RE: [EXT] Re: [PATCH v4 6/7] firmware: imx: add driver for NXP EdgeLock Enclave

[Pankaj Gupta]

> -----Original Message-----
> From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> Sent: Thursday, July 13, 2023 12:27 AM
> To: Pankaj Gupta <pankaj.gupta@xxxxxxx>; shawnguo@xxxxxxxxxx;
> s.hauer@xxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx; clin@xxxxxxxx;
> conor+dt@xxxxxxxxxx; pierre.gondois@xxxxxxx; Jacky Bai
> <ping.bai@xxxxxxx>; Clark Wang <xiaoning.wang@xxxxxxx>; Wei Fang
> <wei.fang@xxxxxxx>; Peng Fan <peng.fan@xxxxxxx>; Bough Chen
> <haibo.chen@xxxxxxx>; festevam@xxxxxxxxx; dl-linux-imx <linux-
> imx@xxxxxxx>; davem@xxxxxxxxxxxxx; robh+dt@xxxxxxxxxx;
> krzysztof.kozlowski+dt@xxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Gaurav Jain
> <gaurav.jain@xxxxxxx>; alexander.stein@xxxxxxxxxxxxxxx; Sahil Malhotra
> <sahil.malhotra@xxxxxxx>; Aisheng Dong <aisheng.dong@xxxxxxx>; Varun
> Sethi <V.Sethi@xxxxxxx>
> Cc: kernel test robot <lkp@xxxxxxxxx>
> Subject: [EXT] Re: [PATCH v4 6/7] firmware: imx: add driver for NXP EdgeLock
> Enclave
> 
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> 
> On 12/07/2023 14:12, Pankaj Gupta wrote:
> > The Edgelock Enclave , is the secure enclave embedded in the SoC to
> > support the features like HSM, SHE & V2X, using message based
> > communication channel.
> >
> > ELE FW communicates on a dedicated MU with application core where
> > kernel is running. It exists on specific i.MX processors. e.g.
> > i.MX8ULP, i.MX93.
> >
> > Signed-off-by: Gaurav Jain <gaurav.jain@xxxxxxx>
> > Signed-off-by: Pankaj Gupta <pankaj.gupta@xxxxxxx>
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> 
> What did the robot report? New driver?
[Pankaj] reported printf format-specifier for size_t. 

> 
> ...
> 
> > +
> > +/* Fill a command message header with a given command ID and length
> > +in bytes. */ static int plat_fill_cmd_msg_hdr(struct mu_hdr *hdr,
> > +                              uint8_t cmd,
> > +                              uint32_t len) {
> > +     struct ele_mu_priv *priv = NULL;
> > +     int err;
> > +
> > +     err = get_ele_mu_priv(&priv);
> > +     if (err) {
> > +             pr_err("Error: iMX EdgeLock Enclave MU, used before
> > + probing.\n");
> 
> dev_err(), everywhere.
> 
Accepted. Will correct in V5.

> > +             return err;
> > +     }
> > +
> > +     hdr->tag = priv->cmd_tag;
> > +     hdr->ver = ELE_BASE_API_VERSION;
> > +     hdr->command = cmd;
> > +     hdr->size = len >> 2;
> > +
> > +     return err;
> > +}
> > +
> > +static u32 plat_add_msg_crc(uint32_t *msg, uint32_t msg_len) {
> > +     uint32_t i;
> > +     uint32_t crc = 0;
> > +     uint32_t nb_words = msg_len >> 2;
> > +
> > +     for (i = 0; i < nb_words - 1; i++)
> > +             crc ^= *(msg + i);
> > +
> > +     return crc;
> > +}
> > +
> > +int imx_ele_msg_send_rcv(struct ele_mu_priv *priv) {
> > +     unsigned int wait;
> > +     int err;
> > +
> > +     mutex_lock(&priv->mu_cmd_lock);
> > +     mutex_lock(&priv->mu_lock);
> > +
> > +     err = mbox_send_message(priv->tx_chan, &priv->tx_msg);
> > +     if (err < 0) {
> > +             pr_err("Error: mbox_send_message failure.\n");
> > +             mutex_unlock(&priv->mu_lock);
> > +             return err;
> > +     }
> > +     mutex_unlock(&priv->mu_lock);
> > +
> > +     wait = msecs_to_jiffies(1000);
> > +     if (!wait_for_completion_timeout(&priv->done, wait)) {
> > +             pr_err("Error: wait_for_completion timed out.\n");
> > +             err = -ETIMEDOUT;
> > +     }
> > +
> > +     mutex_unlock(&priv->mu_cmd_lock);
> > +
> > +     return err;
> > +}
> > +
> > +static int read_otp_uniq_id(struct ele_mu_priv *priv, u32 *value) {
> > +     unsigned int tag, command, size, ver, status;
> > +
> > +     tag = MSG_TAG(priv->rx_msg.header);
> > +     command = MSG_COMMAND(priv->rx_msg.header);
> > +     size = MSG_SIZE(priv->rx_msg.header);
> > +     ver = MSG_VER(priv->rx_msg.header);
> > +     status = RES_STATUS(priv->rx_msg.data[0]);
> > +
> > +     if (tag == priv->rsp_tag &&
> > +         command == ELE_READ_FUSE_REQ &&
> > +         size == ELE_READ_FUSE_RSP_MSG_SZ &&
> > +         ver == ELE_BASE_API_VERSION &&
> > +         status == ELE_SUCCESS_IND) {
> > +             value[0] = priv->rx_msg.data[1];
> > +             value[1] = priv->rx_msg.data[2];
> > +             value[2] = priv->rx_msg.data[3];
> > +             value[3] = priv->rx_msg.data[4];
> > +             return 0;
> > +     }
> > +
> > +     return -EINVAL;
> > +}
> > +
> > +static int read_fuse_word(struct ele_mu_priv *priv, u32 *value) {
> > +     unsigned int tag, command, size, ver, status;
> > +
> > +     tag = MSG_TAG(priv->rx_msg.header);
> > +     command = MSG_COMMAND(priv->rx_msg.header);
> > +     size = MSG_SIZE(priv->rx_msg.header);
> > +     ver = MSG_VER(priv->rx_msg.header);
> > +     status = RES_STATUS(priv->rx_msg.data[0]);
> > +
> > +     if (tag == priv->rsp_tag &&
> > +         command == ELE_READ_FUSE_REQ &&
> > +         size == ELE_READ_FUSE_REQ_MSG_SZ &&
> > +         ver == ELE_BASE_API_VERSION &&
> > +         status == ELE_SUCCESS_IND) {
> > +             value[0] = priv->rx_msg.data[1];
> > +             return 0;
> > +     }
> > +
> > +     return -EINVAL;
> > +}
> > +
> > +int read_common_fuse(uint16_t fuse_id, u32 *value) {
> > +     struct ele_mu_priv *priv = NULL;
> > +     int err;
> > +
> > +     err = get_ele_mu_priv(&priv);
> > +     if (err) {
> > +             pr_err("Error: iMX EdgeLock Enclave MU, used before probing.\n");
> > +             return err;
> > +     }
> > +     err = plat_fill_cmd_msg_hdr((struct mu_hdr *)&priv->tx_msg.header,
> > +                                 ELE_READ_FUSE_REQ, 8);
> > +     if (err) {
> > +             pr_err("Error: plat_fill_cmd_msg_hdr failed.\n");
> > +             return err;
> > +     }
> > +
> > +     priv->tx_msg.data[0] = fuse_id;
> > +     err = imx_ele_msg_send_rcv(priv);
> > +     if (err < 0)
> > +             return err;
> > +
> > +     switch (fuse_id) {
> > +     case OTP_UNIQ_ID:
> > +             err = read_otp_uniq_id(priv, value);
> > +             break;
> > +     default:
> > +             err = read_fuse_word(priv, value);
> > +             break;
> > +     }
> > +
> > +     return err;
> > +}
> > +EXPORT_SYMBOL_GPL(read_common_fuse);
> > +
> > +int ele_ping(void)
> 
> No, why this is void? Don't do some singletons when not necessary. It's wrong
> design, error prone and tricky to make work with deferred probe.
