1 files changed, 512 insertions, 3 deletions

diff --git a/drivers/misc/habanalabs/common/memory.c b/drivers/misc/habanalabs/common/memory.c
index 33986933aa9e..9bd626a00de3 100644
--- a/drivers/misc/habanalabs/common/memory.c
+++ b/drivers/misc/habanalabs/common/memory.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 
 /*
- * Copyright 2016-2019 HabanaLabs, Ltd.
+ * Copyright 2016-2021 HabanaLabs, Ltd.
  * All Rights Reserved.
  */
 
@@ -11,6 +11,9 @@
 
 #include <linux/uaccess.h>
 #include <linux/slab.h>
+#include <linux/pci-p2pdma.h>
+
+MODULE_IMPORT_NS(DMA_BUF);
 
 #define HL_MMU_DEBUG	0
 
@@ -347,6 +350,12 @@ static int free_device_memory(struct hl_ctx *ctx, struct hl_mem_in *args)
 			return -EINVAL;
 		}
 
+		if (phys_pg_pack->exporting_cnt) {
+			dev_dbg(hdev->dev, "handle %u is exported, cannot free\n", handle);
+			spin_unlock(&vm->idr_lock);
+			return -EINVAL;
+		}
+
 		/*
 		 * must remove from idr before the freeing of the physical
 		 * pages as the refcount of the pool is also the trigger of the
@@ -1487,13 +1496,487 @@ int hl_hw_block_mmap(struct hl_fpriv *hpriv, struct vm_area_struct *vma)
 	return 0;
 }
 
