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Date: Mon, 1 Sep 2014 15:08:42 +0200
From: Arend van Spriel <arend@...adcom.com>
To: Dan Carpenter <dan.carpenter@...cle.com>
CC: Eli Billauer <eli.billauer@...il.com>,
<gregkh@...uxfoundation.org>, <arnd@...db.de>,
<devel@...verdev.osuosl.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] staging: xillybus: Move out of staging
On 09/01/14 14:13, Dan Carpenter wrote:
> Pretty nice. This is very special purpose hardware and the UAPI for
> this is fine. The documentation seems good. I had some minor style
> comments but nothing major stands out.
Maybe it would be better to use the DMA-API instead of the PCI wrappers.
Regards,
Arend
> These days I quite like the --strict option for checkpatch.pl.
>
> for i in $(find drivers/staging/xillybus/ -name \*\.c)
> do ./scripts/checkpatch.pl --strict -f $i
> done
>
>> +irqreturn_t xillybus_isr(int irq, void *data)
>> +{
>> + struct xilly_endpoint *ep = data;
>> + u32 *buf;
>> + unsigned int buf_size;
>> + int i;
>> + int opcode;
>> + unsigned int msg_channel, msg_bufno, msg_data, msg_dir;
>> + struct xilly_channel *channel;
>> +
>> + buf = ep->msgbuf_addr;
>> + buf_size = ep->msg_buf_size/sizeof(u32);
>> +
>> + ep->ephw->hw_sync_sgl_for_cpu(ep,
>> + ep->msgbuf_dma_addr,
>> + ep->msg_buf_size,
>> + DMA_FROM_DEVICE);
>> +
>> + for (i = 0; i< buf_size; i += 2)
>
> Add an open curly brace here for the multi-line indent.
>
>> + if (((buf[i+1]>> 28)& 0xf) != ep->msg_counter) {
>> + malformed_message(ep,&buf[i]);
>> + dev_warn(ep->dev,
>> + "Sending a NACK on counter %x (instead of %x) on entry %d\n",
>> + ((buf[i+1]>> 28)& 0xf),
>> + ep->msg_counter,
>> + i/2);
>> +
>> + if (++ep->failed_messages> 10) {
>> + dev_err(ep->dev,
>> + "Lost sync with interrupt messages. Stopping.\n");
>> + } else {
>> + ep->ephw->hw_sync_sgl_for_device(
>> + ep,
>> + ep->msgbuf_dma_addr,
>> + ep->msg_buf_size,
>> + DMA_FROM_DEVICE);
>> +
>> + iowrite32(0x01, /* Message NACK */
>> + ep->registers + fpga_msg_ctrl_reg);
>> + }
>> + return IRQ_HANDLED;
>> + } else if (buf[i]& (1<< 22)) /* Last message */
>> + break;
>> +
>> + if (i>= buf_size) {
>> + dev_err(ep->dev, "Bad interrupt message. Stopping.\n");
>> + return IRQ_HANDLED;
>> + }
>> +
>> + buf_size = i;
>
> The buf_size is actually "i + 2". "i" is the second last index.
>
>> +
>> + for (i = 0; i<= buf_size; i += 2) { /* Scan through messages */
>
> Then this loop becomes a more normal "i< buf_size".
>
>> + opcode = (buf[i]>> 24)& 0xff;
>> +
>> + msg_dir = buf[i]& 1;
>> + msg_channel = (buf[i]>> 1)& 0x7ff;
>> + msg_bufno = (buf[i]>> 12)& 0x3ff;
>> + msg_data = buf[i+1]& 0xfffffff;
>> +
>> + switch (opcode) {
>> + case XILLYMSG_OPCODE_RELEASEBUF:
>> +
>> + if ((msg_channel> ep->num_channels) ||
>> + (msg_channel == 0)) {
>> + malformed_message(ep,&buf[i]);
>> + break;
>> + }
>> +
>> + channel = ep->channels[msg_channel];
>> +
>> + if (msg_dir) { /* Write channel */
>> + if (msg_bufno>= channel->num_wr_buffers) {
>> + malformed_message(ep,&buf[i]);
>> + break;
>> + }
>> + spin_lock(&channel->wr_spinlock);
>> + channel->wr_buffers[msg_bufno]->end_offset =
>> + msg_data;
>> + channel->wr_fpga_buf_idx = msg_bufno;
>> + channel->wr_empty = 0;
>> + channel->wr_sleepy = 0;
>> + spin_unlock(&channel->wr_spinlock);
>> +
>> + wake_up_interruptible(&channel->wr_wait);
>> +
>> + } else {
>> + /* Read channel */
>> +
>> + if (msg_bufno>= channel->num_rd_buffers) {
>> + malformed_message(ep,&buf[i]);
>> + break;
>> + }
>> +
>> + spin_lock(&channel->rd_spinlock);
>> + channel->rd_fpga_buf_idx = msg_bufno;
>> + channel->rd_full = 0;
>> + spin_unlock(&channel->rd_spinlock);
>> +
>> + wake_up_interruptible(&channel->rd_wait);
>> + if (!channel->rd_synchronous)
>> + queue_delayed_work(
>> + xillybus_wq,
>> + &channel->rd_workitem,
>> + XILLY_RX_TIMEOUT);
>> + }
>> +
>> + break;
>> + case XILLYMSG_OPCODE_NONEMPTY:
>> + if ((msg_channel> ep->num_channels) ||
>> + (msg_channel == 0) || (!msg_dir) ||
>> + !ep->channels[msg_channel]->wr_supports_nonempty) {
>> + malformed_message(ep,&buf[i]);
>> + break;
>> + }
>> +
>> + channel = ep->channels[msg_channel];
>> +
>> + if (msg_bufno>= channel->num_wr_buffers) {
>> + malformed_message(ep,&buf[i]);
>> + break;
>> + }
>> + spin_lock(&channel->wr_spinlock);
>> + if (msg_bufno == channel->wr_host_buf_idx)
>> + channel->wr_ready = 1;
>> + spin_unlock(&channel->wr_spinlock);
>> +
>> + wake_up_interruptible(&channel->wr_ready_wait);
>> +
>> + break;
>> + case XILLYMSG_OPCODE_QUIESCEACK:
>> + ep->idtlen = msg_data;
>> + wake_up_interruptible(&ep->ep_wait);
>> +
>> + break;
>> + case XILLYMSG_OPCODE_FIFOEOF:
>> + if ((msg_channel> ep->num_channels) ||
>> + (msg_channel == 0) || (!msg_dir) ||
>> + !ep->channels[msg_channel]->num_wr_buffers) {
>> + malformed_message(ep,&buf[i]);
>> + break;
>> + }
>> + channel = ep->channels[msg_channel];
>> + spin_lock(&channel->wr_spinlock);
>> + channel->wr_eof = msg_bufno;
>> + channel->wr_sleepy = 0;
>> +
>> + channel->wr_hangup = channel->wr_empty&&
>> + (channel->wr_host_buf_idx == msg_bufno);
>> +
>> + spin_unlock(&channel->wr_spinlock);
>> +
>> + wake_up_interruptible(&channel->wr_wait);
>> +
>> + break;
>> + case XILLYMSG_OPCODE_FATAL_ERROR:
>> + ep->fatal_error = 1;
>> + wake_up_interruptible(&ep->ep_wait); /* For select() */
>> + dev_err(ep->dev,
>> + "FPGA reported a fatal error. This means that the low-level communication with the device has failed. This hardware problem is most likely unrelated to Xillybus (neither kernel module nor FPGA core), but reports are still welcome. All I/O is aborted.\n");
>> + break;
>> + default:
>> + malformed_message(ep,&buf[i]);
>> + break;
>> + }
>> + }
>> +
>> + ep->ephw->hw_sync_sgl_for_device(ep,
>> + ep->msgbuf_dma_addr,
>> + ep->msg_buf_size,
>> + DMA_FROM_DEVICE);
>> +
>> + ep->msg_counter = (ep->msg_counter + 1)& 0xf;
>> + ep->failed_messages = 0;
>> + iowrite32(0x03, ep->registers + fpga_msg_ctrl_reg); /* Message ACK */
>> +
>> + return IRQ_HANDLED;
>> +}
>> +EXPORT_SYMBOL(xillybus_isr);
>> +
>> +/*
>> + * A few trivial memory management functions.
>> + * NOTE: These functions are used only on probe and remove, and therefore
>> + * no locks are applied!
>> + */
>> +
>> +static void xillybus_autoflush(struct work_struct *work);
>> +
>> +struct xilly_alloc_state {
>> + void *salami;
>> + int left_of_salami;
>> + int nbuffer;
>> + enum dma_data_direction direction;
>> + u32 regdirection;
>> +};
>> +
>> +static int xilly_get_dma_buffers(struct xilly_endpoint *ep,
>> + struct xilly_alloc_state *s,
>> + struct xilly_buffer **buffers,
>> + int bufnum, int bytebufsize)
>> +{
>> + int i, rc;
>> + dma_addr_t dma_addr;
>> + struct device *dev = ep->dev;
>> + struct xilly_buffer *this_buffer = NULL; /* Init to silence warning */
>> +
>> + if (buffers) { /* Not the message buffer */
>> + this_buffer = devm_kzalloc(
>> + dev, bufnum * sizeof(struct xilly_buffer),
>
> Use devm_kcalloc().
>
>> + GFP_KERNEL);
>> +
>> + if (!this_buffer)
>
> Remove the blank line between the allocation and the test. The same
> throughout.
>
>> + return -ENOMEM;
>> + }
>> +
>> + for (i = 0; i< bufnum; i++) {
>> + /*
>> + * Buffers are expected in descending size order, so there
>> + * is either enough space for this buffer or none at all.
>> + */
>> +
>> + if ((s->left_of_salami< bytebufsize)&&
>> + (s->left_of_salami> 0)) {
>> + dev_err(ep->dev,
>> + "Corrupt buffer allocation in IDT. Aborting.\n");
>> + return -ENODEV;
>> + }
>> +
>> + if (s->left_of_salami == 0) {
>> + int allocorder, allocsize;
>> +
>> + allocsize = PAGE_SIZE;
>> + allocorder = 0;
>> + while (bytebufsize> allocsize) {
>> + allocsize *= 2;
>> + allocorder++;
>> + }
>> +
>> + s->salami = (void *) devm_get_free_pages(
>> + dev,
>> + GFP_KERNEL | __GFP_DMA32 | __GFP_ZERO,
>> + allocorder);
>> +
>> + if (!s->salami)
>> + return -ENOMEM;
>> + s->left_of_salami = allocsize;
>> + }
>> +
>> + rc = ep->ephw->map_single(ep, s->salami,
>> + bytebufsize, s->direction,
>> + &dma_addr);
>> +
>> + if (rc)
>> + return rc;
>> +
>> + iowrite32((u32) (dma_addr& 0xffffffff),
>> + ep->registers + fpga_dma_bufaddr_lowaddr_reg);
>> + iowrite32(((u32) ((((u64) dma_addr)>> 32)& 0xffffffff)),
>> + ep->registers + fpga_dma_bufaddr_highaddr_reg);
>> +
>> + if (buffers) { /* Not the message buffer */
>> + this_buffer->addr = s->salami;
>> + this_buffer->dma_addr = dma_addr;
>> + buffers[i] = this_buffer++;
>> +
>> + iowrite32(s->regdirection | s->nbuffer++,
>> + ep->registers + fpga_dma_bufno_reg);
>> + } else {
>> + ep->msgbuf_addr = s->salami;
>> + ep->msgbuf_dma_addr = dma_addr;
>> + ep->msg_buf_size = bytebufsize;
>> +
>> + iowrite32(s->regdirection,
>> + ep->registers + fpga_dma_bufno_reg);
>> + }
>> +
>> + s->left_of_salami -= bytebufsize;
>> + s->salami += bytebufsize;
>> + }
>> + return 0; /* Success */
>
> Remove the obvious comment. Grep for "Success" and remove all those
> comments.