> 

> Why the consumers cannot be designed like a consumer - take a respective
> phandle from producer?
> 
[Pankaj] Accepted. Device reference is used.
Thanks for pointing it out. 

> > +{
> > +     struct ele_mu_priv *priv = NULL;
> > +     unsigned int tag, command, size, ver, status;
> > +     int err;
> > +
> > +     err = get_ele_mu_priv(&priv);
> > +     if (err) {
> > +             pr_err("Error: iMX EdgeLock Enclave MU, used before probing.\n");
> > +             return err;
> > +     }
> > +     err = plat_fill_cmd_msg_hdr((struct mu_hdr *)&priv->tx_msg.header,
> > +                                 ELE_PING_REQ, 4);
> > +     if (err) {
> > +             pr_err("Error: plat_fill_cmd_msg_hdr failed.\n");
> > +             return err;
> > +     }
> > +
> > +     err = imx_ele_msg_send_rcv(priv);
> > +     if (err < 0)
> > +             return err;
> > +
> > +     tag = MSG_TAG(priv->rx_msg.header);
> > +     command = MSG_COMMAND(priv->rx_msg.header);
> > +     size = MSG_SIZE(priv->rx_msg.header);
> > +     ver = MSG_VER(priv->rx_msg.header);
> > +     status = RES_STATUS(priv->rx_msg.data[0]);
> > +
> > +     if (tag == priv->rsp_tag && command == ELE_PING_REQ &&
> > +         size == ELE_PING_REQ_MSG_SZ && ver == ELE_BASE_API_VERSION
> &&
> > +         status == ELE_SUCCESS_IND)
> > +             return 0;
> > +
> > +     return -EAGAIN;
> > +}
> > +EXPORT_SYMBOL_GPL(ele_ping);
> 
> Nope. You have one driver. This does not have to be exported.
> 
> This is a strong NAK.
> 
[Pankaj] Accepted. Will be removed in V5.
> 
> > +
> > +int ele_service_swap(phys_addr_t addr, u32 addr_size, u16 flag) {
> > +     struct ele_mu_priv *priv;
> > +     int ret;
> > +     unsigned int tag, command, size, ver, status;
> > +
> > +     ret = get_ele_mu_priv(&priv);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = plat_fill_cmd_msg_hdr((struct mu_hdr *)&priv->tx_msg.header,
> > +                                 ELE_SERVICE_SWAP_REQ, 24);
> > +     if (ret)
> > +             return ret;
> > +
> > +     priv->tx_msg.data[0] = flag;
> > +     priv->tx_msg.data[1] = addr_size;
> > +     priv->tx_msg.data[2] = ELE_NONE_VAL;
> > +     priv->tx_msg.data[3] = lower_32_bits(addr);
> > +     priv->tx_msg.data[4] = plat_add_msg_crc((uint32_t *)&priv->tx_msg,
> 24);
> > +     ret = imx_ele_msg_send_rcv(priv);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     tag = MSG_TAG(priv->rx_msg.header);
> > +     command = MSG_COMMAND(priv->rx_msg.header);
> > +     size = MSG_SIZE(priv->rx_msg.header);
> > +     ver = MSG_VER(priv->rx_msg.header);
> > +     status = RES_STATUS(priv->rx_msg.data[0]);
> > +     if (tag == priv->rsp_tag &&
> > +         command == ELE_SERVICE_SWAP_REQ &&
> > +         size == ELE_SERVICE_SWAP_REQ_MSG_SZ &&
> > +         ver == ELE_BASE_API_VERSION &&
> > +         status == ELE_SUCCESS_IND) {
> > +             if (flag == ELE_IMEM_EXPORT)
> > +                     return priv->rx_msg.data[1];
> > +             else
> > +                     return 0;
> > +     }
> > +
> > +     return -EINVAL;
> > +}
> > +EXPORT_SYMBOL_GPL(ele_service_swap);
> > +
> > +int ele_get_info(phys_addr_t addr, u32 data_size) {
> > +     struct ele_mu_priv *priv;
> > +     int ret;
> > +     unsigned int tag, command, size, ver, status;
> > +
> > +     ret = get_ele_mu_priv(&priv);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = plat_fill_cmd_msg_hdr((struct mu_hdr *)&priv->tx_msg.header,
> > +                                 ELE_GET_INFO_REQ, 16);
> > +     if (ret)
> > +             return ret;
> > +
> > +     priv->tx_msg.data[0] = upper_32_bits(addr);
> > +     priv->tx_msg.data[1] = lower_32_bits(addr);
> > +     priv->tx_msg.data[2] = data_size;
> > +     ret = imx_ele_msg_send_rcv(priv);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     tag = MSG_TAG(priv->rx_msg.header);
> > +     command = MSG_COMMAND(priv->rx_msg.header);
> > +     size = MSG_SIZE(priv->rx_msg.header);
> > +     ver = MSG_VER(priv->rx_msg.header);
> > +     status = RES_STATUS(priv->rx_msg.data[0]);
> > +     if (tag == priv->rsp_tag &&
> > +         command == ELE_GET_INFO_REQ &&
> > +         size == ELE_GET_INFO_REQ_MSG_SZ &&
> > +         ver == ELE_BASE_API_VERSION &&
> > +         status == ELE_SUCCESS_IND)
> > +             return 0;
> > +
> > +     return -EINVAL;
> > +}
> > +EXPORT_SYMBOL_GPL(ele_get_info);
> > +
> > +/*
> > + * ele_get_trng_state() - prepare and send the command to read
> > + *                        crypto lib and TRNG state
> > + * TRNG state
> > + *  0x1              TRNG is in program mode
> > + *  0x2              TRNG is still generating entropy
> > + *  0x3              TRNG entropy is valid and ready to be read
> > + *  0x4              TRNG encounter an error while generating entropy
> > + *
> > + * CSAL state
> > + *  0x0              Crypto Lib random context initialization is not done yet
> > + *  0x1              Crypto Lib random context initialization is on-going
> > + *  0x2              Crypto Lib random context initialization succeed
> > + *  0x3              Crypto Lib random context initialization failed
> > + *
> > + * returns: csal and trng state.
