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 <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>
This commit is contained in:
Russ Weight 2022-06-06 09:00:36 -07:00 committed by Xu Yilun
parent bdf86d0e6c
commit 154afa5c31
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2 changed files with 51 additions and 0 deletions

View File

@ -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".

View File

@ -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,