0030-rpmb-VRPMB-FE-create-virtio-rpmb-frontend-driver.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Tomas Winkler <tomas.winkler@intel.com>
Date: Thu, 24 May 2018 14:57:02 +0300
Subject: [PATCH] rpmb: VRPMB-FE create virtio rpmb frontend driver

This patch implements virtio rpmb frontend driver.
The driver will work with RPMB VBS-U together to
provide one communication channel between UOS and SOS.

V2: 1. Change license to dual BSD/GPL
    2. Fix coding style.
    3. Use pr_fmt macro instead of ERR, DBG, ...
V3: 1. Replace - with _ in file name.
    2. Plug to rpmb framework instead of using own misc device
    3. Use arrays of scatter lists instead of linearizing the data.
V4: 1. Allocate memory for control structures, it's not possible to DMA
       from the stack.
V5: 1. Add mutex and use wait queue instead of completion.
    2. WIP code for getting capabilities
V6: 1. Fix calculation of the allocation size for seq cmd
    2. WIP code for getting capabilities
    3. Drop unused constant RPMB_MAX_FRAMES

Change-Id: I88a42f2e8f2ea1573aad9b5cafeae812c669a73e
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
---
 drivers/char/rpmb/Kconfig       |  10 ++
 drivers/char/rpmb/Makefile      |   1 +
 drivers/char/rpmb/virtio_rpmb.c | 305 ++++++++++++++++++++++++++++++++
 3 files changed, 316 insertions(+)
 create mode 100644 drivers/char/rpmb/virtio_rpmb.c

diff --git a/drivers/char/rpmb/Kconfig b/drivers/char/rpmb/Kconfig
index c069664eec92..48f11c19bbda 100644
--- a/drivers/char/rpmb/Kconfig
+++ b/drivers/char/rpmb/Kconfig
@@ -30,3 +30,13 @@ config RPMB_SIM
 	  suitable only for testing of the RPMB subsystem or RPMB applications
 	  prior to RPMB key provisioning.
           Most people should say N here.
+
+config VIRTIO_RPMB
+	tristate "Virtio RPMB character device interface /dev/vrpmb"
+	default n
+	depends on VIRTIO
+	select RPMB
+	help
+	  Say yes here if you want to access virtio RPMB from user space
+	  via character device interface /dev/vrpmb.
+	  This device interface is only for guest/frontend virtio driver.
diff --git a/drivers/char/rpmb/Makefile b/drivers/char/rpmb/Makefile
index 8bd1186948b0..281c012712ca 100644
--- a/drivers/char/rpmb/Makefile
+++ b/drivers/char/rpmb/Makefile
@@ -3,5 +3,6 @@ obj-$(CONFIG_RPMB) += rpmb.o
 rpmb-objs += core.o
 rpmb-$(CONFIG_RPMB_INTF_DEV) += cdev.o
 obj-$(CONFIG_RPMB_SIM) += rpmb_sim.o
+obj-$(CONFIG_VIRTIO_RPMB) += virtio_rpmb.o
 