> > + *
> > + */
> > +int ele_get_trng_state(void)
> > +{
> > +     struct ele_mu_priv *priv;
> > +     int ret;
> > +     unsigned int tag, command, size, ver, status;
> > +
> > +     /* access ele_mu_priv data structure pointer*/
> > +     ret = get_ele_mu_priv(&priv);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = plat_fill_cmd_msg_hdr((struct mu_hdr *)&priv->tx_msg.header,
> > +                                 ELE_GET_TRNG_STATE_REQ, 4);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = imx_ele_msg_send_rcv(priv);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     tag = MSG_TAG(priv->rx_msg.header);
> > +     command = MSG_COMMAND(priv->rx_msg.header);
> > +     size = MSG_SIZE(priv->rx_msg.header);
> > +     ver = MSG_VER(priv->rx_msg.header);
> > +     status = RES_STATUS(priv->rx_msg.data[0]);
> > +     if (tag == priv->rsp_tag &&
> > +         command == ELE_GET_TRNG_STATE_REQ &&
> > +         size == ELE_GET_TRNG_STATE_REQ_MSG_SZ &&
> > +         ver == ELE_BASE_API_VERSION &&
> > +         status == ELE_SUCCESS_IND) {
> > +             return (priv->rx_msg.data[1] & CSAL_TRNG_STATE_MASK);
> > +     }
> > +
> > +     return -EINVAL;
> > +}
> > +EXPORT_SYMBOL_GPL(ele_get_trng_state);
> > +
> > +/*
> > + * ele_start_rng() - prepare and send the command to start
> > + *                   initialization of the ELE RNG context
> > + *
> > + * returns:  0 on success.
> > + */
> > +int ele_start_rng(void)
> > +{
> > +     struct ele_mu_priv *priv;
> > +     int ret;
> > +     unsigned int tag, command, size, ver, status;
> > +
> > +     /* access ele_mu_priv data structure pointer*/
> > +     ret = get_ele_mu_priv(&priv);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = plat_fill_cmd_msg_hdr((struct mu_hdr *)&priv->tx_msg.header,
> > +                                 ELE_START_RNG_REQ, 4);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = imx_ele_msg_send_rcv(priv);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     tag = MSG_TAG(priv->rx_msg.header);
> > +     command = MSG_COMMAND(priv->rx_msg.header);
> > +     size = MSG_SIZE(priv->rx_msg.header);
> > +     ver = MSG_VER(priv->rx_msg.header);
> > +     status = RES_STATUS(priv->rx_msg.data[0]);
> > +     if (tag == priv->rsp_tag &&
> > +         command == ELE_START_RNG_REQ &&
> > +         size == ELE_START_RNG_REQ_MSG_SZ &&
> > +         ver == ELE_BASE_API_VERSION &&
> > +         status == ELE_SUCCESS_IND) {
> > +             return 0;
> > +     }
> > +
> > +     return -EINVAL;
> > +}
> > +EXPORT_SYMBOL_GPL(ele_start_rng);
> > diff --git a/drivers/firmware/imx/ele_fw_api.c
> > b/drivers/firmware/imx/ele_fw_api.c
> > new file mode 100644
> > index 000000000000..2a3fdc42294b
> > --- /dev/null
> > +++ b/drivers/firmware/imx/ele_fw_api.c
> > @@ -0,0 +1,112 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Copyright 2023 NXP
> > + */
> > +
> > +#include <linux/dma-mapping.h>
> > +#include <linux/firmware/imx/ele_fw_api.h>
> > +
> > +#include "se_fw.h"
> > +
> > +/* Fill a command message header with a given command ID and length
> > +in bytes. */ static int plat_fill_cmd_msg_hdr(struct mu_hdr *hdr,
> > +uint8_t cmd, uint32_t len) {
> > +     struct ele_mu_priv *priv = NULL;
> > +     int err = 0;
> > +
> > +     err = get_ele_mu_priv(&priv);
> > +     if (err) {
> > +             pr_err("Error: iMX EdgeLock Enclave MU is not probed
> successfully.\n");
> > +             return err;
> > +     }
> > +     hdr->tag = priv->cmd_tag;
> > +     hdr->ver = MESSAGING_VERSION_7;
> > +     hdr->command = cmd;
> > +     hdr->size = (uint8_t)(len / sizeof(uint32_t));
> > +
> > +     return err;
> > +}
> > +
> > +/*
> > + * ele_get_random() - prepare and send the command to proceed
> > + *                    with a random number generation operation
> > + *
> > + * returns:  size of the rondom number generated  */ int
> > +ele_get_random(struct hwrng *rng, void *data, size_t len, bool wait)
> > +{
> > +     struct ele_mu_priv *priv;
> > +     unsigned int tag, command, size, ver, status;
> > +     dma_addr_t dst_dma;
> > +     u8 *buf;
> > +     int ret;
> > +
> > +     /* access ele_mu_priv data structure pointer*/
> > +     ret = get_ele_mu_priv(&priv);
> > +     if (ret)
> > +             return ret;
> > +
> > +     buf = dmam_alloc_coherent(priv->dev, len, &dst_dma, GFP_KERNEL);
> > +     if (!buf) {
> > +             dev_err(priv->dev, "Failed to map destination buffer memory\n");
> > +             return -ENOMEM;
> > +     }
> > +
> > +     ret = plat_fill_cmd_msg_hdr((struct mu_hdr *)&priv->tx_msg.header,
> ELE_GET_RANDOM_REQ, 16);
> > +     if (ret)
> > +             goto exit;
> > +
> > +     priv->tx_msg.data[0] = 0x0;
> > +     priv->tx_msg.data[1] = dst_dma;
> > +     priv->tx_msg.data[2] = len;
> > +     ret = imx_ele_msg_send_rcv(priv);
> > +     if (ret < 0)
> > +             goto exit;
> > +
> > +     tag = MSG_TAG(priv->rx_msg.header);
> > +     command = MSG_COMMAND(priv->rx_msg.header);
> > +     size = MSG_SIZE(priv->rx_msg.header);
> > +     ver = MSG_VER(priv->rx_msg.header);
> > +     status = RES_STATUS(priv->rx_msg.data[0]);
> > +     if (tag == 0xe1 && command == ELE_GET_RANDOM_REQ && size ==
> 0x02 &&
> > +         ver == 0x07 && status == 0xd6) {
> > +             memcpy(data, buf, len);
> > +             ret = len;
> > +     } else
> > +             ret = -EINVAL;
> > +
> > +exit:
> > +     dmam_free_coherent(priv->dev, len, buf, dst_dma);
> > +     return ret;
> > +}
> > +
> > +int ele_init_fw(void)
> > +{
> > +     struct ele_mu_priv *priv;
> > +     int ret;
> > +     unsigned int tag, command, size, ver, status;
> > +
> > +     ret = get_ele_mu_priv(&priv);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = plat_fill_cmd_msg_hdr((struct mu_hdr *)&priv->tx_msg.header,
> ELE_INIT_FW_REQ, 4);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = imx_ele_msg_send_rcv(priv);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     tag = MSG_TAG(priv->rx_msg.header);
> > +     command = MSG_COMMAND(priv->rx_msg.header);
> > +     size = MSG_SIZE(priv->rx_msg.header);
