habanalabs: add command submission module

This patch adds the main flow for the user to submit work to the device.

Each work is described by a command submission object (CS). The CS contains
3 arrays of command buffers: One for execution, and two for context-switch
(store and restore).

For each CB, the user specifies on which queue to put that CB. In case of
an internal queue, the entry doesn't contain a pointer to the CB but the
address in the on-chip memory that the CB resides at.

The driver parses some of the CBs to enforce security restrictions.

The user receives a sequence number that represents the CS object. The user
can then query the driver regarding the status of the CS, using that
sequence number.

In case the CS doesn't finish before the timeout expires, the driver will
perform a soft-reset of the device.

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 198 insertions, 0 deletions

diff --git a/drivers/misc/habanalabs/memory.c b/drivers/misc/habanalabs/memory.c
new file mode 100644
index 000000000000..ad14376a1c25
--- /dev/null
+++ b/drivers/misc/habanalabs/memory.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright 2016-2019 HabanaLabs, Ltd.
+ * All Rights Reserved.
+ */
+
+#include "habanalabs.h"
+
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+
+/*
+ * hl_pin_host_memory - pins a chunk of host memory
+ *
+ * @hdev                : pointer to the habanalabs device structure
+ * @addr                : the user-space virtual address of the memory area
+ * @size                : the size of the memory area
+ * @userptr	        : pointer to hl_userptr structure
+ *
+ * This function does the following:
+ * - Pins the physical pages
+ * - Create a SG list from those pages
+ */
+int hl_pin_host_memory(struct hl_device *hdev, u64 addr, u32 size,
+			struct hl_userptr *userptr)
+{
+	u64 start, end;
+	u32 npages, offset;
+	int rc;
+
+	if (!size) {
+		dev_err(hdev->dev, "size to pin is invalid - %d\n",
+			size);
+		return -EINVAL;
+	}
+
+	if (!access_ok((void __user *) (uintptr_t) addr, size)) {
+		dev_err(hdev->dev, "user pointer is invalid - 0x%llx\n",
+			addr);
+		return -EFAULT;
+	}
+
+	/*
+	 * If the combination of the address and size requested for this memory
+	 * region causes an integer overflow, return error.
+	 */
+	if (((addr + size) < addr) ||
+			PAGE_ALIGN(addr + size) < (addr + size)) {
+		dev_err(hdev->dev,
+			"user pointer 0x%llx + %u causes integer overflow\n",
+			addr, size);
+		return -EINVAL;
+	}
+
+	start = addr & PAGE_MASK;
+	offset = addr & ~PAGE_MASK;
+	end = PAGE_ALIGN(addr + size);
+	npages = (end - start) >> PAGE_SHIFT;
+
+	userptr->size = size;
+	userptr->addr = addr;
+	userptr->dma_mapped = false;
+	INIT_LIST_HEAD(&userptr->job_node);
+
+	userptr->vec = frame_vector_create(npages);
+	if (!userptr->vec) {
+		dev_err(hdev->dev, "Failed to create frame vector\n");
+		return -ENOMEM;
+	}
+
+	rc = get_vaddr_frames(start, npages, FOLL_FORCE | FOLL_WRITE,
+				userptr->vec);
+
+	if (rc != npages) {
+		dev_err(hdev->dev,
+			"Failed to map host memory, user ptr probably wrong\n");
+		if (rc < 0)
+			goto destroy_framevec;
+		rc = -EFAULT;
+		goto put_framevec;
+	}
+
+	if (frame_vector_to_pages(userptr->vec) < 0) {
+		dev_err(hdev->dev,
+			"Failed to translate frame vector to pages\n");
+		rc = -EFAULT;
+		goto put_framevec;
+	}
+
+	userptr->sgt = kzalloc(sizeof(*userptr->sgt), GFP_ATOMIC);
+	if (!userptr->sgt) {
+		rc = -ENOMEM;
+		goto put_framevec;
+	}
+
+	rc = sg_alloc_table_from_pages(userptr->sgt,
+					frame_vector_pages(userptr->vec),
+					npages, offset, size, GFP_ATOMIC);
+	if (rc < 0) {
+		dev_err(hdev->dev, "failed to create SG table from pages\n");
+		goto free_sgt;
+	}
+
+	return 0;
+
+free_sgt:
+	kfree(userptr->sgt);
+put_framevec:
+	put_vaddr_frames(userptr->vec);
+destroy_framevec:
+	frame_vector_destroy(userptr->vec);
+	return rc;
+}
+
+/*
+ * hl_unpin_host_memory - unpins a chunk of host memory
+ *
+ * @hdev                : pointer to the habanalabs device structure
+ * @userptr             : pointer to hl_userptr structure
+ *
+ * This function does the following:
+ * - Unpins the physical pages related to the host memory
+ * - Free the SG list
+ */
+int hl_unpin_host_memory(struct hl_device *hdev, struct hl_userptr *userptr)
+{
+	struct page **pages;
+
+	if (userptr->dma_mapped)
+		hdev->asic_funcs->hl_dma_unmap_sg(hdev,
+				userptr->sgt->sgl,
+				userptr->sgt->nents,
+				userptr->dir);
+
+	pages = frame_vector_pages(userptr->vec);
+	if (!IS_ERR(pages)) {
+		int i;
+
+		for (i = 0; i < frame_vector_count(userptr->vec); i++)
+			set_page_dirty_lock(pages[i]);
+	}
+	put_vaddr_frames(userptr->vec);
+	frame_vector_destroy(userptr->vec);
+
+	list_del(&userptr->job_node);
+
+	sg_free_table(userptr->sgt);
+	kfree(userptr->sgt);
+
+	return 0;
+}
+
+/*
+ * hl_userptr_delete_list - clear userptr list
+ *
+ * @hdev                : pointer to the habanalabs device structure
+ * @userptr_list        : pointer to the list to clear
+ *
+ * This function does the following:
+ * - Iterates over the list and unpins the host memory and frees the userptr
+ *   structure.
+ */
+void hl_userptr_delete_list(struct hl_device *hdev,
+				struct list_head *userptr_list)
+{
+	struct hl_userptr *userptr, *tmp;
+
+	list_for_each_entry_safe(userptr, tmp, userptr_list, job_node) {
+		hl_unpin_host_memory(hdev, userptr);
+		kfree(userptr);
+	}
+
+	INIT_LIST_HEAD(userptr_list);
+}
+
+/*
+ * hl_userptr_is_pinned - returns whether the given userptr is pinned
+ *
+ * @hdev                : pointer to the habanalabs device structure
+ * @userptr_list        : pointer to the list to clear
+ * @userptr             : pointer to userptr to check
+ *
+ * This function does the following:
+ * - Iterates over the list and checks if the given userptr is in it, means is
+ *   pinned. If so, returns true, otherwise returns false.
+ */
+bool hl_userptr_is_pinned(struct hl_device *hdev, u64 addr,
+				u32 size, struct list_head *userptr_list,
+				struct hl_userptr **userptr)
+{
+	list_for_each_entry((*userptr), userptr_list, job_node) {
+		if ((addr == (*userptr)->addr) && (size == (*userptr)->size))
+			return true;
+	}
+
+	return false;
+}