>
>> +}
>> +
>> +static int xilly_setupchannels(struct xilly_endpoint *ep,
>> + unsigned char *chandesc,
>> + int entries
>> + )
>
> Put the ')' on the line before.
>
>> +{
>> + struct device *dev = ep->dev;
>> + int i, entry, rc;
>> + struct xilly_channel *channel;
>> + int channelnum, bufnum, bufsize, format, is_writebuf;
>> + int bytebufsize;
>> + int synchronous, allowpartial, exclusive_open, seekable;
>> + int supports_nonempty;
>> + int msg_buf_done = 0;
>> +
>> + struct xilly_alloc_state rd_alloc = {
>> + .salami = NULL,
>> + .left_of_salami = 0,
>> + .nbuffer = 1,
>> + .direction = DMA_TO_DEVICE,
>> + .regdirection = 0,
>> + };
>> +
>> + struct xilly_alloc_state wr_alloc = {
>> + .salami = NULL,
>> + .left_of_salami = 0,
>> + .nbuffer = 1,
>> + .direction = DMA_FROM_DEVICE,
>> + .regdirection = 0x80000000,
>> + };
>> +
>> + channel = devm_kzalloc(dev, ep->num_channels *
>> + sizeof(struct xilly_channel), GFP_KERNEL);
>> +
>> + if (!channel)
>> + goto memfail;
>
> Use devm_kcalloc(). Remove the blank line between the alloc and the
> test for NULL. Just return directly. The error message at memfail is
> useless and pointless gotos are annoying.
>
>> +
>> + ep->channels = devm_kzalloc(dev, (ep->num_channels + 1) *
>> + sizeof(struct xilly_channel *),
>> + GFP_KERNEL);
>> +
>> + if (!ep->channels)
>> + goto memfail;
>
> Same throughout.
>
>> +
>> + ep->channels[0] = NULL; /* Channel 0 is message buf. */
>> +
>> + /* Initialize all channels with defaults */
>> +
>> + for (i = 1; i<= ep->num_channels; i++) {
>> + channel->wr_buffers = NULL;
>> + channel->rd_buffers = NULL;
>> + channel->num_wr_buffers = 0;
>> + channel->num_rd_buffers = 0;
>> + channel->wr_fpga_buf_idx = -1;
>> + channel->wr_host_buf_idx = 0;
>> + channel->wr_host_buf_pos = 0;
>> + channel->wr_empty = 1;
>> + channel->wr_ready = 0;
>> + channel->wr_sleepy = 1;
>> + channel->rd_fpga_buf_idx = 0;
>> + channel->rd_host_buf_idx = 0;
>> + channel->rd_host_buf_pos = 0;
>> + channel->rd_full = 0;
>> + channel->wr_ref_count = 0;
>> + channel->rd_ref_count = 0;
>> +
>> + spin_lock_init(&channel->wr_spinlock);
>> + spin_lock_init(&channel->rd_spinlock);
>> + mutex_init(&channel->wr_mutex);
>> + mutex_init(&channel->rd_mutex);
>> + init_waitqueue_head(&channel->rd_wait);
>> + init_waitqueue_head(&channel->wr_wait);
>> + init_waitqueue_head(&channel->wr_ready_wait);
>> +
>> + INIT_DELAYED_WORK(&channel->rd_workitem, xillybus_autoflush);
>> +
>> + channel->endpoint = ep;
>> + channel->chan_num = i;
>> +
>> + channel->log2_element_size = 0;
>> +
>> + ep->channels[i] = channel++;
>> + }
>> +
>> + for (entry = 0; entry< entries; entry++, chandesc += 4) {
>> + struct xilly_buffer **buffers = NULL;
>> +
>> + is_writebuf = chandesc[0]& 0x01;
>> + channelnum = (chandesc[0]>> 1) | ((chandesc[1]& 0x0f)<< 7);
>> + format = (chandesc[1]>> 4)& 0x03;
>> + allowpartial = (chandesc[1]>> 6)& 0x01;
>> + synchronous = (chandesc[1]>> 7)& 0x01;
>> + bufsize = 1<< (chandesc[2]& 0x1f);
>> + bufnum = 1<< (chandesc[3]& 0x0f);
>> + exclusive_open = (chandesc[2]>> 7)& 0x01;
>> + seekable = (chandesc[2]>> 6)& 0x01;
>> + supports_nonempty = (chandesc[2]>> 5)& 0x01;
>> +
>> + if ((channelnum> ep->num_channels) ||
>> + ((channelnum == 0)&& !is_writebuf)) {
>> + dev_err(ep->dev,
>> + "IDT requests channel out of range. Aborting.\n");
>> + return -ENODEV;
>> + }
>> +
>> + channel = ep->channels[channelnum]; /* NULL for msg channel */
>> +
>> + if (!is_writebuf || channelnum> 0) {
>> + channel->log2_element_size = ((format> 2) ?
>> + 2 : format);
>> +
>> + bytebufsize = channel->rd_buf_size = bufsize *
>> + (1<< channel->log2_element_size);
>> +
>> + buffers = devm_kzalloc(dev,
>> + bufnum * sizeof(struct xilly_buffer *),
>> + GFP_KERNEL);
>> +
>> + if (!buffers)
>> + goto memfail;
>> + } else {
>> + bytebufsize = bufsize<< 2;
>> + }
>> +
>> + if (!is_writebuf) {
>> + channel->num_rd_buffers = bufnum;
>> + channel->rd_allow_partial = allowpartial;
>> + channel->rd_synchronous = synchronous;
>> + channel->rd_exclusive_open = exclusive_open;
>> + channel->seekable = seekable;
>> +
>> + channel->rd_buffers = buffers;
>> + rc = xilly_get_dma_buffers(ep,&rd_alloc, buffers,
>> + bufnum, bytebufsize);
>> + } else if (channelnum> 0) {
>> + channel->num_wr_buffers = bufnum;
>> +
>> + channel->seekable = seekable;
>> + channel->wr_supports_nonempty = supports_nonempty;
>> +
>> + channel->wr_allow_partial = allowpartial;
>> + channel->wr_synchronous = synchronous;
>> + channel->wr_exclusive_open = exclusive_open;
>> +
>> + channel->wr_buffers = buffers;
>> + rc = xilly_get_dma_buffers(ep,&wr_alloc, buffers,
>> + bufnum, bytebufsize);
>> + } else {
>> + rc = xilly_get_dma_buffers(ep,&wr_alloc, NULL,
>> + bufnum, bytebufsize);
>> + msg_buf_done++;
>> + }
>> +
>> + if (rc)
>> + goto memfail;
>> + }
>> +
>> + if (!msg_buf_done) {
>> + dev_err(ep->dev,
>> + "Corrupt IDT: No message buffer. Aborting.\n");
>> + return -ENODEV;
>> + }
>> + return 0;
>> +
>> +memfail:
>> + dev_err(ep->dev,
>> + "Failed to assign DMA buffer memory. Aborting.\n");
>> + return -ENOMEM;
>> +}
>> +
>> +static void xilly_scan_idt(struct xilly_endpoint *endpoint,
>> + struct xilly_idt_handle *idt_handle)
>> +{
>> + int count = 0;
>> + unsigned char *idt = endpoint->channels[1]->wr_buffers[0]->addr;
>> + unsigned char *end_of_idt = idt + endpoint->idtlen - 4;
>> + unsigned char *scan;
>> + int len;
>> +
>> + scan = idt;
>> + idt_handle->idt = idt;
>> +
>> + scan++; /* Skip version number */
>> +
>> + while ((scan<= end_of_idt)&& *scan) {
>> + while ((scan<= end_of_idt)&& *scan++)
>> + /* Do nothing, just scan thru string */;
>> + count++;
>> + }
>> +
>> + scan++;
>> +
>> + if (scan> end_of_idt) {
>> + dev_err(endpoint->dev,
>> + "IDT device name list overflow. Aborting.\n");
>> + idt_handle->chandesc = NULL;
>> + return;
>
> This is a ugly kind of error handling where the caller has to check a
> magical variable to test for success. Just return an error code.
>
>
>> + }
>> + idt_handle->chandesc = scan;
>> +
>> + len = endpoint->idtlen - (3 + ((int) (scan - idt)));
>> +
>> + if (len& 0x03) {
>> + idt_handle->chandesc = NULL;
>> +
>> + dev_err(endpoint->dev,
>> + "Corrupt IDT device name list. Aborting.\n");
>> + }
>> +
>> + idt_handle->entries = len>> 2;
>> +
>> + endpoint->num_channels = count;
>> +}
>> +
>> +static int xilly_obtain_idt(struct xilly_endpoint *endpoint)
>> +{
>> + int rc = 0;
>
>
> No need for this. grep for "rc = 0" and remove half of them.
>
>> + struct xilly_channel *channel;
>> + unsigned char *version;
>> +
>> + channel = endpoint->channels[1]; /* This should be generated ad-hoc */
>> +
>> + channel->wr_sleepy = 1;
>> +
>> + iowrite32(1 |
>> + (3<< 24), /* Opcode 3 for channel 0 = Send IDT */
>> + endpoint->registers + fpga_buf_ctrl_reg);
>> +
>> + wait_event_interruptible_timeout(channel->wr_wait,
>> + (!channel->wr_sleepy),
>> + XILLY_TIMEOUT);
>> +
>> + if (channel->wr_sleepy) {
>> + dev_err(endpoint->dev, "Failed to obtain IDT. Aborting.\n");
>> +
>> + if (endpoint->fatal_error)
>> + return -EIO;
>> +
>> + rc = -ENODEV;
>> + return rc;
>
> Just return -ENODEV;
>
>> + }
>> +
>> + endpoint->ephw->hw_sync_sgl_for_cpu(
>> + channel->endpoint,
>> + channel->wr_buffers[0]->dma_addr,
>> + channel->wr_buf_size,
>> + DMA_FROM_DEVICE);
>> +
>> + if (channel->wr_buffers[0]->end_offset != endpoint->idtlen) {
>> + dev_err(endpoint->dev,
>> + "IDT length mismatch (%d != %d). Aborting.\n",
>> + channel->wr_buffers[0]->end_offset, endpoint->idtlen);
>> + rc = -ENODEV;
>> + return rc;
>
> return -ENODEV;
>
>> + }
>> +
>> + if (crc32_le(~0, channel->wr_buffers[0]->addr,
>> + endpoint->idtlen+1) != 0) {
>> + dev_err(endpoint->dev, "IDT failed CRC check. Aborting.\n");
>> + rc = -ENODEV;
>> + return rc;
>
> Same throughout.