> > +     ver = MSG_VER(priv->rx_msg.header);
> > +     status = RES_STATUS(priv->rx_msg.data[0]);
> > +
> > +     if (tag == 0xe1 && command == ELE_INIT_FW_REQ && size == 0x02 &&
> > +         ver == 0x06 && status == 0xd6)
> > +             return 0;
> > +
> > +     return -EINVAL;
> > +}
> > diff --git a/drivers/firmware/imx/se_fw.c
> > b/drivers/firmware/imx/se_fw.c new file mode 100644 index
> > 000000000000..14e4bb4225e1
> > --- /dev/null
> > +++ b/drivers/firmware/imx/se_fw.c
> > @@ -0,0 +1,1443 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Copyright 2021-2023 NXP
> > + */
> > +
> > +#include <linux/dma-mapping.h>
> > +#include <linux/completion.h>
> > +#include <linux/dev_printk.h>
> > +#include <linux/errno.h>
> > +#include <linux/export.h>
> > +#include <linux/firmware/imx/ele_fw_api.h> #include
> > +<linux/firmware/imx/ele_base_msg.h>
> > +#include <linux/firmware/imx/ele_mu_ioctl.h>
> > +#include <linux/genalloc.h>
> > +#include <linux/io.h>
> > +#include <linux/init.h>
> > +#include <linux/miscdevice.h>
> > +#include <linux/mod_devicetable.h>
> > +#include <linux/module.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/of_reserved_mem.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +#include <linux/delay.h>
> > +#include <linux/sys_soc.h>
> > +#include <linux/workqueue.h>
> > +
> > +#include "se_fw.h"
> > +
> > +#define ELE_PING_INTERVAL            (3600 * HZ)
> > +#define ELE_TRNG_STATE_OK            0x203
> > +#define ELE_GET_TRNG_STATE_RETRY_COUNT       0x5
> > +
> > +#define ELE_GET_INFO_BUFF_SZ         0x100
> > +#define ELE_GET_INFO_READ_SZ         0xA0
> > +#define ELE_IMEM_SIZE                        0x10000
> > +#define ELE_IMEM_STATE_OK            0xCA
> > +#define ELE_IMEM_STATE_BAD           0xFE
> > +#define ELE_IMEM_STATE_WORD          0x27
> > +#define ELE_IMEM_STATE_MASK          0x00ff0000
> > +
> > +#define SOC_ID_OF_IMX8ULP            0x084D
> > +#define SOC_ID_OF_IMX93                      0x9300
> > +#define SOC_VER_MASK                 0xFFFF0000
> > +#define SOC_ID_MASK                  0x0000FFFF
> > +#define DEVICE_GET_INFO_SZ           0x100
> > +
> > +#define GET_INFO_SOC_INFO_WORD_OFFSET        1
> > +#define GET_INFO_UUID_WORD_OFFSET    3
> > +#define GET_INFO_SL_NUM_MSB_WORD_OFF \
> > +     (GET_INFO_UUID_WORD_OFFSET + 3)
> > +#define GET_INFO_SL_NUM_LSB_WORD_OFF \
> > +     (GET_INFO_UUID_WORD_OFFSET + 0)
> > +
> > +#define RESERVED_DMA_POOL            BIT(1)
> > +
> > +struct ele_mu_priv *ele_priv_export;
> > +
> > +struct imx_info {
> > +     bool socdev;
> > +     uint8_t max_dev_ctx;
> > +     uint8_t cmd_tag;
> > +     uint8_t rsp_tag;
> > +     uint8_t *pool_name;
> > +     /* platform specific flag to enable/disable the ELE True RNG */
> > +     bool start_rng;
> > +     bool enable_ele_trng;
> > +     bool reserved_dma_ranges;
> > +     bool init_fw;
> > +     bool imem_mgmt;
> > +};
> > +
> > +static const struct imx_info imx8ulp_info = {
> > +     .socdev = true,
> > +     .max_dev_ctx = 4,
> > +     .cmd_tag = 0x17,
> > +     .rsp_tag = 0xe1,
> > +     .pool_name = "sram-pool",
> > +     .start_rng = true,
> > +     .enable_ele_trng = false,
> > +     .reserved_dma_ranges = true,
> > +     .init_fw = false,
> > +     .imem_mgmt = true,
> > +};
> > +
> > +static const struct imx_info imx93_info = {
> > +     .socdev = true,
> > +     .max_dev_ctx = 4,
> > +     .cmd_tag = 0x17,
> > +     .rsp_tag = 0xe1,
> > +     .pool_name = NULL,
> > +     .start_rng = true,
> > +     .enable_ele_trng = true,
> > +     .reserved_dma_ranges = true,
> > +     .init_fw = true,
> > +     .imem_mgmt = false,
> > +};
> > +
> > +static const struct of_device_id ele_mu_match[] = {
> > +     { .compatible = "fsl,imx-ele", .data = (void *)&imx8ulp_info},
> > +     { .compatible = "fsl,imx93-ele", .data = (void *)&imx93_info},
> > +     {},
> > +};
> > +
> > +int get_ele_mu_priv(struct ele_mu_priv **export) {
> > +     if (!ele_priv_export)
> > +             return -EPROBE_DEFER;
> > +
> > +     *export = ele_priv_export;
> > +     return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(get_ele_mu_priv);
> > +
> > +/*
> > + * Callback called by mailbox FW when data are received  */ static
> > +void ele_mu_rx_callback(struct mbox_client *c, void *msg) {
> > +     struct device *dev = c->dev;
> > +     struct ele_mu_priv *priv = dev_get_drvdata(dev);
> > +     struct ele_mu_device_ctx *dev_ctx;
> > +     bool is_response = false;
> > +     int msg_size;
> > +     struct mu_hdr header;
> > +
> > +     dev_dbg(dev, "Message received on mailbox\n");
> 
> Drop.
> 
[Accepted.] will correct in V5.
> > +
> > +     /* The function can be called with NULL msg */
> > +     if (!msg) {
> > +             dev_err(dev, "Message is invalid\n");
> > +             return;
> > +     }
> > +
> > +     if (IS_ERR(msg)) {
> 
> IS_ERR_OR_NULL is a sign of poor coding or bug.
> 
> > +             dev_err(dev, "Error during reception of message: %ld\n",
> > +                             PTR_ERR(msg));
> > +             return;
> > +     }
> 
[Accepted] will be removed in V5.

> > +
> > +     header.tag = ((u8 *)msg)[TAG_OFFSET];
> > +     header.command = ((u8 *)msg)[CMD_OFFSET];
> > +     header.size = ((u8 *)msg)[SZ_OFFSET];
> > +     header.ver = ((u8 *)msg)[VER_OFFSET];
> > +
> > +     dev_dbg(dev, "Selecting device\n");
> 
> Drop, useless debug.
> 
[Accepted.] will correct in V5.
> > +
> > +     /* Incoming command: wake up the receiver if any. */
> > +     if (header.tag == priv->cmd_tag) {
> > +             dev_dbg(dev, "Selecting cmd receiver\n");
> > +             dev_ctx = priv->cmd_receiver_dev;
> > +     } else if (header.tag == priv->rsp_tag) {
> > +             if (priv->waiting_rsp_dev) {
> > +                     dev_dbg(dev, "Selecting rsp waiter\n");
> > +                     dev_ctx = priv->waiting_rsp_dev;
> > +                     is_response = true;
> > +             } else {
> > +                     /* Reading the EdgeLock Enclave response
> > +                      * to the command sent by other
> > +                      * linux kernel services.
