diff mbox series

[v4,2/3] mmc: block: register RPMB partition with the RPMB subsystem

Message ID 20240405115318.904143-3-jens.wiklander@linaro.org
State Superseded
Headers show
Series Replay Protected Memory Block (RPMB) subsystem | expand

Commit Message

Jens Wiklander April 5, 2024, 11:53 a.m. UTC
Register eMMC RPMB partition with the RPMB subsystem and provide
an implementation for the RPMB access operations abstracting
the actual multi step process.

Add a callback to extract the needed device information at registration
to avoid accessing the struct mmc_card at a later stage as we're not
holding a reference counter for this struct.

Taking the needed reference to md->disk in mmc_blk_alloc_rpmb_part()
instead of in mmc_rpmb_chrdev_open(). This is needed by the
route_frames() function pointer in struct rpmb_ops.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
 drivers/mmc/core/block.c | 230 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 228 insertions(+), 2 deletions(-)

Comments

Jens Wiklander April 9, 2024, noon UTC | #1
On Sat, Apr 6, 2024 at 5:31 PM Winkler, Tomas <tomas.winkler@intel.com> wrote:
>
> >
> >
> > > +
> > > +#define RPMB_PROGRAM_KEY       0x1    /* Program RPMB Authentication
> > You expect the key to be already programmed - so you don't really need this
> > operation?
> Depends in what manufacturing flow you program the device,  second I believe in the original series was also a simulation device,
> This is important as the real device can be programmed only once.

This isn't strictly needed, this is the only "nice to have" feature
I've kept because it's easy enough and can be useful. I can remove it
if it's important.

> >
> > > Key */
> > > +#define RPMB_GET_WRITE_COUNTER 0x2    /* Read RPMB write counter
> > */
> > > +#define RPMB_WRITE_DATA        0x3    /* Write data to RPMB partition */
> > > +#define RPMB_READ_DATA         0x4    /* Read data from RPMB partition
> > */
> > > +#define RPMB_RESULT_READ       0x5    /* Read result request  (Internal)
> > */
> > > +
> > >  static DEFINE_MUTEX(block_mutex);
> > >
> > >  /*
> > > @@ -163,6 +205,7 @@ struct mmc_rpmb_data {
> > >         int id;
> > >         unsigned int part_index;
> > >         struct mmc_blk_data *md;
> > > +       struct rpmb_dev *rdev;
> > >         struct list_head node;
> > >  };
> > >
> > > @@ -2672,7 +2715,6 @@ static int mmc_rpmb_chrdev_open(struct inode
> > > *inode, struct file *filp)
> > >
> > >         get_device(&rpmb->dev);
> > >         filp->private_data = rpmb;
> > > -       mmc_blk_get(rpmb->md->disk);
> > Maybe add a comment that this has moved to mmc_blk_alloc_rpmb_part?
> > For those who will look for it.

Such a comment seems odd. Those looking for mmc_blk_get() should be
able to find it easily. I'll add the comment if it's important.

> >
> > >
> > >         return nonseekable_open(inode, filp);  } @@ -2682,7 +2724,6 @@
> > > static int mmc_rpmb_chrdev_release(struct inode *inode, struct file *filp)
> > >         struct mmc_rpmb_data *rpmb = container_of(inode->i_cdev,
> > >                                                   struct
> > > mmc_rpmb_data, chrdev);
> > >
> > > -       mmc_blk_put(rpmb->md);
> > Ditto.

See my answer above.