 ccflags-y += -D__CHECK_ENDIAN__
diff --git a/drivers/char/rpmb/virtio_rpmb.c b/drivers/char/rpmb/virtio_rpmb.c
new file mode 100644
index 000000000000..ef3487c98805
--- /dev/null
+++ b/drivers/char/rpmb/virtio_rpmb.c
@@ -0,0 +1,305 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/*
+ * Virtio RPMB Front End Driver
+ *
+ * Copyright (c) 2018 Intel Corporation. All rights reserved.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/err.h>
+#include <linux/scatterlist.h>
+#include <linux/spinlock.h>
+#include <linux/virtio.h>
+#include <linux/module.h>
+#include <linux/virtio_ids.h>
+#include <linux/fs.h>
+#include <linux/virtio_config.h>
+#include <linux/uaccess.h>
+#include <linux/rpmb.h>
+
+static const char id[] = "RPMB:VIRTIO";
+#ifndef VIRTIO_ID_RPMB
+#define	VIRTIO_ID_RPMB		0xFFFF
+#endif
+
+#define RPMB_SEQ_CMD_MAX 3  /* support up to 3 cmds */
+
+struct virtio_rpmb_info {
+	struct virtqueue *vq;
+	struct mutex lock; /* info lock */
+	wait_queue_head_t have_data;
+	struct rpmb_dev *rdev;
+};
+
+struct virtio_rpmb_ioc {
+	unsigned int ioc_cmd;
+	int result;
+	u8 target;
+	u8 reserved[3];
+};
+
+static void virtio_rpmb_recv_done(struct virtqueue *vq)
+{
+	struct virtio_rpmb_info *vi;
+	struct virtio_device *vdev = vq->vdev;
+
+	vi = vq->vdev->priv;
+	if (!vi) {
+		dev_err(&vdev->dev, "Error: no found vi data.\n");
+		return;
+	}
+
+	wake_up(&vi->have_data);
+}
+
+static int rpmb_virtio_cmd_seq(struct device *dev, u8 target,
+			       struct rpmb_cmd *cmds, u32 ncmds)
+{
+	struct virtio_device *vdev = dev_to_virtio(dev);
+	struct virtio_rpmb_info *vi = vdev->priv;
+	unsigned int i;
+	struct virtio_rpmb_ioc *vio_cmd;
+	struct rpmb_ioc_seq_cmd *seq_cmd;
+	size_t seq_cmd_sz;
+	struct scatterlist vio_ioc, vio_seq, frame[3];
+	struct scatterlist *sgs[5];
+	unsigned int num_out = 0, num_in = 0;
+	size_t sz;
+	int ret;
+	unsigned int len;
+
+	if (ncmds > RPMB_SEQ_CMD_MAX)
+		return -EINVAL;
+
+	mutex_lock(&vi->lock);
+
+	vio_cmd = kzalloc(sizeof(*vio_cmd), GFP_KERNEL);
+	seq_cmd_sz = sizeof(*seq_cmd) + sizeof(struct rpmb_ioc_cmd) * ncmds;
+	seq_cmd = kzalloc(seq_cmd_sz, GFP_KERNEL);
+	if (!vio_cmd || !seq_cmd) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	vio_cmd->ioc_cmd = RPMB_IOC_SEQ_CMD;
+	vio_cmd->result = 0;
+	vio_cmd->target = target;
+	sg_init_one(&vio_ioc, vio_cmd, sizeof(*vio_cmd));
+	sgs[num_out + num_in++] = &vio_ioc;
+
+	seq_cmd->num_of_cmds = ncmds;
+	for (i = 0; i < ncmds; i++) {
+		seq_cmd->cmds[i].flags   = cmds[i].flags;
+		seq_cmd->cmds[i].nframes = cmds[i].nframes;
+		seq_cmd->cmds[i].frames_ptr = i;
+	}
+	sg_init_one(&vio_seq, seq_cmd, seq_cmd_sz);
+	sgs[num_out + num_in++] = &vio_seq;
+
+	for (i = 0; i < ncmds; i++) {
+		sz = sizeof(struct rpmb_frame_jdec) * (cmds[i].nframes ?: 1);
+		sg_init_one(&frame[i], cmds[i].frames, sz);
+		sgs[num_out + num_in++] = &frame[i];
+	}
+
+	virtqueue_add_sgs(vi->vq, sgs, num_out, num_in, vi, GFP_KERNEL);
+	virtqueue_kick(vi->vq);
+
+	wait_event(vi->have_data, virtqueue_get_buf(vi->vq, &len));
+
+	ret = 0;
+
+	if (vio_cmd->result != 0) {
+		dev_err(dev, "Error: command error = %d.\n", vio_cmd->result);
+		ret = -EIO;
+	}
+
+out:
+	kfree(vio_cmd);
+	kfree(seq_cmd);
+	mutex_unlock(&vi->lock);
+	return ret;
+}
+
+static int rpmb_virtio_cmd_cap(struct device *dev, u8 target)
+{
+	struct virtio_device *vdev = dev_to_virtio(dev);
+	struct virtio_rpmb_info *vi = vdev->priv;
+	struct virtio_rpmb_ioc *vio_cmd;
+	struct rpmb_ioc_cap_cmd *cap_cmd;
+	struct scatterlist vio_ioc, cap_ioc;
+	struct scatterlist *sgs[2];
+	unsigned int num_out = 0, num_in = 0;
+	unsigned int len;
+	int ret;
+
+	mutex_lock(&vi->lock);
+
+	vio_cmd = kzalloc(sizeof(*vio_cmd), GFP_KERNEL);