> > +                      */
> > +                     spin_lock(&priv->lock);
> > +                     priv->rx_msg = *(struct ele_api_msg *)msg;
> > +                     complete(&priv->done);
> > +                     spin_unlock(&priv->lock);
> > +                     return;
> > +             }
> > +     } else {
> > +             dev_err(dev, "Failed to select a device for message: %.8x\n",
> > +                             *((u32 *) &header));
> > +             return;
> > +     }
> > +
> > +     if (!dev_ctx) {
> > +             dev_err(dev, "No device context selected for message: %.8x\n",
> > +                             *((u32 *)&header));
> > +             return;
> > +     }
> > +     /* Init reception */
> > +     msg_size = header.size;
> > +     if (msg_size > MAX_RECV_SIZE) {
> > +             devctx_err(dev_ctx, "Message is too big (%d > %d)", msg_size,
> > +                             MAX_RECV_SIZE);
> > +             return;
> > +     }
> > +
> > +     memcpy(dev_ctx->temp_resp, msg, msg_size << 2);
> > +     dev_ctx->temp_resp_size = msg_size;
> > +
> > +     /* Allow user to read */
> > +     dev_ctx->pending_hdr = dev_ctx->temp_resp[0];
> > +     wake_up_interruptible(&dev_ctx->wq);
> > +
> > +     if (is_response)
> > +             priv->waiting_rsp_dev = NULL;
> > +
> > +}
> > +
> > +static void ele_ping_handler(struct work_struct *work) {
> > +     int ret;
> > +
> > +     ret = ele_ping();
> > +     if (ret)
> > +             pr_err("ping ele failed, try again!\n");
> 
> Why? How to try again?
> 
[Pankaj] Accepted.

> > +
> > +     /* reschedule the delay work */
> > +     schedule_delayed_work(to_delayed_work(work), ELE_PING_INTERVAL);
> > +} static DECLARE_DELAYED_WORK(ele_ping_work, ele_ping_handler);
> > +
> > +static phys_addr_t get_phy_buf_mem_pool(struct device_node *of_node,
> > +                                     char *mem_pool_name,
> > +                                     u32 **buf,
> > +                                     uint32_t size) {
> > +     struct gen_pool *mem_pool = of_gen_pool_get(of_node,
> > +                                                 mem_pool_name, 0);
> > +     if (!mem_pool) {
> > +             pr_err("Unable to get sram pool\n");
> > +             return 0;
> > +     }
> > +
> > +     *buf = (u32 *)gen_pool_alloc(mem_pool, size);
> > +     if (!buf) {
> > +             pr_err("Unable to alloc sram from sram pool\n");
> > +             return 0;
> > +     }
> > +
> > +     return gen_pool_virt_to_phys(mem_pool, (ulong)*buf); }
> > +
> > +static void free_phybuf_mem_pool(struct device_node *of_node,
> > +                              char *mem_pool_name,
> > +                              u32 *buf,
> > +                              uint32_t size) {
> > +     struct gen_pool *mem_pool = of_gen_pool_get(of_node,
> > +                                                 mem_pool_name, 0);
> > +     if (!mem_pool)
> > +             pr_err("%s failed: Unable to get sram pool.\n",
> > +__func__);
> > +
> > +     gen_pool_free(mem_pool, (unsigned long)buf, size); }
> > +
> > +
> > +static int imx_soc_device_register(struct platform_device *pdev,
> > +                                struct imx_info *info) {
> > +     struct soc_device_attribute *attr;
> > +     struct soc_device *dev;
> > +     phys_addr_t get_info_addr = 0;
> > +     u32 *get_info_data = NULL;
> > +     u8 major_ver, minor_ver;
> > +     int err;
> > +
> > +     if (info->pool_name) {
> > +             get_info_addr = get_phy_buf_mem_pool(pdev->dev.of_node,
> > +                                                  info->pool_name,
> > +                                                  &get_info_data,
> > +                                                  DEVICE_GET_INFO_SZ);
> > +     } else {
> > +             get_info_data = dmam_alloc_coherent(&pdev->dev,
> > +                                                 DEVICE_GET_INFO_SZ,
> > +                                                 &get_info_addr,
> > +                                                 GFP_KERNEL);
> > +     }
> > +     if (!get_info_addr) {
> > +             pr_err("Unable to alloc buffer for device info.\n");
> > +             return -ENOMEM;
> > +     }
> > +
> > +     attr = kzalloc(sizeof(*attr), GFP_KERNEL);
> > +     if (!attr)
> > +             return -ENOMEM;
> > +
> > +     err = ele_get_info(get_info_addr, ELE_GET_INFO_READ_SZ);
> > +     if (err) {
> > +             attr->revision = kasprintf(GFP_KERNEL, "A0");
> > +     } else {
> > +             major_ver = (get_info_data[GET_INFO_SOC_INFO_WORD_OFFSET]
> > +                             & SOC_VER_MASK) >> 24;
> > +             minor_ver = ((get_info_data[GET_INFO_SOC_INFO_WORD_OFFSET]
> > +                             & SOC_VER_MASK) >> 16) & 0xFF;
> > +             if (minor_ver)
> > +                     attr->revision = kasprintf(GFP_KERNEL,
> > +                                                "%x.%x",
> > +                                                major_ver,
> > +                                                minor_ver);
> > +             else
> > +                     attr->revision = kasprintf(GFP_KERNEL,
> > +                                                "%x",
> > +                                                major_ver);
> > +
> > +             switch (get_info_data[GET_INFO_SOC_INFO_WORD_OFFSET]
> > +                             & SOC_ID_MASK) {
> > +                     case SOC_ID_OF_IMX8ULP:
> > +                             attr->soc_id = kasprintf(GFP_KERNEL,
> > +                                                      "i.MX8ULP");
> > +                             break;
> > +                     case SOC_ID_OF_IMX93:
> > +                             attr->soc_id = kasprintf(GFP_KERNEL,
> > +                                                      "i.MX93");
> > +                             break;
> > +             }
> > +     }
> > +
> > +     err = of_property_read_string(of_root, "model",
> > +                                   &attr->machine);
> > +     if (err) {
> > +             kfree(attr);
> > +             return -EINVAL;
> > +     }
> > +     attr->family = kasprintf(GFP_KERNEL, "Freescale i.MX");
> 
> Why are you doing soc attr for entire machine in unrelated driver?
> 
[Pankaj] This driver enables the path to FW. Which has the access permission to read the fuses of SoC. These fuses contains SoC serial number.
	This can be fetched post this driver initialization only.
	There are other information too, like soc revision etc, which is fetched after API(GET-INFO) exchange with FW.
> > +
> > +     attr->serial_number
> > +             = kasprintf(GFP_KERNEL, "%016llX",
> > +                         (u64)get_info_data[GET_INFO_SL_NUM_MSB_WORD_OFF]
> << 32
> > +                         |
> > + get_info_data[GET_INFO_SL_NUM_LSB_WORD_OFF]);
> > +
> > +     if (info->pool_name) {
> > +             free_phybuf_mem_pool(pdev->dev.of_node, info->pool_name,
> > +                                  get_info_data, DEVICE_GET_INFO_SZ);
> > +     } else {
> > +             dmam_free_coherent(&pdev->dev,
> > +                                DEVICE_GET_INFO_SZ,
> > +                                get_info_data,
> > +                                get_info_addr);
> > +     }
> > +
> > +     dev = soc_device_register(attr);
> 
> Nope, this is not a soc device.
[Pankaj] Accepted. Corrected in V5.
> 
> > +     if (IS_ERR(dev)) {
> > +             kfree(attr->soc_id);
> > +             kfree(attr->serial_number);
> > +             kfree(attr->revision);
> > +             kfree(attr->family);
> > +             kfree(attr->machine);
> > +             kfree(attr);
> > +             return PTR_ERR(dev);
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> 
> ...