> >
> > >         put_device(&rpmb->dev);
> > >
> > >         return 0;
> > > @@ -2703,10 +2744,157 @@ static void
> > > mmc_blk_rpmb_device_release(struct
> > > device *dev)  {
> > >         struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
> > >
> > > +       rpmb_dev_unregister(rpmb->rdev);
> > > +       mmc_blk_put(rpmb->md);
> > >         ida_simple_remove(&mmc_rpmb_ida, rpmb->id);
> > >         kfree(rpmb);
> > >  }
> > >
> > > +static void free_idata(struct mmc_blk_ioc_data **idata, unsigned int
> > > +cmd_count) {
> > > +       unsigned int n;
> > > +
> > > +       for (n = 0; n < cmd_count; n++)
> > > +               kfree(idata[n]);
> > > +       kfree(idata);
> > > +}
> > > +
> > > +static struct mmc_blk_ioc_data **alloc_idata(struct mmc_rpmb_data
> > *rpmb,
> > > +                                            unsigned int cmd_count) {
> > > +       struct mmc_blk_ioc_data **idata;
> > > +       unsigned int n;
> > > +
> > > +       idata = kcalloc(cmd_count, sizeof(*idata), GFP_KERNEL);
> > > +       if (!idata)
> > > +               return NULL;
> > > +
> > > +       for (n = 0; n < cmd_count; n++) {
> > > +               idata[n] = kcalloc(1, sizeof(**idata), GFP_KERNEL);
> > > +               if (!idata[n]) {
> > > +                       free_idata(idata, n);
> > > +                       return NULL;
> > > +               }
> > > +               idata[n]->rpmb = rpmb;
> > > +       }
> > > +
> > > +       return idata;
> > > +}
> > > +
> > > +static void set_idata(struct mmc_blk_ioc_data *idata, u32 opcode,
> > > +                     int write_flag, u8 *buf, unsigned int buf_bytes) {
> > > +       idata->ic.opcode = opcode;
> > > +       idata->ic.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
> > > +       idata->ic.write_flag = write_flag;
> > > +       idata->ic.blksz = sizeof(struct rpmb_frame);
> > blksz = 512, so maybe add a compile-time check on sizeof(struct
> > rpmb_frame)?

That makes sense, I'll add it.

> >
> > > +       idata->ic.blocks = buf_bytes /  idata->ic.blksz;
> > > +       idata->buf = buf;
> > > +       idata->buf_bytes = buf_bytes;
> > > +}
> > > +
> > > +static int mmc_route_rpmb_frames(struct device *dev, u8 *req,
> > > +                                unsigned int req_len, u8 *resp,
> > > +                                unsigned int resp_len) {
> > > +       struct rpmb_frame *frm = (struct rpmb_frame *)req;
> > > +       struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
> > > +       struct mmc_blk_data *md = rpmb->md;
> > > +       struct mmc_blk_ioc_data **idata;
> > > +       unsigned int cmd_count;
> > > +       struct request *rq;
> > > +       u16 req_type;
> > > +       bool write;
> > > +       int ret;
> > > +
> > > +       if (IS_ERR(md->queue.card))
> > > +               return PTR_ERR(md->queue.card);
> > > +
> > > +       if (req_len < sizeof(*frm))
> > > +               return -EINVAL;
> > > +
> > > +       req_type = be16_to_cpu(frm->req_resp);
> > > +       switch (req_type) {
> > > +       case RPMB_PROGRAM_KEY:
> > > +               if (req_len != sizeof(struct rpmb_frame) ||
> > > +                   resp_len != sizeof(struct rpmb_frame))
> > > +                       return -EINVAL;
> > > +               write = true;
> > > +               break;
> > > +       case RPMB_GET_WRITE_COUNTER:
> > > +               if (req_len != sizeof(struct rpmb_frame) ||
> > > +                   resp_len != sizeof(struct rpmb_frame))
> > > +                       return -EINVAL;
> > > +               write = false;
> > > +               break;
> > > +       case RPMB_WRITE_DATA:
> > > +               if (req_len % sizeof(struct rpmb_frame) ||
> > > +                   resp_len != sizeof(struct rpmb_frame))
> > > +                       return -EINVAL;
> > > +               write = true;
> > > +               break;
> > > +       case RPMB_READ_DATA:
> > > +               if (req_len != sizeof(struct rpmb_frame) ||
> > > +                   resp_len % sizeof(struct rpmb_frame))
> > > +                       return -EINVAL;
> > > +               write = false;
> > > +               break;
> > > +       default:
> > > +               return -EINVAL;
> > > +       }
> > Looks like the above input validation section can be reduced to is
> > RPMB_WRITE_DATA and default?

RPMB_GET_WRITE_COUNTER and RPMB_READ_DATA have different checks for resp_len.

