1 files changed, 364 insertions, 0 deletions
diff --git a/drivers/dma/idxd/dma.c b/drivers/dma/idxd/dma.c
new file mode 100644
index 000000000..e0874cb47
--- /dev/null
+++ b/drivers/dma/idxd/dma.c
@@ -0,0 +1,364 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2019 Intel Corporation. All rights rsvd. */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/device.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/dmaengine.h>
+#include <uapi/linux/idxd.h>
+#include "../dmaengine.h"
+#include "registers.h"
+#include "idxd.h"
+
+static inline struct idxd_wq *to_idxd_wq(struct dma_chan *c)
+{
+	struct idxd_dma_chan *idxd_chan;
+
+	idxd_chan = container_of(c, struct idxd_dma_chan, chan);
+	return idxd_chan->wq;
+}
+
+void idxd_dma_complete_txd(struct idxd_desc *desc,
+			   enum idxd_complete_type comp_type,
+			   bool free_desc)
+{
+	struct idxd_device *idxd = desc->wq->idxd;
+	struct dma_async_tx_descriptor *tx;
+	struct dmaengine_result res;
+	int complete = 1;
+
+	if (desc->completion->status == DSA_COMP_SUCCESS) {
+		res.result = DMA_TRANS_NOERROR;
+	} else if (desc->completion->status) {
+		if (idxd->request_int_handles && comp_type != IDXD_COMPLETE_ABORT &&
+		    desc->completion->status == DSA_COMP_INT_HANDLE_INVAL &&
+		    idxd_queue_int_handle_resubmit(desc))
+			return;
+		res.result = DMA_TRANS_WRITE_FAILED;
+	} else if (comp_type == IDXD_COMPLETE_ABORT) {
+		res.result = DMA_TRANS_ABORTED;
+	} else {
+		complete = 0;
+	}
+
+	tx = &desc->txd;
+	if (complete && tx->cookie) {
+		dma_cookie_complete(tx);
+		dma_descriptor_unmap(tx);
+		dmaengine_desc_get_callback_invoke(tx, &res);
+		tx->callback = NULL;
+		tx->callback_result = NULL;
+	}
+
+	if (free_desc)
+		idxd_free_desc(desc->wq, desc);
+}
+
+static void op_flag_setup(unsigned long flags, u32 *desc_flags)
+{
+	*desc_flags = IDXD_OP_FLAG_CRAV | IDXD_OP_FLAG_RCR;
+	if (flags & DMA_PREP_INTERRUPT)
+		*desc_flags |= IDXD_OP_FLAG_RCI;
+}
+
+static inline void set_completion_address(struct idxd_desc *desc,
+					  u64 *compl_addr)
+{
+		*compl_addr = desc->compl_dma;
+}
+
+static inline void idxd_prep_desc_common(struct idxd_wq *wq,
+					 struct dsa_hw_desc *hw, char opcode,
+					 u64 addr_f1, u64 addr_f2, u64 len,
+					 u64 compl, u32 flags)
+{
+	hw->flags = flags;
+	hw->opcode = opcode;
+	hw->src_addr = addr_f1;
+	hw->dst_addr = addr_f2;
+	hw->xfer_size = len;
+	/*
+	 * For dedicated WQ, this field is ignored and HW will use the WQCFG.priv
+	 * field instead. This field should be set to 1 for kernel descriptors.
