Re: [PATCH V2 1/3] firmware: broadcom: add OP-TEE based BNXT f/w manager

From: Jakub Kicinski
Date: Thu Oct 17 2019 - 15:16:54 EST

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In reply to: Sheetal Tigadoli: "[PATCH V2 1/3] firmware: broadcom: add OP-TEE based BNXT f/w manager"
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On Thu, 17 Oct 2019 17:31:20 +0530, Sheetal Tigadoli wrote:
> From: Vikas Gupta <vikas.gupta@xxxxxxxxxxxx>
>
> This driver registers on TEE bus to interact with OP-TEE based
> BNXT firmware management modules
>
> Signed-off-by: Vikas Gupta <vikas.gupta@xxxxxxxxxxxx>
> Signed-off-by: Sheetal Tigadoli <sheetal.tigadoli@xxxxxxxxxxxx>
> ---
> drivers/firmware/broadcom/Kconfig | 8 +
> drivers/firmware/broadcom/Makefile | 1 +
> drivers/firmware/broadcom/tee_bnxt_fw.c | 283 ++++++++++++++++++++++++++
> include/linux/firmware/broadcom/tee_bnxt_fw.h | 14 ++
> 4 files changed, 306 insertions(+)
> create mode 100644 drivers/firmware/broadcom/tee_bnxt_fw.c
> create mode 100644 include/linux/firmware/broadcom/tee_bnxt_fw.h
>
> diff --git a/drivers/firmware/broadcom/Kconfig b/drivers/firmware/broadcom/Kconfig
> index d03ed8e..79505ad 100644
> --- a/drivers/firmware/broadcom/Kconfig
> +++ b/drivers/firmware/broadcom/Kconfig
> @@ -22,3 +22,11 @@ config BCM47XX_SPROM
> In case of SoC devices SPROM content is stored on a flash used by
> bootloader firmware CFE. This driver provides method to ssb and bcma
> drivers to read SPROM on SoC.
> +
> +config TEE_BNXT_FW
> + bool "Broadcom BNXT firmware manager"
> + depends on (ARCH_BCM_IPROC && OPTEE) || COMPILE_TEST
> + default ARCH_BCM_IPROC
> + help
> + This module help to manage firmware on Broadcom BNXT device. The module
> + registers on tee bus and invoke calls to manage firmware on BNXT device.
> diff --git a/drivers/firmware/broadcom/Makefile b/drivers/firmware/broadcom/Makefile
> index 72c7fdc..17c5061 100644
> --- a/drivers/firmware/broadcom/Makefile
> +++ b/drivers/firmware/broadcom/Makefile
> @@ -1,3 +1,4 @@
> # SPDX-License-Identifier: GPL-2.0-only
> obj-$(CONFIG_BCM47XX_NVRAM) += bcm47xx_nvram.o
> obj-$(CONFIG_BCM47XX_SPROM) += bcm47xx_sprom.o
> +obj-$(CONFIG_TEE_BNXT_FW) += tee_bnxt_fw.o
> diff --git a/drivers/firmware/broadcom/tee_bnxt_fw.c b/drivers/firmware/broadcom/tee_bnxt_fw.c
> new file mode 100644
> index 0000000..1e1e54c
> --- /dev/null
> +++ b/drivers/firmware/broadcom/tee_bnxt_fw.c
> @@ -0,0 +1,283 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2019 Broadcom.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/tee_drv.h>
> +#include <linux/uuid.h>
> +
> +#include <linux/firmware/broadcom/tee_bnxt_fw.h>
> +
> +#define MAX_SHM_MEM_SZ SZ_4M
> +
> +#define MAX_TEE_PARAM_ARRY_MEMB 4
> +
> +#define HANDLE_ERROR(ret, tee_ret, cmd) \
> +do { \
> + if ((ret < 0) || (tee_ret != 0)) { \

The parenthesis should be around macro parameters.

if ((ret) < 0 || (tee_ret) != 0) {

|| has low priority

> + dev_err(pvt_data.dev, \
> + #cmd " invoke failed TEE err: %x, ret:%x\n", \
> + tee_ret, ret); \
> + return -EINVAL; \

