From 154afa5c31cd2de5e6c2c4f35eee390993ee345a Mon Sep 17 00:00:00 2001 From: Russ Weight Date: Mon, 6 Jun 2022 09:00:36 -0700 Subject: [PATCH] fpga: m10bmc-sec: expose max10 flash update count Extend the MAX10 BMC Secure Update driver to provide a sysfs file to expose the flash update count. Reviewed-by: Tom Rix Tested-by: Tianfei Zhang Signed-off-by: Russ Weight Link: https://lore.kernel.org/r/20220606160038.846236-4-russell.h.weight@intel.com Signed-off-by: Xu Yilun --- .../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 +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,