>
>> + }
>> +
>> + version = channel->wr_buffers[0]->addr;
>> +
>> + /* Check version number. Accept anything below 0x82 for now. */
>> + if (*version> 0x82) {
>> + dev_err(endpoint->dev,
>> + "No support for IDT version 0x%02x. Maybe the xillybus driver needs an upgarde. Aborting.\n",
>> + (int) *version);
>
> This cast isn't correct.
>
>> + rc = -ENODEV;
>> + return rc;
>> + }
>> +
>> + return 0; /* Success */
>> +}
>> +
>> +static ssize_t xillybus_read(struct file *filp, char __user *userbuf,
>> + size_t count, loff_t *f_pos)
>> +{
>> + ssize_t rc;
>> + unsigned long flags;
>> + int bytes_done = 0;
>> + int no_time_left = 0;
>> + long deadline, left_to_sleep;
>> + struct xilly_channel *channel = filp->private_data;
>> +
>> + int empty, reached_eof, exhausted, ready;
>> + /* Initializations are there only to silence warnings */
>> +
>> + int howmany = 0, bufpos = 0, bufidx = 0, bufferdone = 0;
>> + int waiting_bufidx;
>> +
>> + if (channel->endpoint->fatal_error)
>> + return -EIO;
>> +
>> + deadline = jiffies + 1 + XILLY_RX_TIMEOUT;
>> +
>> + rc = mutex_lock_interruptible(&channel->wr_mutex);
>> +
>> + if (rc)
>> + return rc;
>> +
>> + rc = 0; /* Just to be clear about it. Compiler optimizes this out */
>
>
> I don't think this adds any clarity. We know "rc" is zero from the line
> before. Just remove it. Same throughout.
>
>> +
>> + while (1) { /* Note that we may drop mutex within this loop */
>> + int bytes_to_do = count - bytes_done;
>> +
>> + spin_lock_irqsave(&channel->wr_spinlock, flags);
>> +
>> + empty = channel->wr_empty;
>> + ready = !empty || channel->wr_ready;
>> +
>> + if (!empty) {
>> + bufidx = channel->wr_host_buf_idx;
>> + bufpos = channel->wr_host_buf_pos;
>> + howmany = ((channel->wr_buffers[bufidx]->end_offset
>> + + 1)<< channel->log2_element_size)
>> + - bufpos;
>> +
>> + /* Update wr_host_* to its post-operation state */
>> + if (howmany> bytes_to_do) {
>> + bufferdone = 0;
>> +
>> + howmany = bytes_to_do;
>> + channel->wr_host_buf_pos += howmany;
>> + } else {
>> + bufferdone = 1;
>> +
>> + channel->wr_host_buf_pos = 0;
>> +
>> + if (bufidx == channel->wr_fpga_buf_idx) {
>> + channel->wr_empty = 1;
>> + channel->wr_sleepy = 1;
>> + channel->wr_ready = 0;
>> + }
>> +
>> + if (bufidx>= (channel->num_wr_buffers - 1))
>> + channel->wr_host_buf_idx = 0;
>> + else
>> + channel->wr_host_buf_idx++;
>> + }
>> + }
>> +
>> + /*
>> + * Marking our situation after the possible changes above,
>> + * for use after releasing the spinlock.
>> + *
>> + * empty = empty before change
>> + * exhasted = empty after possible change
>> + */
>> +
>> + reached_eof = channel->wr_empty&&
>> + (channel->wr_host_buf_idx == channel->wr_eof);
>> + channel->wr_hangup = reached_eof;
>> + exhausted = channel->wr_empty;
>> + waiting_bufidx = channel->wr_host_buf_idx;
>> +
>> + spin_unlock_irqrestore(&channel->wr_spinlock, flags);
>> +
>> + if (!empty) { /* Go on, now without the spinlock */
>> +
>> + if (bufpos == 0) /* Position zero means it's virgin */
>> + channel->endpoint->ephw->hw_sync_sgl_for_cpu(
>> + channel->endpoint,
>> + channel->wr_buffers[bufidx]->dma_addr,
>> + channel->wr_buf_size,
>> + DMA_FROM_DEVICE);
>> +
>> + if (copy_to_user(
>> + userbuf,
>> + channel->wr_buffers[bufidx]->addr
>> + + bufpos, howmany))
>> + rc = -EFAULT;
>> +
>> + userbuf += howmany;
>> + bytes_done += howmany;
>> +
>> + if (bufferdone) {
>> + channel->endpoint->ephw->
>> + hw_sync_sgl_for_device
>> + (
>> + channel->endpoint,
>> + channel->wr_buffers[bufidx]->
>> + dma_addr,
>> + channel->wr_buf_size,
>> + DMA_FROM_DEVICE);
>
> This isn't broken up in the nicest way. It's actually better to go over
> the 80 charact limit here I think instead of putting the '(' on the next
> line or breaking it up at the -> mark.
>
> if (bufferdone) {
> channel->endpoint->ephw->hw_sync_sgl_for_device(
> channel->endpoint,
> channel->wr_buffers[bufidx]->dma_addr,
> channel->wr_buf_size,
> DMA_FROM_DEVICE);
>
>
>> +
>> + /*
>> + * Tell FPGA the buffer is done with. It's an
>> + * atomic operation to the FPGA, so what
>> + * happens with other channels doesn't matter,
>> + * and the certain channel is protected with
>> + * the channel-specific mutex.
>> + */
>> +
>> + iowrite32(1 | (channel->chan_num<< 1)
>> + | (bufidx<< 12),
>> + channel->endpoint->registers +
>> + fpga_buf_ctrl_reg);
>
> This should be:
>
> iowrite32(1 | (channel->chan_num<< 1) |
> (bufidx<< 12),
> channel->endpoint->registers +
> fpga_buf_ctrl_reg);
>
>> + }
>> +
>> + if (rc) {
>> + mutex_unlock(&channel->wr_mutex);
>> + return rc;
>> + }
>> + }
>> +
>> + /* This includes a zero-count return = EOF */
>> + if ((bytes_done>= count) || reached_eof)
>> + break;
>> +
>> + if (!exhausted)
>> + continue; /* More in RAM buffer(s)? Just go on. */
>> +
>> + if ((bytes_done> 0)&&
>> + (no_time_left ||
>> + (channel->wr_synchronous&& channel->wr_allow_partial)))
>> + break;
>> +
>> + /*
>> + * Nonblocking read: The "ready" flag tells us that the FPGA
>> + * has data to send. In non-blocking mode, if it isn't on,
>> + * just return. But if there is, we jump directly to the point
>> + * where we ask for the FPGA to send all it has, and wait
>> + * until that data arrives. So in a sense, we *do* block in
>> + * nonblocking mode, but only for a very short time.
>> + */
>> +
>> + if (!no_time_left&& (filp->f_flags& O_NONBLOCK)) {
>> + if (bytes_done> 0)
>> + break;
>> +
>> + if (ready)
>> + goto desperate;
>> +
>> + bytes_done = -EAGAIN;
>
> It would be more clear if this said "rc = -EAGAIN" and there was a check
> for that after the loop.
>
>> + break;
>> + }
>> +
>> + if (!no_time_left || (bytes_done> 0)) {
>> + /*
>> + * Note that in case of an element-misaligned read
>> + * request, offsetlimit will include the last element,
>> + * which will be partially read from.
>> + */
>> + int offsetlimit = ((count - bytes_done) - 1)>>
>> + channel->log2_element_size;
>> + int buf_elements = channel->wr_buf_size>>
>> + channel->log2_element_size;
>> +
>> + /*
>> + * In synchronous mode, always send an offset limit.
>> + * Just don't send a value too big.
>> + */
>> +
>> + if (channel->wr_synchronous) {
>> + /* Don't request more than one buffer */
>> + if (channel->wr_allow_partial&&
>> + (offsetlimit>= buf_elements))
>> + offsetlimit = buf_elements - 1;
>> +
>> + /* Don't request more than all buffers */
>> + if (!channel->wr_allow_partial&&
>> + (offsetlimit>=
>> + (buf_elements * channel->num_wr_buffers)))
>> + offsetlimit = buf_elements *
>> + channel->num_wr_buffers - 1;
>> + }
>> +
>> + /*
>> + * In asynchronous mode, force early flush of a buffer
>> + * only if that will allow returning a full count. The
>> + * "offsetlimit< ( ... )" rather than "<=" excludes
>> + * requesting a full buffer, which would obviously
>> + * cause a buffer transmission anyhow
>> + */
>> +
>> + if (channel->wr_synchronous ||
>> + (offsetlimit< (buf_elements - 1))) {
>> +
>> + mutex_lock(&channel->endpoint->register_mutex);
>> +
>> + iowrite32(offsetlimit,
>> + channel->endpoint->registers +
>> + fpga_buf_offset_reg);
>> +
>> + iowrite32(1 | (channel->chan_num<< 1) |
>> + (2<< 24) | /* 2 = offset limit */
>> + (waiting_bufidx<< 12),
>> + channel->endpoint->registers +
>> + fpga_buf_ctrl_reg);
>> +
>> + mutex_unlock(&channel->endpoint->
>> + register_mutex);
>> + }
>> +
>> + }
>> +
>> + /*
>> + * If partial completion is disallowed, there is no point in
>> + * timeout sleeping. Neither if no_time_left is set and
>> + * there's no data.
>> + */
>> +
>> + if (!channel->wr_allow_partial ||
>> + (no_time_left&& (bytes_done == 0))) {
>> +
>> + /*
>> + * This do-loop will run more than once if another
>> + * thread reasserted wr_sleepy before we got the mutex
>> + * back, so we try again.
>> + */
>> +
>> + do {
>> + mutex_unlock(&channel->wr_mutex);
>> +
>> + if (wait_event_interruptible(
>> + channel->wr_wait,
>> + (!channel->wr_sleepy)))
>> + goto interrupted;
>> +
>> + if (mutex_lock_interruptible(
>> + &channel->wr_mutex))
>> + goto interrupted;
>> + } while (channel->wr_sleepy);
>> +
>> + continue;
>> +
>> +interrupted: /* Mutex is not held if got here */
>> + if (channel->endpoint->fatal_error)
>> + return -EIO;
>> + if (bytes_done)
>> + return bytes_done;
>> + if (filp->f_flags& O_NONBLOCK)
>> + return -EAGAIN; /* Don't admit snoozing */
>> + return -EINTR;
>> + }
>> +
>> + left_to_sleep = deadline - ((long) jiffies);
>> +
>> + /*
>> + * If our time is out, skip the waiting. We may miss wr_sleepy
>> + * being deasserted but hey, almost missing the train is like
>> + * missing it.
