Re: [PATCH v2 1/7] fpga: sec-mgr: intel fpga security manager class driver

[Russ Weight]

On 10/5/20 5:05 PM, Russ Weight wrote:
>
> On 10/5/20 12:38 AM, Wu, Hao wrote:
>>> Subject: [PATCH v2 1/7] fpga: sec-mgr: intel fpga security manager class
>>> driver
>>>
>>> Create the Intel Security Manager class driver. The security
>>> manager provides interfaces to manage secure updates for the
>>> FPGA and BMC images that are stored in FLASH. The driver can
>>> also be used to update root entry hashes and to cancel code
>>> signing keys.
>>>
>>> This patch creates the class driver and provides sysfs
>>> interfaces for displaying root entry hashes, canceled code
>>> signing keys and flash counts.
>>>
>>> Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
>>> Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx>
>>> ---
>>> v2:
>>>   - Bumped documentation dates and versions
>>>   - Added Documentation/fpga/ifpga-sec-mgr.rst
>>>   - Removed references to bmc_flash_count & smbus_flash_count (not
>>> supported)
>>>   - Split ifpga_sec_mgr_register() into create() and register() functions
>>>   - Added devm_ifpga_sec_mgr_create()
>>>   - Removed typedefs for imgr ops
>>> ---
>>>  .../ABI/testing/sysfs-class-ifpga-sec-mgr     |  67 +++
>>>  Documentation/fpga/ifpga-sec-mgr.rst          |  50 ++
>>>  Documentation/fpga/index.rst                  |   1 +
>>>  MAINTAINERS                                   |   9 +
>>>  drivers/fpga/Kconfig                          |   9 +
>>>  drivers/fpga/Makefile                         |   3 +
>>>  drivers/fpga/ifpga-sec-mgr.c                  | 432 ++++++++++++++++++
>>>  include/linux/fpga/ifpga-sec-mgr.h            |  81 ++++
>>>  8 files changed, 652 insertions(+)
>>>  create mode 100644 Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
>>>  create mode 100644 Documentation/fpga/ifpga-sec-mgr.rst
>>>  create mode 100644 drivers/fpga/ifpga-sec-mgr.c
>>>  create mode 100644 include/linux/fpga/ifpga-sec-mgr.h
>>>
>>> diff --git a/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
>>> b/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
>>> new file mode 100644
>>> index 000000000000..707958971bcb
>>> --- /dev/null
>>> +++ b/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
>>> @@ -0,0 +1,67 @@
>>> +What: /sys/class/ifpga_sec_mgr/ifpga_secX/name
>>> +Date:Oct 2020
>>> +KernelVersion:  5.11
>>> +Contact:Russ Weight <russell.h.weight@xxxxxxxxx>
>>> +Description:Name of low level fpga security manager driver.
>>> +
>>> +What:
>>> /sys/class/ifpga_sec_mgr/ifpga_secX/security/sr_root_entry_hash
>>> +Date:Oct 2020
>>> +KernelVersion:  5.11
>>> +Contact:Russ Weight <russell.h.weight@xxxxxxxxx>
>>> +Description:Read only. Returns the root entry hash for the static
>>> +region if one is programmed, else it returns the
>>> +string: "hash not programmed".  This file is only
>>> +visible if the underlying device supports it.
>>> +Format: "0x%x".
>>> +
>>> +What:
>>> /sys/class/ifpga_sec_mgr/ifpga_secX/security/pr_root_entry_hash
>>> +Date:Oct 2020
>>> +KernelVersion:  5.11
>>> +Contact:Russ Weight <russell.h.weight@xxxxxxxxx>
>>> +Description:Read only. Returns the root entry hash for the partial
>>> +reconfiguration region if one is programmed, else it
>>> +returns the string: "hash not programmed".  This file
>>> +is only visible if the underlying device supports it.
>>> +Format: "0x%x".
>>> +
>>> +What:
>>> /sys/class/ifpga_sec_mgr/ifpga_secX/security/bmc_root_entry_hash
>>> +Date:Oct 2020
>>> +KernelVersion:  5.11
>>> +Contact:Russ Weight <russell.h.weight@xxxxxxxxx>
>>> +Description:Read only. Returns the root entry hash for the BMC image
>>> +if one is programmed, else it returns the string:
>>> +"hash not programmed".  This file is only visible if the
>>> +underlying device supports it.
>>> +Format: "0x%x".
>>> +
>>> +What:
>>> /sys/class/ifpga_sec_mgr/ifpga_secX/security/sr_canceled_csks
>>> +Date:Oct 2020
>>> +KernelVersion:  5.11
>>> +Contact:Russ Weight <russell.h.weight@xxxxxxxxx>
>>> +Description:Read only. Returns a list of indices for canceled code
>>> +signing keys for the static region. The standard bitmap
>>> +list format is used (e.g. "1,2-6,9").