> 
> > +     return err;
> > +}
> > +
> > +
> > +
> 
> Drop stray blank lines. Everywhere.
> 
> 
Will correct in V5.

> > +/* Open a char device. */
> > +static int ele_mu_fops_open(struct inode *nd, struct file *fp) {
> > +     struct ele_mu_device_ctx *dev_ctx
> > +             = container_of(fp->private_data,
> > +                            struct ele_mu_device_ctx,
> > +                            miscdev);
> > +     int err;
> > +
> > +     /* Avoid race if opened at the same time */
> > +     if (down_trylock(&dev_ctx->fops_lock))
> > +             return -EBUSY;
> > +
> > +     /* Authorize only 1 instance. */
> > +     if (dev_ctx->status != MU_FREE) {
> > +             err = -EBUSY;
> > +             goto exit;
> > +     }
> > +
> > +     /*
> > +      * Allocate some memory for data exchanges with S40x.
> > +      * This will be used for data not requiring secure memory.
> > +      */
> > +     dev_ctx->non_secure_mem.ptr = dmam_alloc_coherent(dev_ctx->dev,
> > +                                     MAX_DATA_SIZE_PER_USER,
> > +                                     &dev_ctx->non_secure_mem.dma_addr,
> > +                                     GFP_KERNEL);
> > +     if (!dev_ctx->non_secure_mem.ptr) {
> > +             err = -ENOMEM;
> > +             devctx_err(dev_ctx, "Failed to map shared memory with S40x\n");
> > +             goto exit;
> > +     }
> > +
> > +     err = ele_mu_setup_ele_mem_access(dev_ctx,
> > +                                       dev_ctx->non_secure_mem.dma_addr,
> > +                                       MAX_DATA_SIZE_PER_USER);
> > +     if (err) {
> > +             err = -EPERM;
> > +             devctx_err(dev_ctx,
> > +                        "Failed to share access to shared memory\n");
> > +             goto free_coherent;
> > +     }
> > +
> > +     dev_ctx->non_secure_mem.size = MAX_DATA_SIZE_PER_USER;
> > +     dev_ctx->non_secure_mem.pos = 0;
> > +     dev_ctx->status = MU_OPENED;
> > +
> > +     dev_ctx->pending_hdr = 0;
> > +
> > +     goto exit;
> > +
> > +free_coherent:
> > +     dmam_free_coherent(dev_ctx->priv->dev, MAX_DATA_SIZE_PER_USER,
> > +                        dev_ctx->non_secure_mem.ptr,
> > +                        dev_ctx->non_secure_mem.dma_addr);
> > +
> > +exit:
> > +     up(&dev_ctx->fops_lock);
> > +     return err;
> > +}
> > +
> > +/* Close a char device. */
> > +static int ele_mu_fops_close(struct inode *nd, struct file *fp) {
> > +     struct ele_mu_device_ctx *dev_ctx = container_of(fp->private_data,
> > +                                     struct ele_mu_device_ctx, miscdev);
> > +     struct ele_mu_priv *priv = dev_ctx->priv;
> > +     struct ele_buf_desc *b_desc;
> > +
> > +     /* Avoid race if closed at the same time */
> > +     if (down_trylock(&dev_ctx->fops_lock))
> > +             return -EBUSY;
> > +
> > +     /* The device context has not been opened */
> > +     if (dev_ctx->status != MU_OPENED)
> > +             goto exit;
> > +
> > +     /* check if this device was registered as command receiver. */
> > +     if (priv->cmd_receiver_dev == dev_ctx)
> > +             priv->cmd_receiver_dev = NULL;
> > +
> > +     /* check if this device was registered as waiting response. */
> > +     if (priv->waiting_rsp_dev == dev_ctx) {
> > +             priv->waiting_rsp_dev = NULL;
> > +             mutex_unlock(&priv->mu_cmd_lock);
> > +     }
> > +
> > +     /* Unmap secure memory shared buffer. */
> > +     if (dev_ctx->secure_mem.ptr)
> > +             devm_iounmap(dev_ctx->dev, dev_ctx->secure_mem.ptr);
> > +
> > +     dev_ctx->secure_mem.ptr = NULL;
> > +     dev_ctx->secure_mem.dma_addr = 0;
> > +     dev_ctx->secure_mem.size = 0;
> > +     dev_ctx->secure_mem.pos = 0;
> > +
> > +     /* Free non-secure shared buffer. */
> > +     dmam_free_coherent(dev_ctx->priv->dev, MAX_DATA_SIZE_PER_USER,
> > +                        dev_ctx->non_secure_mem.ptr,
> > +                        dev_ctx->non_secure_mem.dma_addr);
> > +
> > +     dev_ctx->non_secure_mem.ptr = NULL;
> > +     dev_ctx->non_secure_mem.dma_addr = 0;
> > +     dev_ctx->non_secure_mem.size = 0;
> > +     dev_ctx->non_secure_mem.pos = 0;
> > +
> > +     while (!list_empty(&dev_ctx->pending_in) ||
> > +            !list_empty(&dev_ctx->pending_out)) {
> > +             if (!list_empty(&dev_ctx->pending_in))
> > +                     b_desc = list_first_entry_or_null(&dev_ctx->pending_in,
> > +                                                       struct ele_buf_desc,
> > +                                                       link);
> > +             else
> > +                     b_desc = list_first_entry_or_null(&dev_ctx->pending_out,
> > +                                                       struct ele_buf_desc,
> > +                                                       link);
> > +
> > +             if (!b_desc)
> > +                     continue;
> > +
> > +             if (b_desc->shared_buf_ptr)
> > +                     memset(b_desc->shared_buf_ptr, 0, b_desc->size);
> > +
> > +             __list_del_entry(&b_desc->link);
> > +             devm_kfree(dev_ctx->dev, b_desc);
> > +     }
> > +
> > +     dev_ctx->status = MU_FREE;
> > +
> > +exit:
> > +     up(&dev_ctx->fops_lock);
> > +     return 0;
> > +}
> > +
> > +/* IOCTL entry point of a char device */ static long
> > +ele_mu_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) {
> > +     struct ele_mu_device_ctx *dev_ctx
> > +             = container_of(fp->private_data,
> > +                            struct ele_mu_device_ctx,
> > +                            miscdev);
> > +     struct ele_mu_priv *ele_mu_priv = dev_ctx->priv;
> > +     int err = -EINVAL;
> > +
> > +     /* Prevent race during change of device context */
> > +     if (down_interruptible(&dev_ctx->fops_lock))
> > +             return -EBUSY;
> > +
> > +     switch (cmd) {
> > +     case ELE_MU_IOCTL_ENABLE_CMD_RCV:
> > +             if (!ele_mu_priv->cmd_receiver_dev) {
> > +                     ele_mu_priv->cmd_receiver_dev = dev_ctx;
> > +                     err = 0;
> > +             };
> > +             break;
> > +     case ELE_MU_IOCTL_GET_MU_INFO:
> > +             err = ele_mu_ioctl_get_mu_info(dev_ctx, arg);
> > +             break;
> > +     case ELE_MU_IOCTL_SHARED_BUF_CFG:
> > +             devctx_err(dev_ctx,
> > +                        "ELE_MU_IOCTL_SHARED_BUF_CFG not supported [0x%x].\n",
> > +                        err);
> > +             break;
> > +     case ELE_MU_IOCTL_SETUP_IOBUF:
> > +             err = ele_mu_ioctl_setup_iobuf_handler(dev_ctx, arg);
> > +             break;
> > +     case ELE_MU_IOCTL_SIGNED_MESSAGE:
> > +             devctx_err(dev_ctx,
> > +                        "ELE_MU_IOCTL_SIGNED_MESSAGE not supported [0x%x].\n",
> > +                        err);
> > +             break;
> > +     default:
> > +             err = -EINVAL;
> > +             devctx_dbg(dev_ctx, "IOCTL %.8x not supported\n", cmd);
> > +     }
> > +
> > +     up(&dev_ctx->fops_lock);
> > +     return (long)err;
> > +}
> > +
> > +/* Char driver setup */
> > +static const struct file_operations ele_mu_fops = {
> 
> Where did you document user-space ABI?