+	 */
+	hw->priv = 1;
+	hw->completion_addr = compl;
+}
+
+static struct dma_async_tx_descriptor *
+idxd_dma_prep_interrupt(struct dma_chan *c, unsigned long flags)
+{
+	struct idxd_wq *wq = to_idxd_wq(c);
+	u32 desc_flags;
+	struct idxd_desc *desc;
+
+	if (wq->state != IDXD_WQ_ENABLED)
+		return NULL;
+
+	op_flag_setup(flags, &desc_flags);
+	desc = idxd_alloc_desc(wq, IDXD_OP_BLOCK);
+	if (IS_ERR(desc))
+		return NULL;
+
+	idxd_prep_desc_common(wq, desc->hw, DSA_OPCODE_NOOP,
+			      0, 0, 0, desc->compl_dma, desc_flags);
+	desc->txd.flags = flags;
+	return &desc->txd;
+}
+
+static struct dma_async_tx_descriptor *
+idxd_dma_submit_memcpy(struct dma_chan *c, dma_addr_t dma_dest,
+		       dma_addr_t dma_src, size_t len, unsigned long flags)
+{
+	struct idxd_wq *wq = to_idxd_wq(c);
+	u32 desc_flags;
+	struct idxd_device *idxd = wq->idxd;
+	struct idxd_desc *desc;
+
+	if (wq->state != IDXD_WQ_ENABLED)
+		return NULL;
+
+	if (len > idxd->max_xfer_bytes)
+		return NULL;
+
+	op_flag_setup(flags, &desc_flags);
+	desc = idxd_alloc_desc(wq, IDXD_OP_BLOCK);
+	if (IS_ERR(desc))
+		return NULL;
+
+	idxd_prep_desc_common(wq, desc->hw, DSA_OPCODE_MEMMOVE,
+			      dma_src, dma_dest, len, desc->compl_dma,
+			      desc_flags);
+
+	desc->txd.flags = flags;
+
+	return &desc->txd;
+}
+
+static int idxd_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct idxd_wq *wq = to_idxd_wq(chan);
+	struct device *dev = &wq->idxd->pdev->dev;
+
+	idxd_wq_get(wq);
+	dev_dbg(dev, "%s: client_count: %d\n", __func__,
+		idxd_wq_refcount(wq));
+	return 0;
+}
+
+static void idxd_dma_free_chan_resources(struct dma_chan *chan)
+{
+	struct idxd_wq *wq = to_idxd_wq(chan);
+	struct device *dev = &wq->idxd->pdev->dev;
+
+	idxd_wq_put(wq);
+	dev_dbg(dev, "%s: client_count: %d\n", __func__,
+		idxd_wq_refcount(wq));
+}
+
+static enum dma_status idxd_dma_tx_status(struct dma_chan *dma_chan,
+					  dma_cookie_t cookie,
+					  struct dma_tx_state *txstate)
+{
+	return DMA_OUT_OF_ORDER;
+}
+
+/*
+ * issue_pending() does not need to do anything since tx_submit() does the job
+ * already.
+ */
+static void idxd_dma_issue_pending(struct dma_chan *dma_chan)
+{
+}
+
+static dma_cookie_t idxd_dma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+	struct dma_chan *c = tx->chan;
+	struct idxd_wq *wq = to_idxd_wq(c);
+	dma_cookie_t cookie;
+	int rc;
+	struct idxd_desc *desc = container_of(tx, struct idxd_desc, txd);
+
+	cookie = dma_cookie_assign(tx);
+
+	rc = idxd_submit_desc(wq, desc);
+	if (rc < 0) {
+		idxd_free_desc(wq, desc);
+		return rc;
+	}
+
+	return cookie;
+}
+
+static void idxd_dma_release(struct dma_device *device)
+{
+	struct idxd_dma_dev *idxd_dma = container_of(device, struct idxd_dma_dev, dma);
+
+	kfree(idxd_dma);
+}
+
+int idxd_register_dma_device(struct idxd_device *idxd)
+{
+	struct idxd_dma_dev *idxd_dma;
+	struct dma_device *dma;
+	struct device *dev = &idxd->pdev->dev;
+	int rc;
+
+	idxd_dma = kzalloc_node(sizeof(*idxd_dma), GFP_KERNEL, dev_to_node(dev));
+	if (!idxd_dma)
+		return -ENOMEM;
+
+	dma = &idxd_dma->dma;
+	INIT_LIST_HEAD(&dma->channels);
+	dma->dev = dev;
+
+	dma_cap_set(DMA_INTERRUPT, dma->cap_mask);
+	dma_cap_set(DMA_PRIVATE, dma->cap_mask);
+	dma_cap_set(DMA_COMPLETION_NO_ORDER, dma->cap_mask);
+	dma->device_release = idxd_dma_release;
+
+	dma->device_prep_dma_interrupt = idxd_dma_prep_interrupt;
+	if (idxd->hw.opcap.bits[0] & IDXD_OPCAP_MEMMOVE) {
+		dma_cap_set(DMA_MEMCPY, dma->cap_mask);
+		dma->device_prep_dma_memcpy = idxd_dma_submit_memcpy;
+	}
+
+	dma->device_tx_status = idxd_dma_tx_status;
+	dma->device_issue_pending = idxd_dma_issue_pending;
+	dma->device_alloc_chan_resources = idxd_dma_alloc_chan_resources;
+	dma->device_free_chan_resources = idxd_dma_free_chan_resources;
+
+	rc = dma_async_device_register(dma);
+	if (rc < 0) {
+		kfree(idxd_dma);
+		return rc;
+	}
+
+	idxd_dma->idxd = idxd;
+	/*
+	 * This pointer is protected by the refs taken by the dma_chan. It will remain valid
+	 * as long as there are outstanding channels.
