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    SubjectRe: [PATCH v5 2/3] mmc: block: register RPMB partition with the RPMB subsystem
    On Mon, Apr 29, 2024 at 11:41 AM Manuel Traut <manut@mecka.net> wrote:
    >
    > On Fri, Apr 26, 2024 at 03:24:21PM +0200, Jens Wiklander wrote:
    > > On Thu, Apr 25, 2024 at 10:43 AM Manuel Traut <manut@mecka.net> wrote:
    > > >
    > > > On Mon, Apr 22, 2024 at 11:19:35AM +0200, 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 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 | 241 ++++++++++++++++++++++++++++++++++++++-
    > > > > 1 file changed, 239 insertions(+), 2 deletions(-)
    > > > >
    > > > > diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
    > > > > index 32d49100dff5..a7f126fbc605 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 +78,48 @@ 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 eMMC 5.1 (JESD84-B51)
    > > > > + *
    > > > > + * @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.
    > > > > + *
    > > > > + * The stuff bytes and big-endian properties are modeled to fit to the spec.
    > > > > + */
    > > > > +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 +207,7 @@ 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 +2717,6 @@ 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 +2726,6 @@ 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 +2746,165 @@ 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)
    > > > > +{
    > > > > + /*
    > > > > + * The size of an RPMB frame must match what's expected by the
    > > > > + * hardware.
    > > > > + */
    > > > > + BUILD_BUG_ON(sizeof(struct rpmb_frame) != 512);
    > > > > +
    > > > > + 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;
    > > >
    > > > I tested the series on a i.MX8MM with a eMMC connected via the imx-sdhci
    > > > controller. Reading from RPMB does not work. It ends in timeouts due to
    > > > no response from the SDHCI controller.
    > > >
    > > > If idata->buf is allocated here with kmalloc(buf_bytes, GFP_KERNEL) and
    > > > the content of buf is copied to the new allocated area, transfers succeed.
    > > >
    > > > Is it possible that idata->buf is not DMA capable? Any other ideas?
    > >
    > > Thanks for testing. I don't know, the idata->buf is allocated using
    > > alloc_pages_exact(nr_pages * PAGE_SIZE, GFP_KERNEL | __GFP_ZERO); in
    > > optee_pool_op_alloc_helper().
    >
    > Is this really true for idata->buf or isnt the complete RPMB frame memory
    > allocated like this and therefore idata->buf not page aligned?

    You're right.

    >
    > For RPMB via tee-supplicant the idata->buf is allocated within memdup_user
    > and therefore page aligned.

    Yes, that's a difference. Have you tested with page-aligned buffers to
    see if it helps?

    >
    > > Alternatively, it's from the memory
    > > range mapped using memremap() in optee_config_shm_memremap(), but
    > > that's only if you don't have "dynamic shared memory is enabled" in
    > > the boot log.
    >
    > "dynamic shared memory is enabled" is in the bootlog, ..

    Great.

    Thanks,
    Jens

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