linux/drivers/ieee1394/ieee1394_transactions.c
Stefan Richter 00fc3072e4 ieee1394: remove superfluous assertions
hpsb_read, hpsb_write, hpsb_lock are sleeping functions which nobody is
in danger to use in atomic context.  Besides, in_interrupt does not
cover all types of atomic context.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2009-02-24 14:51:28 +01:00

595 lines
14 KiB
C

/*
* IEEE 1394 for Linux
*
* Transaction support.
*
* Copyright (C) 1999 Andreas E. Bombe
*
* This code is licensed under the GPL. See the file COPYING in the root
* directory of the kernel sources for details.
*/
#include <linux/bitops.h>
#include <linux/compiler.h>
#include <linux/hardirq.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/sched.h> /* because linux/wait.h is broken if CONFIG_SMP=n */
#include <linux/wait.h>
#include <asm/bug.h>
#include <asm/errno.h>
#include <asm/system.h>
#include "ieee1394.h"
#include "ieee1394_types.h"
#include "hosts.h"
#include "ieee1394_core.h"
#include "ieee1394_transactions.h"
#define PREP_ASYNC_HEAD_ADDRESS(tc) \
packet->tcode = tc; \
packet->header[0] = (packet->node_id << 16) | (packet->tlabel << 10) \
| (1 << 8) | (tc << 4); \
packet->header[1] = (packet->host->node_id << 16) | (addr >> 32); \
packet->header[2] = addr & 0xffffffff
#ifndef HPSB_DEBUG_TLABELS
static
#endif
DEFINE_SPINLOCK(hpsb_tlabel_lock);
static DECLARE_WAIT_QUEUE_HEAD(tlabel_wq);
static void fill_async_readquad(struct hpsb_packet *packet, u64 addr)
{
PREP_ASYNC_HEAD_ADDRESS(TCODE_READQ);
packet->header_size = 12;
packet->data_size = 0;
packet->expect_response = 1;
}
static void fill_async_readblock(struct hpsb_packet *packet, u64 addr,
int length)
{
PREP_ASYNC_HEAD_ADDRESS(TCODE_READB);
packet->header[3] = length << 16;
packet->header_size = 16;
packet->data_size = 0;
packet->expect_response = 1;
}
static void fill_async_writequad(struct hpsb_packet *packet, u64 addr,
quadlet_t data)
{
PREP_ASYNC_HEAD_ADDRESS(TCODE_WRITEQ);
packet->header[3] = data;
packet->header_size = 16;
packet->data_size = 0;
packet->expect_response = 1;
}
static void fill_async_writeblock(struct hpsb_packet *packet, u64 addr,
int length)
{
PREP_ASYNC_HEAD_ADDRESS(TCODE_WRITEB);
packet->header[3] = length << 16;
packet->header_size = 16;
packet->expect_response = 1;
packet->data_size = length + (length % 4 ? 4 - (length % 4) : 0);
}
static void fill_async_lock(struct hpsb_packet *packet, u64 addr, int extcode,
int length)
{
PREP_ASYNC_HEAD_ADDRESS(TCODE_LOCK_REQUEST);
packet->header[3] = (length << 16) | extcode;
packet->header_size = 16;
packet->data_size = length;
packet->expect_response = 1;
}
static void fill_phy_packet(struct hpsb_packet *packet, quadlet_t data)
{
packet->header[0] = data;
packet->header[1] = ~data;
packet->header_size = 8;
packet->data_size = 0;
packet->expect_response = 0;
packet->type = hpsb_raw; /* No CRC added */
packet->speed_code = IEEE1394_SPEED_100; /* Force speed to be 100Mbps */
}
static void fill_async_stream_packet(struct hpsb_packet *packet, int length,
int channel, int tag, int sync)
{
packet->header[0] = (length << 16) | (tag << 14) | (channel << 8)
| (TCODE_STREAM_DATA << 4) | sync;
packet->header_size = 4;
packet->data_size = length;
packet->type = hpsb_async;
packet->tcode = TCODE_ISO_DATA;
}
/* same as hpsb_get_tlabel, except that it returns immediately */
static int hpsb_get_tlabel_atomic(struct hpsb_packet *packet)
{
unsigned long flags, *tp;
u8 *next;
int tlabel, n = NODEID_TO_NODE(packet->node_id);
/* Broadcast transactions are complete once the request has been sent.
