habanalabs: add skeleton driver

This patch adds the habanalabs skeleton driver. The driver does nothing at
this stage except very basic operations. It contains the minimal code to
insmod and rmmod the driver and to create a /dev/hlX file per PCI 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, 358 insertions, 0 deletions

diff --git a/drivers/misc/habanalabs/habanalabs_drv.c b/drivers/misc/habanalabs/habanalabs_drv.c
new file mode 100644
index 000000000000..a5251ed277d1
--- /dev/null
+++ b/drivers/misc/habanalabs/habanalabs_drv.c
@@ -0,0 +1,358 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright 2016-2019 HabanaLabs, Ltd.
+ * All Rights Reserved.
+ *
+ */
+
+#include "habanalabs.h"
+
+#include <linux/pci.h>
+#include <linux/module.h>
+
+#define HL_DRIVER_AUTHOR	"HabanaLabs Kernel Driver Team"
+
+#define HL_DRIVER_DESC		"Driver for HabanaLabs's AI Accelerators"
+
+MODULE_AUTHOR(HL_DRIVER_AUTHOR);
+MODULE_DESCRIPTION(HL_DRIVER_DESC);
+MODULE_LICENSE("GPL v2");
+
+static int hl_major;
+static struct class *hl_class;
+DEFINE_IDR(hl_devs_idr);
+DEFINE_MUTEX(hl_devs_idr_lock);
+
+#define PCI_VENDOR_ID_HABANALABS	0x1da3
+
+#define PCI_IDS_GOYA			0x0001
+
+static const struct pci_device_id ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_HABANALABS, PCI_IDS_GOYA), },
+	{ 0, }
+};
+MODULE_DEVICE_TABLE(pci, ids);
+
+/*
+ * get_asic_type - translate device id to asic type
+ *
+ * @device: id of the PCI device
+ *
+ * Translate device id to asic type.
+ * In case of unidentified device, return -1
+ */
+static enum hl_asic_type get_asic_type(u16 device)
+{
+	enum hl_asic_type asic_type;
+
+	switch (device) {
+	case PCI_IDS_GOYA:
+		asic_type = ASIC_GOYA;
+		break;
+	default:
+		asic_type = ASIC_INVALID;
+		break;
+	}
+
+	return asic_type;
+}
+
+/*
+ * hl_device_open - open function for habanalabs device
+ *
+ * @inode: pointer to inode structure
+ * @filp: pointer to file structure
+ *
+ * Called when process opens an habanalabs device.
+ */
+int hl_device_open(struct inode *inode, struct file *filp)
+{
+	struct hl_device *hdev;
+	struct hl_fpriv *hpriv;
+
+	mutex_lock(&hl_devs_idr_lock);
+	hdev = idr_find(&hl_devs_idr, iminor(inode));
+	mutex_unlock(&hl_devs_idr_lock);
+
+	if (!hdev) {
+		pr_err("Couldn't find device %d:%d\n",
+			imajor(inode), iminor(inode));
+		return -ENXIO;
+	}
+
+	hpriv = kzalloc(sizeof(*hpriv), GFP_KERNEL);
+	if (!hpriv)
+		return -ENOMEM;
+
+	hpriv->hdev = hdev;
+	filp->private_data = hpriv;
+	hpriv->filp = filp;
+	kref_init(&hpriv->refcount);
+	nonseekable_open(inode, filp);
+
+	hpriv->taskpid = find_get_pid(current->pid);
+
+	return 0;
+}
+
+/*
+ * create_hdev - create habanalabs device instance
+ *
+ * @dev: will hold the pointer to the new habanalabs device structure
+ * @pdev: pointer to the pci device
+ * @asic_type: in case of simulator device, which device is it
+ * @minor: in case of simulator device, the minor of the device
+ *
+ * Allocate memory for habanalabs device and initialize basic fields
+ * Identify the ASIC type
+ * Allocate ID (minor) for the device (only for real devices)
+ */
+int create_hdev(struct hl_device **dev, struct pci_dev *pdev,
+		enum hl_asic_type asic_type, int minor)
+{
+	struct hl_device *hdev;
+	int rc;
+
+	*dev = NULL;
+
+	hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
+	if (!hdev)
+		return -ENOMEM;
+
+	hdev->major = hl_major;
+
+	hdev->disabled = true;
+	hdev->pdev = pdev; /* can be NULL in case of simulator device */
+
+	if (asic_type == ASIC_AUTO_DETECT) {
+		hdev->asic_type = get_asic_type(pdev->device);
+		if (hdev->asic_type == ASIC_INVALID) {
+			dev_err(&pdev->dev, "Unsupported ASIC\n");
+			rc = -ENODEV;
+			goto free_hdev;
+		}
+	} else {
+		hdev->asic_type = asic_type;
+	}
+
+	mutex_lock(&hl_devs_idr_lock);
+
+	if (minor == -1) {
+		rc = idr_alloc(&hl_devs_idr, hdev, 0, HL_MAX_MINORS,
+				GFP_KERNEL);
+	} else {
+		void *old_idr = idr_replace(&hl_devs_idr, hdev, minor);
+
+		if (IS_ERR_VALUE(old_idr)) {
+			rc = PTR_ERR(old_idr);
+			pr_err("Error %d when trying to replace minor %d\n",