> >
> > > +
> > > +       if (write)
> > > +               cmd_count = 3;
> > > +       else
> > > +               cmd_count = 2;
> > > +
> > > +       idata = alloc_idata(rpmb, cmd_count);
> > > +       if (!idata)
> > > +               return -ENOMEM;
> > > +
> > > +       if (write) {
> > > +               struct rpmb_frame *frm = (struct rpmb_frame *)resp;
> > > +
> > > +               /* Send write request frame(s) */
> > > +               set_idata(idata[0], MMC_WRITE_MULTIPLE_BLOCK,
> > > +                         1 | MMC_CMD23_ARG_REL_WR, req, req_len);
> > > +
> > > +               /* Send result request frame */
> > > +               memset(frm, 0, sizeof(*frm));
> > > +               frm->req_resp = cpu_to_be16(RPMB_RESULT_READ);
> > > +               set_idata(idata[1], MMC_WRITE_MULTIPLE_BLOCK, 1, resp,
> > > +                         resp_len);
> > > +
> > > +               /* Read response frame */
> > > +               set_idata(idata[2], MMC_READ_MULTIPLE_BLOCK, 0, resp,
> > > resp_len);
> > It is confusing to me that your response is holding 2 frame types:
> > The status frame and the response frame.
> Refer to the spec.
>
> >
> >
> > > +       } else {
> > > +               /* Send write request frame(s) */
> > > +               set_idata(idata[0], MMC_WRITE_MULTIPLE_BLOCK, 1, req,
> > > + req_len);
> > > +
> > > +               /* Read response frame */
> > > +               set_idata(idata[1], MMC_READ_MULTIPLE_BLOCK, 0, resp,
> > > resp_len);
> > > +       }
> > > +
> > > +       rq = blk_mq_alloc_request(md->queue.queue, REQ_OP_DRV_OUT,
> > 0);
> > > +       if (IS_ERR(rq)) {
> > > +               ret = PTR_ERR(rq);
> > > +               goto out;
> > > +       }
> > > +
> > > +       req_to_mmc_queue_req(rq)->drv_op =
> > MMC_DRV_OP_IOCTL_RPMB;
> > > +       req_to_mmc_queue_req(rq)->drv_op_result = -EIO;
> > > +       req_to_mmc_queue_req(rq)->drv_op_data = idata;
> > > +       req_to_mmc_queue_req(rq)->ioc_count = cmd_count;
> > Maybe have an additional struct mmc_queue_req *mq_rq =
> > req_to_mmc_queue_req(rq);

Sure, I'll add it.

> >
> > > +       blk_execute_rq(rq, false);
> > > +       ret = req_to_mmc_queue_req(rq)->drv_op_result;
> > > +
> > > +       blk_mq_free_request(rq);
> > > +
> > > +out:
> > > +       free_idata(idata, cmd_count);
> > > +       return ret;
> > > +}
> > > +
> > >  static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
> > >                                    struct mmc_blk_data *md,
> > >                                    unsigned int part_index, @@ -2741,6
> > > +2929,7 @@ static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
> > >         rpmb->dev.release = mmc_blk_rpmb_device_release;
> > >         device_initialize(&rpmb->dev);
> > >         dev_set_drvdata(&rpmb->dev, rpmb);
> > > +       mmc_blk_get(md->disk);
> > >         rpmb->md = md;
> > >
> > >         cdev_init(&rpmb->chrdev, &mmc_rpmb_fileops); @@ -3002,6
> > > +3191,41 @@ static void mmc_blk_remove_debugfs(struct mmc_card
> > *card,
> > >
> > >  #endif /* CONFIG_DEBUG_FS */
> > >
> > > +static void mmc_blk_rpmb_add(struct mmc_card *card) {
> > > +       struct mmc_blk_data *md = dev_get_drvdata(&card->dev);
> > > +       struct mmc_rpmb_data *rpmb;
> > > +       struct rpmb_dev *rdev;
> > > +       unsigned int n;
> > > +       u32 cid[4];
> > > +       struct rpmb_descr descr = {
> > > +               .type = RPMB_TYPE_EMMC,
> > > +               .route_frames = mmc_route_rpmb_frames,
> > > +               .reliable_wr_count = card->ext_csd.raw_rpmb_size_mult,
> > > +               .capacity = card->ext_csd.rel_sectors,
> > The capacity is RPMB_SIZE_MULT and also limited to 16MB?

Thanks for noticing this, I'll fix it. Yes, the spec says it's limited to 16MB.

> > And you also need the region size you are writing to.
> > If I get your intention regarding reliable_wr_count, AFAIK, rpmb can be
> > written either as a single, double, or 32 frames.
> > And this should be induced from card->ext_csd.rel_param, and not card-
> > >ext_csd.rel_sectors.
> This may change in the spec since this patch was written it was few years ago.

Thanks, I'll fix it.

> >
> > > +               .dev_id = (void *)cid,
> > > +               .dev_id_len = sizeof(cid),
> > > +       };
> > > +
> > > +       /*
> > > +        * Provice CID as an octet array. The CID needs to be interpreted
> > > +        * when used as input to derive the RPMB key since some fields
> > > +        * will change due to firmware updates.
> > > +        */
> > Not sure how the CID register is related to RPMB?
> > Is this something internal to TEE?
> Yes to identify the device.