* Use the same transaction label for all broadcast transactions. */
if (unlikely(n == ALL_NODES)) {
packet->tlabel = 0;
return 0;
}
tp = packet->host->tl_pool[n].map;
next = &packet->host->next_tl[n];
spin_lock_irqsave(&hpsb_tlabel_lock, flags);
tlabel = find_next_zero_bit(tp, 64, *next);
if (tlabel > 63)
tlabel = find_first_zero_bit(tp, 64);
if (tlabel > 63) {
spin_unlock_irqrestore(&hpsb_tlabel_lock, flags);
return -EAGAIN;
}
__set_bit(tlabel, tp);
*next = (tlabel + 1) & 63;
spin_unlock_irqrestore(&hpsb_tlabel_lock, flags);
packet->tlabel = tlabel;
return 0;
}
/**
* hpsb_get_tlabel - allocate a transaction label
* @packet: the packet whose tlabel and tl_pool we set
*
* Every asynchronous transaction on the 1394 bus needs a transaction
* label to match the response to the request. This label has to be
* different from any other transaction label in an outstanding request to
* the same node to make matching possible without ambiguity.
*
* There are 64 different tlabels, so an allocated tlabel has to be freed
* with hpsb_free_tlabel() after the transaction is complete (unless it's
* reused again for the same target node).
*
* Return value: Zero on success, otherwise non-zero. A non-zero return
* generally means there are no available tlabels. If this is called out
* of interrupt or atomic context, then it will sleep until can return a
* tlabel or a signal is received.
*/
int hpsb_get_tlabel(struct hpsb_packet *packet)
{
if (irqs_disabled() || in_atomic())
return hpsb_get_tlabel_atomic(packet);
/* NB: The macro wait_event_interruptible() is called with a condition
* argument with side effect. This is only possible because the side
* effect does not occur until the condition became true, and
* wait_event_interruptible() won't evaluate the condition again after
* that. */
return wait_event_interruptible(tlabel_wq,
!hpsb_get_tlabel_atomic(packet));
}
/**
* hpsb_free_tlabel - free an allocated transaction label
* @packet: packet whose tlabel and tl_pool needs to be cleared
*
* Frees the transaction label allocated with hpsb_get_tlabel(). The
* tlabel has to be freed after the transaction is complete (i.e. response
* was received for a split transaction or packet was sent for a unified
* transaction).
*
* A tlabel must not be freed twice.
*/
void hpsb_free_tlabel(struct hpsb_packet *packet)
{
unsigned long flags, *tp;
int tlabel, n = NODEID_TO_NODE(packet->node_id);
if (unlikely(n == ALL_NODES))
return;
tp = packet->host->tl_pool[n].map;
tlabel = packet->tlabel;
BUG_ON(tlabel > 63 || tlabel < 0);
spin_lock_irqsave(&hpsb_tlabel_lock, flags);
BUG_ON(!__test_and_clear_bit(tlabel, tp));
spin_unlock_irqrestore(&hpsb_tlabel_lock, flags);
wake_up_interruptible(&tlabel_wq);
}
/**
* hpsb_packet_success - Make sense of the ack and reply codes
*
* Make sense of the ack and reply codes and return more convenient error codes:
* 0 = success. -%EBUSY = node is busy, try again. -%EAGAIN = error which can
* probably resolved by retry. -%EREMOTEIO = node suffers from an internal
* error. -%EACCES = this transaction is not allowed on requested address.
* -%EINVAL = invalid address at node.
