[PATCH v2 3/3] optee: probe RPMB device using RPMB subsystem

From: Jens Wiklander
Date: Wed Jan 31 2024 - 12:45:05 EST

Adds support in the OP-TEE drivers (both SMC and FF-A ABIs) to probe and
use an RPMB device via the RPBM subsystem instead of passing the RPMB
frames via tee-supplicant in user space. A fallback mechanism is kept to
route RPMB frames via tee-supplicant if the RPMB subsystem isn't
available.

The OP-TEE RPC ABI is extended to support iterating over all RPMB
devices until one is found with the expected RPMB key already
programmed.

Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
---
drivers/tee/optee/core.c | 1 +
drivers/tee/optee/ffa_abi.c | 2 +
drivers/tee/optee/optee_private.h | 6 +
drivers/tee/optee/optee_rpc_cmd.h | 33 +++++
drivers/tee/optee/rpc.c | 221 ++++++++++++++++++++++++++++++
drivers/tee/optee/smc_abi.c | 2 +
6 files changed, 265 insertions(+)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index 3aed554bc8d8..21bcccbe2207 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -177,6 +177,7 @@ void optee_remove_common(struct optee *optee)
tee_shm_pool_free(optee->pool);
optee_supp_uninit(&optee->supp);
mutex_destroy(&optee->call_queue.mutex);
+ mutex_destroy(&optee->rpmb_dev_mutex);
}

static int smc_abi_rc;
diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
index ecb5eb079408..1d207a9d4f3b 100644
--- a/drivers/tee/optee/ffa_abi.c
+++ b/drivers/tee/optee/ffa_abi.c
@@ -934,6 +934,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
optee_cq_init(&optee->call_queue, 0);
optee_supp_init(&optee->supp);
optee_shm_arg_cache_init(optee, arg_cache_flags);
+ mutex_init(&optee->rpmb_dev_mutex);
ffa_dev_set_drvdata(ffa_dev, optee);
ctx = teedev_open(optee->teedev);
if (IS_ERR(ctx)) {
@@ -968,6 +969,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
teedev_close_context(ctx);
err_rhashtable_free:
rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
+ mutex_destroy(&optee->rpmb_dev_mutex);
optee_supp_uninit(&optee->supp);
mutex_destroy(&optee->call_queue.mutex);
mutex_destroy(&optee->ffa.mutex);
diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
index 7a5243c78b55..3a87ad4ef1e2 100644
--- a/drivers/tee/optee/optee_private.h
+++ b/drivers/tee/optee/optee_private.h
@@ -20,6 +20,7 @@
/* Some Global Platform error codes used in this driver */
#define TEEC_SUCCESS 0x00000000
#define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006
+#define TEEC_ERROR_ITEM_NOT_FOUND 0xFFFF0008
#define TEEC_ERROR_NOT_SUPPORTED 0xFFFF000A
#define TEEC_ERROR_COMMUNICATION 0xFFFF000E
#define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C
@@ -197,6 +198,8 @@ struct optee_ops {
* @notif: notification synchronization struct
* @supp: supplicant synchronization struct for RPC to supplicant
* @pool: shared memory pool
+ * @mutex: mutex protecting @rpmb_dev
+ * @rpmb_dev: current RPMB device or NULL
* @rpc_param_count: If > 0 number of RPC parameters to make room for
* @scan_bus_done flag if device registation was already done.
* @scan_bus_work workq to scan optee bus and register optee drivers
@@ -215,6 +218,9 @@ struct optee {
struct optee_notif notif;
struct optee_supp supp;
struct tee_shm_pool *pool;
+ /* Protects rpmb_dev pointer */
+ struct mutex rpmb_dev_mutex;
+ struct rpmb_dev *rpmb_dev;
unsigned int rpc_param_count;
bool scan_bus_done;
struct work_struct scan_bus_work;
diff --git a/drivers/tee/optee/optee_rpc_cmd.h b/drivers/tee/optee/optee_rpc_cmd.h
index f3f06e0994a7..672e5dcdf041 100644
--- a/drivers/tee/optee/optee_rpc_cmd.h
+++ b/drivers/tee/optee/optee_rpc_cmd.h
@@ -16,6 +16,14 @@
* and sends responses.
*/

