 -*-
*
* fw-card.c - card level functions
*
* Copyright (C) 2005-2006 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/module.h>
#include <linux/errno.h>
#include <linux/device.h>
#include <linux/rwsem.h>
#include "fw-transaction.h"
#include "fw-topology.h"
#include "fw-device.h"
/* The lib/crc16.c implementation uses the standard (0x8005)
* polynomial, but we need the ITU-T (or CCITT) polynomial (0x1021).
* The implementation below works on an array of host-endian u32
* words, assuming they'll be transmited msb first. */
u16
crc16_itu_t(const u32 *buffer, size_t length)
{
int shift, i;
u32 data;
u16 sum, crc = 0;
for (i = 0; i < length; i++) {
data = *buffer++;
for (shift = 28; shift >= 0; shift -= 4 ) {
sum = ((crc >> 12) ^ (data >> shift)) & 0xf;
crc = (crc << 4) ^ (sum << 12) ^ (sum << 5) ^ (sum);
}
crc &= 0xffff;
}
return crc;
}
static DECLARE_RWSEM(card_rwsem);
static LIST_HEAD(card_list);
static LIST_HEAD(descriptor_list);
static int descriptor_count;
#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 u32 *
generate_config_rom (struct fw_card *card, size_t *config_rom_length)
{
struct fw_descriptor *desc;
static u32 config_rom[256];
int i, j, 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 mathces
* the version stored in the OHCI registers. */
memset(config_rom, 0, sizeof config_rom);
config_rom[0] = bib_crc_length(4) | bib_info_length(4) | bib_crc(0);
config_rom[1] = 0x31333934;
config_rom[2] =
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] = card->guid >> 32;
config_rom[4] = card->guid;
/* Generate root directory. */
i = 5;
config_rom[i++] = 0;
config_rom[i++] = 0x0c0083c0; /* node capabilities */
j = i + descriptor_count;
/* Generate root directory entries for descriptors. */
list_for_each_entry (desc, &descriptor_list, link) {
if (desc->immediate > 0)
config_rom[i++] = desc->immediate;
config_rom[i] = desc->key | (j - i);
i++;
j += desc->length;
}
/* Update root directory length. */
config_rom[5] = (i - 5 - 1) << 16;
/* End of root directory, now copy in descriptors. */
list_for_each_entry (desc, &descriptor_list, link) {
memcpy(&config_rom[i], desc->data, desc->length * 4);
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 = (config_rom[i] >> 16) & 0xff;
config_rom[i] |= crc16_itu_t(&config_rom[i + 1], length);
}
*config_rom_length = j;
return config_rom;
}
static void
update_config_roms (void)
{
struct fw_card *card;
u32 *config_rom;
size_t length;
list_for_each_entry (card, &card_list, link) {
config_rom = generate_config_rom(card, &length);
card->driver->set_config_rom(card, 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;
down_write(&card_rwsem);
list_add_tail (&desc->link, &descriptor_list);
descriptor_count++;
if (desc->immediate > 0)
descriptor_count++;
update_config_roms();
up_write(&card_rwsem);
return 0;
}
EXPORT_SYMBOL(fw_core_add_descriptor);
void
fw_core_remove_descriptor (struct fw_descriptor *desc)
{
down_write(&card_rwsem);
list_del(&desc->link);
descriptor_count--;
if (desc->immediate > 0)
descriptor_count--;
update_config_roms();
up_write(&card_rwsem);
}
EXPORT_SYMBOL(fw_core_remove_descriptor);
static const char gap_count_table[] = {
63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40
};
struct bm_data {
struct fw_transaction t;
struct {
__be32 arg;
__be32 data;
} lock;
u32 old;
int rcode;
struct completion done;
};
static void
complete_bm_lock(struct fw_card *card, int rcode,
void *payload, size_t length, void *data)
{
struct bm_data *bmd = data;
if (rcode == RCODE_COMPLETE)
bmd->old = be32_to_cpu(*(__be32 *) payload);
bmd->rcode = rcode;
complete(&bmd->done);
}
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;
struct bm_data bmd;
unsigned long flags;
int root_id, new_root_id, irm_id, gap_count, generation, grace;
int do_reset = 0;
spin_lock_irqsave(&card->lock, flags);
generation = card->generation;
root = card->root_node->data;
root_id = card->root_node->node_id;
grace = time_after(jiffies, card->reset_jiffies + DIV_ROUND_UP(HZ, 10));
if (card->bm_generation + 1 == 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. */
irm_id = card->irm_node->node_id;
if (!card->irm_node->link_on) {
new_root_id = card->local_node->node_id;
fw_notify("IRM has link off, making local node (%02x) root.\n",
new_root_id);
goto pick_me;
}
bmd.lock.arg = cpu_to_be32(0x3f);
bmd.lock.data = cpu_to_be32(card->local_node->node_id);
spin_unlock_irqrestore(&card->lock, flags);
init_completion(&bmd.done);
