1 files changed, 413 insertions, 0 deletions

diff --git a/drivers/dma/ptdma/ptdma-dmaengine.c b/drivers/dma/ptdma/ptdma-dmaengine.c
new file mode 100644
index 000000000..1aa65e5de
--- /dev/null
+++ b/drivers/dma/ptdma/ptdma-dmaengine.c
@@ -0,0 +1,413 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Passthrough DMA device driver
+ * -- Based on the CCP driver
+ *
+ * Copyright (C) 2016,2021 Advanced Micro Devices, Inc.
+ *
+ * Author: Sanjay R Mehta <sanju.mehta@amd.com>
+ * Author: Gary R Hook <gary.hook@amd.com>
+ */
+
+#include "ptdma.h"
+#include "../dmaengine.h"
+#include "../virt-dma.h"
+
+static inline struct pt_dma_chan *to_pt_chan(struct dma_chan *dma_chan)
+{
+	return container_of(dma_chan, struct pt_dma_chan, vc.chan);
+}
+
+static inline struct pt_dma_desc *to_pt_desc(struct virt_dma_desc *vd)
+{
+	return container_of(vd, struct pt_dma_desc, vd);
+}
+
+static void pt_free_chan_resources(struct dma_chan *dma_chan)
+{
+	struct pt_dma_chan *chan = to_pt_chan(dma_chan);
+
+	vchan_free_chan_resources(&chan->vc);
+}
+
+static void pt_synchronize(struct dma_chan *dma_chan)
+{
+	struct pt_dma_chan *chan = to_pt_chan(dma_chan);
+
+	vchan_synchronize(&chan->vc);
+}
+
+static void pt_do_cleanup(struct virt_dma_desc *vd)
+{
+	struct pt_dma_desc *desc = to_pt_desc(vd);
+	struct pt_device *pt = desc->pt;
+
+	kmem_cache_free(pt->dma_desc_cache, desc);
+}
+
+static int pt_dma_start_desc(struct pt_dma_desc *desc)
+{
+	struct pt_passthru_engine *pt_engine;
+	struct pt_device *pt;
+	struct pt_cmd *pt_cmd;
+	struct pt_cmd_queue *cmd_q;
+
+	desc->issued_to_hw = 1;
+
+	pt_cmd = &desc->pt_cmd;
+	pt = pt_cmd->pt;
+	cmd_q = &pt->cmd_q;
+	pt_engine = &pt_cmd->passthru;
+
+	pt->tdata.cmd = pt_cmd;
+
+	/* Execute the command */
+	pt_cmd->ret = pt_core_perform_passthru(cmd_q, pt_engine);
+
+	return 0;
+}
+
+static struct pt_dma_desc *pt_next_dma_desc(struct pt_dma_chan *chan)
+{
+	/* Get the next DMA descriptor on the active list */
+	struct virt_dma_desc *vd = vchan_next_desc(&chan->vc);
+
+	return vd ? to_pt_desc(vd) : NULL;
+}
+
+static struct pt_dma_desc *pt_handle_active_desc(struct pt_dma_chan *chan,
+						 struct pt_dma_desc *desc)
+{
+	struct dma_async_tx_descriptor *tx_desc;
+	struct virt_dma_desc *vd;
+	unsigned long flags;
+
+	/* Loop over descriptors until one is found with commands */
+	do {
+		if (desc) {
+			if (!desc->issued_to_hw) {
+				/* No errors, keep going */
+				if (desc->status != DMA_ERROR)
+					return desc;
+			}
+
+			tx_desc = &desc->vd.tx;
+			vd = &desc->vd;
+		} else {
+			tx_desc = NULL;
+		}
+
+		spin_lock_irqsave(&chan->vc.lock, flags);
+
+		if (desc) {
+			if (desc->status != DMA_COMPLETE) {
+				if (desc->status != DMA_ERROR)
+					desc->status = DMA_COMPLETE;
+
+				dma_cookie_complete(tx_desc);
+				dma_descriptor_unmap(tx_desc);
+				list_del(&desc->vd.node);
+			} else {
+				/* Don't handle it twice */
+				tx_desc = NULL;
+			}
+		}
+
+		desc = pt_next_dma_desc(chan);
+
+		spin_unlock_irqrestore(&chan->vc.lock, flags);
+
+		if (tx_desc) {
+			dmaengine_desc_get_callback_invoke(tx_desc, NULL);
+			dma_run_dependencies(tx_desc);
+			vchan_vdesc_fini(vd);
+		}
+	} while (desc);
+
+	return NULL;
+}
+
+static void pt_cmd_callback(void *data, int err)
+{
+	struct pt_dma_desc *desc = data;
+	struct dma_chan *dma_chan;
+	struct pt_dma_chan *chan;
+	int ret;
+
+	if (err == -EINPROGRESS)
+		return;
+