*/
int hpsb_packet_success(struct hpsb_packet *packet)
{
switch (packet->ack_code) {
case ACK_PENDING:
switch ((packet->header[1] >> 12) & 0xf) {
case RCODE_COMPLETE:
return 0;
case RCODE_CONFLICT_ERROR:
return -EAGAIN;
case RCODE_DATA_ERROR:
return -EREMOTEIO;
case RCODE_TYPE_ERROR:
return -EACCES;
case RCODE_ADDRESS_ERROR:
return -EINVAL;
default:
HPSB_ERR("received reserved rcode %d from node %d",
(packet->header[1] >> 12) & 0xf,
packet->node_id);
return -EAGAIN;
}
case ACK_BUSY_X:
case ACK_BUSY_A:
case ACK_BUSY_B:
return -EBUSY;
case ACK_TYPE_ERROR:
return -EACCES;
case ACK_COMPLETE:
if (packet->tcode == TCODE_WRITEQ
|| packet->tcode == TCODE_WRITEB) {
return 0;
} else {
HPSB_ERR("impossible ack_complete from node %d "
"(tcode %d)", packet->node_id, packet->tcode);
return -EAGAIN;
}
case ACK_DATA_ERROR:
if (packet->tcode == TCODE_WRITEB
|| packet->tcode == TCODE_LOCK_REQUEST) {
return -EAGAIN;
} else {
HPSB_ERR("impossible ack_data_error from node %d "
"(tcode %d)", packet->node_id, packet->tcode);
return -EAGAIN;
}
case ACK_ADDRESS_ERROR:
return -EINVAL;
case ACK_TARDY:
case ACK_CONFLICT_ERROR:
case ACKX_NONE:
case ACKX_SEND_ERROR:
case ACKX_ABORTED:
case ACKX_TIMEOUT:
/* error while sending */
return -EAGAIN;
default:
HPSB_ERR("got invalid ack %d from node %d (tcode %d)",
packet->ack_code, packet->node_id, packet->tcode);
return -EAGAIN;
}
}
struct hpsb_packet *hpsb_make_readpacket(struct hpsb_host *host, nodeid_t node,
u64 addr, size_t length)
{
struct hpsb_packet *packet;
if (length == 0)
return NULL;
packet = hpsb_alloc_packet(length);
if (!packet)
return NULL;
packet->host = host;
packet->node_id = node;
if (hpsb_get_tlabel(packet)) {
hpsb_free_packet(packet);
return NULL;
}
if (length == 4)
fill_async_readquad(packet, addr);
else
fill_async_readblock(packet, addr, length);
return packet;
}
struct hpsb_packet *hpsb_make_writepacket(struct hpsb_host *host, nodeid_t node,
u64 addr, quadlet_t * buffer,
size_t length)
{
struct hpsb_packet *packet;
if (length == 0)
return NULL;
packet = hpsb_alloc_packet(length);
if (!packet)
return NULL;
if (length % 4) { /* zero padding bytes */
packet->data[length >> 2] = 0;
}
packet->host = host;
packet->node_id = node;
if (hpsb_get_tlabel(packet)) {
hpsb_free_packet(packet);
return NULL;
}
if (length == 4) {
fill_async_writequad(packet, addr, buffer ? *buffer : 0);
} else {
fill_async_writeblock(packet, addr, length);
if (buffer)
memcpy(packet->data, buffer, length);
}
return packet;
}
struct hpsb_packet *hpsb_make_streampacket(struct hpsb_host *host, u8 * buffer,
int length, int channel, int tag,
int sync)
{
struct hpsb_packet *packet;
if (length == 0)
return NULL;
packet = hpsb_alloc_packet(length);
if (!packet)
return NULL;
if (length % 4) { /* zero padding bytes */
packet->data[length >> 2] = 0;
}
packet->host = host;
/* Because it is too difficult to determine all PHY speeds and link
* speeds here, we use S100... */
packet->speed_code = IEEE1394_SPEED_100;
/* ...and prevent hpsb_send_packet() from overriding it. */
packet->node_id = LOCAL_BUS | ALL_NODES;
if (hpsb_get_tlabel(packet)) {
hpsb_free_packet(packet);
return NULL;
}
fill_async_stream_packet(packet, length, channel, tag, sync);
if (buffer)
memcpy(packet->data, buffer, length);
return packet;
}
struct hpsb_packet *hpsb_make_lockpacket(struct hpsb_host *host, nodeid_t node,
u64 addr, int extcode,
quadlet_t * data, quadlet_t arg)
{
struct hpsb_packet *p;
u32 length;
p = hpsb_alloc_packet(8);
if (!p)
return NULL;
p->host = host;
p->node_id = node;
if (hpsb_get_tlabel(p)) {
hpsb_free_packet(p);
return NULL;
}
switch (extcode) {
case EXTCODE_FETCH_ADD:
case EXTCODE_LITTLE_ADD:
length = 4;
if (data)
p->data[0] = *data;
break;
default:
length = 8;
