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

From: Winkler, Tomas
Date: Sat Apr 06 2024 - 11:31:41 EST

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In reply to: Avri Altman: "RE: [PATCH v4 2/3] mmc: block: register RPMB partition with the RPMB subsystem"
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>
>
> > +
> > +#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.
>
> > 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.
>
> >
> > 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.
>
> > 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)?
>
> > + 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?
>
> > +
> > + 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);
>
> > + 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?
> 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.
>
> > + .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.
>
> > + 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

Next message: Jonathan Cameron: "Re: [PATCH 16/34] iio: ad5755: hook up of_device_id lookup to platform driver"
Previous message: Luca Weiss: "[PATCH] Documentation: ABI: document in_temp_input file"
In reply to: Avri Altman: "RE: [PATCH v4 2/3] mmc: block: register RPMB partition with the RPMB subsystem"
Next in thread: Jens Wiklander: "[PATCH v4 3/3] optee: probe RPMB device using RPMB subsystem"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]