+static int set_dma_sg(struct scatterlist *sg, u64 bar_address, u64 chunk_size,
+			struct device *dev, enum dma_data_direction dir)
+{
+	dma_addr_t addr;
+	int rc;
+
+	addr = dma_map_resource(dev, bar_address, chunk_size, dir,
+				DMA_ATTR_SKIP_CPU_SYNC);
+	rc = dma_mapping_error(dev, addr);
+	if (rc)
+		return rc;
+
+	sg_set_page(sg, NULL, chunk_size, 0);
+	sg_dma_address(sg) = addr;
+	sg_dma_len(sg) = chunk_size;
+
+	return 0;
+}
+
+static struct sg_table *alloc_sgt_from_device_pages(struct hl_device *hdev, u64 *pages, u64 npages,
+						u64 page_size, struct device *dev,
+						enum dma_data_direction dir)
+{
+	u64 chunk_size, bar_address, dma_max_seg_size;
+	struct asic_fixed_properties *prop;
+	int rc, i, j, nents, cur_page;
+	struct scatterlist *sg;
+	struct sg_table *sgt;
+
+	prop = &hdev->asic_prop;
+
+	dma_max_seg_size = dma_get_max_seg_size(dev);
+
+	/* We would like to align the max segment size to PAGE_SIZE, so the
+	 * SGL will contain aligned addresses that can be easily mapped to
+	 * an MMU
+	 */
+	dma_max_seg_size = ALIGN_DOWN(dma_max_seg_size, PAGE_SIZE);
+	if (dma_max_seg_size < PAGE_SIZE) {
+		dev_err_ratelimited(hdev->dev,
+				"dma_max_seg_size %llu can't be smaller than PAGE_SIZE\n",
+				dma_max_seg_size);
+		return ERR_PTR(-EINVAL);
+	}
+
+	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+	if (!sgt)
+		return ERR_PTR(-ENOMEM);
+
+	/* If the size of each page is larger than the dma max segment size,
+	 * then we can't combine pages and the number of entries in the SGL
+	 * will just be the
+	 * <number of pages> * <chunks of max segment size in each page>
+	 */
+	if (page_size > dma_max_seg_size)
+		nents = npages * DIV_ROUND_UP_ULL(page_size, dma_max_seg_size);
+	else
+		/* Get number of non-contiguous chunks */
+		for (i = 1, nents = 1, chunk_size = page_size ; i < npages ; i++) {
+			if (pages[i - 1] + page_size != pages[i] ||
+					chunk_size + page_size > dma_max_seg_size) {
+				nents++;
+				chunk_size = page_size;
+				continue;
+			}
+
+			chunk_size += page_size;
+		}
+
+	rc = sg_alloc_table(sgt, nents, GFP_KERNEL | __GFP_ZERO);
+	if (rc)
+		goto error_free;
+
+	cur_page = 0;
+
+	if (page_size > dma_max_seg_size) {
+		u64 size_left, cur_device_address = 0;
+
+		size_left = page_size;
+
+		/* Need to split each page into the number of chunks of
+		 * dma_max_seg_size
+		 */
+		for_each_sgtable_dma_sg(sgt, sg, i) {
+			if (size_left == page_size)
+				cur_device_address =
+					pages[cur_page] - prop->dram_base_address;
+			else
+				cur_device_address += dma_max_seg_size;
+
+			chunk_size = min(size_left, dma_max_seg_size);
+
+			bar_address = hdev->dram_pci_bar_start + cur_device_address;
+
+			rc = set_dma_sg(sg, bar_address, chunk_size, dev, dir);
+			if (rc)
+				goto error_unmap;
+
+			if (size_left > dma_max_seg_size) {
+				size_left -= dma_max_seg_size;
+			} else {
+				cur_page++;
+				size_left = page_size;
+			}
+		}
+	} else {
+		/* Merge pages and put them into the scatterlist */
+		for_each_sgtable_dma_sg(sgt, sg, i) {
+			chunk_size = page_size;
+			for (j = cur_page + 1 ; j < npages ; j++) {
+				if (pages[j - 1] + page_size != pages[j] ||
+						chunk_size + page_size > dma_max_seg_size)
+					break;
+
+				chunk_size += page_size;
+			}
+
+			bar_address = hdev->dram_pci_bar_start +
+					(pages[cur_page] - prop->dram_base_address);
+
+			rc = set_dma_sg(sg, bar_address, chunk_size, dev, dir);
+			if (rc)
+				goto error_unmap;
+
+			cur_page = j;
+		}
+	}
+
+	/* Because we are not going to include a CPU list we want to have some
+	 * chance that other users will detect this by setting the orig_nents
+	 * to 0 and using only nents (length of DMA list) when going over the
+	 * sgl
+	 */
+	sgt->orig_nents = 0;
+
+	return sgt;
+
+error_unmap:
+	for_each_sgtable_dma_sg(sgt, sg, i) {
+		if (!sg_dma_len(sg))
+			continue;
+
+		dma_unmap_resource(dev, sg_dma_address(sg),
+					sg_dma_len(sg), dir,
+					DMA_ATTR_SKIP_CPU_SYNC);
+	}
+
+	sg_free_table(sgt);
+
+error_free:
+	kfree(sgt);
+	return ERR_PTR(rc);
+}
+
+static int hl_dmabuf_attach(struct dma_buf *dmabuf,
+				struct dma_buf_attachment *attachment)
+{
+	struct hl_dmabuf_priv *hl_dmabuf;
+	struct hl_device *hdev;
+	int rc;
+
+	hl_dmabuf = dmabuf->priv;
+	hdev = hl_dmabuf->ctx->hdev;
+
+	rc = pci_p2pdma_distance_many(hdev->pdev, &attachment->dev, 1, true);