+	dma_chan = desc->vd.tx.chan;
+	chan = to_pt_chan(dma_chan);
+
+	if (err)
+		desc->status = DMA_ERROR;
+
+	while (true) {
+		/* Check for DMA descriptor completion */
+		desc = pt_handle_active_desc(chan, desc);
+
+		/* Don't submit cmd if no descriptor or DMA is paused */
+		if (!desc)
+			break;
+
+		ret = pt_dma_start_desc(desc);
+		if (!ret)
+			break;
+
+		desc->status = DMA_ERROR;
+	}
+}
+
+static struct pt_dma_desc *pt_alloc_dma_desc(struct pt_dma_chan *chan,
+					     unsigned long flags)
+{
+	struct pt_dma_desc *desc;
+
+	desc = kmem_cache_zalloc(chan->pt->dma_desc_cache, GFP_NOWAIT);
+	if (!desc)
+		return NULL;
+
+	vchan_tx_prep(&chan->vc, &desc->vd, flags);
+
+	desc->pt = chan->pt;
+	desc->pt->cmd_q.int_en = !!(flags & DMA_PREP_INTERRUPT);
+	desc->issued_to_hw = 0;
+	desc->status = DMA_IN_PROGRESS;
+
+	return desc;
+}
+
+static struct pt_dma_desc *pt_create_desc(struct dma_chan *dma_chan,
+					  dma_addr_t dst,
+					  dma_addr_t src,
+					  unsigned int len,
+					  unsigned long flags)
+{
+	struct pt_dma_chan *chan = to_pt_chan(dma_chan);
+	struct pt_passthru_engine *pt_engine;
+	struct pt_dma_desc *desc;
+	struct pt_cmd *pt_cmd;
+
+	desc = pt_alloc_dma_desc(chan, flags);
+	if (!desc)
+		return NULL;
+
+	pt_cmd = &desc->pt_cmd;
+	pt_cmd->pt = chan->pt;
+	pt_engine = &pt_cmd->passthru;
+	pt_cmd->engine = PT_ENGINE_PASSTHRU;
+	pt_engine->src_dma = src;
+	pt_engine->dst_dma = dst;
+	pt_engine->src_len = len;
+	pt_cmd->pt_cmd_callback = pt_cmd_callback;
+	pt_cmd->data = desc;
+
+	desc->len = len;
+
+	return desc;
+}
+
+static struct dma_async_tx_descriptor *
+pt_prep_dma_memcpy(struct dma_chan *dma_chan, dma_addr_t dst,
+		   dma_addr_t src, size_t len, unsigned long flags)
+{
+	struct pt_dma_desc *desc;
+
+	desc = pt_create_desc(dma_chan, dst, src, len, flags);
+	if (!desc)
+		return NULL;
+
+	return &desc->vd.tx;
+}
+
+static struct dma_async_tx_descriptor *
+pt_prep_dma_interrupt(struct dma_chan *dma_chan, unsigned long flags)
+{
+	struct pt_dma_chan *chan = to_pt_chan(dma_chan);
+	struct pt_dma_desc *desc;
+
+	desc = pt_alloc_dma_desc(chan, flags);
+	if (!desc)
+		return NULL;
+
+	return &desc->vd.tx;
+}
+
+static void pt_issue_pending(struct dma_chan *dma_chan)
+{
+	struct pt_dma_chan *chan = to_pt_chan(dma_chan);
+	struct pt_dma_desc *desc;
+	unsigned long flags;
+	bool engine_is_idle = true;
+
+	spin_lock_irqsave(&chan->vc.lock, flags);
+
+	desc = pt_next_dma_desc(chan);
+	if (desc)
+		engine_is_idle = false;
+
+	vchan_issue_pending(&chan->vc);
+
+	desc = pt_next_dma_desc(chan);
+
+	spin_unlock_irqrestore(&chan->vc.lock, flags);
+
+	/* If there was nothing active, start processing */
+	if (engine_is_idle && desc)
+		pt_cmd_callback(desc, 0);
+}
+
+static enum dma_status
+pt_tx_status(struct dma_chan *c, dma_cookie_t cookie,
+		struct dma_tx_state *txstate)
+{
+	struct pt_device *pt = to_pt_chan(c)->pt;
+	struct pt_cmd_queue *cmd_q = &pt->cmd_q;
+
+	pt_check_status_trans(pt, cmd_q);
+	return dma_cookie_status(c, cookie, txstate);
+}
+
+static int pt_pause(struct dma_chan *dma_chan)
+{
+	struct pt_dma_chan *chan = to_pt_chan(dma_chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&chan->vc.lock, flags);
+	pt_stop_queue(&chan->pt->cmd_q);
+	spin_unlock_irqrestore(&chan->vc.lock, flags);
+
+	return 0;
+}
+
+static int pt_resume(struct dma_chan *dma_chan)
+{
+	struct pt_dma_chan *chan = to_pt_chan(dma_chan);
