[PATCH v1 02/12] fpga: create intel max10 bmc security engine

[Russ Weight <russell.h.weight@intel.com>]

Create a platform driver that can be invoked as a sub
driver for the Intel MAX10 BMC in order to support
secure updates. This sub-driver will invoke an
instance of the Intel FPGA Security Manager class driver
in order to expose sysfs interfaces for managing and
monitoring secure updates to FPGA and BMC images.

This patch creates the MAX10 BMC Security Engine driver and
provides support for displaying the current root entry hashes
for the FPGA static region, the FPGA PR region, and the MAX10
BMC.

Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Wu Hao <hao.wu@intel.com>
---
 drivers/fpga/Kconfig                |  11 ++
 drivers/fpga/Makefile               |   3 +
 drivers/fpga/intel-m10-bmc-secure.c | 170 ++++++++++++++++++++++++++++
 include/linux/mfd/intel-m10-bmc.h   |  15 +++
 4 files changed, 199 insertions(+)
 create mode 100644 drivers/fpga/intel-m10-bmc-secure.c

diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index 97c0a6cc2ba7..0f0bed68e618 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -244,4 +244,15 @@ config IFPGA_SEC_MGR
 	  region and for the BMC. Select this option to enable
 	  updates for secure FPGA devices.
 
+config IFPGA_M10_BMC_SECURE
+        tristate "Intel MAX10 BMC security engine"
+	depends on MFD_INTEL_M10_BMC && IFPGA_SEC_MGR
+        help
+          Secure update support for the Intel MAX10 board management
+	  controller.
+
+	  This is a subdriver of the Intel MAX10 board management controller
+	  (BMC) and provides support for secure updates for the BMC image,
+	  the FPGA image, the Root Entry Hashes, etc.
+
 endif # FPGA
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index ec9fbacdedd8..451a23ec3168 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -24,6 +24,9 @@ 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
 