>>> +
>>> +What:
>>> /sys/class/ifpga_sec_mgr/ifpga_secX/security/pr_canceled_csks
>>> +Date:Oct 2020
>>> +KernelVersion:  5.11
>>> +Contact:Russ Weight <russell.h.weight@xxxxxxxxx>
>>> +Description:Read only. Returns a list of indices for canceled code
>>> +signing keys for the partial reconfiguration region. The
>>> +standard bitmap list format is used (e.g. "1,2-6,9").
>>> +
>>> +What:
>>> /sys/class/ifpga_sec_mgr/ifpga_secX/security/bmc_canceled_csks
>>> +Date:Oct 2020
>>> +KernelVersion:  5.11
>>> +Contact:Russ Weight <russell.h.weight@xxxxxxxxx>
>>> +Description:Read only. Returns a list of indices for canceled code
>>> +signing keys for the BMC.  The standard bitmap list format
>>> +is used (e.g. "1,2-6,9").
>>> +
>>> +What:
>>> /sys/class/ifpga_sec_mgr/ifpga_secX/security/user_flash_count
>>> +Date:Oct 2020
>>> +KernelVersion:  5.11
>>> +Contact:Russ Weight <russell.h.weight@xxxxxxxxx>
>>> +Description:Read only. Returns number of times the user image for the
>>> +static region has been flashed.
>>> +Format: "%u".
>>> diff --git a/Documentation/fpga/ifpga-sec-mgr.rst
>>> b/Documentation/fpga/ifpga-sec-mgr.rst
>>> new file mode 100644
>>> index 000000000000..02f3f65b182b
>>> --- /dev/null
>>> +++ b/Documentation/fpga/ifpga-sec-mgr.rst
>>> @@ -0,0 +1,50 @@
>>> +.. SPDX-License-Identifier: GPL-2.0
>>> +
>>> +========================================
>>> +Intel FPGA Security Manager Class Driver
>>> +========================================
>>> +
>>> +The Intel FPGA Security Manager class driver provides a common
>>> +API for user-space tools to manage updates for secure Intel FPGA
>>> +devices. Device drivers that instantiate the Intel Security
>>> +Manager class driver will interact with a HW secure update
>>> +engine in order to transfer new FPGA and BMC images to FLASH so
>>> +that they will be automatically loaded when the FPGA card reboots.
>>> +
>>> +A significant difference between the FPGA Manager and the Intel FPGA
>>> +Security Manager is that the FPGA Manager does a live update (Partial
>>> +Reconfiguration) to a device, whereas the Intel FPGA Security Manager
>>> +updates the FLASH images for the Static Region and the BMC so that
>>> +they will be loaded the next time the FPGA card boots. Security is
>>> +enforced by hardware and firmware. The security manager interacts
>>> +with the firmware to initiate an update, pass in the necessary data,
>>> +and collect status on the update.
>>> +
>>> +In addition to managing secure updates of the FPGA and BMC images,
>>> +the Intel FPGA Security Manager update process may also used to
>>> +program root entry hashes and cancellation keys for the FPGA static
>>> +region, the FPGA partial reconfiguration region, and the BMC.
>>> +
>>> +Secure updates make use of the request_firmware framework, which
>>> +requires that image files are accessible under /lib/firmware. A request
>>> +for a secure update returns immediately, while the update itself
>>> +proceeds in the context of a kernel worker thread. Sysfs files provide
>>> +a means for monitoring the progress of a secure update and for
>>> +retrieving error information in the event of a failure.
>>> +
>>> +Sysfs Attributes
>>> +================
>>> +
>>> +The API consists of two groups of sysfs attributes as described below.
>>> +
>>> +1. Files in the *security* sub-directory can be used to read security
>>> +   information including: Root Entry Hashes (REH), Cancelled Code
>>> +   Signing Keys (CSK), and the flash update count for FPGA images.
>>> +
>>> +2. Files in the *update* sub-directory can be used to instantiate and
>>> +   monitor a secure update.
>>> +
>>> +
>>> +See `<../ABI/testing/sysfs-class-ifpga-sec-mgr>`__ for a full
>>> +description of the sysfs attributes for the Intel FPGA Security
>>> +Manager.
