mmc: rpmb: add mmc_rpmb_route_frames()

Adds mmc_rpmb_route_frames() to route RPMB data frames from/to an
external entity.

Tested-by: Igor Opaniuk <igor.opaniuk@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/mmc/rpmb.c b/drivers/mmc/rpmb.c
index dfbdb0deb107f06ac3604000ccc8beeac1fa1fca..908f19208955b966c27186d7f100038598b60a92 100644 (file)
--- a/drivers/mmc/rpmb.c
+++ b/drivers/mmc/rpmb.c
@@ -321,3 +321,163 @@ int mmc_rpmb_write(struct mmc *mmc, void *addr, unsigned short blk,
        }
        return i;
 }
+
+static int send_write_mult_block(struct mmc *mmc, const struct s_rpmb *frm,
+                                unsigned short cnt)
+{
+       struct mmc_cmd cmd = {
+               .cmdidx = MMC_CMD_WRITE_MULTIPLE_BLOCK,
+               .resp_type = MMC_RSP_R1b,
+       };
+       struct mmc_data data = {
+               .src = (const void *)frm,
+               .blocks = cnt,
+               .blocksize = sizeof(*frm),
+               .flags = MMC_DATA_WRITE,
+       };
+
+       return mmc_send_cmd(mmc, &cmd, &data);
+}
+
+static int send_read_mult_block(struct mmc *mmc, struct s_rpmb *frm,
+                               unsigned short cnt)
+{
+       struct mmc_cmd cmd = {
+               .cmdidx = MMC_CMD_READ_MULTIPLE_BLOCK,
+               .resp_type = MMC_RSP_R1,
+       };
+       struct mmc_data data = {
+               .dest = (void *)frm,
+               .blocks = cnt,
+               .blocksize = sizeof(*frm),
+               .flags = MMC_DATA_READ,
+       };
+
+       return mmc_send_cmd(mmc, &cmd, &data);
+}
+
+static int rpmb_route_write_req(struct mmc *mmc, struct s_rpmb *req,
+                               unsigned short req_cnt, struct s_rpmb *rsp,
+                               unsigned short rsp_cnt)
+{
+       int ret;
+
+       /*
+        * Send the write request.
+        */
+       ret = mmc_set_blockcount(mmc, req_cnt, true);
+       if (ret)
+               return ret;
+
+       ret = send_write_mult_block(mmc, req, req_cnt);
+       if (ret)
+               return ret;
+
+       /*
+        * Read the result of the request.
+        */
+       ret = mmc_set_blockcount(mmc, 1, false);
+       if (ret)
+               return ret;
+
+       memset(rsp, 0, sizeof(*rsp));
+       rsp->request = cpu_to_be16(RPMB_REQ_STATUS);
+       ret = send_write_mult_block(mmc, rsp, 1);
+       if (ret)
+               return ret;
+
+       ret = mmc_set_blockcount(mmc, 1, false);
+       if (ret)
+               return ret;
+
+       return send_read_mult_block(mmc, rsp, 1);
+}
+
+static int rpmb_route_read_req(struct mmc *mmc, struct s_rpmb *req,
+                              unsigned short req_cnt, struct s_rpmb *rsp,
+                              unsigned short rsp_cnt)
+{
+       int ret;
+
+       /*
+        * Send the read request.
+        */
+       ret = mmc_set_blockcount(mmc, 1, false);
+       if (ret)
+               return ret;
+
+       ret = send_write_mult_block(mmc, req, 1);
+       if (ret)
+               return ret;
+
+       /*
+        * Read the result of the request.
+        */
+
+       ret = mmc_set_blockcount(mmc, rsp_cnt, false);
+       if (ret)
+               return ret;
+
+       return send_read_mult_block(mmc, rsp, rsp_cnt);
+}
+
+static int rpmb_route_frames(struct mmc *mmc, struct s_rpmb *req,
+                            unsigned short req_cnt, struct s_rpmb *rsp,
+                            unsigned short rsp_cnt)
+{
+       unsigned short n;
+
+       /*
+        * If multiple request frames are provided, make sure that all are
+        * of the same type.
+        */
+       for (n = 1; n < req_cnt; n++)
+               if (req[n].request != req->request)
+                       return -EINVAL;
+
+       switch (be16_to_cpu(req->request)) {
+       case RPMB_REQ_KEY:
+               if (req_cnt != 1 || rsp_cnt != 1)
+                       return -EINVAL;
+               return rpmb_route_write_req(mmc, req, req_cnt, rsp, rsp_cnt);
+
+       case RPMB_REQ_WRITE_DATA:
+               if (!req_cnt || rsp_cnt != 1)
+                       return -EINVAL;
+               return rpmb_route_write_req(mmc, req, req_cnt, rsp, rsp_cnt);
+
+       case RPMB_REQ_WCOUNTER:
+               if (req_cnt != 1 || rsp_cnt != 1)
+                       return -EINVAL;
+               return rpmb_route_read_req(mmc, req, req_cnt, rsp, rsp_cnt);
+
+       case RPMB_REQ_READ_DATA:
+               if (req_cnt != 1 || !req_cnt)
+                       return -EINVAL;
+               return rpmb_route_read_req(mmc, req, req_cnt, rsp, rsp_cnt);
+
+       default:
+               debug("Unsupported message type: %d\n",
+                     be16_to_cpu(req->request));
+               return -EINVAL;
+       }
+}
+
+int mmc_rpmb_route_frames(struct mmc *mmc, void *req, unsigned long reqlen,
+                         void *rsp, unsigned long rsplen)
+{
+       /*
+        * Whoever crafted the data supplied to this function knows how to
+        * format the PRMB frames and which response is expected. If
+        * there's some unexpected mismatch it's more helpful to report an
+        * error immediately than trying to guess what was the intention
+        * and possibly just delay an eventual error which will be harder
+        * to track down.
+        */
+
+       if (reqlen % sizeof(struct s_rpmb) || rsplen % sizeof(struct s_rpmb))
+               return -EINVAL;
+
+       return rpmb_route_frames(mmc, req, reqlen / sizeof(struct s_rpmb),
+                                rsp, rsplen / sizeof(struct s_rpmb));
+}

diff --git a/include/mmc.h b/include/mmc.h
index 9b9cbedadc81c9d7b659fa4ef714c346138856cd..95548e94c4d89f87f9620d86fc2590425c97e670 100644 (file)
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -759,6 +759,25 @@ int mmc_rpmb_read(struct mmc *mmc, void *addr, unsigned short blk,
                  unsigned short cnt, unsigned char *key);
 int mmc_rpmb_write(struct mmc *mmc, void *addr, unsigned short blk,
                   unsigned short cnt, unsigned char *key);
+
+/**
+ * mmc_rpmb_route_frames() - route RPMB data frames
+ * @mmc                Pointer to a MMC device struct
+ * @req                Request data frames
+ * @reqlen     Length of data frames in bytes
+ * @rsp                Supplied buffer for response data frames
+ * @rsplen     Length of supplied buffer for response data frames
+ *
+ * The RPMB data frames are routed to/from some external entity, for
+ * example a Trusted Exectuion Environment in an arm TrustZone protected
+ * secure world. It's expected that it's the external entity who is in
+ * control of the RPMB key.
+ *
+ * Returns 0 on success, < 0 on error.
+ */
+int mmc_rpmb_route_frames(struct mmc *mmc, void *req, unsigned long reqlen,
+                         void *rsp, unsigned long rsplen);
+
 #ifdef CONFIG_CMD_BKOPS_ENABLE
 int mmc_set_bkops_enable(struct mmc *mmc);
 #endif