crypto/NX: Set receive window credits to max number of CRBs in RxFIFO

crypto/NX: Set receive window credits to max number of CRBs in RxFIFO

[Haren Myneni]

    
System gets checkstop if RxFIFO overruns with more requests than the
maximum possible number of CRBs in FIFO at the same time. So find max
CRBs from FIFO size and set it to receive window credits.
   
CC: stable@vger.kernel.org # v4.14+
Signed-off-by:Haren Myneni <haren@us.ibm.com>

diff --git a/drivers/crypto/nx/nx-842-powernv.c b/drivers/crypto/nx/nx-842-powernv.c
index 4acbc47..e78ff5c 100644
--- a/drivers/crypto/nx/nx-842-powernv.c
+++ b/drivers/crypto/nx/nx-842-powernv.c
@@ -27,8 +27,6 @@
 #define WORKMEM_ALIGN	(CRB_ALIGN)
 #define CSB_WAIT_MAX	(5000) /* ms */
 #define VAS_RETRIES	(10)
-/* # of requests allowed per RxFIFO at a time. 0 for unlimited */
-#define MAX_CREDITS_PER_RXFIFO	(1024)
 
 struct nx842_workmem {
 	/* Below fields must be properly aligned */
@@ -812,7 +810,11 @@ static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
 	rxattr.lnotify_lpid = lpid;
 	rxattr.lnotify_pid = pid;
 	rxattr.lnotify_tid = tid;
-	rxattr.wcreds_max = MAX_CREDITS_PER_RXFIFO;
+	/*
+	 * Maximum RX window credits can not be more than #CRBs in
+	 * RxFIFO. Otherwise, can get checkstop if RxFIFO overruns.
+	 */
+	rxattr.wcreds_max = fifo_size / CRB_SIZE;
 
 	/*
 	 * Open a VAS receice window which is used to configure RxFIFO

Re: crypto/NX: Set receive window credits to max number of CRBs in RxFIFO

[Michael Ellerman]

Haren Myneni <haren@linux.vnet.ibm.com> writes:
>     
> System gets checkstop if RxFIFO overruns with more requests than the
> maximum possible number of CRBs in FIFO at the same time. So find max
> CRBs from FIFO size and set it to receive window credits.
>    
> CC: stable@vger.kernel.org # v4.14+
> Signed-off-by:Haren Myneni <haren@us.ibm.com>

It's helpful to mention the actual commit that's fixed, so that people
with backports can join things up, so should that be:

  Fixes: b0d6c9bab5e4 ("crypto/nx: Add P9 NX support for 842 compression engine")

???

cheers

> diff --git a/drivers/crypto/nx/nx-842-powernv.c b/drivers/crypto/nx/nx-842-powernv.c
> index 4acbc47..e78ff5c 100644
> --- a/drivers/crypto/nx/nx-842-powernv.c
> +++ b/drivers/crypto/nx/nx-842-powernv.c
> @@ -27,8 +27,6 @@
>  #define WORKMEM_ALIGN	(CRB_ALIGN)
>  #define CSB_WAIT_MAX	(5000) /* ms */
>  #define VAS_RETRIES	(10)
> -/* # of requests allowed per RxFIFO at a time. 0 for unlimited */
> -#define MAX_CREDITS_PER_RXFIFO	(1024)
>  
>  struct nx842_workmem {
>  	/* Below fields must be properly aligned */
> @@ -812,7 +810,11 @@ static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
>  	rxattr.lnotify_lpid = lpid;
>  	rxattr.lnotify_pid = pid;
>  	rxattr.lnotify_tid = tid;
> -	rxattr.wcreds_max = MAX_CREDITS_PER_RXFIFO;
> +	/*
> +	 * Maximum RX window credits can not be more than #CRBs in
> +	 * RxFIFO. Otherwise, can get checkstop if RxFIFO overruns.
> +	 */
> +	rxattr.wcreds_max = fifo_size / CRB_SIZE;
>  
>  	/*
>  	 * Open a VAS receice window which is used to configure RxFIFO

Re: [EXTERNAL] Re: crypto/NX: Set receive window credits to max number of CRBs in RxFIFO

[Haren Myneni]

On 06/18/2019 05:35 AM, Michael Ellerman wrote:
> Haren Myneni <haren@linux.vnet.ibm.com> writes:
>>     
>> System gets checkstop if RxFIFO overruns with more requests than the
>> maximum possible number of CRBs in FIFO at the same time. So find max
>> CRBs from FIFO size and set it to receive window credits.
>>    
>> CC: stable@vger.kernel.org # v4.14+
>> Signed-off-by:Haren Myneni <haren@us.ibm.com>
> 
> It's helpful to mention the actual commit that's fixed, so that people
> with backports can join things up, so should that be:
> 
>   Fixes: b0d6c9bab5e4 ("crypto/nx: Add P9 NX support for 842 compression engine")
> 
> ???

Sorry, Yes, We use 1K for Rx window credits in b0d6c9bab5e41d07f (crypto/nx: Add P9 NX support for 842 compression engine). But credits should be based on FIFO size. 

I will repost the patch.  

> 
> cheers
> 
>> diff --git a/drivers/crypto/nx/nx-842-powernv.c b/drivers/crypto/nx/nx-842-powernv.c
>> index 4acbc47..e78ff5c 100644
>> --- a/drivers/crypto/nx/nx-842-powernv.c
>> +++ b/drivers/crypto/nx/nx-842-powernv.c
>> @@ -27,8 +27,6 @@
>>  #define WORKMEM_ALIGN	(CRB_ALIGN)
>>  #define CSB_WAIT_MAX	(5000) /* ms */
>>  #define VAS_RETRIES	(10)
>> -/* # of requests allowed per RxFIFO at a time. 0 for unlimited */
>> -#define MAX_CREDITS_PER_RXFIFO	(1024)
>>  
>>  struct nx842_workmem {
>>  	/* Below fields must be properly aligned */
>> @@ -812,7 +810,11 @@ static int __init vas_cfg_coproc_info(struct device_node *dn, int chip_id,
>>  	rxattr.lnotify_lpid = lpid;
>>  	rxattr.lnotify_pid = pid;
>>  	rxattr.lnotify_tid = tid;
>> -	rxattr.wcreds_max = MAX_CREDITS_PER_RXFIFO;
>> +	/*
>> +	 * Maximum RX window credits can not be more than #CRBs in
>> +	 * RxFIFO. Otherwise, can get checkstop if RxFIFO overruns.
>> +	 */
>> +	rxattr.wcreds_max = fifo_size / CRB_SIZE;
>>  
>>  	/*
>>  	 * Open a VAS receice window which is used to configure RxFIFO
>