>>> diff --git a/Documentation/fpga/index.rst b/Documentation/fpga/index.rst
>>> index f80f95667ca2..ba9c6b1917bd 100644
>>> --- a/Documentation/fpga/index.rst
>>> +++ b/Documentation/fpga/index.rst
>>> @@ -8,6 +8,7 @@ fpga
>>>      :maxdepth: 1
>>>
>>>      dfl
>>> +    ifpga-sec-mgr
>>>
>>>  .. only::  subproject and html
>>>
>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>> index 6d1175bf8529..5ffc0e02d741 100644
>>> --- a/MAINTAINERS
>>> +++ b/MAINTAINERS
>>> @@ -6858,6 +6858,15 @@ F:Documentation/fpga/
>>>  F:drivers/fpga/
>>>  F:include/linux/fpga/
>>>
>>> +INTEL FPGA SECURITY MANAGER DRIVERS
>>> +M:Russ Weight <russell.h.weight@xxxxxxxxx>
>>> +L:linux-fpga@xxxxxxxxxxxxxxx
>>> +S:Maintained
>>> +F:Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
>>> +F:Documentation/fpga/ifpga-sec-mgr.rst
>>> +F:drivers/fpga/ifpga-sec-mgr.c
>>> +F:include/linux/fpga/ifpga-sec-mgr.h
>>> +
>>>  FPU EMULATOR
>>>  M:Bill Metzenthen <billm@xxxxxxxxxxxxx>
>>>  S:Maintained
>>> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
>>> index 7cd5a29fc437..bf566a625be7 100644
>>> --- a/drivers/fpga/Kconfig
>>> +++ b/drivers/fpga/Kconfig
>>> @@ -215,4 +215,13 @@ config FPGA_MGR_ZYNQMP_FPGA
>>>    to configure the programmable logic(PL) through PS
>>>    on ZynqMP SoC.
>>>
>>> +config IFPGA_SEC_MGR
>>> +tristate "Intel Security Manager for FPGA"
>>> +help
>>> +  The Intel Security Manager class driver presents a common
>>> +  user API for managing secure updates for Intel FPGA
>>> +  devices, including flash images for the FPGA static
>>> +  region and for the BMC. Select this option to enable
>>> +  updates for secure FPGA devices.
>>> +
>>>  endif # FPGA
>>> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
>>> index d8e21dfc6778..2e1d29c3d915 100644
>>> --- a/drivers/fpga/Makefile
>>> +++ b/drivers/fpga/Makefile
>>> @@ -21,6 +21,9 @@ obj-$(CONFIG_FPGA_MGR_ZYNQMP_FPGA)+=
>>> zynqmp-fpga.o
>>>  obj-$(CONFIG_ALTERA_PR_IP_CORE)         += altera-pr-ip-core.o
>>>  obj-$(CONFIG_ALTERA_PR_IP_CORE_PLAT)    += altera-pr-ip-core-plat.o
>>>
>>> +# Intel FPGA Security Manager Framework
>>> +obj-$(CONFIG_IFPGA_SEC_MGR)+= ifpga-sec-mgr.o
>>> +
>>>  # FPGA Bridge Drivers
>>>  obj-$(CONFIG_FPGA_BRIDGE)+= fpga-bridge.o
>>>  obj-$(CONFIG_SOCFPGA_FPGA_BRIDGE)+= altera-hps2fpga.o altera-
>>> fpga2sdram.o
>>> diff --git a/drivers/fpga/ifpga-sec-mgr.c b/drivers/fpga/ifpga-sec-mgr.c
>>> new file mode 100644
>>> index 000000000000..f1caa4602ab3
>>> --- /dev/null
>>> +++ b/drivers/fpga/ifpga-sec-mgr.c
>>> @@ -0,0 +1,432 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/*
>>> + * Intel Security Manager for FPGA
>>> + *
>>> + * Copyright (C) 2019-2020 Intel Corporation, Inc.