+/*
+ * Replay Protected Memory Block access
+ *
+ * [in] memref[0] Frames to device
+ * [out] memref[1] Frames from device
+ */
+#define OPTEE_RPC_CMD_RPMB 1
+
/*
* Get time
*
@@ -103,4 +111,29 @@
/* I2C master control flags */
#define OPTEE_RPC_I2C_FLAGS_TEN_BIT BIT(0)

+/*
+ * Reset RPMB probing
+ *
+ * Releases an eventually already used RPMB devices and starts over searching
+ * for RPMB devices. Returns the kind of shared memory to use in subsequent
+ * OPTEE_RPC_CMD_RPMB_PROBE_NEXT and OPTEE_RPC_CMD_RPMB calls.
+ *
+ * [out] value[0].a OPTEE_RPC_SHM_TYPE_*, the parameter for
+ * OPTEE_RPC_CMD_SHM_ALLOC
+ */
+#define OPTEE_RPC_CMD_RPMB_PROBE_RESET 22
+
+/*
+ * Probe next RPMB device
+ *
+ * [out] value[0].a Must be OPTEE_RPC_RPMB_EMMC
+ * [out] value[0].b EXT CSD-slice 168 "RPMB Size"
+ * [out] value[0].c EXT CSD-slice 222 "Reliable Write Sector Count"
+ * [out] memref[1] Buffer with the raw CID
+ */
+#define OPTEE_RPC_CMD_RPMB_PROBE_NEXT 23
+
+/* Type of RPMB device */
+#define OPTEE_RPC_RPMB_EMMC 0
+
#endif /*__OPTEE_RPC_CMD_H*/
diff --git a/drivers/tee/optee/rpc.c b/drivers/tee/optee/rpc.c
index e69bc6380683..6fd6f99dafab 100644
--- a/drivers/tee/optee/rpc.c
+++ b/drivers/tee/optee/rpc.c
@@ -7,6 +7,7 @@

#include <linux/delay.h>
#include <linux/i2c.h>
+#include <linux/rpmb.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
#include "optee_private.h"
@@ -255,6 +256,217 @@ void optee_rpc_cmd_free_suppl(struct tee_context *ctx, struct tee_shm *shm)
optee_supp_thrd_req(ctx, OPTEE_RPC_CMD_SHM_FREE, 1, &param);
}

