dmatest: convert to dma_request_channel
Replace the client registration infrastructure with a custom loop to poll for channels. Once dma_request_channel returns NULL stop asking for channels. A userspace side effect of this change if that loading the dmatest module before loading a dma driver will result in no channels being found, previously dmatest would get a callback. To facilitate testing in the built-in case dmatest_init is marked as a late_initcall. Another side effect is that channels under test can not be used for any other purpose. Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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@ -35,7 +35,7 @@ MODULE_PARM_DESC(threads_per_chan,
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static unsigned int max_channels;
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module_param(max_channels, uint, S_IRUGO);
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MODULE_PARM_DESC(nr_channels,
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MODULE_PARM_DESC(max_channels,
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"Maximum number of channels to use (default: all)");
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/*
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@ -71,7 +71,7 @@ struct dmatest_chan {
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/*
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* These are protected by dma_list_mutex since they're only used by
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* the DMA client event callback
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* the DMA filter function callback
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*/
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static LIST_HEAD(dmatest_channels);
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static unsigned int nr_channels;
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@ -317,21 +317,16 @@ static void dmatest_cleanup_channel(struct dmatest_chan *dtc)
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kfree(dtc);
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}
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static enum dma_state_client dmatest_add_channel(struct dma_chan *chan)
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static int dmatest_add_channel(struct dma_chan *chan)
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{
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struct dmatest_chan *dtc;
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struct dmatest_thread *thread;
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unsigned int i;
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/* Have we already been told about this channel? */
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list_for_each_entry(dtc, &dmatest_channels, node)
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if (dtc->chan == chan)
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return DMA_DUP;
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dtc = kmalloc(sizeof(struct dmatest_chan), GFP_KERNEL);
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if (!dtc) {
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pr_warning("dmatest: No memory for %s\n", dev_name(&chan->dev));
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return DMA_NAK;
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return -ENOMEM;
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}
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dtc->chan = chan;
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@ -365,81 +360,57 @@ static enum dma_state_client dmatest_add_channel(struct dma_chan *chan)
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list_add_tail(&dtc->node, &dmatest_channels);
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nr_channels++;
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return DMA_ACK;
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return 0;
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}
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static enum dma_state_client dmatest_remove_channel(struct dma_chan *chan)
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static enum dma_state_client filter(struct dma_chan *chan, void *param)
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{
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struct dmatest_chan *dtc, *_dtc;
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list_for_each_entry_safe(dtc, _dtc, &dmatest_channels, node) {
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if (dtc->chan == chan) {
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list_del(&dtc->node);
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dmatest_cleanup_channel(dtc);
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pr_debug("dmatest: lost channel %s\n",
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dev_name(&chan->dev));
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return DMA_ACK;
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}
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}
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return DMA_DUP;
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if (!dmatest_match_channel(chan) || !dmatest_match_device(chan->device))
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return DMA_DUP;
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else
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return DMA_ACK;
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}
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/*
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* Start testing threads as new channels are assigned to us, and kill
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* them when the channels go away.
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*
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* When we unregister the client, all channels are removed so this
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* will also take care of cleaning things up when the module is
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* unloaded.
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*/
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static enum dma_state_client
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dmatest_event(struct dma_client *client, struct dma_chan *chan,
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enum dma_state state)
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{
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enum dma_state_client ack = DMA_NAK;
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switch (state) {
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case DMA_RESOURCE_AVAILABLE:
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if (!dmatest_match_channel(chan)
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|| !dmatest_match_device(chan->device))
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ack = DMA_DUP;
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else if (max_channels && nr_channels >= max_channels)
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ack = DMA_NAK;
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else
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ack = dmatest_add_channel(chan);
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break;
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case DMA_RESOURCE_REMOVED:
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ack = dmatest_remove_channel(chan);
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break;
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default:
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pr_info("dmatest: Unhandled event %u (%s)\n",
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state, dev_name(&chan->dev));
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break;
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}
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return ack;
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}
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static struct dma_client dmatest_client = {
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.event_callback = dmatest_event,
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};
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static int __init dmatest_init(void)
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{
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dma_cap_set(DMA_MEMCPY, dmatest_client.cap_mask);
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dma_async_client_register(&dmatest_client);
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dma_async_client_chan_request(&dmatest_client);
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dma_cap_mask_t mask;
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struct dma_chan *chan;
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int err = 0;
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return 0;
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dma_cap_zero(mask);
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dma_cap_set(DMA_MEMCPY, mask);
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for (;;) {
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chan = dma_request_channel(mask, filter, NULL);
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if (chan) {
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err = dmatest_add_channel(chan);
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if (err == 0)
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continue;
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else {
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dma_release_channel(chan);
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break; /* add_channel failed, punt */
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}
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} else
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break; /* no more channels available */
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if (max_channels && nr_channels >= max_channels)
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break; /* we have all we need */
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}
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return err;
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}
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module_init(dmatest_init);
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/* when compiled-in wait for drivers to load first */
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late_initcall(dmatest_init);
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static void __exit dmatest_exit(void)
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{
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dma_async_client_unregister(&dmatest_client);
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struct dmatest_chan *dtc, *_dtc;
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list_for_each_entry_safe(dtc, _dtc, &dmatest_channels, node) {
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list_del(&dtc->node);
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dmatest_cleanup_channel(dtc);
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pr_debug("dmatest: dropped channel %s\n",
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dev_name(&dtc->chan->dev));
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dma_release_channel(dtc->chan);
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}
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}
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module_exit(dmatest_exit);
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@ -400,6 +400,12 @@ __dma_cap_set(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp)
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set_bit(tx_type, dstp->bits);
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}
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#define dma_cap_zero(mask) __dma_cap_zero(&(mask))
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static inline void __dma_cap_zero(dma_cap_mask_t *dstp)
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{
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bitmap_zero(dstp->bits, DMA_TX_TYPE_END);
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}
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#define dma_has_cap(tx, mask) __dma_has_cap((tx), &(mask))
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static inline int
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__dma_has_cap(enum dma_transaction_type tx_type, dma_cap_mask_t *srcp)
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