+
+	if (rc < 0)
+		attachment->peer2peer = false;
+	return 0;
+}
+
+static struct sg_table *hl_map_dmabuf(struct dma_buf_attachment *attachment,
+					enum dma_data_direction dir)
+{
+	struct dma_buf *dma_buf = attachment->dmabuf;
+	struct hl_vm_phys_pg_pack *phys_pg_pack;
+	struct hl_dmabuf_priv *hl_dmabuf;
+	struct hl_device *hdev;
+	struct sg_table *sgt;
+
+	hl_dmabuf = dma_buf->priv;
+	hdev = hl_dmabuf->ctx->hdev;
+	phys_pg_pack = hl_dmabuf->phys_pg_pack;
+
+	if (!attachment->peer2peer) {
+		dev_dbg(hdev->dev, "Failed to map dmabuf because p2p is disabled\n");
+		return ERR_PTR(-EPERM);
+	}
+
+	if (phys_pg_pack)
+		sgt = alloc_sgt_from_device_pages(hdev,
+						phys_pg_pack->pages,
+						phys_pg_pack->npages,
+						phys_pg_pack->page_size,
+						attachment->dev,
+						dir);
+	else
+		sgt = alloc_sgt_from_device_pages(hdev,
+						&hl_dmabuf->device_address,
+						1,
+						hl_dmabuf->dmabuf->size,
+						attachment->dev,
+						dir);
+
+	if (IS_ERR(sgt))
+		dev_err(hdev->dev, "failed (%ld) to initialize sgt for dmabuf\n", PTR_ERR(sgt));
+
+	return sgt;
+}
+
+static void hl_unmap_dmabuf(struct dma_buf_attachment *attachment,
+				  struct sg_table *sgt,
+				  enum dma_data_direction dir)
+{
+	struct scatterlist *sg;
+	int i;
+
+	/* The memory behind the dma-buf has *always* resided on the device itself, i.e. it lives
+	 * only in the 'device' domain (after all, it maps a PCI bar address which points to the
+	 * device memory).
+	 *
+	 * Therefore, it was never in the 'CPU' domain and hence, there is no need to perform
+	 * a sync of the memory to the CPU's cache, as it never resided inside that cache.
+	 */
+	for_each_sgtable_dma_sg(sgt, sg, i)
+		dma_unmap_resource(attachment->dev, sg_dma_address(sg),
+					sg_dma_len(sg), dir,
+					DMA_ATTR_SKIP_CPU_SYNC);
+
+	/* Need to restore orig_nents because sg_free_table use that field */
+	sgt->orig_nents = sgt->nents;
+	sg_free_table(sgt);
+	kfree(sgt);
+}
+
+static void hl_release_dmabuf(struct dma_buf *dmabuf)
+{
+	struct hl_dmabuf_priv *hl_dmabuf = dmabuf->priv;
+	struct hl_ctx *ctx = hl_dmabuf->ctx;
+	struct hl_device *hdev = ctx->hdev;
+	struct hl_vm *vm = &hdev->vm;
+
+	if (hl_dmabuf->phys_pg_pack) {
+		spin_lock(&vm->idr_lock);
+		hl_dmabuf->phys_pg_pack->exporting_cnt--;
+		spin_unlock(&vm->idr_lock);
+	}
+
+	hl_ctx_put(hl_dmabuf->ctx);
+
+	kfree(hl_dmabuf);
+}
+
+static const struct dma_buf_ops habanalabs_dmabuf_ops = {
+	.attach = hl_dmabuf_attach,
+	.map_dma_buf = hl_map_dmabuf,
+	.unmap_dma_buf = hl_unmap_dmabuf,
+	.release = hl_release_dmabuf,
+};
+
+static int export_dmabuf_common(struct hl_ctx *ctx,
+				struct hl_dmabuf_priv *hl_dmabuf,
+				u64 total_size, int flags, int *dmabuf_fd)
+{
+	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+	struct hl_device *hdev = ctx->hdev;
+	int rc, fd;
+
+	exp_info.ops = &habanalabs_dmabuf_ops;
+	exp_info.size = total_size;
+	exp_info.flags = flags;
+	exp_info.priv = hl_dmabuf;
+
+	hl_dmabuf->dmabuf = dma_buf_export(&exp_info);
+	if (IS_ERR(hl_dmabuf->dmabuf)) {
+		dev_err(hdev->dev, "failed to export dma-buf\n");
+		return PTR_ERR(hl_dmabuf->dmabuf);
+	}
+
+	fd = dma_buf_fd(hl_dmabuf->dmabuf, flags);
+	if (fd < 0) {
+		dev_err(hdev->dev, "failed to get a file descriptor for a dma-buf\n");
+		rc = fd;
+		goto err_dma_buf_put;
+	}
+
+	hl_dmabuf->ctx = ctx;
+	hl_ctx_get(hdev, hl_dmabuf->ctx);
+
+	*dmabuf_fd = fd;
+
+	return 0;
+
+err_dma_buf_put:
+	dma_buf_put(hl_dmabuf->dmabuf);
+	return rc;
+}
+
+/**
+ * export_dmabuf_from_addr() - export a dma-buf object for the given memory
+ *                             address and size.
+ * @ctx: pointer to the context structure.
+ * @device_addr:  device memory physical address.
+ * @size: size of device memory.
+ * @flags: DMA-BUF file/FD flags.
+ * @dmabuf_fd: pointer to result FD that represents the dma-buf object.
+ *
+ * Create and export a dma-buf object for an existing memory allocation inside
+ * the device memory, and return a FD which is associated with the dma-buf
+ * object.
+ *
+ * Return: 0 on success, non-zero for failure.
+ */
+static int export_dmabuf_from_addr(struct hl_ctx *ctx, u64 device_addr,
+					u64 size, int flags, int *dmabuf_fd)
+{
+	struct hl_dmabuf_priv *hl_dmabuf;
+	struct hl_device *hdev = ctx->hdev;
+	struct asic_fixed_properties *prop;
+	u64 bar_address;
