On 11/15/20 12:03 PM, Moritz Fischer wrote:
> On Fri, Nov 13, 2020 at 04:55:56PM -0800, Russ Weight wrote:
>> Extend the MAX10 BMC Secure Update driver to provide a
>> sysfs file to expose the flash update count for the FPGA
>> user image.
>>
>> Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
>> Reviewed-by: Tom Rix <trix@xxxxxxxxxx>
>> ---
>> v5:
>> - Renamed sysfs node user_flash_count to flash_count and updated the
>> sysfs documentation accordingly.
>> v4:
>> - Moved the sysfs file for displaying the flash count from the
>> FPGA Security Manager class driver to here. The
>> m10bmc_user_flash_count() function is removed and the
>> functionality is moved into a user_flash_count_show()
>> function.
>> - Added ABI documentation for the new sysfs entry
>> v3:
>> - Changed: iops -> sops, imgr -> smgr, IFPGA_ -> FPGA_, ifpga_ to fpga_
>> - Changed "MAX10 BMC Secure Engine driver" to "MAX10 BMC Secure Update
>> driver"
>> - Removed wrapper functions (m10bmc_raw_*, m10bmc_sys_*). The
>> underlying functions are now called directly.
>> v2:
>> - Renamed get_qspi_flash_count() to m10bmc_user_flash_count()
>> - Minor code cleanup per review comments
>> - Added m10bmc_ prefix to functions in m10bmc_iops structure
>> ---
>> .../testing/sysfs-driver-intel-m10-bmc-secure | 8 +++++
>> drivers/fpga/intel-m10-bmc-secure.c | 34 +++++++++++++++++++
>> 2 files changed, 42 insertions(+)
>>
>> diff --git a/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc-secure b/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc-secure
>> index 2992488b717a..73a3aba750e8 100644
>> --- a/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc-secure
>> +++ b/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc-secure
>> @@ -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: "0x%x".
>> +
>> +What: /sys/bus/platform/devices/n3000bmc-secure.*.auto/security/flash_count
>> +Date: Oct 2020
>> +KernelVersion: 5.11
>> +Contact: Russ Weight <russell.h.weight@xxxxxxxxx>
>> +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-secure.c b/drivers/fpga/intel-m10-bmc-secure.c
>> index 198bc8273d6b..6ad897001086 100644
>> --- a/drivers/fpga/intel-m10-bmc-secure.c
>> +++ b/drivers/fpga/intel-m10-bmc-secure.c
>> @@ -11,6 +11,7 @@
>> #include <linux/mfd/intel-m10-bmc.h>
>> #include <linux/module.h>
>> #include <linux/platform_device.h>
>> +#include <linux/slab.h>
>>
>> struct m10bmc_sec {
>> struct device *dev;
>> @@ -77,7 +78,40 @@ 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 = regmap_get_reg_stride(sec->m10bmc->regmap);
>> + unsigned int num_bits = FLASH_COUNT_SIZE * 8;
>> + u8 *flash_buf;
>> + int cnt, ret;
> (Nit) Can you make this:
>
> 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;
Sure - I'll make the change. Thanks,
- Russ
>
>
>> +
>> + flash_buf = kmalloc(FLASH_COUNT_SIZE, GFP_KERNEL);
>> + if (!flash_buf)
>> + return -ENOMEM;
>> +
>> + 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,
>> --
>> 2.25.1
>>
> Otherwise looks good to me,
>
> - Moritz