>>> + */
>>> +
>>> +#include <linux/fpga/ifpga-sec-mgr.h>
>>> +#include <linux/idr.h>
>>> +#include <linux/module.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/vmalloc.h>
>>> +
>>> +static DEFINE_IDA(ifpga_sec_mgr_ida);
>>> +static struct class *ifpga_sec_mgr_class;
>>> +
>>> +#define to_sec_mgr(d) container_of(d, struct ifpga_sec_mgr, dev)
>>> +
>>> +static ssize_t
>>> +show_canceled_csk(struct ifpga_sec_mgr *imgr,
>>> +  int (*get_csk)(struct ifpga_sec_mgr *imgr,
>>> + unsigned long *csk_map, unsigned int nbits),
>>> +  int (*get_csk_nbits)(struct ifpga_sec_mgr *imgr),
>>> +  char *buf)
>>> +{
>>> +unsigned long *csk_map = NULL;
>>> +unsigned int nbits;
>>> +int ret;
>>> +
>>> +ret = get_csk_nbits(imgr);
>>> +if (ret < 0)
>>> +return ret;
>>> +
>>> +nbits = (unsigned int)ret;
>>> +csk_map = vmalloc(sizeof(unsigned long) * BITS_TO_LONGS(nbits));
>>> +if (!csk_map)
>>> +return -ENOMEM;
>>> +
>>> +ret = get_csk(imgr, csk_map, nbits);
>>> +if (ret)
>>> +goto vfree_exit;
>>> +
>>> +ret = bitmap_print_to_pagebuf(1, buf, csk_map, nbits);
>>> +
>>> +vfree_exit:
>>> +vfree(csk_map);
>>> +return ret;
>>> +}
>>> +
>>> +static ssize_t
>>> +show_root_entry_hash(struct ifpga_sec_mgr *imgr,
>>> +     int (*get_reh)(struct ifpga_sec_mgr *imgr, u8 *hash,
>>> +    unsigned int size),
>>> +     int (*get_reh_size)(struct ifpga_sec_mgr *imgr),
>>> +     char *buf)
>>> +{
>>> +int size, i, cnt, ret;
>>> +u8 *hash;
>>> +
>>> +ret = get_reh_size(imgr);
>>> +if (ret < 0)
>>> +return ret;
>>> +else if (!ret)
>>> +return sprintf(buf, "hash not programmed\n");
>>> +
>>> +size = ret;
>>> +hash = vmalloc(size);
>>> +if (!hash)
>>> +return -ENOMEM;
>>> +
>>> +ret = get_reh(imgr, hash, size);
>>> +if (ret)
>>> +goto vfree_exit;
>>> +
>>> +cnt = sprintf(buf, "0x");
>>> +for (i = 0; i < size; i++)
>>> +cnt += sprintf(buf + cnt, "%02x", hash[i]);
>>> +cnt += sprintf(buf + cnt, "\n");
>>> +
>>> +vfree_exit:
>>> +vfree(hash);
>>> +return ret ? : cnt;
>>> +}
>>> +
>>> +#define DEVICE_ATTR_SEC_CSK(_name) \
>>> +static ssize_t _name##_canceled_csks_show(struct device *dev, \
>>> +  struct device_attribute *attr, \
>>> +  char *buf) \
>>> +{ \
>>> +struct ifpga_sec_mgr *imgr = to_sec_mgr(dev); \
>>> +return show_canceled_csk(imgr, \
>>> +       imgr->iops->_name##_canceled_csks, \
>>> +       imgr->iops->_name##_canceled_csk_nbits, buf); \
>>> +} \
>>> +static DEVICE_ATTR_RO(_name##_canceled_csks)
>>> +
>>> +#define DEVICE_ATTR_SEC_ROOT_ENTRY_HASH(_name) \
>>> +static ssize_t _name##_root_entry_hash_show(struct device *dev, \
>>> +     struct device_attribute *attr, \
>>> +     char *buf) \
>>> +{ \
>>> +struct ifpga_sec_mgr *imgr = to_sec_mgr(dev); \
>>> +return show_root_entry_hash(imgr, \
>>> +       imgr->iops->_name##_root_entry_hash, \
>>> +       imgr->iops->_name##_reh_size, buf); \
>>> +} \
>>> +static DEVICE_ATTR_RO(_name##_root_entry_hash)
>>> +
>>> +static ssize_t user_flash_count_show(struct device *dev,
>>> +     struct device_attribute *attr, char *buf)
>>> +{
>>> +struct ifpga_sec_mgr *imgr = to_sec_mgr(dev);
>>> +
>>> +int cnt = imgr->iops->user_flash_count(imgr);
>>> +return cnt < 0 ? cnt : sprintf(buf, "%u\n", cnt);
>>> +}
>>> +static DEVICE_ATTR_RO(user_flash_count);
>>> +
>>> +DEVICE_ATTR_SEC_ROOT_ENTRY_HASH(sr);
>>> +DEVICE_ATTR_SEC_ROOT_ENTRY_HASH(pr);
>>> +DEVICE_ATTR_SEC_ROOT_ENTRY_HASH(bmc);
>>> +DEVICE_ATTR_SEC_CSK(sr);
>>> +DEVICE_ATTR_SEC_CSK(pr);
>>> +DEVICE_ATTR_SEC_CSK(bmc);
>>> +
>>> +static struct attribute *sec_mgr_security_attrs[] = {
>>> +&dev_attr_user_flash_count.attr,
>>> +&dev_attr_bmc_root_entry_hash.attr,
>>> +&dev_attr_sr_root_entry_hash.attr,
