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Message-ID: <d29feeca-fff1-36c5-2ce5-4f8664fb487b@intel.com>
Date: Fri, 2 Oct 2020 16:03:59 -0700
From: Russ Weight <russell.h.weight@...el.com>
To: mdf@...nel.org, linux-fpga@...r.kernel.org,
linux-kernel@...r.kernel.org
Cc: trix@...hat.com, lgoncalv@...hat.com, yilun.xu@...el.com,
hao.wu@...el.com, matthew.gerlach@...el.com
Subject: Re: [PATCH v2 1/7] fpga: sec-mgr: intel fpga security manager class
driver
Hi Moritz,
This patch aligns with FPGA Manager implementation as you requested by
splitting up the create() and register() functions and adding a devm_
version of the create() function. I have a question (below) regarding the
device_add() function call.
On 10/2/20 3:36 PM, Russ Weight wrote:
> 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@...el.com>
> Signed-off-by: Xu Yilun <yilun.xu@...el.com>
> ---
> 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@...el.com>
> +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@...el.com>
> +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@...el.com>
> +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@...el.com>
> +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@...el.com>
> +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@...el.com>
> +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@...el.com>
> +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@...el.com>
> +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@...el.com>
> +L: linux-fpga@...r.kernel.org
> +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@...bpc.org.au>
> 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;
> + }
> + 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;
The comment header for device_add() includes the following text:
* NOTE: _Never_ directly free @dev after calling this function, even
* if it returned an error! Always use put_device() to give up your
* reference instead.
*
* Rule of thumb is: if device_add() succeeds, you should call
* device_del() when you want to get rid of it. If device_add() has
* *not* succeeded, use *only* put_device() to drop the reference
* count.
This implementation of the security manager requires that the parent
driver (which implements the security manager) explicitly free the
ifpga_sec_mgr structure or implicitly free it as a managed resource
(of the parent device) using the devm_ version of the create() function.
The device structure that is passed to device_add() above is embedded
in the ifpga_sec_mgr structure.
Does this implementation conflict with the core driver functions?
Is it possible that we are deleting a device structure that is still
being tracked by the core driver code?
- Russ
> +
> + 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);
> +};
> +
> +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
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