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authorRijo Thomas <Rijo-john.Thomas@amd.com>2019-12-27 10:54:02 +0530
committerHerbert Xu <herbert@gondor.apana.org.au>2020-01-04 13:49:51 +0800
commitbade7e1fbd34f46462e6eb1db5474832a4144ac2 (patch)
treec3c35b39cf2bdc10b841bc0ca21df3844ca74f09
parent757cc3e9ff1d72d014096399d6e2bf03974d9da1 (diff)
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tee: amdtee: check TEE status during driver initialization
The AMD-TEE driver should check if TEE is available before registering itself with TEE subsystem. This ensures that there is a TEE which the driver can talk to before proceeding with tee device node allocation. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Tom Lendacky <thomas.lendacky@amd.com> Acked-by: Jens Wiklander <jens.wiklander@linaro.org> Co-developed-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com> Signed-off-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com> Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com> Reviewed-by: Gary R Hook <gary.hook@amd.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--drivers/crypto/ccp/tee-dev.c11
-rw-r--r--drivers/tee/amdtee/core.c6
-rw-r--r--include/linux/psp-tee.h18
3 files changed, 35 insertions, 0 deletions
diff --git a/drivers/crypto/ccp/tee-dev.c b/drivers/crypto/ccp/tee-dev.c
index 555c8a7c5684..5e697a90ea7f 100644
--- a/drivers/crypto/ccp/tee-dev.c
+++ b/drivers/crypto/ccp/tee-dev.c
@@ -362,3 +362,14 @@ int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, size_t len,
return 0;
}
EXPORT_SYMBOL(psp_tee_process_cmd);
+
+int psp_check_tee_status(void)
+{
+ struct psp_device *psp = psp_get_master_device();
+
+ if (!psp || !psp->tee_data)
+ return -ENODEV;
+
+ return 0;
+}
+EXPORT_SYMBOL(psp_check_tee_status);
diff --git a/drivers/tee/amdtee/core.c b/drivers/tee/amdtee/core.c
index dd360f378ef0..9d0cee1c837f 100644
--- a/drivers/tee/amdtee/core.c
+++ b/drivers/tee/amdtee/core.c
@@ -16,6 +16,7 @@
#include <linux/firmware.h>
#include "amdtee_private.h"
#include "../tee_private.h"
+#include <linux/psp-tee.h>
static struct amdtee_driver_data *drv_data;
static DEFINE_MUTEX(session_list_mutex);
@@ -438,6 +439,10 @@ static int __init amdtee_driver_init(void)
struct tee_shm_pool *pool = ERR_PTR(-EINVAL);
int rc;
+ rc = psp_check_tee_status();
+ if (rc)
+ goto err_fail;
+
drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
if (IS_ERR(drv_data))
return -ENOMEM;
@@ -485,6 +490,7 @@ err_kfree_drv_data:
kfree(drv_data);
drv_data = NULL;
+err_fail:
pr_err("amd-tee driver initialization failed\n");
return rc;
}
diff --git a/include/linux/psp-tee.h b/include/linux/psp-tee.h
index 63bb2212fce0..cb0c95d6d76b 100644
--- a/include/linux/psp-tee.h
+++ b/include/linux/psp-tee.h
@@ -62,6 +62,19 @@ enum tee_cmd_id {
int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf, size_t len,
u32 *status);
+/**
+ * psp_check_tee_status() - Checks whether there is a TEE which a driver can
+ * talk to.
+ *
+ * This function can be used by AMD-TEE driver to query if there is TEE with
+ * which it can communicate.
+ *
+ * Returns:
+ * 0 if the device has TEE
+ * -%ENODEV if there is no TEE available
+ */
+int psp_check_tee_status(void);
+
#else /* !CONFIG_CRYPTO_DEV_SP_PSP */
static inline int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf,
@@ -69,5 +82,10 @@ static inline int psp_tee_process_cmd(enum tee_cmd_id cmd_id, void *buf,
{
return -ENODEV;
}
+
+static inline int psp_check_tee_status(void)
+{
+ return -ENODEV;
+}
#endif /* CONFIG_CRYPTO_DEV_SP_PSP */
#endif /* __PSP_TEE_H_ */