>> + */
>> +
>> + if (left_to_sleep> 0) {
>> + left_to_sleep =
>> + wait_event_interruptible_timeout(
>> + channel->wr_wait,
>> + (!channel->wr_sleepy),
>> + left_to_sleep);
>> +
>> + if (!channel->wr_sleepy)
>> + continue;
>> +
>> + if (left_to_sleep< 0) { /* Interrupt */
>> + mutex_unlock(&channel->wr_mutex);
>> + if (channel->endpoint->fatal_error)
>> + return -EIO;
>> + if (bytes_done)
>> + return bytes_done;
>> + return -EINTR;
>> + }
>> + }
>> +
>> +desperate:
>> + no_time_left = 1; /* We're out of sleeping time. Desperate! */
>> +
>> + if (bytes_done == 0) {
>> + /*
>> + * Reaching here means that we allow partial return,
>> + * that we've run out of time, and that we have
>> + * nothing to return.
>> + * So tell the FPGA to send anything it has or gets.
>> + */
>> +
>> + iowrite32(1 | (channel->chan_num<< 1) |
>> + (3<< 24) | /* Opcode 3, flush it all! */
>> + (waiting_bufidx<< 12),
>> + channel->endpoint->registers +
>> + fpga_buf_ctrl_reg);
>> + }
>> +
>> + /*
>> + * Formally speaking, we should block for data at this point.
>> + * But to keep the code cleaner, we'll just finish the loop,
>> + * make the unlikely check for data, and then block at the
>> + * usual place.
>> + */
>
> I don't really understand this comment...
>
>> + }
>> +
>> + mutex_unlock(&channel->wr_mutex);
>> +
>> + if (channel->endpoint->fatal_error)
>> + return -EIO;
>> +
>> + return bytes_done;
>> +}
>> +
>> +/*
>> + * The timeout argument takes values as follows:
>> + *>0 : Flush with timeout
>> + * ==0 : Flush, and wait idefinitely for the flush to complete
>> + *<0 : Autoflush: Flush only if there's a single buffer occupied
>> + */
>> +
>> +static int xillybus_myflush(struct xilly_channel *channel, long timeout)
>> +{
>> + int rc = 0;
>> + unsigned long flags;
>> +
>> + int end_offset_plus1;
>> + int bufidx, bufidx_minus1;
>> + int i;
>> + int empty;
>> + int new_rd_host_buf_pos;
>> +
>> + if (channel->endpoint->fatal_error)
>> + return -EIO;
>> + rc = mutex_lock_interruptible(&channel->rd_mutex);
>> +
>> + if (rc)
>> + return rc;
>> +
>> + /*
>> + * Don't flush a closed channel. This can happen when the work queued
>> + * autoflush thread fires off after the file has closed. This is not
>> + * an error, just something to dismiss.
>> + */
>> +
>> + if (!channel->rd_ref_count)
>> + goto done;
>> +
>> + bufidx = channel->rd_host_buf_idx;
>> +
>> + bufidx_minus1 = (bufidx == 0) ? channel->num_rd_buffers - 1 : bufidx-1;
>
> There are spaces removed so that it fits in the 80 character limit.
> That's kind of ugly. Just do:
>
> bufidx_minus1 = (bufidx == 0) ?
> channel->num_rd_buffers - 1 :
> bufidx - 1;
>
>> +
>> + end_offset_plus1 = channel->rd_host_buf_pos>>
>> + channel->log2_element_size;
>> +
>> + new_rd_host_buf_pos = channel->rd_host_buf_pos -
>> + (end_offset_plus1<< channel->log2_element_size);
>> +
>> + /* Submit the current buffer if it's nonempty */
>> + if (end_offset_plus1) {
>> + unsigned char *tail = channel->rd_buffers[bufidx]->addr +
>> + (end_offset_plus1<< channel->log2_element_size);
>> +
>> + /* Copy unflushed data, so we can put it in next buffer */
>> + for (i = 0; i< new_rd_host_buf_pos; i++)
>> + channel->rd_leftovers[i] = *tail++;
>> +
>> + spin_lock_irqsave(&channel->rd_spinlock, flags);
>> +
>> + /* Autoflush only if a single buffer is occupied */
>> +
>> + if ((timeout< 0)&&
>> + (channel->rd_full ||
>> + (bufidx_minus1 != channel->rd_fpga_buf_idx))) {
>> + spin_unlock_irqrestore(&channel->rd_spinlock, flags);
>> + /*
>> + * A new work item may be queued by the ISR exactly
>> + * now, since the execution of a work item allows the
>> + * queuing of a new one while it's running.
>> + */
>> + goto done;
>> + }
>> +
>> + /* The 4th element is never needed for data, so it's a flag */
>> + channel->rd_leftovers[3] = (new_rd_host_buf_pos != 0);
>> +
>> + /* Set up rd_full to reflect a certain moment's state */
>> +
>> + if (bufidx == channel->rd_fpga_buf_idx)
>> + channel->rd_full = 1;
>> + spin_unlock_irqrestore(&channel->rd_spinlock, flags);
>> +
>> + if (bufidx>= (channel->num_rd_buffers - 1))
>> + channel->rd_host_buf_idx = 0;
>> + else
>> + channel->rd_host_buf_idx++;
>> +
>> + channel->endpoint->ephw->hw_sync_sgl_for_device(
>> + channel->endpoint,
>> + channel->rd_buffers[bufidx]->dma_addr,
>> + channel->rd_buf_size,
>> + DMA_TO_DEVICE);
>> +
>> + mutex_lock(&channel->endpoint->register_mutex);
>> +
>> + iowrite32(end_offset_plus1 - 1,
>> + channel->endpoint->registers + fpga_buf_offset_reg);
>> +
>> + iowrite32((channel->chan_num<< 1) | /* Channel ID */
>> + (2<< 24) | /* Opcode 2, submit buffer */
>> + (bufidx<< 12),
>> + channel->endpoint->registers + fpga_buf_ctrl_reg);
>> +
>> + mutex_unlock(&channel->endpoint->register_mutex);
>> + } else if (bufidx == 0)
>> + bufidx = channel->num_rd_buffers - 1;
>> + else
>> + bufidx--;
>> +
>> + channel->rd_host_buf_pos = new_rd_host_buf_pos;
>> +
>> + if (timeout< 0)
>> + goto done; /* Autoflush */
>> +
>> +
>> + /*
>> + * bufidx is now the last buffer written to (or equal to
>> + * rd_fpga_buf_idx if buffer was never written to), and
>> + * channel->rd_host_buf_idx the one after it.
>> + *
>> + * If bufidx == channel->rd_fpga_buf_idx we're either empty or full.
>> + */
>> +
>> + rc = 0;
>> +
>> + while (1) { /* Loop waiting for draining of buffers */
>> + spin_lock_irqsave(&channel->rd_spinlock, flags);
>> +
>> + if (bufidx != channel->rd_fpga_buf_idx)
>> + channel->rd_full = 1; /*
>> + * Not really full,
>> + * but needs waiting.
>> + */
>> +
>> + empty = !channel->rd_full;
>> +
>> + spin_unlock_irqrestore(&channel->rd_spinlock, flags);
>> +
>> + if (empty)
>> + break;
>> +
>> + /*
>> + * Indefinite sleep with mutex taken. With data waiting for
>> + * flushing user should not be surprised if open() for write
>> + * sleeps.
>> + */
>> + if (timeout == 0)
>> + wait_event_interruptible(channel->rd_wait,
>> + (!channel->rd_full));
>> +
>> + else if (wait_event_interruptible_timeout(
>> + channel->rd_wait,
>> + (!channel->rd_full),
>> + timeout) == 0) {
>> + dev_warn(channel->endpoint->dev,
>> + "Timed out while flushing. Output data may be lost.\n");
>> +
>> + rc = -ETIMEDOUT;
>> + break;
>> + }
>> +
>> + if (channel->rd_full) {
>> + rc = -EINTR;
>> + break;
>> + }
>> + }
>> +
>> +done:
>> + mutex_unlock(&channel->rd_mutex);
>> +
>> + if (channel->endpoint->fatal_error)
>> + return -EIO;
>> +
>> + return rc;
>> +}
>> +
>> +static int xillybus_flush(struct file *filp, fl_owner_t id)
>> +{
>> + if (!(filp->f_mode& FMODE_WRITE))
>> + return 0;
>> +
>> + return xillybus_myflush(filp->private_data, HZ); /* 1 second timeout */
>> +}
>> +
>> +static void xillybus_autoflush(struct work_struct *work)
>> +{
>> + struct delayed_work *workitem = container_of(
>> + work, struct delayed_work, work);
>> + struct xilly_channel *channel = container_of(
>> + workitem, struct xilly_channel, rd_workitem);
>> + int rc;
>> +
>> + rc = xillybus_myflush(channel, -1);
>> +
>> + if (rc == -EINTR)
>> + dev_warn(channel->endpoint->dev,
>> + "Autoflush failed because work queue thread got a signal.\n");
>> + else if (rc)
>> + dev_err(channel->endpoint->dev,
>> + "Autoflush failed under weird circumstances.\n");
>> +}
>> +
>> +static ssize_t xillybus_write(struct file *filp, const char __user *userbuf,
>> + size_t count, loff_t *f_pos)
>> +{
>> + ssize_t rc;
>> + unsigned long flags;
>> + int bytes_done = 0;
>> + struct xilly_channel *channel = filp->private_data;
>> +
>> + int full, exhausted;
>> + /* Initializations are there only to silence warnings */
>> +
>> + int howmany = 0, bufpos = 0, bufidx = 0, bufferdone = 0;
>> + int end_offset_plus1 = 0;
>> +
>> + if (channel->endpoint->fatal_error)
>> + return -EIO;
>> +
>> + rc = mutex_lock_interruptible(&channel->rd_mutex);
>> +
>> + if (rc)
>> + return rc;
>> +
>> + rc = 0; /* Just to be clear about it. Compiler optimizes this out */
>> +
>> + while (1) {
>> + int bytes_to_do = count - bytes_done;
>> +
>> + spin_lock_irqsave(&channel->rd_spinlock, flags);
>> +
>> + full = channel->rd_full;
>> +
>> + if (!full) {
>> + bufidx = channel->rd_host_buf_idx;
>> + bufpos = channel->rd_host_buf_pos;
>> + howmany = channel->rd_buf_size - bufpos;
>> +
>> + /*
>> + * Update rd_host_* to its state after this operation.
>> + * count=0 means committing the buffer immediately,
>> + * which is like flushing, but not necessarily block.