+	 */
+	idxd->idxd_dma = idxd_dma;
+	return 0;
+}
+
+void idxd_unregister_dma_device(struct idxd_device *idxd)
+{
+	dma_async_device_unregister(&idxd->idxd_dma->dma);
+}
+
+static int idxd_register_dma_channel(struct idxd_wq *wq)
+{
+	struct idxd_device *idxd = wq->idxd;
+	struct dma_device *dma = &idxd->idxd_dma->dma;
+	struct device *dev = &idxd->pdev->dev;
+	struct idxd_dma_chan *idxd_chan;
+	struct dma_chan *chan;
+	int rc, i;
+
+	idxd_chan = kzalloc_node(sizeof(*idxd_chan), GFP_KERNEL, dev_to_node(dev));
+	if (!idxd_chan)
+		return -ENOMEM;
+
+	chan = &idxd_chan->chan;
+	chan->device = dma;
+	list_add_tail(&chan->device_node, &dma->channels);
+
+	for (i = 0; i < wq->num_descs; i++) {
+		struct idxd_desc *desc = wq->descs[i];
+
+		dma_async_tx_descriptor_init(&desc->txd, chan);
+		desc->txd.tx_submit = idxd_dma_tx_submit;
+	}
+
+	rc = dma_async_device_channel_register(dma, chan);
+	if (rc < 0) {
+		kfree(idxd_chan);
+		return rc;
+	}
+
+	wq->idxd_chan = idxd_chan;
+	idxd_chan->wq = wq;
+	get_device(wq_confdev(wq));
+
+	return 0;
+}
+
+static void idxd_unregister_dma_channel(struct idxd_wq *wq)
+{
+	struct idxd_dma_chan *idxd_chan = wq->idxd_chan;
+	struct dma_chan *chan = &idxd_chan->chan;
+	struct idxd_dma_dev *idxd_dma = wq->idxd->idxd_dma;
+
+	dma_async_device_channel_unregister(&idxd_dma->dma, chan);
+	list_del(&chan->device_node);
+	kfree(wq->idxd_chan);
+	wq->idxd_chan = NULL;
+	put_device(wq_confdev(wq));
+}
+
+static int idxd_dmaengine_drv_probe(struct idxd_dev *idxd_dev)
+{
+	struct device *dev = &idxd_dev->conf_dev;
+	struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
+	struct idxd_device *idxd = wq->idxd;
+	int rc;
+
+	if (idxd->state != IDXD_DEV_ENABLED)
+		return -ENXIO;
+
+	mutex_lock(&wq->wq_lock);
+	wq->type = IDXD_WQT_KERNEL;
+
+	rc = drv_enable_wq(wq);
+	if (rc < 0) {
+		dev_dbg(dev, "Enable wq %d failed: %d\n", wq->id, rc);
+		rc = -ENXIO;
+		goto err;
+	}
+
+	rc = idxd_register_dma_channel(wq);
+	if (rc < 0) {
+		idxd->cmd_status = IDXD_SCMD_DMA_CHAN_ERR;
+		dev_dbg(dev, "Failed to register dma channel\n");
+		goto err_dma;
+	}
+
+	idxd->cmd_status = 0;
+	mutex_unlock(&wq->wq_lock);
+	return 0;
+
+err_dma:
+	drv_disable_wq(wq);
+err:
+	wq->type = IDXD_WQT_NONE;
+	mutex_unlock(&wq->wq_lock);
+	return rc;
+}
+
+static void idxd_dmaengine_drv_remove(struct idxd_dev *idxd_dev)
+{
+	struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
+
+	mutex_lock(&wq->wq_lock);
+	__idxd_wq_quiesce(wq);
+	idxd_unregister_dma_channel(wq);
+	drv_disable_wq(wq);
+	mutex_unlock(&wq->wq_lock);
+}
+
+static enum idxd_dev_type dev_types[] = {
+	IDXD_DEV_WQ,
+	IDXD_DEV_NONE,
+};
+
+struct idxd_device_driver idxd_dmaengine_drv = {
+	.probe = idxd_dmaengine_drv_probe,
+	.remove = idxd_dmaengine_drv_remove,
+	.name = "dmaengine",
+	.type = dev_types,
+};
+EXPORT_SYMBOL_GPL(idxd_dmaengine_drv);