linux-kernel - Re: [PATCH v4] misc: fastrpc: Increase unsigned PD initmem size

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Message-ID: <1fa821d4-eeba-4df9-8c08-f289832e0632@quicinc.com>
Date: Mon, 22 Jul 2024 09:51:48 +0530
From: Ekansh Gupta <quic_ekangupt@...cinc.com>
To: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
CC: <srinivas.kandagatla@...aro.org>, <linux-arm-msm@...r.kernel.org>,
        <gregkh@...uxfoundation.org>, <quic_bkumar@...cinc.com>,
        <linux-kernel@...r.kernel.org>, <quic_chennak@...cinc.com>,
        <dri-devel@...ts.freedesktop.org>, <arnd@...db.de>,
        stable
	<stable@...nel.org>
Subject: Re: [PATCH v4] misc: fastrpc: Increase unsigned PD initmem size



On 7/19/2024 3:36 PM, Dmitry Baryshkov wrote:
> On Fri, Jul 19, 2024 at 02:27:08PM GMT, Ekansh Gupta wrote:
>> For user PD initialization, initmem is allocated and sent to DSP for
>> initial memory requirements like shell loading. This size is the shell
>> size that is  passed by user space and is checked against a max size.
>> For unsigned PD offloading requirement, additional memory is required
>> because of additional static heap initialization. Without this
>> additional memory, PD initialization would fail. Increase the initmem
>> size by 2MB for unsigned PD initmem buffer allocation. Any additional
>> memory sent to DSP during PD init is used as the PD heap.
>>
>> Fixes: 7f1f481263c3 ("misc: fastrpc: check before loading process to the DSP")
>> Cc: stable <stable@...nel.org>
>> Signed-off-by: Ekansh Gupta <quic_ekangupt@...cinc.com>
>> ---
>> Changes in v2:
>>   - Modified commit text.
>>   - Removed size check instead of updating max file size.
>> Changes in v3:
>>   - Added bound check again with a higher max size definition.
>>   - Modified commit text accordingly.
>> Changes in v4:
>>   - Defined new initmem specific MACROs.
>>   - Adding extra memory for unsigned PD.
>>   - Added comment suggesting the reason for this change.
>>   - Modified commit text.
>>
>>  drivers/misc/fastrpc.c | 10 +++++++++-
>>  1 file changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
>> index a7a2bcedb37e..18668b020a87 100644
>> --- a/drivers/misc/fastrpc.c
>> +++ b/drivers/misc/fastrpc.c
>> @@ -39,6 +39,8 @@
>>  #define FASTRPC_DSP_UTILITIES_HANDLE	2
>>  #define FASTRPC_CTXID_MASK (0xFF0)
>>  #define INIT_FILELEN_MAX (2 * 1024 * 1024)
>> +#define FASTRPC_INITLEN_MIN (3 * 1024 * 1024)
>> +#define FASTRPC_STATIC_HEAP_LEN (2 * 1024 * 1024)
>>  #define INIT_FILE_NAMELEN_MAX (128)
>>  #define FASTRPC_DEVICE_NAME	"fastrpc"
>>  
>> @@ -1410,8 +1412,14 @@ static int fastrpc_init_create_process(struct fastrpc_user *fl,
>>  			goto err;
>>  	}
>>  
>> -	memlen = ALIGN(max(INIT_FILELEN_MAX, (int)init.filelen * 4),
>> +	/* Allocate buffer in kernel for donating to remote process.
>> +	 * Unsigned PD requires additional memory because of the
>> +	 * additional static heap initialized within the process.
>> +	 */
>> +	memlen = ALIGN(max(FASTRPC_INITLEN_MIN, (int)init.filelen * 4),
>>  		       1024 * 1024);
> Ok, here you have two changes in the same patch. First one changes
> the allocated memory size for the signed usecase and another one adds
> separate handling for the unsigned case. Please split them into two
> separate commits.
Sure, will be splitting the patches. Thanks.

--Ekansh
>
>> +	if (unsigned_module)
>> +		memlen += FASTRPC_STATIC_HEAP_LEN;
>>  	err = fastrpc_buf_alloc(fl, fl->sctx->dev, memlen,
>>  				&imem);
>>  	if (err)
>> -- 
>> 2.34.1
>>