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Date:   Thu, 12 Sep 2019 10:48:57 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Ray Jui <ray.jui@broadcom.com>
Cc:     Sheetal Tigadoli <sheetal.tigadoli@broadcom.com>,
        =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= <zajec5@gmail.com>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Ingo Molnar <mingo@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Michal Simek <michal.simek@xilinx.com>,
        Rajan Vaja <rajan.vaja@xilinx.com>,
        Scott Branden <scott.branden@broadcom.com>,
        Vikram Prakash <vikram.prakash@broadcom.com>,
        tee-dev@lists.linaro.org,
        BCM Kernel Feedback <bcm-kernel-feedback-list@broadcom.com>,
        linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org,
        Vikas Gupta <vikas.gupta@broadcom.com>
Subject: Re: [PATCH] firmware: broadcom: add OP-TEE based BNXT f/w manager
Message-ID: <20190912094857.GA54192@kroah.com>
References: <1568128624-2902-1-git-send-email-sheetal.tigadoli@broadcom.com>
 <20190910171601.GA12665@kroah.com>
 <CAFD6DHjOV9ChRXsuoanXh0JN6DW-AUxTFdcu8PKTwGa5wW7e8A@mail.gmail.com>
 <ce00990d-b2ad-ee66-cb0f-13ff2580bfaf@broadcom.com>
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On Wed, Sep 11, 2019 at 10:56:31AM -0700, Ray Jui wrote:
> 
> 
> On 9/11/19 10:53 AM, Sheetal Tigadoli wrote:
> > Thanks for the review and  comments.
> > 
> > On Tue, Sep 10, 2019 at 10:46 PM Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org> wrote:
> > > 
> > > On Tue, Sep 10, 2019 at 08:47:04PM +0530, Sheetal Tigadoli wrote:
> > > > From: Vikas Gupta <vikas.gupta@broadcom.com>
> > > > 
> > > > This driver registers on TEE bus to interact with OP-TEE based
> > > > BNXT firmware management modules
> > > > 
> > > > Signed-off-by: Vikas Gupta <vikas.gupta@broadcom.com>
> > > > Signed-off-by: Sheetal Tigadoli <sheetal.tigadoli@broadcom.com>
> > > > ---
> > > >   drivers/firmware/broadcom/Kconfig             |   8 +
> > > >   drivers/firmware/broadcom/Makefile            |   1 +
> > > >   drivers/firmware/broadcom/tee_bnxt_fw.c       | 447 ++++++++++++++++++++++++++
> > > >   include/linux/firmware/broadcom/tee_bnxt_fw.h |  17 +
> > > >   4 files changed, 473 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 6468082..a846a21 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
> > > 
> > > No ability to build with compile testing?
> > Will add "|| 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 00000000..89a48fd
> > > > --- /dev/null
> > > > +++ b/drivers/firmware/broadcom/tee_bnxt_fw.c
> > > > @@ -0,0 +1,447 @@
> > > > +// 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 DRIVER_NAME  "tee-bnxt-fw"
> > > 
> > > KBUILD_MODNAME?
> > Will remove DRIVER_NAME macro and use KBUILD_MODNAME instead.
> > > 
> > > > +#define MAX_SHM_MEM_SZ       SZ_4M
> > > 
> > > Why?
> > Limiting max data buffer size per request to optee to 4MB.
> > > 
> > > > +
> > > > +#define MAX_TEE_PARAM_ARRY_MEMB              4
> > > > +
> > > > +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,
> > > > +
> > > 
> > > Please indent the comments too.  As-is this is hard to read.
> > Will do
> > > 
> > > 
> > > > +/*
> > > > + * TA_CMD_BNXT_HEALTH_STATUS - to check health of bnxt device
> > > > + *
> > > > + * param[0] (out value) - value.a: health status
> > > > + * param[1] unused
> > > > + * param[2] unused
> > > > + * param[3] unused
> > > > + *
> > > > + * Result:
> > > > + * TEE_SUCCESS - Invoke command success
> > > > + * TEE_ERROR_BAD_PARAMETERS - Incorrect input param
> > > > + */
> > > > +     TA_CMD_BNXT_HEALTH_STATUS,
