This is the kernel patch corresponding to the change landed in TF-A here: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/18635

This appears to be the right place to post this, let me know if not please.

From 81d97a06a48d01eb53661b41905768271f07b870 Mon Sep 17 00:00:00 2001 From: Jeffrey Kardatzke jkardatzke@google.com Date: Fri, 3 Feb 2023 11:33:17 -0800 Subject: [PATCH] tee: optee: Add SMC for loading OP-TEE image

Adds an SMC call that will pass an OP-TEE binary image to EL3 and instruct it to load it as the BL32 payload. This works in conjunction with a feature added to Trusted Firmware for ARM that supports this.

Signed-off-by: Jeffrey Kardatzke jkardatzke@google.com --- drivers/tee/optee/Kconfig | 9 +++++ drivers/tee/optee/optee_msg.h | 14 +++++++ drivers/tee/optee/optee_smc.h | 22 +++++++++++ drivers/tee/optee/smc_abi.c | 70 +++++++++++++++++++++++++++++++++++ 4 files changed, 115 insertions(+)

diff --git a/drivers/tee/optee/Kconfig b/drivers/tee/optee/Kconfig index f121c224e682..b96b5db52b37 100644 --- a/drivers/tee/optee/Kconfig +++ b/drivers/tee/optee/Kconfig @@ -7,3 +7,12 @@ config OPTEE help This implements the OP-TEE Trusted Execution Environment (TEE) driver. + +config OPTEE_LOAD_IMAGE + bool "Load Op-Tee image as firmware" + default n + depends on OPTEE + help + This loads the BL32 image for OP-TEE as firmware when the driver is probed. + This returns -EPROBE_DEFER until the firmware is loadable from the + filesystem. diff --git a/drivers/tee/optee/optee_msg.h b/drivers/tee/optee/optee_msg.h index 70e9cc2ee96b..84c1b15032a9 100644 --- a/drivers/tee/optee/optee_msg.h +++ b/drivers/tee/optee/optee_msg.h @@ -284,6 +284,20 @@ struct optee_msg_arg { */ #define OPTEE_MSG_FUNCID_GET_OS_REVISION 0x0001

+/* + * Load Trusted OS from optee/tee.bin in the Linux firmware. + * + * WARNING: Use this cautiously as it could lead to insecure loading of the + * Trusted OS. + * This SMC instructs EL3 to load a binary and excute it as the Trusted OS. + * The first two params are the high and low 32 bits of the size of the payload + * and the third and fourth params are the high and low 32 bits of the physical + * address of the payload. The payload is in the OP-TEE image format. + * + * Returns 0 on success and an error code otherwise. + */ +#define OPTEE_MSG_FUNCID_LOAD_IMAGE 0x0002 + /* * Do a secure call with struct optee_msg_arg as argument * The OPTEE_MSG_CMD_* below defines what goes in struct optee_msg_arg::cmd diff --git a/drivers/tee/optee/optee_smc.h b/drivers/tee/optee/optee_smc.h index 73b5e7760d10..908b1005e9db 100644 --- a/drivers/tee/optee/optee_smc.h +++ b/drivers/tee/optee/optee_smc.h @@ -104,6 +104,28 @@ struct optee_smc_call_get_os_revision_result { unsigned long reserved1; };

+/* + * Load Trusted OS from optee/tee.bin in the Linux firmware. + * + * WARNING: Use this cautiously as it could lead to insecure loading of the + * Trusted OS. + * This SMC instructs EL3 to load a binary and excute it as the Trusted OS. + * + * Call register usage: + * a0 SMC Function ID, OPTEE_SMC_CALL_LOAD_IMAGE + * a1 Upper 32bit of a 64bit size for the payload + * a2 Lower 32bit of a 64bit size for the payload + * a3 Upper 32bit of the physical address for the payload + * a4 Lower 32bit of the physical address for the payload + * + * The payload is in the OP-TEE image format. + * + * Returns result in a0, 0 on success and an error code otherwise. + */ +#define OPTEE_SMC_FUNCID_LOAD_IMAGE OPTEE_MSG_FUNCID_LOAD_IMAGE +#define OPTEE_SMC_CALL_LOAD_IMAGE \ + OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_LOAD_IMAGE) + /* * Call with struct optee_msg_arg as argument * diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index a1c1fa1a9c28..b1e6c4a807db 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -8,6 +8,7 @@

#include <linux/arm-smccc.h> #include <linux/errno.h> +#include <linux/firmware.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/irqdomain.h> @@ -1354,6 +1355,69 @@ static void optee_shutdown(struct platform_device *pdev) optee_disable_shm_cache(optee); }

+#ifdef CONFIG_OPTEE_LOAD_IMAGE + +#define OPTEE_FW_IMAGE "optee/tee.bin" + +static int optee_load_fw(struct platform_device *pdev, + optee_invoke_fn *invoke_fn) +{ + const struct firmware *fw = NULL; + struct arm_smccc_res res; + phys_addr_t data_pa; + u8 *data_buf = NULL; + u64 data_size; + u32 data_pa_high, data_pa_low; + u32 data_size_high, data_size_low; + int rc; + + rc = request_firmware(&fw, OPTEE_FW_IMAGE, &pdev->dev); + if (rc) + return -EPROBE_DEFER; + + data_size = fw->size; + /* + * This uses the GFP_DMA flag to ensure we are allocated memory in the + * 32-bit space since TF-A cannot map memory beyond the 32-bit boundary. + */ + data_buf = kmalloc(fw->size, GFP_KERNEL | GFP_DMA); + if (!data_buf) { + rc = -ENOMEM; + goto fw_err; + } + memcpy(data_buf, fw->data, fw->size); + data_pa = virt_to_phys(data_buf); + reg_pair_from_64(&data_pa_high, &data_pa_low, data_pa); + reg_pair_from_64(&data_size_high, &data_size_low, data_size); + goto fw_load; + +fw_err: + pr_warn("image loading failed\n"); + data_pa_high = data_pa_low = data_size_high = data_size_low = 0; + +fw_load: + /* + * Always invoke the SMC, even if loading the image fails, to indicate + * to EL3 that we have passed the point where it should allow invoking + * this SMC. + */ + invoke_fn(OPTEE_SMC_CALL_LOAD_IMAGE, data_size_high, data_size_low, + data_pa_high, data_pa_low, 0, 0, 0, &res); + if (!rc) + rc = res.a0; + if (fw) + release_firmware(fw); + kfree(data_buf); + + return rc; +} +#else +static inline int optee_load_fw(struct platform_device *__unused, + optee_invoke_fn *__unused) { + return 0; +} +#endif + static int optee_probe(struct platform_device *pdev) { optee_invoke_fn *invoke_fn; @@ -1372,6 +1436,12 @@ static int optee_probe(struct platform_device *pdev) if (IS_ERR(invoke_fn)) return PTR_ERR(invoke_fn);

+ rc = optee_load_fw(pdev, invoke_fn); + if (rc) { + pr_warn("image loading failed\n"); + return rc; + } + if (!optee_msg_api_uid_is_optee_api(invoke_fn)) { pr_warn("api uid mismatch\n"); return -EINVAL;