>>> +&dev_attr_pr_root_entry_hash.attr,
>>> +&dev_attr_sr_canceled_csks.attr,
>>> +&dev_attr_pr_canceled_csks.attr,
>>> +&dev_attr_bmc_canceled_csks.attr,
>>> +NULL,
>>> +};
>>> +
>>> +#define check_attr(attribute, _name) \
>>> +((attribute) == &dev_attr_##_name.attr && imgr->iops->_name)
>>> +
>>> +static umode_t sec_mgr_visible(struct kobject *kobj,
>>> +       struct attribute *attr, int n)
>>> +{
>>> +struct ifpga_sec_mgr *imgr = to_sec_mgr(kobj_to_dev(kobj));
>>> +
>>> +/*
>>> + * Only display optional sysfs attributes if a
>>> + * corresponding handler is provided
>>> + */
>>> +if (check_attr(attr, user_flash_count) ||
>>> +    check_attr(attr, bmc_root_entry_hash) ||
>>> +    check_attr(attr, sr_root_entry_hash) ||
>>> +    check_attr(attr, pr_root_entry_hash) ||
>>> +    check_attr(attr, sr_canceled_csks) ||
>>> +    check_attr(attr, pr_canceled_csks) ||
>>> +    check_attr(attr, bmc_canceled_csks))
>>> +return attr->mode;
>>> +
>>> +return 0;
>>> +}
>>> +
>>> +static struct attribute_group sec_mgr_security_attr_group = {
>>> +.name = "security",
>>> +.attrs = sec_mgr_security_attrs,
>>> +.is_visible = sec_mgr_visible,
>>> +};
>>> +
>>> +static ssize_t name_show(struct device *dev,
>>> + struct device_attribute *attr, char *buf)
>>> +{
>>> +struct ifpga_sec_mgr *imgr = to_sec_mgr(dev);
>>> +
>>> +return sprintf(buf, "%s\n", imgr->name);
>>> +}
>>> +static DEVICE_ATTR_RO(name);
>>> +
>>> +static struct attribute *sec_mgr_attrs[] = {
>>> +&dev_attr_name.attr,
>>> +NULL,
>>> +};
>>> +
>>> +static struct attribute_group sec_mgr_attr_group = {
>>> +.attrs = sec_mgr_attrs,
>>> +};
>>> +
>>> +static const struct attribute_group *ifpga_sec_mgr_attr_groups[] = {
>>> +&sec_mgr_attr_group,
>>> +&sec_mgr_security_attr_group,
>>> +NULL,
>>> +};
>>> +
>>> +static bool check_sysfs_handler(struct device *dev,
>>> +void *sysfs_handler, void *size_handler,
>>> +const char *sysfs_handler_name,
>>> +const char *size_handler_name)
>>> +{
>>> +/*
>>> + * sysfs_handler and size_handler must either both be
>>> + * defined or both be NULL.
>>> + */
>>> +if (sysfs_handler) {
>>> +if (!size_handler) {
>>> +dev_err(dev, "%s registered without %s\n",
>>> +sysfs_handler_name, size_handler_name);
>>> +return false;
>>> +}
>>> +} else if (size_handler) {
>>> +dev_err(dev, "%s registered without %s\n",
>>> +size_handler_name, sysfs_handler_name);
>>> +return false;
>>> +}
>> Optional:
>>
>> If (sysfs_handler && !size_handler) {
>>
>> } else if (!sysfs_handler && size_handler) {
>>
>> }
> Yes, I can code it that way. It would be more readable.
>>> +return true;
>>> +}
>>> +
>>> +#define check_reh_handler(_dev, _iops, _name) \
>>> +check_sysfs_handler(_dev, (_iops)->_name##_root_entry_hash, \
>>> +    (_iops)->_name##_reh_size, \
>>> +    __stringify(_name##_root_entry_hash), \
>>> +    __stringify(_name##_reh_size))
>>> +
>>> +#define check_csk_handler(_dev, _iops, _name) \
>>> +check_sysfs_handler(_dev, (_iops)->_name##_canceled_csks, \
>>> +    (_iops)->_name##_canceled_csk_nbits, \
>>> +    __stringify(_name##_canceled_csks), \
>>> +    __stringify(_name##_canceled_csk_nbits))
>>> +
>>> +/**
>>> + * ifpga_sec_mgr_create - create and initialize an Intel FPGA
>>> + *  security manager struct
>>> + *
>>> + * @dev:  Intel fpga security manager device from pdev
>>> + * @name: ifpga security manager name
>>> + * @iops: pointer to a structure of ifpga callback functions
>>> + * @priv: ifpga security manager private data
>>> + *
>>> + * The caller of this function is responsible for freeing the struct
>>> + * with ifpg_sec_mgr_free(). Using devm_ifpga_sec_mgr_create() instead
>>> + * is recommended.