+1

Thanks,
Jens

> >
> > > +       for (n = 0; n < 4; n++)
> > > +               cid[n] = be32_to_cpu(card->raw_cid[n]);
> > > +
> > > +       list_for_each_entry(rpmb, &md->rpmbs, node) {
> > > +               rdev = rpmb_dev_register(&rpmb->dev, &descr);
> > > +               if (IS_ERR(rdev)) {
> > > +                       pr_warn("%s: could not register RPMB device\n",
> > > +                               dev_name(&rpmb->dev));
> > > +                       continue;
> > > +               }
> > > +               rpmb->rdev = rdev;
> > > +       }
> > > +}
> > > +
> >
> > Thanks,
> > Avri
Jens Wiklander April 9, 2024, 12:01 p.m. UTC | #2
Hi Linus,

On Mon, Apr 8, 2024 at 11:07 AM Linus Walleij <linus.walleij@linaro.org> wrote:
>
> Hi Jens,
>
> On Fri, Apr 5, 2024 at 1:53 PM Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> > +/**
> > + * struct rpmb_frame - rpmb frame as defined by specs
>
> As Tomas said maybe we can write the name of the spec or the number or
> something so users can find it?
>
> I would also write explicitly "the stuff bytes and big-endian properties are
> modeled to fit to the spec".

That makes sense, I'll add it.

Thanks,
Jens

>
> Yours,
> Linus Walleij
diff mbox series

Patch

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 32d49100dff5..e040d4df0b6f 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -33,6 +33,7 @@ 
 #include <linux/cdev.h>
 #include <linux/mutex.h>
 #include <linux/scatterlist.h>
+#include <linux/string.h>
 #include <linux/string_helpers.h>
 #include <linux/delay.h>
 #include <linux/capability.h>
@@ -40,6 +41,7 @@ 
 #include <linux/pm_runtime.h>
 #include <linux/idr.h>
 #include <linux/debugfs.h>
+#include <linux/rpmb.h>
 
 #include <linux/mmc/ioctl.h>
 #include <linux/mmc/card.h>
@@ -76,6 +78,46 @@  MODULE_ALIAS("mmc:block");
 #define MMC_EXTRACT_INDEX_FROM_ARG(x) ((x & 0x00FF0000) >> 16)
 #define MMC_EXTRACT_VALUE_FROM_ARG(x) ((x & 0x0000FF00) >> 8)
 
+/**
+ * struct rpmb_frame - rpmb frame as defined by specs
+ *
+ * @stuff        : stuff bytes
+ * @key_mac      : The authentication key or the message authentication
+ *                 code (MAC) depending on the request/response type.
+ *                 The MAC will be delivered in the last (or the only)
+ *                 block of data.
+ * @data         : Data to be written or read by signed access.
+ * @nonce        : Random number generated by the host for the requests
+ *                 and copied to the response by the RPMB engine.
+ * @write_counter: Counter value for the total amount of the successful
+ *                 authenticated data write requests made by the host.
+ * @addr         : Address of the data to be programmed to or read
+ *                 from the RPMB. Address is the serial number of
+ *                 the accessed block (half sector 256B).
+ * @block_count  : Number of blocks (half sectors, 256B) requested to be
+ *                 read/programmed.
+ * @result       : Includes information about the status of the write counter
+ *                 (valid, expired) and result of the access made to the RPMB.
+ * @req_resp     : Defines the type of request and response to/from the memory.
+ */
+struct rpmb_frame {
+	u8     stuff[196];
+	u8     key_mac[32];
+	u8     data[256];
+	u8     nonce[16];
+	__be32 write_counter;
+	__be16 addr;
+	__be16 block_count;
+	__be16 result;
+	__be16 req_resp;
+} __packed;
+
+#define RPMB_PROGRAM_KEY       0x1    /* Program RPMB Authentication Key */
+#define RPMB_GET_WRITE_COUNTER 0x2    /* Read RPMB write counter */
+#define RPMB_WRITE_DATA        0x3    /* Write data to RPMB partition */
+#define RPMB_READ_DATA         0x4    /* Read data from RPMB partition */
+#define RPMB_RESULT_READ       0x5    /* Read result request  (Internal) */
+
 static DEFINE_MUTEX(block_mutex);
 