+	struct pt_dma_desc *desc = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&chan->vc.lock, flags);
+	pt_start_queue(&chan->pt->cmd_q);
+	desc = pt_next_dma_desc(chan);
+	spin_unlock_irqrestore(&chan->vc.lock, flags);
+
+	/* If there was something active, re-start */
+	if (desc)
+		pt_cmd_callback(desc, 0);
+
+	return 0;
+}
+
+static int pt_terminate_all(struct dma_chan *dma_chan)
+{
+	struct pt_dma_chan *chan = to_pt_chan(dma_chan);
+	unsigned long flags;
+	struct pt_cmd_queue *cmd_q = &chan->pt->cmd_q;
+	LIST_HEAD(head);
+
+	iowrite32(SUPPORTED_INTERRUPTS, cmd_q->reg_control + 0x0010);
+	spin_lock_irqsave(&chan->vc.lock, flags);
+	vchan_get_all_descriptors(&chan->vc, &head);
+	spin_unlock_irqrestore(&chan->vc.lock, flags);
+
+	vchan_dma_desc_free_list(&chan->vc, &head);
+	vchan_free_chan_resources(&chan->vc);
+
+	return 0;
+}
+
+int pt_dmaengine_register(struct pt_device *pt)
+{
+	struct pt_dma_chan *chan;
+	struct dma_device *dma_dev = &pt->dma_dev;
+	char *cmd_cache_name;
+	char *desc_cache_name;
+	int ret;
+
+	pt->pt_dma_chan = devm_kzalloc(pt->dev, sizeof(*pt->pt_dma_chan),
+				       GFP_KERNEL);
+	if (!pt->pt_dma_chan)
+		return -ENOMEM;
+
+	cmd_cache_name = devm_kasprintf(pt->dev, GFP_KERNEL,
+					"%s-dmaengine-cmd-cache",
+					dev_name(pt->dev));
+	if (!cmd_cache_name)
+		return -ENOMEM;
+
+	desc_cache_name = devm_kasprintf(pt->dev, GFP_KERNEL,
+					 "%s-dmaengine-desc-cache",
+					 dev_name(pt->dev));
+	if (!desc_cache_name) {
+		ret = -ENOMEM;
+		goto err_cache;
+	}
+
+	pt->dma_desc_cache = kmem_cache_create(desc_cache_name,
+					       sizeof(struct pt_dma_desc), 0,
+					       SLAB_HWCACHE_ALIGN, NULL);
+	if (!pt->dma_desc_cache) {
+		ret = -ENOMEM;
+		goto err_cache;
+	}
+
+	dma_dev->dev = pt->dev;
+	dma_dev->src_addr_widths = DMA_SLAVE_BUSWIDTH_64_BYTES;
+	dma_dev->dst_addr_widths = DMA_SLAVE_BUSWIDTH_64_BYTES;
+	dma_dev->directions = DMA_MEM_TO_MEM;
+	dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
+	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
+	dma_cap_set(DMA_INTERRUPT, dma_dev->cap_mask);
+
+	/*
+	 * PTDMA is intended to be used with the AMD NTB devices, hence
+	 * marking it as DMA_PRIVATE.
+	 */
+	dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
+
+	INIT_LIST_HEAD(&dma_dev->channels);
+
+	chan = pt->pt_dma_chan;
+	chan->pt = pt;
+
+	/* Set base and prep routines */
+	dma_dev->device_free_chan_resources = pt_free_chan_resources;
+	dma_dev->device_prep_dma_memcpy = pt_prep_dma_memcpy;
+	dma_dev->device_prep_dma_interrupt = pt_prep_dma_interrupt;
+	dma_dev->device_issue_pending = pt_issue_pending;
+	dma_dev->device_tx_status = pt_tx_status;
+	dma_dev->device_pause = pt_pause;
+	dma_dev->device_resume = pt_resume;
+	dma_dev->device_terminate_all = pt_terminate_all;
+	dma_dev->device_synchronize = pt_synchronize;
+
+	chan->vc.desc_free = pt_do_cleanup;
+	vchan_init(&chan->vc, dma_dev);
+
+	dma_set_mask_and_coherent(pt->dev, DMA_BIT_MASK(64));
+
+	ret = dma_async_device_register(dma_dev);
+	if (ret)
+		goto err_reg;
+
+	return 0;
+
+err_reg:
+	kmem_cache_destroy(pt->dma_desc_cache);
+
+err_cache:
+	kmem_cache_destroy(pt->dma_cmd_cache);
+
+	return ret;
+}
+
+void pt_dmaengine_unregister(struct pt_device *pt)
+{
+	struct dma_device *dma_dev = &pt->dma_dev;
+
+	dma_async_device_unregister(dma_dev);
+
+	kmem_cache_destroy(pt->dma_desc_cache);
+	kmem_cache_destroy(pt->dma_cmd_cache);
+}