macros shouldn't change control flow, return statements in macros are
bad

> + } \
> +} while (0)
> +
> +enum ta_cmd {
> + /*
> + * TA_CMD_BNXT_FASTBOOT - boot bnxt device by copying f/w into sram
> + *
> + * param[0] unused
> + * param[1] unused
> + * param[2] unused
> + * param[3] unused
> + *
> + * Result:
> + * TEE_SUCCESS - Invoke command success
> + * TEE_ERROR_ITEM_NOT_FOUND - Corrupt f/w image found on memory
> + */
> + TA_CMD_BNXT_FASTBOOT = 0,
> +
> + /*
> + * TA_CMD_BNXT_COPY_COREDUMP - copy the core dump into shm
> + *
> + * param[0] (in value) - value.a: offset, data to be copied from
> + * value.b: size of the data
> + * param[1] unused
> + * param[2] unused
> + * param[3] unused
> + *
> + * Result:
> + * TEE_SUCCESS - Invoke command success
> + * TEE_ERROR_BAD_PARAMETERS - Incorrect input param
> + * TEE_ERROR_ITEM_NOT_FOUND - Corrupt core dump
> + */
> + TA_CMD_BNXT_COPY_COREDUMP = 3,
> +};
> +
> +/**
> + * struct tee_bnxt_fw_private - OP-TEE bnxt private data
> + * @dev: OP-TEE based bnxt device.
> + * @ctx: OP-TEE context handler.
> + * @session_id: TA session identifier.
> + */
> +struct tee_bnxt_fw_private {
> + struct device *dev;
> + struct tee_context *ctx;
> + u32 session_id;
> + struct tee_shm *fw_shm_pool;
> +};
> +
> +static struct tee_bnxt_fw_private pvt_data;
> +
> +static inline void prepare_args(int cmd,

No static inlines in .c files, please, the compiler will know what to
inline.

> + struct tee_ioctl_invoke_arg *inv_arg,

inv usually means invalid, please rename to arg

> + struct tee_param *param)
> +{
> + memset(inv_arg, 0, sizeof(*inv_arg));
> + memset(param, 0, (MAX_TEE_PARAM_ARRY_MEMB * sizeof(*param)));

array_size(), outer parens unnecessary

> +
> + inv_arg->func = cmd;
> + inv_arg->session = pvt_data.session_id;
> + inv_arg->num_params = MAX_TEE_PARAM_ARRY_MEMB;
> +
> + /* Fill invoke cmd params */
> + switch (cmd) {
> + case TA_CMD_BNXT_COPY_COREDUMP:
> + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT;
> + param[0].u.memref.shm = pvt_data.fw_shm_pool;
> + param[0].u.memref.size = MAX_SHM_MEM_SZ;
> + param[0].u.memref.shm_offs = 0;
> + param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
> + break;
> + case TA_CMD_BNXT_FASTBOOT:
> + default:
> + /* Nothing to do */
> + break;
> + }
> +}
> +
> +/**
> + * tee_bnxt_fw_load() - Load the bnxt firmware
> + * Uses an OP-TEE call to start a secure
> + * boot process.
> + * Returns 0 on success, negative errno otherwise.
> + */
> +int tee_bnxt_fw_load(void)

This is a little strange. This function takes no parameters, so how
does this thing know where to load the firmware? Is it not possible
to have two devices that'd both require FW?

> +{
> + int ret = 0;
> + struct tee_ioctl_invoke_arg inv_arg;
> + struct tee_param param[MAX_TEE_PARAM_ARRY_MEMB];
> +
> + if (!pvt_data.ctx)
> + return -ENODEV;
> +
> + prepare_args(TA_CMD_BNXT_FASTBOOT, &inv_arg, param);
> +
> + ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param);
> + HANDLE_ERROR(ret, inv_arg.ret, TA_CMD_BNXT_FASTBOOT);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(tee_bnxt_fw_load);
> +
> +/**
> + * tee_bnxt_copy_coredump() - Copy coredump from the allocated memory
> + * Uses an OP-TEE call to copy coredump
> + * @buf: desintation buffer where core dump is copied into
> + * @offset: offset from the base address of core dump area
> + * @size: size of the dump
> + *
> + * Returns 0 on success, negative errno otherwise.
> + */
> +int tee_bnxt_copy_coredump(void *buf, u32 offset, u32 size)
> +{
> + struct tee_ioctl_invoke_arg inv_arg;
> + struct tee_param param[MAX_TEE_PARAM_ARRY_MEMB];
> + void *core_data;
> + u32 rbytes = size;
> + u32 nbytes = 0;
> + int ret = 0;
> +
> + if (!pvt_data.ctx)
> + return -ENODEV;
> +
> + if (!buf)
> + return -EINVAL;

Generally we don't check args like that in the kernel, callers should
not be broken.

> + prepare_args(TA_CMD_BNXT_COPY_COREDUMP, &inv_arg, param);
> +
> + while (rbytes) {
> + nbytes = rbytes;
> +
> + nbytes = min_t(u32, rbytes, param[0].u.memref.size);
> +
> + /* Fill additional invoke cmd params */
> + param[1].u.value.a = offset;
> + param[1].u.value.b = nbytes;

But the doc above says param 1 is unused

> + ret = tee_client_invoke_func(pvt_data.ctx, &inv_arg, param);
> + HANDLE_ERROR(ret, inv_arg.ret, TA_CMD_BNXT_COPY_COREDUMP);
> +
> + core_data = tee_shm_get_va(pvt_data.fw_shm_pool, 0);
> + if (IS_ERR(core_data)) {
> + dev_err(pvt_data.dev, "tee_shm_get_va failed\n");
> + return PTR_ERR(core_data);
> + }
> +
> + memcpy(buf, core_data, nbytes);
> +
> + rbytes -= nbytes;
> + buf += nbytes;
> + offset += nbytes;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(tee_bnxt_copy_coredump);
> +
> +static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
> +{
> + if (ver->impl_id == TEE_IMPL_ID_OPTEE)
> + return 1;
> + else
> + return 0;

Also known as return ver->impl_id == TEE_IMPL_ID_OPTEE; ...