>> + */
>> +
>> + if ((howmany> bytes_to_do)&&
>> + (count ||
>> + ((bufpos>> channel->log2_element_size) == 0))) {
>> + bufferdone = 0;
>> +
>> + howmany = bytes_to_do;
>> + channel->rd_host_buf_pos += howmany;
>> + } else {
>> + bufferdone = 1;
>> +
>> + if (count) {
>> + end_offset_plus1 =
>> + channel->rd_buf_size>>
>> + channel->log2_element_size;
>> + channel->rd_host_buf_pos = 0;
>> + } else {
>> + unsigned char *tail;
>> + int i;
>> +
>> + end_offset_plus1 = bufpos>>
>> + channel->log2_element_size;
>> +
>> + channel->rd_host_buf_pos -=
>> + end_offset_plus1<<
>> + channel->log2_element_size;
>> +
>> + tail = channel->
>> + rd_buffers[bufidx]->addr +
>> + (end_offset_plus1<<
>> + channel->log2_element_size);
>> +
>> + for (i = 0;
>> + i< channel->rd_host_buf_pos;
>> + i++)
>> + channel->rd_leftovers[i] =
>> + *tail++;
>> + }
>> +
>> + if (bufidx == channel->rd_fpga_buf_idx)
>> + channel->rd_full = 1;
>> +
>> + if (bufidx>= (channel->num_rd_buffers - 1))
>> + channel->rd_host_buf_idx = 0;
>> + else
>> + channel->rd_host_buf_idx++;
>> + }
>> + }
>> +
>> + /*
>> + * Marking our situation after the possible changes above,
>> + * for use after releasing the spinlock.
>> + *
>> + * full = full before change
>> + * exhasted = full after possible change
>> + */
>> +
>> + exhausted = channel->rd_full;
>> +
>> + spin_unlock_irqrestore(&channel->rd_spinlock, flags);
>> +
>> + if (!full) { /* Go on, now without the spinlock */
>> + unsigned char *head =
>> + channel->rd_buffers[bufidx]->addr;
>> + int i;
>> +
>> + if ((bufpos == 0) || /* Zero means it's virgin */
>> + (channel->rd_leftovers[3] != 0)) {
>> + channel->endpoint->ephw->hw_sync_sgl_for_cpu(
>> + channel->endpoint,
>> + channel->rd_buffers[bufidx]->dma_addr,
>> + channel->rd_buf_size,
>> + DMA_TO_DEVICE);
>> +
>> + /* Virgin, but leftovers are due */
>> + for (i = 0; i< bufpos; i++)
>> + *head++ = channel->rd_leftovers[i];
>> +
>> + channel->rd_leftovers[3] = 0; /* Clear flag */
>> + }
>> +
>> + if (copy_from_user(
>> + channel->rd_buffers[bufidx]->addr + bufpos,
>> + userbuf, howmany))
>> + rc = -EFAULT;
>> +
>> + userbuf += howmany;
>> + bytes_done += howmany;
>> +
>> + if (bufferdone) {
>> + channel->endpoint->ephw->
>> + hw_sync_sgl_for_device(
>> + channel->endpoint,
>> + channel->rd_buffers[bufidx]->
>> + dma_addr,
>> + channel->rd_buf_size,
>> + DMA_TO_DEVICE);
>> +
>> + mutex_lock(&channel->endpoint->register_mutex);
>> +
>> + iowrite32(end_offset_plus1 - 1,
>> + channel->endpoint->registers +
>> + fpga_buf_offset_reg);
>> +
>> + iowrite32((channel->chan_num<< 1) |
>> + (2<< 24) | /* 2 = submit buffer */
>> + (bufidx<< 12),
>> + channel->endpoint->registers +
>> + fpga_buf_ctrl_reg);
>> +
>> + mutex_unlock(&channel->endpoint->
>> + register_mutex);
>> +
>> + channel->rd_leftovers[3] =
>> + (channel->rd_host_buf_pos != 0);
>> + }
>> +
>> + if (rc) {
>> + mutex_unlock(&channel->rd_mutex);
>> +
>> + if (channel->endpoint->fatal_error)
>> + return -EIO;
>> +
>> + if (!channel->rd_synchronous)
>> + queue_delayed_work(
>> + xillybus_wq,
>> + &channel->rd_workitem,
>> + XILLY_RX_TIMEOUT);
>> +
>> + return rc;
>> + }
>> + }
>> +
>> + if (bytes_done>= count)
>> + break;
>> +
>> + if (!exhausted)
>> + continue; /* If there's more space, just go on */
>> +
>> + if ((bytes_done> 0)&& channel->rd_allow_partial)
>> + break;
>> +
>> + /*
>> + * Indefinite sleep with mutex taken. With data waiting for
>> + * flushing, user should not be surprised if open() for write
>> + * sleeps.
>> + */
>> +
>> + if (filp->f_flags& O_NONBLOCK) {
>> + bytes_done = -EAGAIN;
>> + break;
>> + }
>> +
>> + wait_event_interruptible(channel->rd_wait,
>> + (!channel->rd_full));
>> +
>> + if (channel->rd_full) {
>> + mutex_unlock(&channel->rd_mutex);
>> +
>> + if (channel->endpoint->fatal_error)
>> + return -EIO;
>> +
>> + if (bytes_done)
>> + return bytes_done;
>> + return -EINTR;
>> + }
>> + }
>> +
>> + mutex_unlock(&channel->rd_mutex);
>> +
>> + if (!channel->rd_synchronous)
>> + queue_delayed_work(xillybus_wq,
>> + &channel->rd_workitem,
>> + XILLY_RX_TIMEOUT);
>> +
>> + if ((channel->rd_synchronous)&& (bytes_done> 0)) {
>> + rc = xillybus_myflush(filp->private_data, 0); /* No timeout */
>> +
>> + if (rc&& (rc != -EINTR))
>> + return rc;
>> + }
>> +
>> + if (channel->endpoint->fatal_error)
>> + return -EIO;
>> +
>> + return bytes_done;
>> +}
>> +
>> +static int xillybus_open(struct inode *inode, struct file *filp)
>> +{
>> + int rc = 0;
>> + unsigned long flags;
>> + int minor = iminor(inode);
>> + int major = imajor(inode);
>> + struct xilly_endpoint *ep_iter, *endpoint = NULL;
>> + struct xilly_channel *channel;
>> +
>> + mutex_lock(&ep_list_lock);
>> +
>> + list_for_each_entry(ep_iter,&list_of_endpoints, ep_list) {
>> + if ((ep_iter->major == major)&&
>> + (minor>= ep_iter->lowest_minor)&&
>> + (minor< (ep_iter->lowest_minor +
>> + ep_iter->num_channels))) {
>> + endpoint = ep_iter;
>> + break;
>> + }
>> + }
>> + mutex_unlock(&ep_list_lock);
>> +
>> + if (!endpoint) {
>> + pr_err("xillybus: open() failed to find a device for major=%d and minor=%d\n",
>> + major, minor);
>> + return -ENODEV;
>> + }
>> +
>> + if (endpoint->fatal_error)
>> + return -EIO;
>> +
>> + channel = endpoint->channels[1 + minor - endpoint->lowest_minor];
>> + filp->private_data = channel;
>> +
>> +
>> + /*
>> + * It gets complicated because:
>> + * 1. We don't want to take a mutex we don't have to
>> + * 2. We don't want to open one direction if the other will fail.
>> + */
>> +
>> + if ((filp->f_mode& FMODE_READ)&& (!channel->num_wr_buffers))
>> + return -ENODEV;
>> +
>> + if ((filp->f_mode& FMODE_WRITE)&& (!channel->num_rd_buffers))
>> + return -ENODEV;
>> +
>> + if ((filp->f_mode& FMODE_READ)&& (filp->f_flags& O_NONBLOCK)&&
>> + (channel->wr_synchronous || !channel->wr_allow_partial ||
>> + !channel->wr_supports_nonempty)) {
>> + dev_err(endpoint->dev,
>> + "open() failed: O_NONBLOCK not allowed for read on this device\n");
>> + return -ENODEV;
>> + }
>> +
>> + if ((filp->f_mode& FMODE_WRITE)&& (filp->f_flags& O_NONBLOCK)&&
>> + (channel->rd_synchronous || !channel->rd_allow_partial)) {
>> + dev_err(endpoint->dev,
>> + "open() failed: O_NONBLOCK not allowed for write on this device\n");
>> + return -ENODEV;
>> + }
>> +
>> + /*
>> + * Note: open() may block on getting mutexes despite O_NONBLOCK.
>> + * This shouldn't occur normally, since multiple open of the same
>> + * file descriptor is almost always prohibited anyhow
>> + * (*_exclusive_open is normally set in real-life systems).
>> + */
>> +
>> + if (filp->f_mode& FMODE_READ) {
>> + rc = mutex_lock_interruptible(&channel->wr_mutex);
>> + if (rc)
>> + return rc;
>> + }
>> +
>> + if (filp->f_mode& FMODE_WRITE) {
>> + rc = mutex_lock_interruptible(&channel->rd_mutex);
>> + if (rc)
>> + goto unlock_wr;
>> + }
>> +
>> + if ((filp->f_mode& FMODE_READ)&&
>> + (channel->wr_ref_count != 0)&&
>> + (channel->wr_exclusive_open)) {
>> + rc = -EBUSY;
>> + goto unlock;
>> + }
>> +
>> + if ((filp->f_mode& FMODE_WRITE)&&
>> + (channel->rd_ref_count != 0)&&
>> + (channel->rd_exclusive_open)) {
>> + rc = -EBUSY;
>> + goto unlock;
>> + }
>> +
>> +
>> + if (filp->f_mode& FMODE_READ) {
>> + if (channel->wr_ref_count == 0) { /* First open of file */
>> + /* Move the host to first buffer */
>> + spin_lock_irqsave(&channel->wr_spinlock, flags);
>> + channel->wr_host_buf_idx = 0;
>> + channel->wr_host_buf_pos = 0;
>> + channel->wr_fpga_buf_idx = -1;
>> + channel->wr_empty = 1;
>> + channel->wr_ready = 0;
>> + channel->wr_sleepy = 1;
>> + channel->wr_eof = -1;
>> + channel->wr_hangup = 0;
>> +
>> + spin_unlock_irqrestore(&channel->wr_spinlock, flags);
>> +
>> + iowrite32(1 | (channel->chan_num<< 1) |
>> + (4<< 24) | /* Opcode 4, open channel */
>> + ((channel->wr_synchronous& 1)<< 23),
>> + channel->endpoint->registers +
>> + fpga_buf_ctrl_reg);
>> + }
>> +
>> + channel->wr_ref_count++;
>> + }
>> +
>> + if (filp->f_mode& FMODE_WRITE) {
>> + if (channel->rd_ref_count == 0) { /* First open of file */
>> + /* Move the host to first buffer */
>> + spin_lock_irqsave(&channel->rd_spinlock, flags);
>> + channel->rd_host_buf_idx = 0;
>> + channel->rd_host_buf_pos = 0;
>> + channel->rd_leftovers[3] = 0; /* No leftovers. */
>> + channel->rd_fpga_buf_idx = channel->num_rd_buffers - 1;
>> + channel->rd_full = 0;
>> +
>> + spin_unlock_irqrestore(&channel->rd_spinlock, flags);
>> +
>> + iowrite32((channel->chan_num<< 1) |
>> + (4<< 24), /* Opcode 4, open channel */
>> + channel->endpoint->registers +
>> + fpga_buf_ctrl_reg);
>> + }
>> +
>> + channel->rd_ref_count++;
>> + }
>> +
>> +unlock:
>> + if (filp->f_mode& FMODE_WRITE)
>> + mutex_unlock(&channel->rd_mutex);
>> +unlock_wr:
>> + if (filp->f_mode& FMODE_READ)
>> + mutex_unlock(&channel->wr_mutex);
>> +
>> + if (!rc&& (!channel->seekable))
>> + return nonseekable_open(inode, filp);
>> +
>> + return rc;
>> +}
>> +
>> +static int xillybus_release(struct inode *inode, struct file *filp)
>> +{
>> + int rc;
>> + unsigned long flags;
>> + struct xilly_channel *channel = filp->private_data;
>> +
>> + int buf_idx;
>> + int eof;
>> +
>> + if (channel->endpoint->fatal_error)
>> + return -EIO;
>> +
>> + if (filp->f_mode& FMODE_WRITE) {
>> + rc = mutex_lock_interruptible(&channel->rd_mutex);
>> +
>> + if (rc) {
>> + dev_warn(channel->endpoint->dev,
>> + "Failed to close file. Hardware left in messy state.\n");
>
> How do we recover from this? Maybe it better to just use mutex_lock()
> instead of mutex_lock_interruptible()?