+	cap_cmd = kzalloc(sizeof(*cap_cmd), GFP_KERNEL);
+	if (!vio_cmd || !cap_cmd) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	vio_cmd->ioc_cmd = RPMB_IOC_CAP_CMD;
+	vio_cmd->result = 0;
+	vio_cmd->target = target;
+	sg_init_one(&vio_ioc, vio_cmd, sizeof(*vio_cmd));
+	sgs[num_out + num_in++] = &vio_ioc;
+
+	sg_init_one(&cap_ioc, cap_cmd, sizeof(*cap_cmd));
+	sgs[num_out + num_in++] = &cap_ioc;
+
+	virtqueue_add_sgs(vi->vq, sgs, num_out, num_in, vi, GFP_KERNEL);
+	virtqueue_kick(vi->vq);
+
+	wait_event(vi->have_data, virtqueue_get_buf(vi->vq, &len));
+
+	ret = 0;
+
+	if (vio_cmd->result != 0) {
+		dev_err(dev, "Error: command error = %d.\n", vio_cmd->result);
+		ret = -EIO;
+	}
+
+out:
+	kfree(vio_cmd);
+	kfree(cap_cmd);
+
+	mutex_unlock(&vi->lock);
+	return ret;
+}
+
+static int rpmb_virtio_get_capacity(struct device *dev, u8 target)
+{
+	return 0;
+}
+
+static struct rpmb_ops rpmb_virtio_ops = {
+	.cmd_seq = rpmb_virtio_cmd_seq,
+	.get_capacity = rpmb_virtio_get_capacity,
+	.type = RPMB_TYPE_EMMC,
+};
+
+static int rpmb_virtio_dev_init(struct virtio_rpmb_info *vi)
+{
+	int ret = 0;
+	struct device *dev = &vi->vq->vdev->dev;
+
+	rpmb_virtio_ops.dev_id_len = strlen(id);
+	rpmb_virtio_ops.dev_id = id;
+	rpmb_virtio_ops.wr_cnt_max = 1;
+	rpmb_virtio_ops.rd_cnt_max = 1;
+	rpmb_virtio_ops.block_size = 1;
+
+	vi->rdev = rpmb_dev_register(dev, 0, &rpmb_virtio_ops);
+	if (IS_ERR(vi->rdev)) {
+		ret = PTR_ERR(vi->rdev);
+		goto err;
+	}
+
+	dev_set_drvdata(dev, vi);
+err:
+	return ret;
+}
+
+static int virtio_rpmb_init(struct virtio_device *vdev)
+{
+	int ret;
+	struct virtio_rpmb_info *vi;
+
+	vi = kzalloc(sizeof(*vi), GFP_KERNEL);
+	if (!vi)
+		return -ENOMEM;
+
+	init_waitqueue_head(&vi->have_data);
+	mutex_init(&vi->lock);
+	vdev->priv = vi;
+
+	/* We expect a single virtqueue. */
+	vi->vq = virtio_find_single_vq(vdev, virtio_rpmb_recv_done, "request");
+	if (IS_ERR(vi->vq)) {
+		dev_err(&vdev->dev, "get single vq failed!\n");
+		ret = PTR_ERR(vi->vq);
+		goto err;
+	}
+
+	/* create vrpmb device. */
+	ret = rpmb_virtio_dev_init(vi);
+	if (ret) {
+		dev_err(&vdev->dev, "create vrpmb device failed.\n");
+		goto err;
+	}
+
+	dev_info(&vdev->dev, "init done!\n");
+
+	return 0;
+
+err:
+	kfree(vi);
+	return ret;
+}
+
+static void virtio_rpmb_remove(struct virtio_device *vdev)
+{
+	struct virtio_rpmb_info *vi;
+
+	vi = vdev->priv;
+	if (!vi)
+		return;
+
+	if (wq_has_sleeper(&vi->have_data))
+		wake_up(&vi->have_data);
+
+	rpmb_dev_unregister(vi->rdev);
+
+	if (vdev->config->reset)
+		vdev->config->reset(vdev);
+
+	if (vdev->config->del_vqs)
+		vdev->config->del_vqs(vdev);
+
+	kfree(vi);
+}
+
+static int virtio_rpmb_probe(struct virtio_device *vdev)
+{
+	return virtio_rpmb_init(vdev);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int virtio_rpmb_freeze(struct virtio_device *vdev)
+{
+	virtio_rpmb_remove(vdev);
+	return 0;
+}
+
+static int virtio_rpmb_restore(struct virtio_device *vdev)
+{
+	return virtio_rpmb_init(vdev);
+}
+#endif
+
+static struct virtio_device_id id_table[] = {
+	{ VIRTIO_ID_RPMB, VIRTIO_DEV_ANY_ID },
+	{ 0 },
+};
+
+static struct virtio_driver virtio_rpmb_driver = {
+	.driver.name =	KBUILD_MODNAME,
+	.driver.owner =	THIS_MODULE,
+	.id_table =	id_table,
+	.probe =	virtio_rpmb_probe,
+	.remove =	virtio_rpmb_remove,
+#ifdef CONFIG_PM_SLEEP
+	.freeze =	virtio_rpmb_freeze,
+	.restore =	virtio_rpmb_restore,
+#endif
+};
+
+module_virtio_driver(virtio_rpmb_driver);
+MODULE_DEVICE_TABLE(virtio, id_table);
+
+MODULE_DESCRIPTION("Virtio rpmb frontend driver");
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("Dual BSD/GPL");
-- 
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