From 154afa5c31cd2de5e6c2c4f35eee390993ee345a Mon Sep 17 00:00:00 2001
From: Russ Weight <russell.h.weight@intel.com>
Date: Mon, 6 Jun 2022 09:00:36 -0700
Subject: [PATCH] fpga: m10bmc-sec: expose max10 flash update count
Git-commit: 154afa5c31cd2de5e6c2c4f35eee390993ee345a
Patch-mainline: v6.0-rc1
References: jsc#PED-1263

Extend the MAX10 BMC Secure Update driver to provide a sysfs file to
expose the flash update count.

Reviewed-by: Tom Rix <trix@redhat.com>
Tested-by: Tianfei Zhang <tianfei.zhang@intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Link: https://lore.kernel.org/r/20220606160038.846236-4-russell.h.weight@intel.com
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 .../sysfs-driver-intel-m10-bmc-sec-update     |  8 ++++
 drivers/fpga/intel-m10-bmc-sec-update.c       | 43 +++++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc-sec-update b/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc-sec-update
index a208367e6956..6114e15885e5 100644
--- a/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc-sec-update
+++ b/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc-sec-update
@@ -27,3 +27,11 @@ Description:	Read only. Returns the root entry hash for the BMC image
 		"hash not programmed".  This file is only visible if the
 		underlying device supports it.
 		Format: string.
+
+What:		/sys/bus/platform/drivers/intel-m10bmc-sec-update/.../security/flash_count
+Date:		Sep 2022
+KernelVersion:	5.20
+Contact:	Russ Weight <russell.h.weight@intel.com>
+Description:	Read only. Returns number of times the secure update
+		staging area has been flashed.
+		Format: "%u".
diff --git a/drivers/fpga/intel-m10-bmc-sec-update.c b/drivers/fpga/intel-m10-bmc-sec-update.c
index f9f39d2cfe5b..25b21f116976 100644
--- a/drivers/fpga/intel-m10-bmc-sec-update.c
+++ b/drivers/fpga/intel-m10-bmc-sec-update.c
@@ -78,7 +78,50 @@ DEVICE_ATTR_SEC_REH_RO(bmc, BMC_PROG_MAGIC, BMC_PROG_ADDR, BMC_REH_ADDR);
 DEVICE_ATTR_SEC_REH_RO(sr, SR_PROG_MAGIC, SR_PROG_ADDR, SR_REH_ADDR);
 DEVICE_ATTR_SEC_REH_RO(pr, PR_PROG_MAGIC, PR_PROG_ADDR, PR_REH_ADDR);
 
+#define FLASH_COUNT_SIZE 4096	/* count stored as inverted bit vector */
+
+static ssize_t flash_count_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct m10bmc_sec *sec = dev_get_drvdata(dev);
+	unsigned int stride, num_bits;
+	u8 *flash_buf;
+	int cnt, ret;
+
+	stride = regmap_get_reg_stride(sec->m10bmc->regmap);
+	num_bits = FLASH_COUNT_SIZE * 8;
+
+	flash_buf = kmalloc(FLASH_COUNT_SIZE, GFP_KERNEL);
+	if (!flash_buf)
+		return -ENOMEM;
+
+	if (FLASH_COUNT_SIZE % stride) {
+		dev_err(sec->dev,
+			"FLASH_COUNT_SIZE (0x%x) not aligned to stride (0x%x)\n",
+			FLASH_COUNT_SIZE, stride);
+		WARN_ON_ONCE(1);
+		return -EINVAL;
+	}
+
+	ret = regmap_bulk_read(sec->m10bmc->regmap, STAGING_FLASH_COUNT,
+			       flash_buf, FLASH_COUNT_SIZE / stride);
+	if (ret) {
+		dev_err(sec->dev,
+			"failed to read flash count: %x cnt %x: %d\n",
+			STAGING_FLASH_COUNT, FLASH_COUNT_SIZE / stride, ret);
+		goto exit_free;
+	}
+	cnt = num_bits - bitmap_weight((unsigned long *)flash_buf, num_bits);
+
+exit_free:
+	kfree(flash_buf);
+
+	return ret ? : sysfs_emit(buf, "%u\n", cnt);
+}
+static DEVICE_ATTR_RO(flash_count);
+
 static struct attribute *m10bmc_security_attrs[] = {
+	&dev_attr_flash_count.attr,
 	&dev_attr_bmc_root_entry_hash.attr,
 	&dev_attr_sr_root_entry_hash.attr,
 	&dev_attr_pr_root_entry_hash.attr,
-- 
2.35.3