+	int rc;
+
+	prop = &hdev->asic_prop;
+
+	if (!IS_ALIGNED(device_addr, PAGE_SIZE)) {
+		dev_dbg(hdev->dev,
+			"exported device memory address 0x%llx should be aligned to 0x%lx\n",
+			device_addr, PAGE_SIZE);
+		return -EINVAL;
+	}
+
+	if (size < PAGE_SIZE) {
+		dev_dbg(hdev->dev,
+			"exported device memory size %llu should be equal to or greater than %lu\n",
+			size, PAGE_SIZE);
+		return -EINVAL;
+	}
+
+	if (device_addr < prop->dram_user_base_address ||
+				device_addr + size > prop->dram_end_address ||
+				device_addr + size < device_addr) {
+		dev_dbg(hdev->dev,
+			"DRAM memory range 0x%llx (+0x%llx) is outside of DRAM boundaries\n",
+			device_addr, size);
+		return -EINVAL;
+	}
+
+	bar_address = hdev->dram_pci_bar_start +
+			(device_addr - prop->dram_base_address);
+
+	if (bar_address + size >
+			hdev->dram_pci_bar_start + prop->dram_pci_bar_size ||
+			bar_address + size < bar_address) {
+		dev_dbg(hdev->dev,
+			"DRAM memory range 0x%llx (+0x%llx) is outside of PCI BAR boundaries\n",
+			device_addr, size);
+		return -EINVAL;
+	}
+
+	hl_dmabuf = kzalloc(sizeof(*hl_dmabuf), GFP_KERNEL);
+	if (!hl_dmabuf)
+		return -ENOMEM;
+
+	hl_dmabuf->device_address = device_addr;
+
+	rc = export_dmabuf_common(ctx, hl_dmabuf, size, flags, dmabuf_fd);
+	if (rc)
+		goto err_free_dmabuf_wrapper;
+
+	return 0;
+
+err_free_dmabuf_wrapper:
+	kfree(hl_dmabuf);
+	return rc;
+}
+
+/**
+ * export_dmabuf_from_handle() - export a dma-buf object for the given memory
+ *                               handle.
+ * @ctx: pointer to the context structure.
+ * @handle: device memory allocation handle.
+ * @flags: DMA-BUF file/FD flags.
+ * @dmabuf_fd: pointer to result FD that represents the dma-buf object.
+ *
+ * Create and export a dma-buf object for an existing memory allocation inside
+ * the device memory, and return a FD which is associated with the dma-buf
+ * object.
+ *
+ * Return: 0 on success, non-zero for failure.
+ */
+static int export_dmabuf_from_handle(struct hl_ctx *ctx, u64 handle, int flags,
+					int *dmabuf_fd)
+{
+	struct hl_vm_phys_pg_pack *phys_pg_pack;
+	struct hl_dmabuf_priv *hl_dmabuf;
+	struct hl_device *hdev = ctx->hdev;
+	struct asic_fixed_properties *prop;
+	struct hl_vm *vm = &hdev->vm;
+	u64 bar_address;
+	int rc, i;
+
+	prop = &hdev->asic_prop;
+
+	if (upper_32_bits(handle)) {
+		dev_dbg(hdev->dev, "no match for handle 0x%llx\n", handle);
+		return -EINVAL;
+	}
+
+	spin_lock(&vm->idr_lock);
+
+	phys_pg_pack = idr_find(&vm->phys_pg_pack_handles, (u32) handle);
+	if (!phys_pg_pack) {
+		spin_unlock(&vm->idr_lock);
+		dev_dbg(hdev->dev, "no match for handle 0x%x\n", (u32) handle);
+		return -EINVAL;
+	}
+
+	/* increment now to avoid freeing device memory while exporting */
+	phys_pg_pack->exporting_cnt++;
+
+	spin_unlock(&vm->idr_lock);
+
+	if (phys_pg_pack->vm_type != VM_TYPE_PHYS_PACK) {
+		dev_dbg(hdev->dev, "handle 0x%llx does not represent DRAM memory\n", handle);
+		rc = -EINVAL;
+		goto err_dec_exporting_cnt;
+	}
+
+	for (i = 0 ; i < phys_pg_pack->npages ; i++) {
+
+		bar_address = hdev->dram_pci_bar_start +
+						(phys_pg_pack->pages[i] -
+						prop->dram_base_address);
+
+		if (bar_address + phys_pg_pack->page_size >
+			hdev->dram_pci_bar_start + prop->dram_pci_bar_size ||
+			bar_address + phys_pg_pack->page_size < bar_address) {
+
+			dev_dbg(hdev->dev,
+				"DRAM memory range 0x%llx (+0x%x) is outside of PCI BAR boundaries\n",
+				phys_pg_pack->pages[i],
+				phys_pg_pack->page_size);
+
+			rc = -EINVAL;
+			goto err_dec_exporting_cnt;
+		}
+	}
+
+	hl_dmabuf = kzalloc(sizeof(*hl_dmabuf), GFP_KERNEL);
+	if (!hl_dmabuf) {
+		rc = -ENOMEM;
+		goto err_dec_exporting_cnt;
+	}
+
+	hl_dmabuf->phys_pg_pack = phys_pg_pack;
+
+	rc = export_dmabuf_common(ctx, hl_dmabuf, phys_pg_pack->total_size,
+				flags, dmabuf_fd);
+	if (rc)
+		goto err_free_dmabuf_wrapper;
+
+	return 0;
+
+err_free_dmabuf_wrapper:
+	kfree(hl_dmabuf);
+
+err_dec_exporting_cnt:
+	spin_lock(&vm->idr_lock);
+	phys_pg_pack->exporting_cnt--;
+	spin_unlock(&vm->idr_lock);
+
+	return rc;
+}
+
 static int mem_ioctl_no_mmu(struct hl_fpriv *hpriv, union hl_mem_args *args)
 {
 	struct hl_device *hdev = hpriv->hdev;
 	struct hl_ctx *ctx = hpriv->ctx;
 	u64 block_handle, device_addr = 0;
 	u32 handle = 0, block_size;
-	int rc;
+	int rc, dmabuf_fd = -EBADF;
 