if (data) {
p->data[0] = arg;
p->data[1] = *data;
}
break;
}
fill_async_lock(p, addr, extcode, length);
return p;
}
struct hpsb_packet *hpsb_make_lock64packet(struct hpsb_host *host,
nodeid_t node, u64 addr, int extcode,
octlet_t * data, octlet_t arg)
{
struct hpsb_packet *p;
u32 length;
p = hpsb_alloc_packet(16);
if (!p)
return NULL;
p->host = host;
p->node_id = node;
if (hpsb_get_tlabel(p)) {
hpsb_free_packet(p);
return NULL;
}
switch (extcode) {
case EXTCODE_FETCH_ADD:
case EXTCODE_LITTLE_ADD:
length = 8;
if (data) {
p->data[0] = *data >> 32;
p->data[1] = *data & 0xffffffff;
}
break;
default:
length = 16;
if (data) {
p->data[0] = arg >> 32;
p->data[1] = arg & 0xffffffff;
p->data[2] = *data >> 32;
p->data[3] = *data & 0xffffffff;
}
break;
}
fill_async_lock(p, addr, extcode, length);
return p;
}
struct hpsb_packet *hpsb_make_phypacket(struct hpsb_host *host, quadlet_t data)
{
struct hpsb_packet *p;
p = hpsb_alloc_packet(0);
if (!p)
return NULL;
p->host = host;
fill_phy_packet(p, data);
return p;
}
/*
* FIXME - these functions should probably read from / write to user space to
* avoid in kernel buffers for user space callers
*/
/**
* hpsb_read - generic read function
*
* Recognizes the local node ID and act accordingly. Automatically uses a
* quadlet read request if @length == 4 and and a block read request otherwise.
* It does not yet support lengths that are not a multiple of 4.
*
* You must explicitly specifiy the @generation for which the node ID is valid,
* to avoid sending packets to the wrong nodes when we race with a bus reset.
*/
int hpsb_read(struct hpsb_host *host, nodeid_t node, unsigned int generation,
u64 addr, quadlet_t * buffer, size_t length)
{
struct hpsb_packet *packet;
int retval = 0;
if (length == 0)
return -EINVAL;
packet = hpsb_make_readpacket(host, node, addr, length);
if (!packet) {
return -ENOMEM;
}
packet->generation = generation;
retval = hpsb_send_packet_and_wait(packet);
if (retval < 0)
goto hpsb_read_fail;
retval = hpsb_packet_success(packet);
if (retval == 0) {
if (length == 4) {
*buffer = packet->header[3];
} else {
memcpy(buffer, packet->data, length);
}
}
hpsb_read_fail:
hpsb_free_tlabel(packet);
hpsb_free_packet(packet);
return retval;
}
/**
* hpsb_write - generic write function
*
* Recognizes the local node ID and act accordingly. Automatically uses a
* quadlet write request if @length == 4 and and a block write request
* otherwise. It does not yet support lengths that are not a multiple of 4.
*
* You must explicitly specifiy the @generation for which the node ID is valid,
* to avoid sending packets to the wrong nodes when we race with a bus reset.
*/
int hpsb_write(struct hpsb_host *host, nodeid_t node, unsigned int generation,
u64 addr, quadlet_t * buffer, size_t length)
{
struct hpsb_packet *packet;
int retval;
if (length == 0)
return -EINVAL;
packet = hpsb_make_writepacket(host, node, addr, buffer, length);
if (!packet)
return -ENOMEM;
packet->generation = generation;
retval = hpsb_send_packet_and_wait(packet);
if (retval < 0)
goto hpsb_write_fail;
retval = hpsb_packet_success(packet);
hpsb_write_fail:
hpsb_free_tlabel(packet);
hpsb_free_packet(packet);
return retval;
}
int hpsb_lock(struct hpsb_host *host, nodeid_t node, unsigned int generation,
u64 addr, int extcode, quadlet_t *data, quadlet_t arg)
{
struct hpsb_packet *packet;
int retval = 0;
packet = hpsb_make_lockpacket(host, node, addr, extcode, data, arg);
if (!packet)
return -ENOMEM;
packet->generation = generation;
retval = hpsb_send_packet_and_wait(packet);
if (retval < 0)
goto hpsb_lock_fail;
retval = hpsb_packet_success(packet);
if (retval == 0)
*data = packet->data[0];
hpsb_lock_fail:
hpsb_free_tlabel(packet);
hpsb_free_packet(packet);
return retval;
}