> +}
> +
> +static int tee_bnxt_fw_probe(struct device *dev)
> +{
> + struct tee_client_device *bnxt_device = to_tee_client_device(dev);
> + int ret, err = -ENODEV;
> + struct tee_ioctl_open_session_arg sess_arg;
> + struct tee_shm *fw_shm_pool;
> +
> + memset(&sess_arg, 0, sizeof(sess_arg));
> +
> + /* Open context with TEE driver */
> + pvt_data.ctx = tee_client_open_context(NULL, optee_ctx_match, NULL,
> + NULL);
> + if (IS_ERR(pvt_data.ctx))
> + return -ENODEV;
> +
> + /* Open session with Bnxt load Trusted App */
> + memcpy(sess_arg.uuid, bnxt_device->id.uuid.b, TEE_IOCTL_UUID_LEN);
> + sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
> + sess_arg.num_params = 0;
> +
> + ret = tee_client_open_session(pvt_data.ctx, &sess_arg, NULL);
> + if ((ret < 0) || (sess_arg.ret != 0)) {

parens unnecessary

> + dev_err(dev, "tee_client_open_session failed, err: %x\n",
> + sess_arg.ret);
> + err = -EINVAL;
> + goto out_ctx;
> + }
> + pvt_data.session_id = sess_arg.session;
> +
> + pvt_data.dev = dev;
> +
> + fw_shm_pool = tee_shm_alloc(pvt_data.ctx, MAX_SHM_MEM_SZ,
> + TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
> + if (IS_ERR(fw_shm_pool)) {
> + tee_client_close_context(pvt_data.ctx);
> + dev_err(pvt_data.dev, "tee_shm_alloc failed\n");
> + err = PTR_ERR(fw_shm_pool);
> + goto out_sess;
> + }
> +
> + pvt_data.fw_shm_pool = fw_shm_pool;
> +
> + return 0;
> +
> +out_sess:
> + tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
> +out_ctx:
> + tee_client_close_context(pvt_data.ctx);
> +
> + return err;
> +}
> +
> +static int tee_bnxt_fw_remove(struct device *dev)
> +{
> + tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
> + tee_client_close_context(pvt_data.ctx);
> + pvt_data.ctx = NULL;
> +
> + return 0;
> +}
> +
> +static const struct tee_client_device_id tee_bnxt_fw_id_table[] = {
> + {UUID_INIT(0x6272636D, 0x2019, 0x0716,
> + 0x42, 0x43, 0x4D, 0x5F, 0x53, 0x43, 0x48, 0x49)},
> + {}
> +};
> +
> +MODULE_DEVICE_TABLE(tee, tee_bnxt_fw_id_table);
> +
> +static struct tee_client_driver tee_bnxt_fw_driver = {
> + .id_table = tee_bnxt_fw_id_table,
> + .driver = {
> + .name = KBUILD_MODNAME,
> + .bus = &tee_bus_type,
> + .probe = tee_bnxt_fw_probe,
> + .remove = tee_bnxt_fw_remove,
> + },
> +};
> +
> +static int __init tee_bnxt_fw_mod_init(void)
> +{
> + return driver_register(&tee_bnxt_fw_driver.driver);
> +}
> +
> +static void __exit tee_bnxt_fw_mod_exit(void)
> +{
> + driver_unregister(&tee_bnxt_fw_driver.driver);
> +}
> +
> +module_init(tee_bnxt_fw_mod_init);
> +module_exit(tee_bnxt_fw_mod_exit);

Someone should add a module_tee_driver macro, perhaps?

> +MODULE_AUTHOR("Broadcom");

I think you can forego the author macro is it's a company.

> +MODULE_DESCRIPTION("Broadcom bnxt firmware manager");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/firmware/broadcom/tee_bnxt_fw.h b/include/linux/firmware/broadcom/tee_bnxt_fw.h
> new file mode 100644
> index 0000000..f24c82d
> --- /dev/null
> +++ b/include/linux/firmware/broadcom/tee_bnxt_fw.h
> @@ -0,0 +1,14 @@
> +/* SPDX-License-Identifier: BSD-2-Clause */
> +/*
> + * Copyright 2019 Broadcom.
> + */
> +
> +#ifndef _BROADCOM_TEE_BNXT_FW_H
> +#define _BROADCOM_TEE_BNXT_FW_H
> +
> +#include <linux/types.h>
> +
> +int tee_bnxt_fw_load(void);
> +int tee_bnxt_copy_coredump(void *buf, u32 offset, u32 size);
> +
> +#endif /* _BROADCOM_TEE_BNXT_FW_H */

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Previous message: John Stultz: "Re: [RESEND][PATCH v8 0/5] DMA-BUF Heaps (destaging ION)"
In reply to: Sheetal Tigadoli: "[PATCH V2 1/3] firmware: broadcom: add OP-TEE based BNXT f/w manager"
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