diff options
Diffstat (limited to 'drivers/ieee1394/ieee1394_transactions.c')
-rw-r--r-- | drivers/ieee1394/ieee1394_transactions.c | 572 |
1 files changed, 572 insertions, 0 deletions
diff --git a/drivers/ieee1394/ieee1394_transactions.c b/drivers/ieee1394/ieee1394_transactions.c new file mode 100644 index 0000000..10c3d9f --- /dev/null +++ b/drivers/ieee1394/ieee1394_transactions.c @@ -0,0 +1,572 @@ +/* + * 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; + + BUG_ON(in_interrupt()); // We can't be called in an interrupt, yet + + 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; + + BUG_ON(in_interrupt()); // We can't be called in an interrupt, yet + + 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; +} |