fw_send_request(card, &bmd.t, TCODE_LOCK_COMPARE_SWAP,
irm_id, generation,
SCODE_100, CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID,
&bmd.lock, sizeof bmd.lock,
complete_bm_lock, &bmd);
wait_for_completion(&bmd.done);
if (bmd.rcode == RCODE_GENERATION) {
/* Another bus reset happened. Just return,
* the BM work has been rescheduled. */
return;
}
if (bmd.rcode == RCODE_COMPLETE && bmd.old != 0x3f)
/* Somebody else is BM, let them do the work. */
return;
spin_lock_irqsave(&card->lock, flags);
if (bmd.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 = card->local_node->node_id;
fw_notify("BM lock failed, making local node (%02x) root.\n",
new_root_id);
goto pick_me;
}
} else if (card->bm_generation != generation) {
/* OK, we weren't BM in the last generation, and it's
* less than 100ms since last bus reset. Reschedule
* this task 100ms from now. */
spin_unlock_irqrestore(&card->lock, flags);
schedule_delayed_work(&card->work, DIV_ROUND_UP(HZ, 10));
return;
}
/* 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 == NULL) {
/* Either link_on is false, or we failed to read the
* config rom. In either case, pick another root. */
new_root_id = card->local_node->node_id;
} else if (atomic_read(&root->state) != FW_DEVICE_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);
return;
} else if (root->config_rom[2] & bib_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 = card->local_node->node_id;
}
pick_me:
/* Now figure out what gap count to set. */
if (card->topology_type == FW_TOPOLOGY_A &&
card->root_node->max_hops < ARRAY_SIZE(gap_count_table))
gap_count = gap_count_table[card->root_node->max_hops];
else
gap_count = 63;
/* Finally, figure out if we should do a reset or not. If we've
* done less that 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 = 1;
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);
}
}
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);
kref_init(&card->kref);
card->index = atomic_inc_return(&index);
card->driver = driver;
card->device = device;
card->current_tlabel = 0;
card->tlabel_mask = 0;
card->color = 0;
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)
{
u32 *config_rom;
size_t length;
card->max_receive = max_receive;
card->link_speed = link_speed;
card->guid = guid;
/* Activate link_on bit and contender bit in our self ID packets.*/
if (card->driver->update_phy_reg(card, 4, 0,
PHY_LINK_ACTIVE | PHY_CONTENDER) < 0)
return -EIO;
/* The subsystem grabs a reference when the card is added and
* drops it when the driver calls fw_core_remove_card. */
fw_card_get(card);
down_write(&card_rwsem);
config_rom = generate_config_rom (card, &length);
list_add_tail(&card->link, &card_list);
up_write(&card_rwsem);
return card->driver->enable(card, config_rom, length);
}
EXPORT_SYMBOL(fw_card_add);
/* The next few functions implements a dummy driver that use 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 by the dummy
* driver instead of calling into the (possibly) unloaded module. The
* dummy driver just fails all IO. */
static int
dummy_enable(struct fw_card *card, u32 *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,
u32 *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 struct fw_card_driver dummy_driver = {
.name = "dummy",
.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_core_remove_card(struct fw_card *card)
{
card->driver->update_phy_reg(card, 4,
PHY_LINK_ACTIVE | PHY_CONTENDER, 0);
fw_core_initiate_bus_reset(card, 1);
down_write(&card_rwsem);
list_del(&card->link);
up_write(&card_rwsem);
/* Set up the dummy driver. */
card->driver = &dummy_driver;
fw_flush_transactions(card);
fw_destroy_nodes(card);
fw_card_put(card);
}
EXPORT_SYMBOL(fw_core_remove_card);
struct fw_card *
fw_card_get(struct fw_card *card)
{
kref_get(&card->kref);
return card;
}
EXPORT_SYMBOL(fw_card_get);
static void
release_card(struct kref *kref)
{
struct fw_card *card = container_of(kref, struct fw_card, kref);
kfree(card);
}
/* An assumption for fw_card_put() is that the card driver allocates
* the fw_card struct with kalloc and that it has been shut down
* before the last ref is dropped. */
void
fw_card_put(struct fw_card *card)
{
kref_put(&card->kref, release_card);
}
EXPORT_SYMBOL(fw_card_put);
int
fw_core_initiate_bus_reset(struct fw_card *card, int short_reset)
{
int reg = short_reset ? 5 : 1;
/* The following values happen to be the same bit. However be
* explicit for clarity. */
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);