 /*
@@ -163,6 +205,7 @@  struct mmc_rpmb_data {
 	int id;
 	unsigned int part_index;
 	struct mmc_blk_data *md;
+	struct rpmb_dev *rdev;
 	struct list_head node;
 };
 
@@ -2672,7 +2715,6 @@  static int mmc_rpmb_chrdev_open(struct inode *inode, struct file *filp)
 
 	get_device(&rpmb->dev);
 	filp->private_data = rpmb;
-	mmc_blk_get(rpmb->md->disk);
 
 	return nonseekable_open(inode, filp);
 }
@@ -2682,7 +2724,6 @@  static int mmc_rpmb_chrdev_release(struct inode *inode, struct file *filp)
 	struct mmc_rpmb_data *rpmb = container_of(inode->i_cdev,
 						  struct mmc_rpmb_data, chrdev);
 
-	mmc_blk_put(rpmb->md);
 	put_device(&rpmb->dev);
 
 	return 0;
@@ -2703,10 +2744,157 @@  static void mmc_blk_rpmb_device_release(struct device *dev)
 {
 	struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
 
+	rpmb_dev_unregister(rpmb->rdev);
+	mmc_blk_put(rpmb->md);
 	ida_simple_remove(&mmc_rpmb_ida, rpmb->id);
 	kfree(rpmb);
 }
 
+static void free_idata(struct mmc_blk_ioc_data **idata, unsigned int cmd_count)
+{
+	unsigned int n;
+
+	for (n = 0; n < cmd_count; n++)
+		kfree(idata[n]);
+	kfree(idata);
+}
+
+static struct mmc_blk_ioc_data **alloc_idata(struct mmc_rpmb_data *rpmb,
+					     unsigned int cmd_count)
+{
+	struct mmc_blk_ioc_data **idata;
+	unsigned int n;
+
+	idata = kcalloc(cmd_count, sizeof(*idata), GFP_KERNEL);
+	if (!idata)
+		return NULL;
+
+	for (n = 0; n < cmd_count; n++) {
+		idata[n] = kcalloc(1, sizeof(**idata), GFP_KERNEL);
+		if (!idata[n]) {
+			free_idata(idata, n);
+			return NULL;
+		}
+		idata[n]->rpmb = rpmb;
+	}
+
+	return idata;
+}
+
+static void set_idata(struct mmc_blk_ioc_data *idata, u32 opcode,
+		      int write_flag, u8 *buf, unsigned int buf_bytes)
+{
+	idata->ic.opcode = opcode;
+	idata->ic.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
+	idata->ic.write_flag = write_flag;
+	idata->ic.blksz = sizeof(struct rpmb_frame);
+	idata->ic.blocks = buf_bytes /  idata->ic.blksz;
+	idata->buf = buf;
+	idata->buf_bytes = buf_bytes;
+}
+
+static int mmc_route_rpmb_frames(struct device *dev, u8 *req,
+				 unsigned int req_len, u8 *resp,
+				 unsigned int resp_len)
+{
+	struct rpmb_frame *frm = (struct rpmb_frame *)req;
+	struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
+	struct mmc_blk_data *md = rpmb->md;
+	struct mmc_blk_ioc_data **idata;
+	unsigned int cmd_count;
+	struct request *rq;
+	u16 req_type;
+	bool write;
+	int ret;
+
+	if (IS_ERR(md->queue.card))
+		return PTR_ERR(md->queue.card);
+
+	if (req_len < sizeof(*frm))
+		return -EINVAL;
+
+	req_type = be16_to_cpu(frm->req_resp);
+	switch (req_type) {
+	case RPMB_PROGRAM_KEY:
+		if (req_len != sizeof(struct rpmb_frame) ||
+		    resp_len != sizeof(struct rpmb_frame))
+			return -EINVAL;
+		write = true;
+		break;
+	case RPMB_GET_WRITE_COUNTER:
+		if (req_len != sizeof(struct rpmb_frame) ||
+		    resp_len != sizeof(struct rpmb_frame))
+			return -EINVAL;
+		write = false;
+		break;
+	case RPMB_WRITE_DATA:
+		if (req_len % sizeof(struct rpmb_frame) ||
+		    resp_len != sizeof(struct rpmb_frame))
+			return -EINVAL;
+		write = true;
+		break;
+	case RPMB_READ_DATA:
+		if (req_len != sizeof(struct rpmb_frame) ||
+		    resp_len % sizeof(struct rpmb_frame))
+			return -EINVAL;
+		write = false;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (write)
+		cmd_count = 3;
+	else
+		cmd_count = 2;
+
+	idata = alloc_idata(rpmb, cmd_count);
+	if (!idata)
+		return -ENOMEM;
+
+	if (write) {
+		struct rpmb_frame *frm = (struct rpmb_frame *)resp;
+
+		/* Send write request frame(s) */
+		set_idata(idata[0], MMC_WRITE_MULTIPLE_BLOCK,
+			  1 | MMC_CMD23_ARG_REL_WR, req, req_len);
+
+		/* Send result request frame */
+		memset(frm, 0, sizeof(*frm));
+		frm->req_resp = cpu_to_be16(RPMB_RESULT_READ);
+		set_idata(idata[1], MMC_WRITE_MULTIPLE_BLOCK, 1, resp,
+			  resp_len);
+
+		/* Read response frame */
+		set_idata(idata[2], MMC_READ_MULTIPLE_BLOCK, 0, resp, resp_len);
+	} else {
+		/* Send write request frame(s) */
+		set_idata(idata[0], MMC_WRITE_MULTIPLE_BLOCK, 1, req, req_len);
+
+		/* Read response frame */
+		set_idata(idata[1], MMC_READ_MULTIPLE_BLOCK, 0, resp, resp_len);
+	}
+
+	rq = blk_mq_alloc_request(md->queue.queue, REQ_OP_DRV_OUT, 0);
+	if (IS_ERR(rq)) {
+		ret = PTR_ERR(rq);
+		goto out;
+	}
+
+	req_to_mmc_queue_req(rq)->drv_op = MMC_DRV_OP_IOCTL_RPMB;
+	req_to_mmc_queue_req(rq)->drv_op_result = -EIO;
+	req_to_mmc_queue_req(rq)->drv_op_data = idata;
+	req_to_mmc_queue_req(rq)->ioc_count = cmd_count;
+	blk_execute_rq(rq, false);
+	ret = req_to_mmc_queue_req(rq)->drv_op_result;
+
+	blk_mq_free_request(rq);
+
+out:
+	free_idata(idata, cmd_count);
+	return ret;
+}
+
 static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
 				   struct mmc_blk_data *md,
 				   unsigned int part_index,
@@ -2741,6 +2929,7 @@  static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
 	rpmb->dev.release = mmc_blk_rpmb_device_release;
 	device_initialize(&rpmb->dev);
 	dev_set_drvdata(&rpmb->dev, rpmb);
+	mmc_blk_get(md->disk);
 	rpmb->md = md;
 
