Re: [PATCH v2 16/19] tools/testing/cxl: add mechanism to lock mem device for testing

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Wed, 21 Sep 2022 08:33:03 -0700
Dave Jiang <dave.jiang@intel.com> wrote:

> The mock cxl mem devs needs a way to go into "locked" status to simulate
> when the platform is rebooted. Add a sysfs mechanism so the device security
> state is set to "locked" and the frozen state bits are cleared.
> 
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Hi Dave

A few minor comments below.

> ---
>  tools/testing/cxl/test/cxl.c |   52 ++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 50 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
> index 6dd286a52839..7f76f494a0d4 100644
> --- a/tools/testing/cxl/test/cxl.c
> +++ b/tools/testing/cxl/test/cxl.c
> @@ -628,6 +628,45 @@ static void mock_companion(struct acpi_device *adev, struct device *dev)
>  #define SZ_512G (SZ_64G * 8)
>  #endif
>  
> +static ssize_t security_lock_show(struct device *dev,
> +				  struct device_attribute *attr, char *buf)
> +{
> +	struct cxl_mock_mem_pdata *mdata = dev_get_platdata(dev);
> +
> +	return sysfs_emit(buf, "%s\n", mdata->security_state & CXL_PMEM_SEC_STATE_LOCKED ?
> +			  "locked" : "unlocked");

It's called lock. So 1 or 0 seems sufficient to me rather than needing strings.
Particularly when you use an int to lock it.

> +}
> +
> +static ssize_t security_lock_store(struct device *dev, struct device_attribute *attr,
> +				   const char *buf, size_t count)
> +{
> +	struct cxl_mock_mem_pdata *mdata = dev_get_platdata(dev);
> +	u32 mask = CXL_PMEM_SEC_STATE_FROZEN | CXL_PMEM_SEC_STATE_USER_PLIMIT |
> +		   CXL_PMEM_SEC_STATE_MASTER_PLIMIT;
> +	int val;
> +
> +	if (kstrtoint(buf, 0, &val) < 0)
> +		return -EINVAL;
> +
> +	if (val == 1) {
> +		if (!(mdata->security_state & CXL_PMEM_SEC_STATE_USER_PASS_SET))
> +			return -ENXIO;
> +		mdata->security_state |= CXL_PMEM_SEC_STATE_LOCKED;
> +		mdata->security_state &= ~mask;
> +	} else {
> +		return -EINVAL;
> +	}
> +	return count;
> +}
> +
> +static DEVICE_ATTR_RW(security_lock);
> +
> +static struct attribute *cxl_mock_mem_attrs[] = {
> +	&dev_attr_security_lock.attr,
> +	NULL
> +};
> +ATTRIBUTE_GROUPS(cxl_mock_mem);
> +
>  static __init int cxl_test_init(void)
>  {
>  	struct cxl_mock_mem_pdata *mem_pdata;
> @@ -757,6 +796,11 @@ static __init int cxl_test_init(void)
>  			platform_device_put(pdev);
>  			goto err_mem;
>  		}
> +
> +		rc = device_add_groups(&pdev->dev, cxl_mock_mem_groups);

Can we just set pdev->dev.groups? and avoid dynamic part of this or need to
remove them manually?   I can't immediately find an example of this for
a platform_device but it's done for lots of other types.


> +		if (rc)
> +			goto err_mem;
> +
>  		cxl_mem[i] = pdev;
>  	}
>  
> @@ -811,8 +855,12 @@ static __exit void cxl_test_exit(void)
>  	int i;
>  
>  	platform_device_unregister(cxl_acpi);
> -	for (i = ARRAY_SIZE(cxl_mem) - 1; i >= 0; i--)
> -		platform_device_unregister(cxl_mem[i]);
> +	for (i = ARRAY_SIZE(cxl_mem) - 1; i >= 0; i--) {
> +		struct platform_device *pdev = cxl_mem[i];
> +
> +		device_remove_groups(&pdev->dev, cxl_mock_mem_groups);
> +		platform_device_unregister(pdev);
> +	}
>  	for (i = ARRAY_SIZE(cxl_switch_dport) - 1; i >= 0; i--)
>  		platform_device_unregister(cxl_switch_dport[i]);
>  	for (i = ARRAY_SIZE(cxl_switch_uport) - 1; i >= 0; i--)
> 
>