>>> + *
>>> + * Return: pointer to struct ifpga_sec_mgr or NULL
>>> + */
>>> +struct ifpga_sec_mgr *
>>> +ifpga_sec_mgr_create(struct device *dev, const char *name,
>>> +     const struct ifpga_sec_mgr_ops *iops, void *priv)
>>> +{
>>> +struct ifpga_sec_mgr *imgr;
>>> +int id, ret;
>>> +
>>> +if (!check_reh_handler(dev, iops, bmc) ||
>>> +    !check_reh_handler(dev, iops, sr) ||
>>> +    !check_reh_handler(dev, iops, pr) ||
>>> +    !check_csk_handler(dev, iops, bmc) ||
>>> +    !check_csk_handler(dev, iops, sr) ||
>>> +    !check_csk_handler(dev, iops, pr)) {
>>> +return NULL;
>>> +}
>>> +
>>> +if (!name || !strlen(name)) {
>>> +dev_err(dev, "Attempt to register with no name!\n");
>>> +return NULL;
>>> +}
>>> +
>>> +imgr = kzalloc(sizeof(*imgr), GFP_KERNEL);
>>> +if (!imgr)
>>> +return NULL;
>>> +
>>> +id = ida_simple_get(&ifpga_sec_mgr_ida, 0, 0, GFP_KERNEL);
>>> +if (id < 0)
>>> +goto error_kfree;
>>> +
>>> +mutex_init(&imgr->lock);
>>> +
>>> +imgr->name = name;
>>> +imgr->priv = priv;
>>> +imgr->iops = iops;
>>> +
>>> +device_initialize(&imgr->dev);
>>> +imgr->dev.class = ifpga_sec_mgr_class;
>>> +imgr->dev.parent = dev;
>>> +imgr->dev.id = id;
>>> +
>>> +ret = dev_set_name(&imgr->dev, "ifpga_sec%d", id);
>>> +if (ret) {
>>> +dev_err(dev, "Failed to set device name: ifpga_sec%d\n", id);
>>> +goto error_device;
>>> +}
>>> +
>>> +return imgr;
>>> +
>>> +error_device:
>>> +ida_simple_remove(&ifpga_sec_mgr_ida, id);
>>> +
>>> +error_kfree:
>>> +kfree(imgr);
>>> +
>>> +return NULL;
>>> +}
>>> +EXPORT_SYMBOL_GPL(ifpga_sec_mgr_create);
>>> +
>>> +/**
>>> + * ifpga_sec_mgr_free - free an Intel FPGA security manager created
>>> + *with ifpga_sec_mgr_create()
>>> + *
>>> + * @imgr:Intel FPGA security manager structure
>>> + */
>>> +void ifpga_sec_mgr_free(struct ifpga_sec_mgr *imgr)
>>> +{
>>> +ida_simple_remove(&ifpga_sec_mgr_ida, imgr->dev.id);
>>> +kfree(imgr);
>>> +}
>>> +EXPORT_SYMBOL_GPL(ifpga_sec_mgr_free);
>>> +
>>> +static void devm_ifpga_sec_mgr_release(struct device *dev, void *res)
>>> +{
>>> +struct ifpga_sec_mgr *imgr = *(struct ifpga_sec_mgr **)res;
>>> +
>>> +ifpga_sec_mgr_free(imgr);
>>> +}
>>> +
>>> +/**
>>> + * devm_ifpga_sec_mgr_create - create and initialize an Intel FPGA
>>> + *       security manager struct
>>> + *
>>> + * @dev:  Intel fpga security manager device from pdev
>>> + * @name: ifpga security manager name
>>> + * @iops: pointer to a structure of ifpga callback functions
>>> + * @priv: ifpga security manager private data
>>> + *
>>> + * This function is intended for use in a Intel FPGA Security manager
>>> + * driver's probe function.  After the security manager driver creates
>>> + * the ifpga_sec_mgr struct with devm_fpga_mgr_create(), it should
>>> + * register it with ifpga_sec_mgr_register().  The security manager
>>> + * driver's remove function should call ifpga_sec_mgr_unregister().
>>> + * The ifpga_sec_mgr struct allocated with this function will be freed
>>> + * automatically on driver detach.  This includes the case of a probe
>>> + * function returning error before calling fpga_mgr_register(), the
>>> + * struct will still get cleaned up.
>>> + *
>>> + * Return: pointer to struct ifpga_sec_mgr or NULL
>>> + */
>>> +struct ifpga_sec_mgr *
>>> +devm_ifpga_sec_mgr_create(struct device *dev, const char *name,
>>> +  const struct ifpga_sec_mgr_ops *iops, void *priv)
>>> +{
>>> +struct ifpga_sec_mgr **ptr, *imgr;
>>> +
>>> +ptr = devres_alloc(devm_ifpga_sec_mgr_release, sizeof(*ptr),
>>> GFP_KERNEL);
>>> +if (!ptr)
>>> +return NULL;
>>> +
>>> +imgr = ifpga_sec_mgr_create(dev, name, iops, priv);
>>> +if (!imgr) {
>>> +devres_free(ptr);
>>> +} else {
>>> +*ptr = imgr;
>>> +devres_add(dev, ptr);
>>> +}
>>> +
>>> +return imgr;
>>> +}
>>> +EXPORT_SYMBOL_GPL(devm_ifpga_sec_mgr_create);
>>> +
>>> +/**
>>> + * ifpga_sec_mgr_register - register an Intel FPGA security manager
>>> + *
>>> + * @imgr: Intel fpga security manager struct
>>> + *
>>> + * Return: 0 on success, negative error code otherwise.