> > > 
> > > Should all of these have explicit values?
> > Will initialize each cmd (TA_CMD_BNXT_*) explicitly
> > > 
> > > > +
> > > > +/*
> > > > + * TA_CMD_BNXT_HANDSHAKE - to check bnxt device is booted
> > > > + *
> > > > + * param[0] (in value)  - value.a: max timeout value
> > > > + * param[0] (out value) - value.a: boot status
> > > > + * param[1] unused
> > > > + * param[2] unused
> > > > + * param[3] unused
> > > > + *
> > > > + * Result:
> > > > + * TEE_SUCCESS - Invoke command success
> > > > + * TEE_ERROR_BAD_PARAMETERS - Incorrect input param
> > > > + */
> > > > +     TA_CMD_BNXT_HANDSHAKE,
> > > > +
> > > > +/*
> > > > + * TA_CMD_BNXT_COPY_COREDUMP - copy the core dump into shm
> > > > + *
> > > > + * param[0] (in value) - value.a: offset at which 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,
> > > > +
> > > > +/*
> > > > + * TA_CMD_BNXT_FW_UPGRADE - upgrade the bnxt firmware
> > > > + *
> > > > + * param[0] (in value) - value.a: size of the f/w image
> > > > + * param[1] unused
> > > > + * param[2] unused
> > > > + * param[3] unused
> > > > + *
> > > > + * Result:
> > > > + * TEE_SUCCESS - Invoke command success
> > > > + * TEE_ERROR_BAD_PARAMETERS - Incorrect input param
> > > > + */
> > > > +     TA_CMD_BNXT_FW_UPGRADE,
> > > > +};
> > > > +
> > > > +/**
> > > > + * 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;
> > > 
> > > Why is the pointer back needed?
> > the dev pointer is used in "dev_err()"
> > > 
> > > > +     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,
> > > > +                             struct tee_ioctl_invoke_arg *inv_arg,
> > > > +                             struct tee_param *param)
> > > > +{
> > > > +     memset(inv_arg, 0, sizeof(*inv_arg));
> > > > +     memset(param, 0, (MAX_TEE_PARAM_ARRY_MEMB * sizeof(*param)));
> > > > +
> > > > +     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_HEALTH_STATUS:
> > > > +             param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
> > > > +             break;
> > > > +     case TA_CMD_BNXT_HANDSHAKE:
> > > > +             param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT;
> > > > +             break;
> > > > +     case TA_CMD_BNXT_COPY_COREDUMP:
> > > > +     case TA_CMD_BNXT_FW_UPGRADE:
> > > > +             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)
> > > > +{
> > > > +     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);
> > > > +     if ((ret < 0) || (inv_arg.ret != 0)) {
> > > > +             dev_err(pvt_data.dev, "TA_CMD_BNXT_LOAD invoke err: %x\n",
> > > > +                     (ret < 0) ? ret : inv_arg.ret);
> > > > +             return -EINVAL;
> > > > +     }
> > > > +
> > > > +     return 0;
> > > > +}
> > > > +EXPORT_SYMBOL(tee_bnxt_fw_load);
> > > 
> > > Why are you exporting symbols for a single file?  What uses these?
> > These apis will be used by bnxt driver, still working on open sourcing changes
> > 
> 
> Hi Greg,
> 
> The above API is used by the bnxt_en Ethernet driver to load firmware that
> is stored in the secure region of DDR that can only be accessed through
> secure calls via TEE.
> 
> EXPORT_SYMBOL is needed given that bnxt_en driver (the client that uses this
> API) is usually loaded as a module.
> 
> > > This feels really wrong, are you sure this all is correct?
> 
> Is there anything specific that looks wrong? Please help to point out and
> we'll fix it.

We can not export symbols when there is no in-kernel user of the code.
Please resend this as a patch series when you have the other "side" of
these symbols ready for submission.

thanks,

greg k-h