Re: [PATCH v1 03/12] fpga: expose max10 flash update counts in sysfs

Tom Rix
2020-09-05T20:40:03Z

On 9/4/20 4:52 PM, Russ Weight wrote:
> Extend the MAX10 BMC Security Engine driver to provide a
> handler to expose the flash update count for the FPGA user
> image.
>
> Signed-off-by: Russ Weight <russell.h.weight@intel.com>
> Reviewed-by: Wu Hao <hao.wu@intel.com>
> ---
> drivers/fpga/intel-m10-bmc-secure.c | 32 +++++++++++++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/drivers/fpga/intel-m10-bmc-secure.c b/drivers/fpga/intel-m10-bmc-secure.c
> index 1f86bfb694b4..b824790e43aa 100644
> --- a/drivers/fpga/intel-m10-bmc-secure.c
> +++ b/drivers/fpga/intel-m10-bmc-secure.c
> @@ -10,6 +10,7 @@
> #include <linux/mfd/intel-m10-bmc.h>
> #include <linux/module.h>
> #include <linux/platform_device.h>
> +#include <linux/slab.h>
> #include <linux/vmalloc.h>
>
> struct m10bmc_sec {
> @@ -99,7 +100,38 @@ SYSFS_GET_REH(bmc, BMC_REH_ADDR)
> SYSFS_GET_REH(sr, SR_REH_ADDR)
> SYSFS_GET_REH(pr, PR_REH_ADDR)
>
> +#define FLASH_COUNT_SIZE 4096
This seems too high at most it should be 64.
> +#define USER_FLASH_COUNT 0x17ffb000
Why shouldn't this be in intel-m10-bmc.h ?
> +
> +static int get_qspi_flash_count(struct ifpga_sec_mgr *imgr)

what does 'qspi' mean ?

unless there are going to be several *flash_count's consider

removing this substring.

> +{
> + struct m10bmc_sec *sec = imgr->priv;
> + unsigned int stride = regmap_get_reg_stride(sec->m10bmc->regmap);
> + unsigned int cnt, num_bits = FLASH_COUNT_SIZE * 8;
> + u8 *flash_buf;
> + int ret;
> +
> + flash_buf = kmalloc(FLASH_COUNT_SIZE, GFP_KERNEL);
> + if (!flash_buf)
> + return -ENOMEM;
> +
> + ret = m10bmc_raw_bulk_read(sec->m10bmc, USER_FLASH_COUNT, flash_buf,
> + FLASH_COUNT_SIZE / stride);
> + if (ret) {
> + dev_err(sec->dev, "%s failed to read %d\n", __func__, ret);
> + goto exit_free;
> + }
> +
> + cnt = num_bits - bitmap_weight((unsigned long *)flash_buf, num_bits);
Simplify ret = num_bits...
> +
> +exit_free:
> + kfree(flash_buf);
> +
> + return ret ? : cnt;

Then simplify

return ret;

Tom

> +}
> +
> static const struct ifpga_sec_mgr_ops m10bmc_iops = {
> + .user_flash_count = get_qspi_flash_count,
> .bmc_root_entry_hash = get_bmc_root_entry_hash,
> .sr_root_entry_hash = get_sr_root_entry_hash,
> .pr_root_entry_hash = get_pr_root_entry_hash,