> 
[Pankaj] Will definitely add it, next to this patch.
Thanks for pointing it out.

> > +     .open           = ele_mu_fops_open,
> > +     .owner          = THIS_MODULE,
> > +     .release        = ele_mu_fops_close,
> > +     .unlocked_ioctl = ele_mu_ioctl,
> > +     .read           = ele_mu_fops_read,
> > +     .write          = ele_mu_fops_write,
> > +};
> > +
> > +/* interface for managed res to free a mailbox channel */ static void
> > +if_mbox_free_channel(void *mbox_chan) {
> > +     mbox_free_channel(mbox_chan);
> > +}
> > +
> > +/* interface for managed res to unregister a char device */ static
> > +void if_misc_deregister(void *miscdevice) {
> > +     misc_deregister(miscdevice);
> > +}
> > +
> > +static int ele_mu_request_channel(struct device *dev,
> > +                              struct mbox_chan **chan,
> > +                              struct mbox_client *cl,
> > +                              const char *name) {
> > +     struct mbox_chan *t_chan;
> > +     int ret = 0;
> > +
> > +     t_chan = mbox_request_channel_byname(cl, name);
> > +     if (IS_ERR(t_chan)) {
> > +             ret = PTR_ERR(t_chan);
> > +             if (ret != -EPROBE_DEFER)
> > +                     dev_err(dev,
> > +                             "Failed to request chan %s ret %d\n", name,
> > +                             ret);
> > +             goto exit;
> > +     }
> > +
> > +     ret = devm_add_action(dev, if_mbox_free_channel, t_chan);
> > +     if (ret) {
> > +             dev_err(dev, "failed to add devm removal of mbox %s\n", name);
> > +             goto exit;
> > +     }
> > +
> > +     *chan = t_chan;
> > +
> > +exit:
> > +     return ret;
> > +}
> > +
> > +static int ele_probe_cleanup(struct platform_device *pdev) {
> > +     int ret;
> > +     int i;
> > +     struct device *dev = &pdev->dev;
> > +     struct ele_mu_priv *priv = dev_get_drvdata(dev);
> > +
> > +     if (!priv) {
> > +             ret = -EINVAL;
> > +             dev_err(dev, "Invalid ELE-MU Priv data");
> > +             return ret;
> > +     }
> > +
> > +     if (priv->tx_chan)
> > +             mbox_free_channel(priv->tx_chan);
> > +     if (priv->rx_chan)
> > +             mbox_free_channel(priv->rx_chan);
> > +
> > +     /* free the buffer in ele-mu remove, previously allocated
> > +      * in ele-mu probe to store encrypted IMEM
> > +      */
> > +     if (priv->imem.buf) {
> > +             dmam_free_coherent(&pdev->dev,
> > +                                ELE_IMEM_SIZE,
> > +                                priv->imem.buf,
> > +                                priv->imem.phyaddr);
> > +             priv->imem.buf = NULL;
> > +     }
> > +
> > +     if (priv->flags & RESERVED_DMA_POOL) {
> > +             of_reserved_mem_device_release(dev);
> > +             priv->flags &= (~RESERVED_DMA_POOL);
> > +     }
> > +     if (priv->ctxs) {
> > +             for (i = 0; i < priv->max_dev_ctx; i++) {
> > +                     if (priv->ctxs[i])
> > +                             devm_kfree(dev, priv->ctxs[i]);
> > +             }
> > +             devm_kfree(dev, priv->ctxs);
> > +     }
> > +     devm_kfree(dev, priv);
> > +     return ret;
> > +}
> > +
> > +static int ele_mu_probe(struct platform_device *pdev) {
> > +     struct ele_mu_device_ctx *dev_ctx;
> > +     struct device *dev = &pdev->dev;
> > +     struct ele_mu_priv *priv;
> > +     struct device_node *np;
> > +     const struct of_device_id *of_id = of_match_device(ele_mu_match,
> dev);
> > +     struct imx_info *info = (of_id != NULL) ? (struct imx_info *)of_id->data
> > +                                             : NULL;
> 
> That's some spaghetti code. Can of_id be NULL?
[Accepted] Corrected it.

> 
> > +     char *devname;
> > +     uint32_t tmp_dt_value = 0;
> > +     int ret;
> > +     int i;
> > +
> > +     if (!info) {
> > +             ret = -EINVAL;
> > +             dev_err(dev, "%s: Incompatible Device.\n", __func__);
> 
> NAK, explain how this is even possible.
> 
[Accepted] will correct in V5.

> > +             return ret;
> > +     }
> > +
> > +     priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> > +     if (!priv) {
> > +             ret = -ENOMEM;
> > +             dev_err(dev, "Fail allocate mem for private data\n");
> 
> I asked about doing internal review. This is trivial mistake, so I doubt you did
> any internal review. Even tools point it out (coccinelle, smatch, sparse).
> 
[Pankaj] Will correct it:
+     if (!priv)
+	return -ENOMEM;

> > +             return ret;
> > +     }
> > +     memset(priv, 0x0, sizeof(*priv));
> > +     priv->dev = dev;
> > +     dev_set_drvdata(dev, priv);
> > +
> > +     /*
> > +      * Get the address of MU to be used for communication with the SCU
> > +      */
> > +     np = pdev->dev.of_node;
> > +     if (!np) {
> > +             dev_err(dev, "Cannot find MU User entry in device
> > + tree\n");
> 
> No, how is this even possible? Please, do not add code which cannot
> work/happen.
>
[Accepted] will be removed from V5. 