+# Intel Security Manager Drivers
+obj-$(CONFIG_IFPGA_M10_BMC_SECURE)	+= intel-m10-bmc-secure.o
+
 # FPGA Bridge Drivers
 obj-$(CONFIG_FPGA_BRIDGE)		+= fpga-bridge.o
 obj-$(CONFIG_SOCFPGA_FPGA_BRIDGE)	+= altera-hps2fpga.o altera-fpga2sdram.o
diff --git a/drivers/fpga/intel-m10-bmc-secure.c b/drivers/fpga/intel-m10-bmc-secure.c
new file mode 100644
index 000000000000..1f86bfb694b4
--- /dev/null
+++ b/drivers/fpga/intel-m10-bmc-secure.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel Max10 Board Management Controller Security Engine Driver
+ *
+ * Copyright (C) 2019-2020 Intel Corporation. All rights reserved.
+ *
+ */
+#include <linux/device.h>
+#include <linux/fpga/ifpga-sec-mgr.h>
+#include <linux/mfd/intel-m10-bmc.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/vmalloc.h>
+
+struct m10bmc_sec {
+	struct device *dev;
+	struct intel_m10bmc *m10bmc;
+	struct ifpga_sec_mgr *imgr;
+};
+
+#define SHA256_REH_SIZE		32
+#define SHA384_REH_SIZE		48
+
+static int get_reh_size(struct ifpga_sec_mgr *imgr,
+			u32 exp_magic, u32 prog_addr)
+{
+	struct m10bmc_sec *sec = imgr->priv;
+	int sha_num_bytes, ret;
+	u32 magic;
+
+	ret = m10bmc_raw_read(sec->m10bmc, prog_addr, &magic);
+	if (ret)
+		return ret;
+
+	dev_dbg(sec->dev, "%s magic 0x%08x\n", __func__, magic);
+
+	if ((magic & 0xffff) != exp_magic)
+		return 0;
+
+	sha_num_bytes = ((magic >> 16) & 0xffff) / 8;
+
+	if (sha_num_bytes != SHA256_REH_SIZE &&
+	    sha_num_bytes != SHA384_REH_SIZE)   {
+		dev_err(sec->dev, "%s bad sha num bytes %d\n", __func__,
+			sha_num_bytes);
+		return -EINVAL;
+	}
+
+	return sha_num_bytes;
+}
+
+#define BMC_REH_ADDR 0x17ffc004
+#define BMC_PROG_ADDR 0x17ffc000
+#define BMC_PROG_MAGIC 0x5746
+
+#define SR_REH_ADDR 0x17ffd004
+#define SR_PROG_ADDR 0x17ffd000
+#define SR_PROG_MAGIC 0x5253
+
+#define PR_REH_ADDR 0x17ffe004
+#define PR_PROG_ADDR 0x17ffe000
+#define PR_PROG_MAGIC 0x5250
+
+#define SYSFS_GET_REH_SIZE(_name, _exp_magic, _prog_addr) \
+static int get_##_name##_reh_size(struct ifpga_sec_mgr *imgr) \
+{ \
+	return get_reh_size(imgr, _exp_magic, _prog_addr); \
+}
+
+SYSFS_GET_REH_SIZE(bmc, BMC_PROG_MAGIC, BMC_PROG_ADDR)
+SYSFS_GET_REH_SIZE(sr, SR_PROG_MAGIC, SR_PROG_ADDR)
+SYSFS_GET_REH_SIZE(pr, PR_PROG_MAGIC, PR_PROG_ADDR)
+
+static int get_root_entry_hash(struct ifpga_sec_mgr *imgr,
+			       u32 hash_addr, u8 *hash,
+			       unsigned int size)
+{
+	struct m10bmc_sec *sec = imgr->priv;
+	unsigned int stride = regmap_get_reg_stride(sec->m10bmc->regmap);
+	int ret;
+
+	ret = m10bmc_raw_bulk_read(sec->m10bmc, hash_addr,
+				   hash, size / stride);
+	if (ret)
+		dev_err(sec->dev, "bulk_read of 0x%x failed %d",
+			hash_addr, ret);
+
+	return ret;
+}
+
+#define SYSFS_GET_REH(_name, _hash_addr) \
+static int get_##_name##_root_entry_hash(struct ifpga_sec_mgr *imgr, \
+					 u8 *hash, unsigned int size) \
+{ \
+	return get_root_entry_hash(imgr, _hash_addr, hash, size); \
+}
+
+SYSFS_GET_REH(bmc, BMC_REH_ADDR)
+SYSFS_GET_REH(sr, SR_REH_ADDR)
+SYSFS_GET_REH(pr, PR_REH_ADDR)
+
+static const struct ifpga_sec_mgr_ops m10bmc_iops = {
+	.bmc_root_entry_hash = get_bmc_root_entry_hash,
+	.sr_root_entry_hash = get_sr_root_entry_hash,
+	.pr_root_entry_hash = get_pr_root_entry_hash,
+	.bmc_reh_size = get_bmc_reh_size,
+	.sr_reh_size = get_sr_reh_size,
+	.pr_reh_size = get_pr_reh_size,
+};
+
+static void ifpga_sec_mgr_uinit(struct m10bmc_sec *sec)
+{
+	ifpga_sec_mgr_unregister(sec->imgr);
+}
+
+static int ifpga_sec_mgr_init(struct m10bmc_sec *sec)
+{
+	struct ifpga_sec_mgr *imgr;
+
+	imgr = ifpga_sec_mgr_register(sec->dev, "Max10 BMC Security Manager",
+				      &m10bmc_iops, sec);
+	if (IS_ERR(imgr))
+		return PTR_ERR(imgr);
+
+	sec->imgr = imgr;
+	return 0;
+}
+
+static int m10bmc_secure_probe(struct platform_device *pdev)
+{
+	struct m10bmc_sec *sec;
+	int ret;
+
+	sec = devm_kzalloc(&pdev->dev, sizeof(*sec), GFP_KERNEL);
+	if (!sec)
+		return -ENOMEM;
+
+	sec->dev = &pdev->dev;
+	sec->m10bmc = dev_get_drvdata(pdev->dev.parent);
+	dev_set_drvdata(&pdev->dev, sec);
+
+	ret = ifpga_sec_mgr_init(sec);
+	if (ret)
+		dev_err(&pdev->dev,
+			"Security manager failed to start: %d\n", ret);
+
+	return ret;
+}
+
+static int m10bmc_secure_remove(struct platform_device *pdev)
+{
+	struct m10bmc_sec *sec = dev_get_drvdata(&pdev->dev);
+
+	ifpga_sec_mgr_uinit(sec);
+	return 0;
+}
+
+static struct platform_driver intel_m10bmc_secure_driver = {
+	.probe = m10bmc_secure_probe,
+	.remove = m10bmc_secure_remove,
+	.driver = {
+		.name = "n3000bmc-secure",
+	},
+};
+module_platform_driver(intel_m10bmc_secure_driver);
+
+MODULE_ALIAS("platform:n3000bmc-secure");
+MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("Intel MAX10 BMC secure engine");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/intel-m10-bmc.h b/include/linux/mfd/intel-m10-bmc.h
index d4cb01b73357..7fe465c320c2 100644
--- a/include/linux/mfd/intel-m10-bmc.h
+++ b/include/linux/mfd/intel-m10-bmc.h
@@ -63,6 +63,7 @@ struct intel_m10bmc {
  * register access helper functions.
  *
  * m10bmc_raw_read - read m10bmc register per addr
+ * m10bmc_raw_bulk_read - bulk_read max10 registers per addr
  * m10bmc_sys_read - read m10bmc system register per offset
  */
 static inline int
@@ -79,6 +80,20 @@ m10bmc_raw_read(struct intel_m10bmc *m10bmc, unsigned int addr,
 	return ret;
 }
 
+static inline int
+m10bmc_raw_bulk_read(struct intel_m10bmc *m10bmc, unsigned int addr,
+		     void *val, size_t cnt)
+{
+	int ret;
+
+	ret = regmap_bulk_read(m10bmc->regmap, addr, val, cnt);
+	if (ret)
+		dev_err(m10bmc->dev, "fail to read raw reg %x cnt %zx: %d\n",
+			addr, cnt, ret);
+
+	return ret;
+}
+
 #define m10bmc_sys_read(m10bmc, offset, val) \
 	m10bmc_raw_read(m10bmc, M10BMC_SYS_BASE + (offset), val)
 
-- 
2.17.1