[U-Boot] [PATCH v6 2/2] armv8: fsl-layerscape: Make DDR non secure in MMU tables

[York Sun]

On 12/02/2015 06:48 PM, Hou Zhiqiang-B48286 wrote:
> 
> 
>> -----Original Message-----
>> From: York Sun [mailto:yorksun at freescale.com]
>> Sent: 2015年12月3日 0:00
>> To: Hou Zhiqiang-B48286; U-Boot Mailing List
>> Cc: Pan Lijun-B44306; Hu Mingkai-B21284; Sharma Bhupesh-B45370; Gong
>> Qianyu-B52263; Tom Rini; Li Yang-Leo-R58472; Albert Aribaud; Kushwaha
>> Prabhakar-B32579; Wang Huan-B18965
>> Subject: Re: [PATCH v6 2/2] armv8: fsl-layerscape: Make DDR non secure in
>> MMU tables
>>
>>
>>
>> On 12/01/2015 10:38 PM, Hou Zhiqiang-B48286 wrote:
>>
>> <snip>
>>
>>>>  	/* Invalidate all table entries */
>>>>  	memset(level0_table, 0, PGTABLE_SIZE); @@ -269,6 +344,22 @@ static
>>>> inline void final_mmu_setup(void)
>>>>  			       &final_mmu_table[i]);
>>>>  		}
>>>>  	}
>>>> +	/* Set the secure memory to secure in MMU */ #ifdef
>>>> +CONFIG_SYS_MEM_RESERVE_SECURE
>>>> +	if (gd->secure_ram & MEM_RESERVE_SECURE_MAINTAINED) { #ifdef
>>>> +CONFIG_FSL_LSCH3
>>>> +		level2_table_secure = level2_table1 + 512; #elif
>>>> +defined(CONFIG_FSL_LSCH2)
>>>> +		level2_table_secure = level2_table2 + 512; #endif
>>>> +		/* update tlb pointer */
>>>> +		gd->arch.tlb_addr = gd->secure_ram & ~0x3;
>>>
>>> The memory reserved for mmu table was lost? If it's better to record it
>> and use for non-sec mmu table?
>>
>> That can be arranged.
>>
>>>
>>> If this func is called from non-secure state, for example EL2, the
>> secure memory cannot be accessed and the PMD_SECT_NS bit should be
>> cleared.
>>
>> We need to setup secure memory at EL3 to have secure memory to begin with.
>> But you have a point here. Will look into it.
>>
> 
> Yes, this func is called at EL3 for now, it is a assumption for this func.
> I mean we'd better make it a API that can be invoked at both EL3 and EL2 
> to setup the MMU table. And do you know if the EL1 should be taken into 
> account in u-boot?

We don't need to differentiate this function for EL2 or EL1 if we ever need to
run at. The only difference is EL3 can handle secure access. So adding a
detection of exception level before setting secure bit will suffice.

York