[PATCH 06/25] powerpc: cleaup AMR, iAMR when a key is allocated or freed

[Aneesh Kumar K.V]

Balbir Singh <bsingharora at gmail.com> writes:

> On Fri,  8 Sep 2017 15:44:54 -0700
> Ram Pai <linuxram at us.ibm.com> wrote:
>
>> cleanup the bits corresponding to a key in the AMR, and IAMR
>> register, when the key is newly allocated/activated or is freed.
>> We dont want some residual bits cause the hardware enforce
>> unintended behavior when the key is activated or freed.
>> 
>> Signed-off-by: Ram Pai <linuxram at us.ibm.com>
>> ---
>>  arch/powerpc/include/asm/pkeys.h |   12 ++++++++++++
>>  1 files changed, 12 insertions(+), 0 deletions(-)
>> 
>> diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
>> index 5a83ed7..53bf13b 100644
>> --- a/arch/powerpc/include/asm/pkeys.h
>> +++ b/arch/powerpc/include/asm/pkeys.h
>> @@ -54,6 +54,8 @@ static inline bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey)
>>  		mm_set_pkey_is_allocated(mm, pkey));
>>  }
>>  
>> +extern void __arch_activate_pkey(int pkey);
>> +extern void __arch_deactivate_pkey(int pkey);
>>  /*
>>   * Returns a positive, 5-bit key on success, or -1 on failure.
>>   */
>> @@ -80,6 +82,12 @@ static inline int mm_pkey_alloc(struct mm_struct *mm)
>>  
>>  	ret = ffz((u32)mm_pkey_allocation_map(mm));
>>  	mm_set_pkey_allocated(mm, ret);
>> +
>> +	/*
>> +	 * enable the key in the hardware
>> +	 */
>> +	if (ret > 0)
>> +		__arch_activate_pkey(ret);
>>  	return ret;
>>  }
>>  
>> @@ -91,6 +99,10 @@ static inline int mm_pkey_free(struct mm_struct *mm, int pkey)
>>  	if (!mm_pkey_is_allocated(mm, pkey))
>>  		return -EINVAL;
>>  
>> +	/*
>> +	 * Disable the key in the hardware
>> +	 */
>> +	__arch_deactivate_pkey(pkey);
>>  	mm_set_pkey_free(mm, pkey);
>>  
>>  	return 0;
>
> I think some of these patches can be merged, too much fine granularity
> is hurting my ability to see the larger function/implementation.


Completely agree

-aneesh