>>> + */
>>> +int ifpga_sec_mgr_register(struct ifpga_sec_mgr *imgr)
>>> +{
>>> +int ret;
>>> +
>>> +ret = device_add(&imgr->dev);
>>> +if (ret)
>>> +goto error_device;
>>> +
>>> +dev_info(&imgr->dev, "%s registered\n", imgr->name);
>>> +
>>> +return 0;
>>> +
>>> +error_device:
>>> +ida_simple_remove(&ifpga_sec_mgr_ida, imgr->dev.id);
>>> +
>>> +return ret;
>>> +}
>>> +EXPORT_SYMBOL_GPL(ifpga_sec_mgr_register);
>>> +
>>> +/**
>>> + * ifpga_sec_mgr_unregister - unregister an Intel FPGA security manager
>>> + *
>>> + * @mgr: fpga manager struct
>>> + *
>>> + * This function is intended for use in an Intel FPGA security manager
>>> + * driver's remove() function.
>>> + */
>>> +void ifpga_sec_mgr_unregister(struct ifpga_sec_mgr *imgr)
>>> +{
>>> +dev_info(&imgr->dev, "%s %s\n", __func__, imgr->name);
>>> +
>>> +device_unregister(&imgr->dev);
>>> +}
>>> +EXPORT_SYMBOL_GPL(ifpga_sec_mgr_unregister);
>>> +
>>> +static void ifpga_sec_mgr_dev_release(struct device *dev)
>>> +{
>>> +}
>>> +
>>> +static int __init ifpga_sec_mgr_class_init(void)
>>> +{
>>> +pr_info("Intel FPGA Security Manager\n");
>>> +
>>> +ifpga_sec_mgr_class = class_create(THIS_MODULE, "ifpga_sec_mgr");
>>> +if (IS_ERR(ifpga_sec_mgr_class))
>>> +return PTR_ERR(ifpga_sec_mgr_class);
>>> +
>>> +ifpga_sec_mgr_class->dev_groups = ifpga_sec_mgr_attr_groups;
>>> +ifpga_sec_mgr_class->dev_release = ifpga_sec_mgr_dev_release;
>>> +
>>> +return 0;
>>> +}
>>> +
>>> +static void __exit ifpga_sec_mgr_class_exit(void)
>>> +{
>>> +class_destroy(ifpga_sec_mgr_class);
>>> +ida_destroy(&ifpga_sec_mgr_ida);
>>> +}
>>> +
>>> +MODULE_DESCRIPTION("Intel FPGA Security Manager Driver");
>>> +MODULE_LICENSE("GPL v2");
>>> +
>>> +subsys_initcall(ifpga_sec_mgr_class_init);
>>> +module_exit(ifpga_sec_mgr_class_exit)
>>> diff --git a/include/linux/fpga/ifpga-sec-mgr.h b/include/linux/fpga/ifpga-
>>> sec-mgr.h
>>> new file mode 100644
>>> index 000000000000..ded62090e9b9
>>> --- /dev/null
>>> +++ b/include/linux/fpga/ifpga-sec-mgr.h
>>> @@ -0,0 +1,81 @@
>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>> +/*
>>> + * Header file for Intel FPGA Security Manager
>>> + *
>>> + * Copyright (C) 2019-2020 Intel Corporation, Inc.