+				rc, minor);
+			mutex_unlock(&hl_devs_idr_lock);
+			goto free_hdev;
+		}
+		rc = minor;
+	}
+
+	mutex_unlock(&hl_devs_idr_lock);
+
+	if (rc < 0) {
+		if (rc == -ENOSPC) {
+			pr_err("too many devices in the system\n");
+			rc = -EBUSY;
+		}
+		goto free_hdev;
+	}
+
+	hdev->id = rc;
+
+	*dev = hdev;
+
+	return 0;
+
+free_hdev:
+	kfree(hdev);
+	return rc;
+}
+
+/*
+ * destroy_hdev - destroy habanalabs device instance
+ *
+ * @dev: pointer to the habanalabs device structure
+ *
+ */
+void destroy_hdev(struct hl_device *hdev)
+{
+	/* Remove device from the device list */
+	mutex_lock(&hl_devs_idr_lock);
+	idr_remove(&hl_devs_idr, hdev->id);
+	mutex_unlock(&hl_devs_idr_lock);
+
+	kfree(hdev);
+}
+
+static int hl_pmops_suspend(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct hl_device *hdev = pci_get_drvdata(pdev);
+
+	pr_debug("Going to suspend PCI device\n");
+
+	if (!hdev) {
+		pr_err("device pointer is NULL in suspend\n");
+		return 0;
+	}
+
+	return hl_device_suspend(hdev);
+}
+
+static int hl_pmops_resume(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct hl_device *hdev = pci_get_drvdata(pdev);
+
+	pr_debug("Going to resume PCI device\n");
+
+	if (!hdev) {
+		pr_err("device pointer is NULL in resume\n");
+		return 0;
+	}
+
+	return hl_device_resume(hdev);
+}
+
+/*
+ * hl_pci_probe - probe PCI habanalabs devices
+ *
+ * @pdev: pointer to pci device
+ * @id: pointer to pci device id structure
+ *
+ * Standard PCI probe function for habanalabs device.
+ * Create a new habanalabs device and initialize it according to the
+ * device's type
+ */
+static int hl_pci_probe(struct pci_dev *pdev,
+				const struct pci_device_id *id)
+{
+	struct hl_device *hdev;
+	int rc;
+
+	dev_info(&pdev->dev, HL_NAME
+		 " device found [%04x:%04x] (rev %x)\n",
+		 (int)pdev->vendor, (int)pdev->device, (int)pdev->revision);
+
+	rc = create_hdev(&hdev, pdev, ASIC_AUTO_DETECT, -1);
+	if (rc)
+		return rc;
+
+	pci_set_drvdata(pdev, hdev);
+
+	rc = hl_device_init(hdev, hl_class);
+	if (rc) {
+		dev_err(&pdev->dev, "Fatal error during habanalabs device init\n");
+		rc = -ENODEV;
+		goto disable_device;
+	}
+
+	return 0;
+
+disable_device:
+	pci_set_drvdata(pdev, NULL);
+	destroy_hdev(hdev);
+
+	return rc;
+}
+
+/*
+ * hl_pci_remove - remove PCI habanalabs devices
+ *
+ * @pdev: pointer to pci device
+ *
+ * Standard PCI remove function for habanalabs device
+ */
+static void hl_pci_remove(struct pci_dev *pdev)
+{
+	struct hl_device *hdev;
+
+	hdev = pci_get_drvdata(pdev);
+	if (!hdev)
+		return;
+
+	hl_device_fini(hdev);
+	pci_set_drvdata(pdev, NULL);
+
+	destroy_hdev(hdev);
+}
+
+static const struct dev_pm_ops hl_pm_ops = {
+	.suspend = hl_pmops_suspend,
+	.resume = hl_pmops_resume,
+};
+
+static struct pci_driver hl_pci_driver = {
+	.name = HL_NAME,
+	.id_table = ids,
+	.probe = hl_pci_probe,
+	.remove = hl_pci_remove,
+	.driver.pm = &hl_pm_ops,
+};
+
+/*
+ * hl_init - Initialize the habanalabs kernel driver
+ */
+static int __init hl_init(void)
+{
+	int rc;
+	dev_t dev;
+
+	pr_info("loading driver\n");
+
+	rc = alloc_chrdev_region(&dev, 0, HL_MAX_MINORS, HL_NAME);
+	if (rc < 0) {
+		pr_err("unable to get major\n");
+		return rc;
+	}
+
+	hl_major = MAJOR(dev);
+
+	hl_class = class_create(THIS_MODULE, HL_NAME);
+	if (IS_ERR(hl_class)) {
+		pr_err("failed to allocate class\n");
+		rc = PTR_ERR(hl_class);
+		goto remove_major;
+	}
+
+	rc = pci_register_driver(&hl_pci_driver);
+	if (rc) {
+		pr_err("failed to register pci device\n");
+		goto remove_class;
+	}
+
+	pr_debug("driver loaded\n");
+
+	return 0;
+
+remove_class:
+	class_destroy(hl_class);
+remove_major:
+	unregister_chrdev_region(MKDEV(hl_major, 0), HL_MAX_MINORS);
+	return rc;
+}
+
+/*
+ * hl_exit - Release all resources of the habanalabs kernel driver
+ */
+static void __exit hl_exit(void)
+{
+	pci_unregister_driver(&hl_pci_driver);
+
+	class_destroy(hl_class);
+	unregister_chrdev_region(MKDEV(hl_major, 0), HL_MAX_MINORS);
+
+	idr_destroy(&hl_devs_idr);
+
+	pr_debug("driver removed\n");
+}
+
+module_init(hl_init);
+module_exit(hl_exit);