+static void handle_rpc_func_rpmb_probe_reset(struct tee_context *ctx,
+ struct optee *optee,
+ struct optee_msg_arg *arg)
+{
+ struct tee_param params[1];
+
+ if (!IS_ENABLED(CONFIG_RPMB)) {
+ handle_rpc_supp_cmd(ctx, optee, arg);
+ return;
+ }
+
+ if (arg->num_params != ARRAY_SIZE(params) ||
+ optee->ops->from_msg_param(optee, params, arg->num_params,
+ arg->params) ||
+ params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT) {
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+ return;
+ }
+
+ params[0].u.value.a = OPTEE_RPC_SHM_TYPE_KERNEL;
+ params[0].u.value.b = 0;
+ params[0].u.value.c = 0;
+ if (optee->ops->to_msg_param(optee, arg->params,
+ arg->num_params, params)) {
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+ return;
+ }
+
+ mutex_lock(&optee->rpmb_dev_mutex);
+ rpmb_dev_put(optee->rpmb_dev);
+ optee->rpmb_dev = NULL;
+ mutex_unlock(&optee->rpmb_dev_mutex);
+
+ arg->ret = TEEC_SUCCESS;
+}
+
+static int rpc_rpmb_match(struct device *dev, const void *data)
+{
+ return 1;
+}
+
+static void handle_rpc_func_rpmb_probe_next(struct tee_context *ctx,
+ struct optee *optee,
+ struct optee_msg_arg *arg)
+{
+ struct rpmb_dev *start_rdev;
+ struct rpmb_dev *rdev;
+ struct tee_param params[2];
+ void *buf;
+
+ if (!IS_ENABLED(CONFIG_RPMB)) {
+ handle_rpc_supp_cmd(ctx, optee, arg);
+ return;
+ }
+
+ if (arg->num_params != ARRAY_SIZE(params) ||
+ optee->ops->from_msg_param(optee, params, arg->num_params,
+ arg->params) ||
+ params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT ||
+ params[1].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT) {
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+ return;
+ }
+ buf = tee_shm_get_va(params[1].u.memref.shm,
+ params[1].u.memref.shm_offs);
+ if (!buf) {
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+ return;
+ }
+
+ mutex_lock(&optee->rpmb_dev_mutex);
+ start_rdev = optee->rpmb_dev;
+ rdev = rpmb_dev_find_device(NULL, start_rdev, rpc_rpmb_match);
+ rpmb_dev_put(start_rdev);
+ optee->rpmb_dev = rdev;
+ mutex_unlock(&optee->rpmb_dev_mutex);
+
+ if (!rdev) {
+ arg->ret = TEEC_ERROR_ITEM_NOT_FOUND;
+ return;
+ }
+
+ if (params[1].u.memref.size < rdev->dev_id_len) {
+ arg->ret = TEEC_ERROR_SHORT_BUFFER;
+ return;
+ }
+ memcpy(buf, rdev->dev_id, rdev->dev_id_len);
+ params[1].u.memref.size = rdev->dev_id_len;
+ params[0].u.value.a = OPTEE_RPC_RPMB_EMMC;
+ params[0].u.value.b = rdev->capacity;
+ params[0].u.value.c = rdev->reliable_wr_count;
+ if (optee->ops->to_msg_param(optee, arg->params,
+ arg->num_params, params)) {
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+ return;
+ }
+
+ arg->ret = TEEC_SUCCESS;
+}
+
+/* Request */
+struct rpmb_req {
+ u16 cmd;
+#define RPMB_CMD_DATA_REQ 0x00
+#define RPMB_CMD_GET_DEV_INFO 0x01
+ u16 dev_id;
+ u16 block_count;
+ /* Optional data frames (rpmb_data_frame) follow */
+};
+
+#define RPMB_REQ_DATA(req) ((void *)((struct rpmb_req *)(req) + 1))
+
+#define RPMB_CID_SZ 16
+
+/* Response to device info request */
+struct rpmb_dev_info {
+ u8 cid[RPMB_CID_SZ];
+ u8 rpmb_size_mult; /* EXT CSD-slice 168: RPMB Size */
+ u8 rel_wr_sec_c; /* EXT CSD-slice 222: Reliable Write Sector */
+ /* Count */
+ u8 ret_code;
+#define RPMB_CMD_GET_DEV_INFO_RET_OK 0x00
+#define RPMB_CMD_GET_DEV_INFO_RET_ERROR 0x01
+};
+
+static int get_dev_info(struct rpmb_dev *rdev, void *rsp, size_t rsp_size)
+{
+ struct rpmb_dev_info *dev_info;
+
+ if (rsp_size != sizeof(*dev_info))
+ return TEEC_ERROR_BAD_PARAMETERS;
+
+ dev_info = rsp;
+ memcpy(dev_info->cid, rdev->dev_id, sizeof(dev_info->cid));