 	cdev_init(&rpmb->chrdev, &mmc_rpmb_fileops);
@@ -3002,6 +3191,41 @@  static void mmc_blk_remove_debugfs(struct mmc_card *card,
 
 #endif /* CONFIG_DEBUG_FS */
 
+static void mmc_blk_rpmb_add(struct mmc_card *card)
+{
+	struct mmc_blk_data *md = dev_get_drvdata(&card->dev);
+	struct mmc_rpmb_data *rpmb;
+	struct rpmb_dev *rdev;
+	unsigned int n;
+	u32 cid[4];
+	struct rpmb_descr descr = {
+		.type = RPMB_TYPE_EMMC,
+		.route_frames = mmc_route_rpmb_frames,
+		.reliable_wr_count = card->ext_csd.raw_rpmb_size_mult,
+		.capacity = card->ext_csd.rel_sectors,
+		.dev_id = (void *)cid,
+		.dev_id_len = sizeof(cid),
+	};
+
+	/*
+	 * Provice CID as an octet array. The CID needs to be interpreted
+	 * when used as input to derive the RPMB key since some fields
+	 * will change due to firmware updates.
+	 */
+	for (n = 0; n < 4; n++)
+		cid[n] = be32_to_cpu(card->raw_cid[n]);
+
+	list_for_each_entry(rpmb, &md->rpmbs, node) {
+		rdev = rpmb_dev_register(&rpmb->dev, &descr);
+		if (IS_ERR(rdev)) {
+			pr_warn("%s: could not register RPMB device\n",
+				dev_name(&rpmb->dev));
+			continue;
+		}
+		rpmb->rdev = rdev;
+	}
+}
+
 static int mmc_blk_probe(struct mmc_card *card)
 {
 	struct mmc_blk_data *md;
@@ -3047,6 +3271,8 @@  static int mmc_blk_probe(struct mmc_card *card)
 		pm_runtime_enable(&card->dev);
 	}
 
+	mmc_blk_rpmb_add(card);
+
 	return 0;
 
 out: