misc: bcm-vk: add ioctl load_image

Add ioctl support to issue load_image operation to VK card.

Co-developed-by: Desmond Yan <[e-mail]>
Co-developed-by: James Hu <[e-mail]>
Acked-by: Olof Johansson <[e-mail]>
Signed-off-by: Desmond Yan <[e-mail]>
Signed-off-by: James Hu <[e-mail]>
Signed-off-by: Scott Branden <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/bcm-vk/bcm_vk.h

···
 #include <linux/mutex.h>
 #include <linux/pci.h>
 #include <linux/sched/signal.h>
+#include <linux/uaccess.h>
 #include <uapi/linux/misc/bcm_vk.h>
 
 #include "bcm_vk_msg.h"
···
 
 	struct bcm_vk_dauth_info dauth_info;
 
+	/* mutex to protect the ioctls */
+	struct mutex mutex;
 	struct miscdevice miscdev;
 	int devid; /* dev id allocated */
 

drivers/misc/bcm-vk/bcm_vk_dev.c

···
 #include <linux/idr.h>
 #include <linux/kref.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/pci.h>
 #include <linux/pci_regs.h>
 #include <uapi/linux/misc/bcm_vk.h>
···
 	}
 }
 
+static long bcm_vk_load_image(struct bcm_vk *vk,
+			      const struct vk_image __user *arg)
+{
+	struct device *dev = &vk->pdev->dev;
+	const char *image_name;
+	struct vk_image image;
+	u32 next_loadable;
+	enum soc_idx idx;
+	int image_idx;
+	int ret = -EPERM;
+
+	if (copy_from_user(&image, arg, sizeof(image)))
+		return -EACCES;
+
+	if ((image.type != VK_IMAGE_TYPE_BOOT1) &&
+	    (image.type != VK_IMAGE_TYPE_BOOT2)) {
+		dev_err(dev, "invalid image.type %u\n", image.type);
+		return ret;
+	}
+
+	next_loadable = bcm_vk_next_boot_image(vk);
+	if (next_loadable != image.type) {
+		dev_err(dev, "Next expected image %u, Loading %u\n",
+			next_loadable, image.type);
+		return ret;
+	}
+
+	/*
+	 * if something is pending download already.  This could only happen
+	 * for now when the driver is being loaded, or if someone has issued
+	 * another download command in another shell.
+	 */
+	if (test_and_set_bit(BCM_VK_WQ_DWNLD_PEND, vk->wq_offload) != 0) {
+		dev_err(dev, "Download operation already pending.\n");
+		return ret;
+	}
+
+	image_name = image.filename;
+	if (image_name[0] == '\0') {
+		/* Use default image name if NULL */
+		idx = get_soc_idx(vk);
+		if (idx == VK_IDX_INVALID)
+			goto err_idx;
+
+		/* Image idx starts with boot1 */
+		image_idx = image.type - VK_IMAGE_TYPE_BOOT1;
+		image_name = get_load_fw_name(vk, &image_tab[idx][image_idx]);
+		if (!image_name) {
+			dev_err(dev, "No suitable image found for type %d",
+				image.type);
+			ret = -ENOENT;
+			goto err_idx;
+		}
+	} else {
+		/* Ensure filename is NULL terminated */
+		image.filename[sizeof(image.filename) - 1] = '\0';
+	}
+	ret = bcm_vk_load_image_by_type(vk, image.type, image_name);
+	dev_info(dev, "Load %s, ret %d\n", image_name, ret);
+err_idx:
+	clear_bit(BCM_VK_WQ_DWNLD_PEND, vk->wq_offload);
+
+	return ret;
+}
+
 static void bcm_to_v_reset_doorbell(struct bcm_vk *vk, u32 db_val)
 {
 	vkwrite32(vk, db_val, BAR_0, VK_BAR0_RESET_DB_BASE);
···
 	return 0;
 }
 
+static long bcm_vk_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	long ret = -EINVAL;
+	struct bcm_vk_ctx *ctx = file->private_data;
+	struct bcm_vk *vk = container_of(ctx->miscdev, struct bcm_vk, miscdev);
+	void __user *argp = (void __user *)arg;
+
+	dev_dbg(&vk->pdev->dev,
+		"ioctl, cmd=0x%02x, arg=0x%02lx\n",
+		cmd, arg);
+
+	mutex_lock(&vk->mutex);
+
+	switch (cmd) {
+	case VK_IOCTL_LOAD_IMAGE:
+		ret = bcm_vk_load_image(vk, argp);
+		break;
+
+	default:
+		break;
+	}
+
+	mutex_unlock(&vk->mutex);
+
+	return ret;
+}
+
 static const struct file_operations bcm_vk_fops = {
 	.owner = THIS_MODULE,
 	.open = bcm_vk_open,
 	.release = bcm_vk_release,
+	.unlocked_ioctl = bcm_vk_ioctl,
 };
 
 static int bcm_vk_on_panic(struct notifier_block *nb,
···
 		return -ENOMEM;
 
 	kref_init(&vk->kref);
+	mutex_init(&vk->mutex);
 
 	err = pci_enable_device(pdev);
 	if (err) {