+ dev_info->rpmb_size_mult = rdev->capacity;
+ dev_info->rel_wr_sec_c = rdev->reliable_wr_count;
+ dev_info->ret_code = RPMB_CMD_GET_DEV_INFO_RET_OK;
+
+ return TEEC_SUCCESS;
+}
+
+/*
+ * req is one struct rpmb_req followed by one or more struct rpmb_data_frame
+ * rsp is either one struct rpmb_dev_info or one or more struct rpmb_data_frame
+ */
+static u32 rpmb_process_request(struct optee *optee, struct rpmb_dev *rdev,
+ void *req, size_t req_size,
+ void *rsp, size_t rsp_size)
+{
+ struct rpmb_req *sreq = req;
+ int rc;
+
+ if (req_size < sizeof(*sreq))
+ return TEEC_ERROR_BAD_PARAMETERS;
+
+ switch (sreq->cmd) {
+ case RPMB_CMD_DATA_REQ:
+ rc = rpmb_route_frames(rdev, RPMB_REQ_DATA(req),
+ req_size - sizeof(struct rpmb_req),
+ rsp, rsp_size);
+ if (rc) // TODO translate error code
+ return TEEC_ERROR_BAD_PARAMETERS;
+ return TEEC_SUCCESS;
+ case RPMB_CMD_GET_DEV_INFO:
+ return get_dev_info(rdev, rsp, rsp_size);
+ default:
+ return TEEC_ERROR_BAD_PARAMETERS;
+ }
+}
+
+static void handle_rpc_func_rpmb(struct tee_context *ctx, struct optee *optee,
+ struct optee_msg_arg *arg)
+{
+ struct tee_param params[2];
+ struct rpmb_dev *rdev;
+ void *p0, *p1;
+
+ mutex_lock(&optee->rpmb_dev_mutex);
+ rdev = rpmb_dev_get(optee->rpmb_dev);
+ mutex_unlock(&optee->rpmb_dev_mutex);
+ if (!rdev) {
+ handle_rpc_supp_cmd(ctx, optee, arg);
+ return;
+ }
+
+ if (arg->num_params != ARRAY_SIZE(params) ||
+ optee->ops->from_msg_param(optee, params, arg->num_params,
+ arg->params) ||
+ params[0].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT ||
+ params[1].attr != TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT) {
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+ goto out;
+ }
+
+ p0 = tee_shm_get_va(params[0].u.memref.shm,
+ params[0].u.memref.shm_offs);
+ p1 = tee_shm_get_va(params[1].u.memref.shm,
+ params[1].u.memref.shm_offs);
+ arg->ret = rpmb_process_request(optee, rdev, p0,
+ params[0].u.memref.size,
+ p1, params[1].u.memref.size);
+ if (arg->ret)
+ goto out;
+
+ if (optee->ops->to_msg_param(optee, arg->params,
+ arg->num_params, params))
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+out:
+ rpmb_dev_put(rdev);
+}
+
void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
struct optee_msg_arg *arg)
{
@@ -271,6 +483,15 @@ void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
case OPTEE_RPC_CMD_I2C_TRANSFER:
handle_rpc_func_cmd_i2c_transfer(ctx, arg);
break;
+ case OPTEE_RPC_CMD_RPMB_PROBE_RESET:
+ handle_rpc_func_rpmb_probe_reset(ctx, optee, arg);
+ break;
+ case OPTEE_RPC_CMD_RPMB_PROBE_NEXT:
+ handle_rpc_func_rpmb_probe_next(ctx, optee, arg);
+ break;
+ case OPTEE_RPC_CMD_RPMB:
+ handle_rpc_func_rpmb(ctx, optee, arg);
+ break;
default:
handle_rpc_supp_cmd(ctx, optee, arg);
}
diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
index a37f87087e5c..8c85c3b8dbb4 100644
--- a/drivers/tee/optee/smc_abi.c
+++ b/drivers/tee/optee/smc_abi.c
@@ -1715,6 +1715,7 @@ static int optee_probe(struct platform_device *pdev)
optee->smc.memremaped_shm = memremaped_shm;
optee->pool = pool;
optee_shm_arg_cache_init(optee, arg_cache_flags);
+ mutex_init(&optee->rpmb_dev_mutex);

platform_set_drvdata(pdev, optee);
ctx = teedev_open(optee->teedev);
@@ -1782,6 +1783,7 @@ static int optee_probe(struct platform_device *pdev)
err_close_ctx:
teedev_close_context(ctx);
err_supp_uninit:
+ mutex_destroy(&optee->rpmb_dev_mutex);
optee_shm_arg_cache_uninit(optee);
optee_supp_uninit(&optee->supp);
mutex_destroy(&optee->call_queue.mutex);
--
2.34.1