Add support in the OP-TEE backend driver for restricted memory
allocation. The support is limited to only the SMC ABI and for secure
video buffers.

OP-TEE is probed for the range of restricted physical memory and a
memory pool allocator is initialized if OP-TEE have support for such
memory.

Signed-off-by: Jens Wiklander <jens.wiklan...@linaro.org>
---
 drivers/tee/optee/core.c          | 21 +++++++++++++++
 drivers/tee/optee/optee_private.h |  6 +++++
 drivers/tee/optee/optee_smc.h     | 35 ++++++++++++++++++++++++
 drivers/tee/optee/smc_abi.c       | 45 ++++++++++++++++++++++++++++---
 4 files changed, 104 insertions(+), 3 deletions(-)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index 39e688d4e974..b6d5cbc6728d 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -95,6 +95,25 @@ void optee_release_supp(struct tee_context *ctx)
        optee_supp_release(&optee->supp);
 }
 
+int optee_rstmem_alloc(struct tee_context *ctx, struct tee_shm *shm,
+                      u32 flags, size_t size)
+{
+       struct optee *optee = tee_get_drvdata(ctx->teedev);
+
+       if (!optee->sdp_pool)
+               return -EINVAL;
+       if (flags != TEE_IOC_FLAG_SECURE_VIDEO)
+               return -EINVAL;
+       return optee->sdp_pool->ops->alloc(optee->sdp_pool, shm, size, 0);
+}
+
+void optee_rstmem_free(struct tee_context *ctx, struct tee_shm *shm)
+{
+       struct optee *optee = tee_get_drvdata(ctx->teedev);
+
+       optee->sdp_pool->ops->free(optee->sdp_pool, shm);
+}
+
 void optee_remove_common(struct optee *optee)
 {
        /* Unregister OP-TEE specific client devices on TEE bus */
@@ -111,6 +130,8 @@ void optee_remove_common(struct optee *optee)
        tee_device_unregister(optee->teedev);
 
        tee_shm_pool_free(optee->pool);
+       if (optee->sdp_pool)
+               optee->sdp_pool->ops->destroy_pool(optee->sdp_pool);
        optee_supp_uninit(&optee->supp);
        mutex_destroy(&optee->call_queue.mutex);
 }
diff --git a/drivers/tee/optee/optee_private.h 
b/drivers/tee/optee/optee_private.h
index 424898cdc4e9..1f6b2cc992a9 100644
--- a/drivers/tee/optee/optee_private.h
+++ b/drivers/tee/optee/optee_private.h
@@ -200,6 +200,7 @@ struct optee_ops {
  * @notif:             notification synchronization struct
  * @supp:              supplicant synchronization struct for RPC to supplicant
  * @pool:              shared memory pool
+ * @sdp_pool:          restricted memory pool for secure data path
  * @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
@@ -218,6 +219,7 @@ struct optee {
        struct optee_notif notif;
        struct optee_supp supp;
        struct tee_shm_pool *pool;
+       struct tee_shm_pool *sdp_pool;
        unsigned int rpc_param_count;
        bool   scan_bus_done;
        struct work_struct scan_bus_work;
@@ -340,6 +342,10 @@ void optee_rpc_cmd(struct tee_context *ctx, struct optee 
*optee,
 int optee_do_bottom_half(struct tee_context *ctx);
 int optee_stop_async_notif(struct tee_context *ctx);
 
+int optee_rstmem_alloc(struct tee_context *ctx, struct tee_shm *shm,
+                      u32 flags, size_t size);
+void optee_rstmem_free(struct tee_context *ctx, struct tee_shm *shm);
+
 /*
  * Small helpers
  */
diff --git a/drivers/tee/optee/optee_smc.h b/drivers/tee/optee/optee_smc.h
index 7d9fa426505b..c3b8a1c204af 100644
--- a/drivers/tee/optee/optee_smc.h
+++ b/drivers/tee/optee/optee_smc.h
@@ -234,6 +234,39 @@ struct optee_smc_get_shm_config_result {
        unsigned long settings;
 };
 
+/*
+ * Get Secure Data Path memory config
+ *
+ * Returns the Secure Data Path memory config.
+ *
+ * Call register usage:
+ * a0   SMC Function ID, OPTEE_SMC_GET_SDP_CONFIG
+ * a2-6 Not used, must be zero
+ * a7   Hypervisor Client ID register
+ *
+ * Have config return register usage:
+ * a0   OPTEE_SMC_RETURN_OK
+ * a1   Physical address of start of SDP memory
+ * a2   Size of SDP memory
+ * a3   Not used
+ * a4-7 Preserved
+ *
+ * Not available register usage:
+ * a0   OPTEE_SMC_RETURN_ENOTAVAIL
+ * a1-3 Not used
+ * a4-7 Preserved
+ */
+#define OPTEE_SMC_FUNCID_GET_SDP_CONFIG        20
+#define OPTEE_SMC_GET_SDP_CONFIG \
+       OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_GET_SDP_CONFIG)
+
+struct optee_smc_get_sdp_config_result {
+       unsigned long status;
+       unsigned long start;
+       unsigned long size;
+       unsigned long flags;
+};
+
 /*
  * Exchanges capabilities between normal world and secure world
  *
@@ -278,6 +311,8 @@ struct optee_smc_get_shm_config_result {
 #define OPTEE_SMC_SEC_CAP_ASYNC_NOTIF          BIT(5)
 /* Secure world supports pre-allocating RPC arg struct */
 #define OPTEE_SMC_SEC_CAP_RPC_ARG              BIT(6)
+/* Secure world supports Secure Data Path */
+#define OPTEE_SMC_SEC_CAP_SDP                  BIT(7)
 