 	switch (args->in.op) {
 	case HL_MEM_OP_ALLOC:
@@ -1542,6 +2025,16 @@ static int mem_ioctl_no_mmu(struct hl_fpriv *hpriv, union hl_mem_args *args)
 		args->out.block_size = block_size;
 		break;
 
+	case HL_MEM_OP_EXPORT_DMABUF_FD:
+		rc = export_dmabuf_from_addr(ctx,
+				args->in.export_dmabuf_fd.handle,
+				args->in.export_dmabuf_fd.mem_size,
+				args->in.flags,
+				&dmabuf_fd);
+		memset(args, 0, sizeof(*args));
+		args->out.fd = dmabuf_fd;
+		break;
+
 	default:
 		dev_err(hdev->dev, "Unknown opcode for memory IOCTL\n");
 		rc = -ENOTTY;
@@ -1560,7 +2053,7 @@ int hl_mem_ioctl(struct hl_fpriv *hpriv, void *data)
 	struct hl_ctx *ctx = hpriv->ctx;
 	u64 block_handle, device_addr = 0;
 	u32 handle = 0, block_size;
-	int rc;
+	int rc, dmabuf_fd = -EBADF;
 
 	if (!hl_device_operational(hdev, &status)) {
 		dev_warn_ratelimited(hdev->dev,
@@ -1651,6 +2144,22 @@ int hl_mem_ioctl(struct hl_fpriv *hpriv, void *data)
 		args->out.block_size = block_size;
 		break;
 
+	case HL_MEM_OP_EXPORT_DMABUF_FD:
+		if (hdev->asic_prop.dram_supports_virtual_memory)
+			rc = export_dmabuf_from_handle(ctx,
+					args->in.export_dmabuf_fd.handle,
+					args->in.flags,
+					&dmabuf_fd);
+		else
+			rc = export_dmabuf_from_addr(ctx,
+					args->in.export_dmabuf_fd.handle,
+					args->in.export_dmabuf_fd.mem_size,
+					args->in.flags,
+					&dmabuf_fd);
+		memset(args, 0, sizeof(*args));
+		args->out.fd = dmabuf_fd;
+		break;
+
 	default:
 		dev_err(hdev->dev, "Unknown opcode for memory IOCTL\n");
 		rc = -ENOTTY;