> > +             ret = -EOPNOTSUPP;
> > +             goto exit;
> > +     }
> > +
> > +     /* Initialize the mutex. */
> > +     mutex_init(&priv->mu_cmd_lock);
> > +     mutex_init(&priv->mu_lock);
> > +
> > +     priv->cmd_receiver_dev = NULL;
> > +     priv->waiting_rsp_dev = NULL;
> > +
> > +     ret = of_property_read_u32(np, "fsl,mu-did", &tmp_dt_value);
> > +     if (ret) {
> > +             ret = -EINVAL;
> > +             dev_err(dev, "%s: Not able to read mu-did", __func__);
> > +             goto exit;
> > +     }
> > +     priv->ele_mu_did = tmp_dt_value & 0xFF;
> > +
> > +     ret = of_property_read_u32(np, "fsl,mu-id", &tmp_dt_value);
> > +     if (ret) {
> > +             ret = -EINVAL;
> > +             dev_err(dev, "%s: Not able to read mu-id", __func__);
> > +             goto exit;
> > +     }
> > +     priv->ele_mu_id = tmp_dt_value & 0xFF;
> > +
> > +     priv->max_dev_ctx = info->max_dev_ctx;
> > +
> > +     priv->cmd_tag = info->cmd_tag;
> > +     priv->rsp_tag = info->rsp_tag;
> > +
> > +     /* Mailbox client configuration */
> > +     priv->ele_mb_cl.dev             = dev;
> > +     priv->ele_mb_cl.tx_block        = false;
> > +     priv->ele_mb_cl.knows_txdone    = true;
> > +     priv->ele_mb_cl.rx_callback     = ele_mu_rx_callback;
> > +
> > +     ret = ele_mu_request_channel(dev, &priv->tx_chan,
> > +                                  &priv->ele_mb_cl, "tx");
> > +     if (ret) {
> > +             if (ret != -EPROBE_DEFER)
> > +                     dev_err(dev, "Failed to request tx channel\n");
> > +
> > +             goto exit;
> > +     }
> > +
> > +     ret = ele_mu_request_channel(dev, &priv->rx_chan,
> > +                                  &priv->ele_mb_cl, "rx");
> > +     if (ret) {
> > +             if (ret != -EPROBE_DEFER)
> > +                     dev_err(dev, "Failed to request rx channel\n");
> > +
> > +             goto exit;
> > +     }
> > +
> > +     priv->ctxs = devm_kzalloc(dev, sizeof(dev_ctx) * priv->max_dev_ctx,
> > +                               GFP_KERNEL);
> > +
> > +     if (!priv->ctxs) {
> > +             ret = -ENOMEM;
> > +             dev_err(dev, "Fail allocate mem for private dev-ctxs.\n");
> > +             goto exit;
> > +     }
> > +
> > +     /* Create users */
> > +     for (i = 0; i < priv->max_dev_ctx; i++) {
> > +             dev_ctx = devm_kzalloc(dev, sizeof(*dev_ctx), GFP_KERNEL);
> > +             if (!dev_ctx) {
> > +                     ret = -ENOMEM;
> > +                     dev_err(dev,
> > +                             "Fail to allocate memory for device context\n");
> > +                     goto exit;
> > +             }
> > +
> > +             dev_ctx->dev = dev;
> > +             dev_ctx->status = MU_FREE;
> > +             dev_ctx->priv = priv;
> > +
> > +             priv->ctxs[i] = dev_ctx;
> > +
> > +             /* Default value invalid for an header. */
> > +             init_waitqueue_head(&dev_ctx->wq);
> > +
> > +             INIT_LIST_HEAD(&dev_ctx->pending_out);
> > +             INIT_LIST_HEAD(&dev_ctx->pending_in);
> > +             sema_init(&dev_ctx->fops_lock, 1);
> > +
> > +             devname = devm_kasprintf(dev, GFP_KERNEL, "ele_mu%d_ch%d",
> > +                                      priv->ele_mu_id, i);
> > +             if (!devname) {
> > +                     ret = -ENOMEM;
> > +                     dev_err(dev,
> > +                             "Fail to allocate memory for misc dev name\n");
> > +                     goto exit;
> > +             }
> > +
> > +             dev_ctx->miscdev.name = devname;
> > +             dev_ctx->miscdev.minor = MISC_DYNAMIC_MINOR;
> > +             dev_ctx->miscdev.fops = &ele_mu_fops;
> > +             dev_ctx->miscdev.parent = dev;
> > +             ret = misc_register(&dev_ctx->miscdev);
> > +             if (ret) {
> > +                     dev_err(dev, "failed to register misc device %d\n",
> > +                             ret);
> > +                     goto exit;
> > +             }
> > +
> > +             ret = devm_add_action(dev, if_misc_deregister,
> > +                                   &dev_ctx->miscdev);
> > +             if (ret) {
> > +                     dev_err(dev,
> > +                             "failed[%d] to add action to the misc-dev\n",
> > +                             ret);
> > +                     goto exit;
> > +             }
> > +     }
> > +
> > +     init_completion(&priv->done);
> > +     spin_lock_init(&priv->lock);
> > +
> > +     ele_priv_export = priv;
> > +
> > +     if (info && info->reserved_dma_ranges) {
> > +             ret = of_reserved_mem_device_init(dev);
> 
> You don't have reserved memory, according to your bindings.
[Pankaj] This was also highlighted as part DTB testing. Now, I have added it in the binding.
> 
> > +             if (ret) {
> > +                     dev_err(dev,
> > +                             "failed to init reserved memory region %d\n",
> > +                             ret);
> > +                     priv->flags &= (~RESERVED_DMA_POOL);
> > +                     goto exit;
> > +             }
> > +             priv->flags |= RESERVED_DMA_POOL;
> > +     }
> > +
> > +     if (info && info->init_fw) {
> > +             /* start initializing ele fw */
> > +             ret = ele_init_fw();
> > +             if (ret)
> > +                     dev_err(dev, "Failed to initialize ele fw.\n");
> > +     }
> > +
> > +     if (info && info->socdev) {
> > +             ret = imx_soc_device_register(pdev, info);
> 
> It's not a soc device.
[Pankaj] it is not a soc device. But the information can be fetched about SoC, from FW post this driver init.

> 
> > +             if (ret) {
> > +                     dev_err(dev,
> > +                             "failed[%d] to register SoC device\n", ret);
> > +                     goto exit;
> > +             }
> > +     }
> > +
> > +     if (info && info->imem_mgmt) {
> > +             /* allocate buffer where ELE store encrypted IMEM */
> > +             priv->imem.buf = dmam_alloc_coherent(dev, ELE_IMEM_SIZE,
> > +                                                  &priv->imem.phyaddr,
> > +                                                  GFP_KERNEL);
> > +             if (!priv->imem.buf) {
> > +                     dev_err(dev,
> > +                             "dmam-alloc-failed: To store encr-IMEM.\n");
> > +                     ret = -ENOMEM;
> > +                     goto exit;
> > +             }
> > +     }
> > +
> > +     /* start ele rng */
> > +     ret = ele_do_start_rng();
> > +     if (ret)
> > +             dev_err(dev, "Failed to start ele rng\n");
> > +
> > +     if (!ret && info && info->enable_ele_trng) {
> > +             ret = ele_trng_init(dev);
> > +             if (ret)
> > +                     dev_err(dev, "Failed to init ele-trng\n");
> > +     }
> > +
> > +     /*
> > +      * A ELE ping request must be send at least once every day(24 hours),
> > +      * so setup a delay work with 1 hour interval
> > +      * to ping ELE periodically.
> > +      */
> > +     schedule_delayed_work(&ele_ping_work, ELE_PING_INTERVAL);
> > +
> > +     dev_set_drvdata(dev, priv);
> > +
> > +     pr_info("Misc-devices on i.MX enclave MU is configured.\n");
> 
> No silly probe success messages.
[Accepted] Will removed in V5.
> 
> 
> > +     return devm_of_platform_populate(dev);
> 
> No. You do not have children. Just open your own binding and look there.
> 
> This driver is in terrible shape and I asked to do some internal review in NXP.
> Internal review should point such trivial comments but your changelog from
> v1 tp v4 says nothing about it.
> 
> So internal review did not happen. Don't use upstream as cheap reviewers for
> poor quality code. Please work internally till it starts looking correct and all
> automated tools pass. NXP is not some small, amateour company which can be
> excused of this. Or is it?
> 
> Best regards,
> Krzysztof