 #define OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES 9
 #define OPTEE_SMC_EXCHANGE_CAPABILITIES \
diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
index 844285d4f03c..05068c70c791 100644
--- a/drivers/tee/optee/smc_abi.c
+++ b/drivers/tee/optee/smc_abi.c
@@ -1164,6 +1164,8 @@ static void optee_get_version(struct tee_device *teedev,
                v.gen_caps |= TEE_GEN_CAP_REG_MEM;
        if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
                v.gen_caps |= TEE_GEN_CAP_MEMREF_NULL;
+       if (optee->sdp_pool)
+               v.gen_caps |= TEE_GEN_CAP_RSTMEM;
        *vers = v;
 }
 
@@ -1186,6 +1188,8 @@ static const struct tee_driver_ops optee_clnt_ops = {
        .cancel_req = optee_cancel_req,
        .shm_register = optee_shm_register,
        .shm_unregister = optee_shm_unregister,
+       .rstmem_alloc = optee_rstmem_alloc,
+       .rstmem_free = optee_rstmem_free,
 };
 
 static const struct tee_desc optee_clnt_desc = {
@@ -1202,6 +1206,8 @@ static const struct tee_driver_ops optee_supp_ops = {
        .supp_send = optee_supp_send,
        .shm_register = optee_shm_register_supp,
        .shm_unregister = optee_shm_unregister_supp,
+       .rstmem_alloc = optee_rstmem_alloc,
+       .rstmem_free = optee_rstmem_free,
 };
 
 static const struct tee_desc optee_supp_desc = {
@@ -1582,6 +1588,32 @@ static inline int optee_load_fw(struct platform_device 
*pdev,
 }
 #endif
 
+static int optee_sdp_pool_init(struct optee *optee)
+{
+       struct tee_shm_pool *pool;
+       union {
+               struct arm_smccc_res smccc;
+               struct optee_smc_get_sdp_config_result result;
+       } res;
+
+       if (!(optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_SDP))
+               return 0;
+
+       optee->smc.invoke_fn(OPTEE_SMC_GET_SDP_CONFIG, 0, 0, 0, 0, 0, 0, 0,
+                            &res.smccc);
+       if (res.result.status != OPTEE_SMC_RETURN_OK) {
+               pr_err("Secure Data Path service not available\n");
+               return 0;
+       }
+
+       pool = tee_rstmem_gen_pool_alloc(res.result.start, res.result.size);
+       if (IS_ERR(pool))
+               return PTR_ERR(pool);
+       optee->sdp_pool = pool;
+
+       return 0;
+}
+
 static int optee_probe(struct platform_device *pdev)
 {
        optee_invoke_fn *invoke_fn;
@@ -1677,7 +1709,7 @@ static int optee_probe(struct platform_device *pdev)
        optee = kzalloc(sizeof(*optee), GFP_KERNEL);
        if (!optee) {
                rc = -ENOMEM;
-               goto err_free_pool;
+               goto err_free_shm_pool;
        }
 
        optee->ops = &optee_ops;
@@ -1685,10 +1717,14 @@ static int optee_probe(struct platform_device *pdev)
        optee->smc.sec_caps = sec_caps;
        optee->rpc_param_count = rpc_param_count;
 
+       rc = optee_sdp_pool_init(optee);
+       if (rc)
+               goto err_free_optee;
+
        teedev = tee_device_alloc(&optee_clnt_desc, NULL, pool, optee);
        if (IS_ERR(teedev)) {
                rc = PTR_ERR(teedev);
-               goto err_free_optee;
+               goto err_sdp_pool_uninit;
        }
        optee->teedev = teedev;
 
@@ -1786,9 +1822,12 @@ static int optee_probe(struct platform_device *pdev)
        tee_device_unregister(optee->supp_teedev);
 err_unreg_teedev:
        tee_device_unregister(optee->teedev);
+err_sdp_pool_uninit:
+       if (optee->sdp_pool)
+               optee->sdp_pool->ops->destroy_pool(optee->sdp_pool);
 err_free_optee:
        kfree(optee);
-err_free_pool:
+err_free_shm_pool:
        tee_shm_pool_free(pool);
        if (memremaped_shm)
                memunmap(memremaped_shm);
-- 
2.43.0

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