>
>> + return rc;
>> + }
>> +
>> + channel->rd_ref_count--;
>> +
>> + if (channel->rd_ref_count == 0) {
>> +
>> + /*
>> + * We rely on the kernel calling flush()
>> + * before we get here.
>> + */
>> +
>> + iowrite32((channel->chan_num<< 1) | /* Channel ID */
>> + (5<< 24), /* Opcode 5, close channel */
>> + channel->endpoint->registers +
>> + fpga_buf_ctrl_reg);
>> + }
>> + mutex_unlock(&channel->rd_mutex);
>> + }
>> +
>> + if (filp->f_mode& FMODE_READ) {
>> + rc = mutex_lock_interruptible(&channel->wr_mutex);
>> + if (rc) {
>> + dev_warn(channel->endpoint->dev,
>> + "Failed to close file. Hardware left in messy state.\n");
>> + return rc;
>
> Same.
>
>> + }
>> +
>> + channel->wr_ref_count--;
>> +
>> + if (channel->wr_ref_count == 0) {
>> +
>> + iowrite32(1 | (channel->chan_num<< 1) |
>> + (5<< 24), /* Opcode 5, close channel */
>> + channel->endpoint->registers +
>> + fpga_buf_ctrl_reg);
>> +
>> + /*
>> + * This is crazily cautious: We make sure that not
>> + * only that we got an EOF (be it because we closed
>> + * the channel or because of a user's EOF), but verify
>> + * that it's one beyond the last buffer arrived, so
>> + * we have no leftover buffers pending before wrapping
>> + * up (which can only happen in asynchronous channels,
>> + * BTW)
>> + */
>> +
>> + while (1) {
>> + spin_lock_irqsave(&channel->wr_spinlock,
>> + flags);
>> + buf_idx = channel->wr_fpga_buf_idx;
>> + eof = channel->wr_eof;
>> + channel->wr_sleepy = 1;
>> + spin_unlock_irqrestore(&channel->wr_spinlock,
>> + flags);
>> +
>> + /*
>> + * Check if eof points at the buffer after
>> + * the last one the FPGA submitted. Note that
>> + * no EOF is marked by negative eof.
>> + */
>> +
>> + buf_idx++;
>> + if (buf_idx == channel->num_wr_buffers)
>> + buf_idx = 0;
>> +
>> + if (buf_idx == eof)
>> + break;
>> +
>> + /*
>> + * Steal extra 100 ms if awaken by interrupt.
>> + * This is a simple workaround for an
>> + * interrupt pending when entering, which would
>> + * otherwise result in declaring the hardware
>> + * non-responsive.
>> + */
>> +
>> + if (wait_event_interruptible(
>> + channel->wr_wait,
>> + (!channel->wr_sleepy)))
>> + msleep(100);
>> +
>> + if (channel->wr_sleepy) {
>> + mutex_unlock(&channel->wr_mutex);
>> + dev_warn(channel->endpoint->dev,
>> + "Hardware failed to respond to close command, therefore left in messy state.\n");
>> + return -EINTR;
>> + }
>> + }
>> + }
>> +
>> + mutex_unlock(&channel->wr_mutex);
>> + }
>> +
>> + return 0;
>> +}
>> +static loff_t xillybus_llseek(struct file *filp, loff_t offset, int whence)
>> +{
>> + struct xilly_channel *channel = filp->private_data;
>> + loff_t pos = filp->f_pos;
>> + int rc = 0;
>> +
>> + /*
>> + * Take both mutexes not allowing interrupts, since it seems like
>> + * common applications don't expect an -EINTR here. Besides, multiple
>> + * access to a single file descriptor on seekable devices is a mess
>> + * anyhow.
>> + */
>> +
>> + if (channel->endpoint->fatal_error)
>> + return -EIO;
>> +
>> + mutex_lock(&channel->wr_mutex);
>> + mutex_lock(&channel->rd_mutex);
>> +
>> + switch (whence) {
>> + case 0:
>> + pos = offset;
>> + break;
>> + case 1:
>> + pos += offset;
>> + break;
>> + case 2:
>> + pos = offset; /* Going to the end => to the beginning */
>> + break;
>
> Please use SEEK_SET, SEEK_CUR, and SEEK_END here.
>
>> + default:
>> + rc = -EINVAL;
>> + goto end;
>> + }
>> +
>> + /* In any case, we must finish on an element boundary */
>> + if (pos& ((1<< channel->log2_element_size) - 1)) {
>> + rc = -EINVAL;
>> + goto end;
>> + }
>> +
>> + mutex_lock(&channel->endpoint->register_mutex);
>> +
>> + iowrite32(pos>> channel->log2_element_size,
>> + channel->endpoint->registers + fpga_buf_offset_reg);
>> +
>> + iowrite32((channel->chan_num<< 1) |
>> + (6<< 24), /* Opcode 6, set address */
>> + channel->endpoint->registers + fpga_buf_ctrl_reg);
>> +
>> + mutex_unlock(&channel->endpoint->register_mutex);
>> +
>> +end:
>> + mutex_unlock(&channel->rd_mutex);
>> + mutex_unlock(&channel->wr_mutex);
>> +
>> + if (rc) /* Return error after releasing mutexes */
>> + return rc;
>> +
>> + filp->f_pos = pos;
>> +
>> + /*
>> + * Since seekable devices are allowed only when the channel is
>> + * synchronous, we assume that there is no data pending in either
>> + * direction (which holds true as long as no concurrent access on the
>> + * file descriptor takes place).
>> + * The only thing we may need to throw away is leftovers from partial
>> + * write() flush.
>> + */
>> +
>> + channel->rd_leftovers[3] = 0;
>> +
>> + return pos;
>> +}
>> +
>> +static unsigned int xillybus_poll(struct file *filp, poll_table *wait)
>> +{
>> + struct xilly_channel *channel = filp->private_data;
>> + unsigned int mask = 0;
>> + unsigned long flags;
>> +
>> + poll_wait(filp,&channel->endpoint->ep_wait, wait);
>> +
>> + /*
>> + * poll() won't play ball regarding read() channels which
>> + * aren't asynchronous and support the nonempty message. Allowing
>> + * that will create situations where data has been delivered at
>> + * the FPGA, and users expecting select() to wake up, which it may
>> + * not.
>> + */
>> +
>> + if (!channel->wr_synchronous&& channel->wr_supports_nonempty) {
>> + poll_wait(filp,&channel->wr_wait, wait);
>> + poll_wait(filp,&channel->wr_ready_wait, wait);
>> +
>> + spin_lock_irqsave(&channel->wr_spinlock, flags);
>> + if (!channel->wr_empty || channel->wr_ready)
>> + mask |= POLLIN | POLLRDNORM;
>> +
>> + if (channel->wr_hangup)
>> + /*
>> + * Not POLLHUP, because its behavior is in the
>> + * mist, and POLLIN does what we want: Wake up
>> + * the read file descriptor so it sees EOF.
>> + */
>> + mask |= POLLIN | POLLRDNORM;
>> + spin_unlock_irqrestore(&channel->wr_spinlock, flags);
>> + }
>> +
>> + /*
>> + * If partial data write is disallowed on a write() channel,
>> + * it's pointless to ever signal OK to write, because is could
>> + * block despite some space being available.
>> + */
>> +
>> + if (channel->rd_allow_partial) {
>> + poll_wait(filp,&channel->rd_wait, wait);
>> +
>> + spin_lock_irqsave(&channel->rd_spinlock, flags);
>> + if (!channel->rd_full)
>> + mask |= POLLOUT | POLLWRNORM;
>> + spin_unlock_irqrestore(&channel->rd_spinlock, flags);
>> + }
>> +
>> + if (channel->endpoint->fatal_error)
>> + mask |= POLLERR;
>> +
>> + return mask;
>> +}
>> +
>> +static const struct file_operations xillybus_fops = {
>> + .owner = THIS_MODULE,
>> + .read = xillybus_read,
>> + .write = xillybus_write,
>> + .open = xillybus_open,
>> + .flush = xillybus_flush,
>> + .release = xillybus_release,
>> + .llseek = xillybus_llseek,
>> + .poll = xillybus_poll,
>> +};
>> +
>> +static int xillybus_init_chrdev(struct xilly_endpoint *endpoint,
>> + const unsigned char *idt)
>> +{
>> + int rc;
>> + dev_t dev;
>> + int devnum, i, minor, major;
>> + char devname[48];
>> + struct device *device;
>> +
>> + rc = alloc_chrdev_region(&dev, 0, /* minor start */
>> + endpoint->num_channels,
>> + xillyname);
>> +
>> + if (rc) {
>> + dev_warn(endpoint->dev, "Failed to obtain major/minors");
>> + goto error1;
>
> GW-BASIC label names. Labels should be named after the label location.
> This label doesn't do anything so it should be a direct return.
>
>> + }
>> +
>> + endpoint->major = major = MAJOR(dev);
>> + endpoint->lowest_minor = minor = MINOR(dev);
>> +
>> + cdev_init(&endpoint->cdev,&xillybus_fops);
>> + endpoint->cdev.owner = endpoint->ephw->owner;
>> + rc = cdev_add(&endpoint->cdev, MKDEV(major, minor),
>> + endpoint->num_channels);
>> + if (rc) {
>> + dev_warn(endpoint->dev, "Failed to add cdev. Aborting.\n");
>> + goto error2;
>
> This label should be "goto unregister_chrdev".