>>> + */
>>> +#ifndef _LINUX_IFPGA_SEC_MGR_H
>>> +#define _LINUX_IFPGA_SEC_MGR_H
>>> +
>>> +#include <linux/device.h>
>>> +#include <linux/mutex.h>
>>> +#include <linux/types.h>
>>> +
>>> +struct ifpga_sec_mgr;
>>> +
>>> +/**
>>> + * struct ifpga_sec_mgr_ops - device specific operations
>>> + * @user_flash_count:    Optional: Return sysfs string output for
>>> FPGA
>>> + *    image flash count
>>> + * @sr_root_entry_hash:    Optional: Return sysfs string output for
>>> static
>>> + *    region root entry hash
>>> + * @pr_root_entry_hash:    Optional: Return sysfs string output for
>>> partial
>>> + *    reconfiguration root entry hash
>>> + * @bmc_root_entry_hash:    Optional: Return sysfs string output for BMC
>>> + *    root entry hash
>>> + * @sr_canceled_csks:    Optional: Return sysfs string output for static
>>> + *    region canceled keys
>>> + * @pr_canceled_csks:    Optional: Return sysfs string output for
>>> partial
>>> + *    reconfiguration canceled keys
>>> + * @bmc_canceled_csks:    Optional: Return sysfs string output for
>>> bmc
>>> + *    canceled keys
>>> + * @bmc_canceled_csk_nbits: Optional: Return BMC canceled csk vector bit
>>> count
>>> + * @sr_canceled_csk_nbits:  Optional: Return SR canceled csk vector bit
>>> count
>>> + * @pr_canceled_csk_nbits:  Optional: Return PR canceled csk vector bit
>>> count
>>> + * @bmc_reh_size:    Optional: Return byte size for BMC root entry hash
>>> + * @sr_reh_size:    Optional: Return byte size for SR root entry hash
>>> + * @pr_reh_size:    Optional: Return byte size for PR root entry hash
>>> + */
>>> +struct ifpga_sec_mgr_ops {
>>> +int (*user_flash_count)(struct ifpga_sec_mgr *imgr);
>>> +int (*bmc_root_entry_hash)(struct ifpga_sec_mgr *imgr, u8 *hash,
>>> +   unsigned int size);
>>> +int (*sr_root_entry_hash)(struct ifpga_sec_mgr *imgr, u8 *hash,
>>> +  unsigned int size);
>>> +int (*pr_root_entry_hash)(struct ifpga_sec_mgr *imgr, u8 *hash,
>>> +  unsigned int size);
>>> +int (*bmc_canceled_csks)(struct ifpga_sec_mgr *imgr,
>>> + unsigned long *csk_map, unsigned int nbits);
>>> +int (*sr_canceled_csks)(struct ifpga_sec_mgr *imgr,
>>> +unsigned long *csk_map, unsigned int nbits);
>>> +int (*pr_canceled_csks)(struct ifpga_sec_mgr *imgr,
>>> +unsigned long *csk_map, unsigned int nbits);
>>> +int (*bmc_reh_size)(struct ifpga_sec_mgr *imgr);
>>> +int (*sr_reh_size)(struct ifpga_sec_mgr *imgr);
>>> +int (*pr_reh_size)(struct ifpga_sec_mgr *imgr);
>>> +int (*bmc_canceled_csk_nbits)(struct ifpga_sec_mgr *imgr);
>>> +int (*sr_canceled_csk_nbits)(struct ifpga_sec_mgr *imgr);
>>> +int (*pr_canceled_csk_nbits)(struct ifpga_sec_mgr *imgr);
>> I am thinking that if these callbacks for size are really needed or not.
>> If these size values are not changed dynamically, which requires no
>> recalculation, then these size values can be stored in ifpga sec mgr
>> data structure directly. I think the checking logic could be simpler too.
>> Do you think if it is possible?
> Yes - it is possible. The size could be calculated before creating the security
> manager. It just means that the iops data structure has to be dynamically created.
> As it turns out, we need to do that (eventually) anyway to handle some differences
> between the n3000 and the d5005 devices, so I can code up the changes and see
> how it looks.
Actually - I remember now why we did it this way. If a root entry hash is not
programmed, the then size of the hash (which is read from FLASH) is zero. Once a
root entry has is programmed, then the size becomes non-zero. So, for root entry
hashes, the size can change after the driver has loaded. So I think we need to
leave it this way.

>> Thanks
>> Hao
>>
>>> +};
>>> +
>>> +struct ifpga_sec_mgr {
>>> +const char *name;
>>> +struct device dev;
>>> +const struct ifpga_sec_mgr_ops *iops;
>>> +struct mutex lock;/* protect data structure contents */
>>> +void *priv;
>>> +};
>>> +
>>> +struct ifpga_sec_mgr *
>>> +ifpga_sec_mgr_create(struct device *dev, const char *name,
>>> +     const struct ifpga_sec_mgr_ops *iops, void *priv);
>>> +
>>> +struct ifpga_sec_mgr *
>>> +devm_ifpga_sec_mgr_create(struct device *dev, const char *name,
>>> +  const struct ifpga_sec_mgr_ops *iops, void *priv);
>>> +
>>> +int ifpga_sec_mgr_register(struct ifpga_sec_mgr *imgr);
>>> +void ifpga_sec_mgr_unregister(struct ifpga_sec_mgr *imgr);
>>> +void ifpga_sec_mgr_free(struct ifpga_sec_mgr *imgr);
>>> +
>>> +#endif
>>> --
>>> 2.17.1