On 31/01/24 18:43:46, Jens Wiklander wrote:
> Register eMMC RPMB partition with the RPMB subsystem and provide
> an implementation for the RPMB access operations abstracting
> the actual multi step process.
>
> Add callbacks for getting and putting the needed resources, that is, the
> RPMB data and the RPMB disk.
>
> 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.
>
> Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
> Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
> Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
> ---
> drivers/mmc/core/block.c | 177 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 177 insertions(+)
>
> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> index 32d49100dff5..5286e0b3a5a2 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>
> @@ -163,6 +165,7 @@ struct mmc_rpmb_data {
> int id;
> unsigned int part_index;
> struct mmc_blk_data *md;
> + struct rpmb_dev *rdev;
> struct list_head node;
> };
>
> @@ -2707,6 +2710,169 @@ static void mmc_blk_rpmb_device_release(struct device *dev)
> kfree(rpmb);
> }
>
> +static void rpmb_op_mmc_get_resources(struct device *dev)
> +{
> + struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
> +
> + /*
> + * When the MMC card is removed rpmb_dev_unregister() is called
> + * from mmc_blk_remove_rpmb_part(). That removes references to the
> + * devices in struct mmc_rpmb_data and rpmb->md. Since struct
> + * rpmb_dev can still reach those structs we must hold a reference
> + * until struct rpmb_dev also is released.
> + *
> + * This is analogous to what's done in mmc_rpmb_chrdev_open() and
> + * mmc_rpmb_chrdev_release() below.
> + */
> + get_device(dev);
> + mmc_blk_get(rpmb->md->disk);
> +}
> +
> +static void rpmb_op_mmc_put_resources(struct device *dev)
> +{
> + struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
> +
> + mmc_blk_put(rpmb->md);
> + put_device(dev);
> +}
> +
> +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]) {
> + kfree(idata);
don't you need to unwind these allocations on error?
> + 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 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 int rpmb_op_mmc_route_frames(struct device *dev, bool write, u8 *req,
> + unsigned int req_len, u8 *resp,
> + unsigned int resp_len)
> +{
> + 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;
> + int ret;
> +
> + if (write)
> + cmd_count = 3;
> + else
> + cmd_count = 2;
> +
> + if (IS_ERR(md->queue.card))
> + return PTR_ERR(md->queue.card);
> +
> + 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 rpmb_op_mmc_set_dev_info(struct device *dev, struct rpmb_dev *rdev)
> +{
> + struct mmc_rpmb_data *rpmb = dev_get_drvdata(dev);
> + struct mmc_card *card = rpmb->md->queue.card;
> + unsigned int n;
> + u32 cid[4];
> +
> + for (n = 0; n < 4; n++)
> + cid[n] = be32_to_cpu(card->raw_cid[n]);
> +
> + rdev->dev_id = kmemdup(cid, sizeof(cid), GFP_KERNEL);
> + if (!rdev->dev_id)
> + return -ENOMEM;
> + rdev->dev_id_len = sizeof(cid);
> + rdev->reliable_wr_count = card->ext_csd.raw_rpmb_size_mult;
> + rdev->capacity = card->ext_csd.rel_sectors;
> +
> + return 0;
> +}
> +
> +static struct rpmb_ops rpmb_mmc_ops = {
> + .type = RPMB_TYPE_EMMC,
> + .get_resources = rpmb_op_mmc_get_resources,
> + .put_resources = rpmb_op_mmc_put_resources,
> + .route_frames = rpmb_op_mmc_route_frames,
> + .set_dev_info = rpmb_op_mmc_set_dev_info,
> +};
> +
> static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
> struct mmc_blk_data *md,
> unsigned int part_index,
> @@ -2751,6 +2917,14 @@ static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
> goto out_put_device;
> }
>
> + rpmb->rdev = rpmb_dev_register(&rpmb->dev, &rpmb_mmc_ops);
> + if (IS_ERR(rpmb->rdev)) {
> + pr_err("%s: could not register RPMB device\n", rpmb_name);
> + ret = PTR_ERR(rpmb->rdev);
> + rpmb->rdev = NULL;
> + goto out_cdev_device_del;
> + }
> +
> list_add(&rpmb->node, &md->rpmbs);
>
> string_get_size((u64)size, 512, STRING_UNITS_2,
> @@ -2762,6 +2936,8 @@ static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
>
> return 0;
>
> +out_cdev_device_del:
> + cdev_device_del(&rpmb->chrdev, &rpmb->dev);
> out_put_device:
> put_device(&rpmb->dev);
> return ret;
> @@ -2770,6 +2946,7 @@ static int mmc_blk_alloc_rpmb_part(struct mmc_card *card,
> static void mmc_blk_remove_rpmb_part(struct mmc_rpmb_data *rpmb)
>
> {
> + rpmb_dev_unregister(rpmb->rdev);
> cdev_device_del(&rpmb->chrdev, &rpmb->dev);
> put_device(&rpmb->dev);
> }
> --
> 2.34.1
>