>
>> + }
>> +
>> + idt++;
>> +
>> + for (i = minor, devnum = 0;
>> + devnum< endpoint->num_channels;
>> + devnum++, i++) {
>> + snprintf(devname, sizeof(devname)-1, "xillybus_%s", idt);
>> +
>> + devname[sizeof(devname)-1] = 0; /* Should never matter */
>> +
>> + while (*idt++)
>> + /* Skip to next */;
>> +
>> + device = device_create(xillybus_class,
>> + NULL,
>> + MKDEV(major, i),
>> + NULL,
>> + "%s", devname);
>> +
>> + if (IS_ERR(device)) {
>> + dev_warn(endpoint->dev,
>> + "Failed to create %s device. Aborting.\n",
>> + devname);
>> + goto error3;
>> + }
>> + }
>> +
>> + dev_info(endpoint->dev, "Created %d device files.\n",
>> + endpoint->num_channels);
>> + return 0; /* succeed */
>> +
>> +error3:
>> + devnum--; i--;
>> + for (; devnum>= 0; devnum--, i--)
>> + device_destroy(xillybus_class, MKDEV(major, i));
>> +
>> + cdev_del(&endpoint->cdev);
>> +error2:
>> + unregister_chrdev_region(MKDEV(major, minor), endpoint->num_channels);
>> +error1:
>> +
>> + return rc;
>> +}
>> +
>> +static void xillybus_cleanup_chrdev(struct xilly_endpoint *endpoint)
>> +{
>> + int minor;
>> +
>> + for (minor = endpoint->lowest_minor;
>> + minor< (endpoint->lowest_minor + endpoint->num_channels);
>> + minor++)
>> + device_destroy(xillybus_class, MKDEV(endpoint->major, minor));
>> + cdev_del(&endpoint->cdev);
>> + unregister_chrdev_region(MKDEV(endpoint->major,
>> + endpoint->lowest_minor),
>> + endpoint->num_channels);
>> +
>> + dev_info(endpoint->dev, "Removed %d device files.\n",
>> + endpoint->num_channels);
>> +}
>> +
>> +
>> +struct xilly_endpoint *xillybus_init_endpoint(struct pci_dev *pdev,
>> + struct device *dev,
>> + struct xilly_endpoint_hardware
>> + *ephw)
>> +{
>> + struct xilly_endpoint *endpoint;
>> +
>> + endpoint = devm_kzalloc(dev, sizeof(*endpoint), GFP_KERNEL);
>> + if (!endpoint)
>> + return NULL;
>> +
>> + endpoint->pdev = pdev;
>> + endpoint->dev = dev;
>> + endpoint->ephw = ephw;
>> + endpoint->msg_counter = 0x0b;
>> + endpoint->failed_messages = 0;
>> + endpoint->fatal_error = 0;
>> +
>> + init_waitqueue_head(&endpoint->ep_wait);
>> + mutex_init(&endpoint->register_mutex);
>> +
>> + return endpoint;
>> +}
>> +EXPORT_SYMBOL(xillybus_init_endpoint);
>> +
>> +static int xilly_quiesce(struct xilly_endpoint *endpoint)
>> +{
>> + endpoint->idtlen = -1;
>> +
>> + iowrite32((u32) (endpoint->dma_using_dac& 0x0001),
>> + endpoint->registers + fpga_dma_control_reg);
>> +
>> + wait_event_interruptible_timeout(endpoint->ep_wait,
>> + (endpoint->idtlen>= 0),
>> + XILLY_TIMEOUT);
>> +
>> + if (endpoint->idtlen< 0) {
>
> It's nicer to check the return code from
> wait_event_interruptible_timeout().
>
>> + dev_err(endpoint->dev,
>> + "Failed to quiesce the device on exit.\n");
>> + return -ENODEV;
>> + }
>> + return 0; /* Success */
>> +}
>> +
>> +int xillybus_endpoint_discovery(struct xilly_endpoint *endpoint)
>> +{
>> + int rc = 0;
>> +
>> + void *bootstrap_resources;
>> + int idtbuffersize = (1<< PAGE_SHIFT);
>> + struct device *dev = endpoint->dev;
>> +
>> + /*
>> + * The bogus IDT is used during bootstrap for allocating the initial
>> + * message buffer, and then the message buffer and space for the IDT
>> + * itself. The initial message buffer is of a single page's size, but
>> + * it's soon replaced with a more modest one (and memory is freed).
>> + */
>> +
>> + unsigned char bogus_idt[8] = { 1, 224, (PAGE_SHIFT)-2, 0,
>> + 3, 192, PAGE_SHIFT, 0 };
>> + struct xilly_idt_handle idt_handle;
>> +
>> + /*
>> + * Writing the value 0x00000001 to Endianness register signals which
>> + * endianness this processor is using, so the FPGA can swap words as
>> + * necessary.
>> + */
>> +
>> + iowrite32(1, endpoint->registers + fpga_endian_reg);
>> +
>> + /* Bootstrap phase I: Allocate temporary message buffer */
>> +
>> + bootstrap_resources = devres_open_group(dev, NULL, GFP_KERNEL);
>> + if (!bootstrap_resources)
>> + return -ENOMEM;
>> +
>> + endpoint->num_channels = 0;
>> +
>> + rc = xilly_setupchannels(endpoint, bogus_idt, 1);
>> +
>> + if (rc)
>> + return rc;
>> +
>> + /* Clear the message subsystem (and counter in particular) */
>> + iowrite32(0x04, endpoint->registers + fpga_msg_ctrl_reg);
>> +
>> + endpoint->idtlen = -1;
>> +
>> + /*
>> + * Set DMA 32/64 bit mode, quiesce the device (?!) and get IDT
>> + * buffer size.
>> + */
>> + iowrite32((u32) (endpoint->dma_using_dac& 0x0001),
>> + endpoint->registers + fpga_dma_control_reg);
>> +
>> + wait_event_interruptible_timeout(endpoint->ep_wait,
>> + (endpoint->idtlen>= 0),
>> + XILLY_TIMEOUT);
>> +
>> + if (endpoint->idtlen< 0) {
>> + dev_err(endpoint->dev, "No response from FPGA. Aborting.\n");
>> + return -ENODEV;
>> + }
>> +
>> + /* Enable DMA */
>> + iowrite32((u32) (0x0002 | (endpoint->dma_using_dac& 0x0001)),
>> + endpoint->registers + fpga_dma_control_reg);
>> +
>> + /* Bootstrap phase II: Allocate buffer for IDT and obtain it */
>> + while (endpoint->idtlen>= idtbuffersize) {
>> + idtbuffersize *= 2;
>> + bogus_idt[6]++;
>> + }
>> +
>> + endpoint->num_channels = 1;
>> +
>> + rc = xilly_setupchannels(endpoint, bogus_idt, 2);
>> +
>> + if (rc)
>> + goto failed_idt;
>> +
>> + rc = xilly_obtain_idt(endpoint);
>> +
>> + if (rc)
>> + goto failed_idt;
>> +
>> + xilly_scan_idt(endpoint,&idt_handle);
>> +
>> + if (!idt_handle.chandesc) {
>> + rc = -ENODEV;
>> + goto failed_idt;
>> + }
>> +
>> + devres_close_group(dev, bootstrap_resources);
>> +
>> + /* Bootstrap phase III: Allocate buffers according to IDT */
>> +
>> + rc = xilly_setupchannels(endpoint,
>> + idt_handle.chandesc,
>> + idt_handle.entries);
>> +
>> + if (rc)
>> + goto failed_idt;
>> +
>> + /*
>> + * endpoint is now completely configured. We put it on the list
>> + * available to open() before registering the char device(s)
>> + */
>> +
>> + mutex_lock(&ep_list_lock);
>> + list_add_tail(&endpoint->ep_list,&list_of_endpoints);
>> + mutex_unlock(&ep_list_lock);
>> +
>> + rc = xillybus_init_chrdev(endpoint, idt_handle.idt);
>> +
>> + if (rc)
>> + goto failed_chrdevs;
>> +
>> + devres_release_group(dev, bootstrap_resources);
>> +
>> + return 0;
>> +
>> +failed_chrdevs:
>> + mutex_lock(&ep_list_lock);
>> + list_del(&endpoint->ep_list);
>> + mutex_unlock(&ep_list_lock);
>> +
>> +failed_idt:
>> + xilly_quiesce(endpoint);
>> + flush_workqueue(xillybus_wq);
>> +
>> + return rc;
>> +}
>> +EXPORT_SYMBOL(xillybus_endpoint_discovery);
>> +
>> +void xillybus_endpoint_remove(struct xilly_endpoint *endpoint)
>> +{
>> + xillybus_cleanup_chrdev(endpoint);
>> +
>> + mutex_lock(&ep_list_lock);
>> + list_del(&endpoint->ep_list);
>> + mutex_unlock(&ep_list_lock);
>> +
>> + xilly_quiesce(endpoint);
>> +
>> + /*
>> + * Flushing is done upon endpoint release to prevent access to memory
>> + * just about to be released. This makes the quiesce complete.
>> + */
>> + flush_workqueue(xillybus_wq);
>> +}
>> +EXPORT_SYMBOL(xillybus_endpoint_remove);
>> +
>> +static int __init xillybus_init(void)
>> +{
>> + int rc = 0;
>> +
>> + mutex_init(&ep_list_lock);
>> +
>> + xillybus_class = class_create(THIS_MODULE, xillyname);
>> + if (IS_ERR(xillybus_class)) {
>> + rc = PTR_ERR(xillybus_class);
>> + pr_warn("Failed to register class xillybus\n");
>
> No need for this warning. Just do "return PTR_ERR(xillybus_class);"
>
>> +
>> + return rc;
>> + }
>> +
>> + xillybus_wq = alloc_workqueue(xillyname, 0, 0);
>> + if (!xillybus_wq) {
>> + class_destroy(xillybus_class);
>> + rc = -ENOMEM;
>
> Return directly here so you don't mix error and success paths
> unnecesarily.
>
>> + }
>> +
>> + return rc;
>
> return 0;
>
>
>> +}
>> +
>> +static void __exit xillybus_exit(void)
>> +{
>> + /* flush_workqueue() was called for each endpoint released */
>> + destroy_workqueue(xillybus_wq);
>> +
>> + class_destroy(xillybus_class);
>> +}
>> +
>> +module_init(xillybus_init);
>> +module_exit(xillybus_exit);
>> diff --git a/drivers/char/xillybus/xillybus_of.c b/drivers/char/xillybus/xillybus_of.c
>> new file mode 100644
>> index 0000000..e0ae234
>> --- /dev/null
>> +++ b/drivers/char/xillybus/xillybus_of.c
>> @@ -0,0 +1,186 @@
>> +/*
>> + * linux/drivers/misc/xillybus_of.c
>> + *
>> + * Copyright 2011 Xillybus Ltd, http://xillybus.com
>> + *
>> + * Driver for the Xillybus FPGA/host framework using Open Firmware.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the smems of the GNU General Public License as published by
>> + * the Free Software Foundation; version 2 of the License.
