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>
diff --git a/drivers/fpga/intel-m10-bmc-sec-update.c b/drivers/fpga/intel-m10-bmc-sec-update.c
index f9f39d2..25b21f1 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,