>> + */
>> +
>> +#include<linux/module.h>
>> +#include<linux/device.h>
>> +#include<linux/slab.h>
>> +#include<linux/platform_device.h>
>> +#include<linux/of.h>
>> +#include<linux/of_irq.h>
>> +#include<linux/of_address.h>
>> +#include<linux/of_device.h>
>> +#include<linux/of_platform.h>
>> +#include<linux/err.h>
>> +#include "xillybus.h"
>> +
>> +MODULE_DESCRIPTION("Xillybus driver for Open Firmware");
>> +MODULE_AUTHOR("Eli Billauer, Xillybus Ltd.");
>> +MODULE_VERSION("1.06");
>> +MODULE_ALIAS("xillybus_of");
>> +MODULE_LICENSE("GPL v2");
>> +
>> +static const char xillyname[] = "xillybus_of";
>> +
>> +/* Match table for of_platform binding */
>> +static struct of_device_id xillybus_of_match[] = {
>> + { .compatible = "xillybus,xillybus-1.00.a", },
>> + { .compatible = "xlnx,xillybus-1.00.a", }, /* Deprecated */
>> + {}
>> +};
>> +
>> +MODULE_DEVICE_TABLE(of, xillybus_of_match);
>> +
>> +static void xilly_dma_sync_single_for_cpu_of(struct xilly_endpoint *ep,
>> + dma_addr_t dma_handle,
>> + size_t size,
>> + int direction)
>> +{
>> + dma_sync_single_for_cpu(ep->dev, dma_handle, size, direction);
>> +}
>> +
>> +static void xilly_dma_sync_single_for_device_of(struct xilly_endpoint *ep,
>> + dma_addr_t dma_handle,
>> + size_t size,
>> + int direction)
>> +{
>> + dma_sync_single_for_device(ep->dev, dma_handle, size, direction);
>> +}
>> +
>> +static void xilly_dma_sync_single_nop(struct xilly_endpoint *ep,
>> + dma_addr_t dma_handle,
>> + size_t size,
>> + int direction)
>> +{
>> +}
>> +
>> +static void xilly_of_unmap(void *ptr)
>> +{
>> + struct xilly_mapping *data = ptr;
>> +
>> + dma_unmap_single(data->device, data->dma_addr,
>> + data->size, data->direction);
>> +
>> + kfree(ptr);
>> +}
>> +
>> +static int xilly_map_single_of(struct xilly_endpoint *ep,
>> + void *ptr,
>> + size_t size,
>> + int direction,
>> + dma_addr_t *ret_dma_handle
>> + )
>> +{
>> + dma_addr_t addr;
>> + struct xilly_mapping *this;
>> + int rc;
>> +
>> + this = kzalloc(sizeof(*this), GFP_KERNEL);
>> + if (!this)
>> + return -ENOMEM;
>> +
>> + addr = dma_map_single(ep->dev, ptr, size, direction);
>> +
>> + if (dma_mapping_error(ep->dev, addr)) {
>> + kfree(this);
>> + return -ENODEV;
>> + }
>> +
>> + this->device = ep->dev;
>> + this->dma_addr = addr;
>> + this->size = size;
>> + this->direction = direction;
>> +
>> + *ret_dma_handle = addr;
>> +
>> + rc = devm_add_action(ep->dev, xilly_of_unmap, this);
>> +
>> + if (rc) {
>> + dma_unmap_single(ep->dev, addr, size, direction);
>> + kfree(this);
>> + }
>> +
>> + return rc;
>> +}
>> +
>> +static struct xilly_endpoint_hardware of_hw = {
>> + .owner = THIS_MODULE,
>> + .hw_sync_sgl_for_cpu = xilly_dma_sync_single_for_cpu_of,
>> + .hw_sync_sgl_for_device = xilly_dma_sync_single_for_device_of,
>> + .map_single = xilly_map_single_of,
>> +};
>> +
>> +static struct xilly_endpoint_hardware of_hw_coherent = {
>> + .owner = THIS_MODULE,
>> + .hw_sync_sgl_for_cpu = xilly_dma_sync_single_nop,
>> + .hw_sync_sgl_for_device = xilly_dma_sync_single_nop,
>> + .map_single = xilly_map_single_of,
>> +};
>> +
>> +static int xilly_drv_probe(struct platform_device *op)
>> +{
>> + struct device *dev =&op->dev;
>> + struct xilly_endpoint *endpoint;
>> + int rc = 0;
>> + int irq;
>> + struct resource res;
>> + struct xilly_endpoint_hardware *ephw =&of_hw;
>> +
>> + if (of_property_read_bool(dev->of_node, "dma-coherent"))
>> + ephw =&of_hw_coherent;
>> +
>> + endpoint = xillybus_init_endpoint(NULL, dev, ephw);
>> +
>> + if (!endpoint)
>> + return -ENOMEM;
>> +
>> + dev_set_drvdata(dev, endpoint);
>> +
>> + rc = of_address_to_resource(dev->of_node, 0,&res);
>> + endpoint->registers = devm_ioremap_resource(dev,&res);
>> +
>> + if (IS_ERR(endpoint->registers))
>> + return PTR_ERR(endpoint->registers);
>> +
>> + irq = irq_of_parse_and_map(dev->of_node, 0);
>> +
>> + rc = devm_request_irq(dev, irq, xillybus_isr, 0, xillyname, endpoint);
>> +
>> + if (rc) {
>> + dev_err(endpoint->dev,
>> + "Failed to register IRQ handler. Aborting.\n");
>> + return -ENODEV;
>> + }
>> +
>> + return xillybus_endpoint_discovery(endpoint);
>> +}
>> +
>> +static int xilly_drv_remove(struct platform_device *op)
>> +{
>> + struct device *dev =&op->dev;
>> + struct xilly_endpoint *endpoint = dev_get_drvdata(dev);
>> +
>> + xillybus_endpoint_remove(endpoint);
>> +
>> + return 0;
>> +}
>> +
>> +static struct platform_driver xillybus_platform_driver = {
>> + .probe = xilly_drv_probe,
>> + .remove = xilly_drv_remove,
>> + .driver = {
>> + .name = xillyname,
>> + .owner = THIS_MODULE,
>> + .of_match_table = xillybus_of_match,
>> + },
>> +};
>> +
>> +module_platform_driver(xillybus_platform_driver);
>> diff --git a/drivers/char/xillybus/xillybus_pcie.c b/drivers/char/xillybus/xillybus_pcie.c
>> new file mode 100644
>> index 0000000..96c2c9f
>> --- /dev/null
>> +++ b/drivers/char/xillybus/xillybus_pcie.c
>> @@ -0,0 +1,230 @@
>> +/*
>> + * linux/drivers/misc/xillybus_pcie.c
>> + *
>> + * Copyright 2011 Xillybus Ltd, http://xillybus.com
>> + *
>> + * Driver for the Xillybus FPGA/host framework using PCI Express.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the smems of the GNU General Public License as published by
>> + * the Free Software Foundation; version 2 of the License.
>> + */
>> +
>> +#include<linux/module.h>
>> +#include<linux/pci.h>
>> +#include<linux/pci-aspm.h>
>> +#include<linux/slab.h>
>> +#include "xillybus.h"
>> +
>> +MODULE_DESCRIPTION("Xillybus driver for PCIe");
>> +MODULE_AUTHOR("Eli Billauer, Xillybus Ltd.");
>> +MODULE_VERSION("1.06");
>> +MODULE_ALIAS("xillybus_pcie");
>> +MODULE_LICENSE("GPL v2");
>> +
>> +#define PCI_DEVICE_ID_XILLYBUS 0xebeb
>> +
>> +#define PCI_VENDOR_ID_ALTERA 0x1172
>> +#define PCI_VENDOR_ID_ACTEL 0x11aa
>> +#define PCI_VENDOR_ID_LATTICE 0x1204
>> +
>> +static const char xillyname[] = "xillybus_pcie";
>> +
>> +static const struct pci_device_id xillyids[] = {
>> + {PCI_DEVICE(PCI_VENDOR_ID_XILINX, PCI_DEVICE_ID_XILLYBUS)},
>> + {PCI_DEVICE(PCI_VENDOR_ID_ALTERA, PCI_DEVICE_ID_XILLYBUS)},
>> + {PCI_DEVICE(PCI_VENDOR_ID_ACTEL, PCI_DEVICE_ID_XILLYBUS)},
>> + {PCI_DEVICE(PCI_VENDOR_ID_LATTICE, PCI_DEVICE_ID_XILLYBUS)},
>> + { /* End: all zeroes */ }
>> +};
>> +
>> +static int xilly_pci_direction(int direction)
>> +{
>> + switch (direction) {
>> + case DMA_TO_DEVICE:
>> + return PCI_DMA_TODEVICE;
>> + case DMA_FROM_DEVICE:
>> + return PCI_DMA_FROMDEVICE;
>> + default:
>> + return PCI_DMA_BIDIRECTIONAL;
>> + }
>> +}
>> +
>> +static void xilly_dma_sync_single_for_cpu_pci(struct xilly_endpoint *ep,
>> + dma_addr_t dma_handle,
>> + size_t size,
>> + int direction)
>> +{
>> + pci_dma_sync_single_for_cpu(ep->pdev,
>> + dma_handle,
>> + size,
>> + xilly_pci_direction(direction));
>> +}
>> +
>> +static void xilly_dma_sync_single_for_device_pci(struct xilly_endpoint *ep,
>> + dma_addr_t dma_handle,
>> + size_t size,
>> + int direction)
>> +{
>> + pci_dma_sync_single_for_device(ep->pdev,
>> + dma_handle,
>> + size,
>> + xilly_pci_direction(direction));
>> +}
>> +
>> +static void xilly_pci_unmap(void *ptr)
>> +{
>> + struct xilly_mapping *data = ptr;
>> +
>> + pci_unmap_single(data->device, data->dma_addr,
>> + data->size, data->direction);
>> +
>> + kfree(ptr);
>> +}
>> +
>> +/*
>> + * Map either through the PCI DMA mapper or the non_PCI one. Behind the
>> + * scenes exactly the same functions are called with the same parameters,
>> + * but that can change.
>> + */
>> +
>> +static int xilly_map_single_pci(struct xilly_endpoint *ep,
>> + void *ptr,
>> + size_t size,
>> + int direction,
>> + dma_addr_t *ret_dma_handle
>> + )
>> +{
>> + int pci_direction;
>> + dma_addr_t addr;
>> + struct xilly_mapping *this;
>> + int rc = 0;
>> +
>> + this = kzalloc(sizeof(*this), GFP_KERNEL);
>> + if (!this)
>> + return -ENOMEM;
>> +
>> + pci_direction = xilly_pci_direction(direction);
>> +
>> + addr = pci_map_single(ep->pdev, ptr, size, pci_direction);
>> +
>> + if (pci_dma_mapping_error(ep->pdev, addr)) {
>> + kfree(this);
>> + return -ENODEV;
>> + }
>> +
>> + this->device = ep->pdev;
>> + this->dma_addr = addr;
>> + this->size = size;
>> + this->direction = pci_direction;
>> +
>> + *ret_dma_handle = addr;
>> +
>> + rc = devm_add_action(ep->dev, xilly_pci_unmap, this);
>> +
>> + if (rc) {
>> + pci_unmap_single(ep->pdev, addr, size, pci_direction);
>> + kfree(this);
>
> return rc;
>
>> + }
>> +
>> + return rc;
>
> return 0;
>
>
>> +}
>> +
>
> regards,
> dan carpenter
>
> --
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