Re: [PATCH] crypto: crc32: make crc32 available in PBL

[Johannes Zink <j.zink@pengutronix.de>]

Hi Ahmad,

thank you for your review.

On 8/29/23 12:45, Ahmad Fatoum wrote:
> On 29.08.23 12:29, Ahmad Fatoum wrote:
>> On 29.08.23 11:28, Johannes Zink wrote:
>>> crc32 may be required in PBL for checking data integrity. Add
>>> CONFIG_CRC32_EARLY to kconfig which allows adding crc32 also in the PBL.
>>>
>>> As the PBL has no dynamic allocation, do not use dynamic CRC table
>>> generation when CRC32 is added in PBL.
>>>
>>> Signed-off-by: Johannes Zink <j.zink@pengutronix.de>
>>> ---
>>> To: Barebox Mailing List <barebox@lists.infradead.org>
>>> Cc: Johannes Zink <j.zink@pengutronix.de>
>>> Cc: patchwork-jzi@pengutronix.de
>>> ---
>>>   crypto/Kconfig  | 3 +++
>>>   crypto/Makefile | 1 +
>>>   crypto/crc32.c  | 6 +++---
>>>   3 files changed, 7 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/crypto/Kconfig b/crypto/Kconfig
>>> index 04e5ef43705b..6e18b5868061 100644
>>> --- a/crypto/Kconfig
>>> +++ b/crypto/Kconfig
>>> @@ -5,6 +5,9 @@ menu "Crypto support"
>>>   config CRC32
>>>   	bool
>>>   
>>> +config CRC32_EARLY
>>> +	bool
>>> +
>>>   config CRC_ITU_T
>>>   	bool
>>>   
>>> diff --git a/crypto/Makefile b/crypto/Makefile
>>> index 22035d4f69ee..24e1f3d91797 100644
>>> --- a/crypto/Makefile
>>> +++ b/crypto/Makefile
>>> @@ -11,6 +11,7 @@ obj-$(CONFIG_DIGEST_SHA1_GENERIC)	+= sha1.o
>>>   obj-$(CONFIG_DIGEST_SHA224_GENERIC)	+= sha2.o
>>>   obj-$(CONFIG_DIGEST_SHA256_GENERIC)	+= sha2.o
>>>   pbl-y					+= sha2.o digest.o
>>> +lwl-$(CONFIG_CRC32_EARLY)		+= crc32.o
>>
>> pbl-obj- is the correct prefix. lwl- means pbl- if we have PBL
>> support at all and obj- otherwise (for legacy systems without PBL),
>> while pbl-obj- is equivalent to duplicating the line once with pbl-
>> and once with obj-
> 
> s/pbl-obj-/obj-pbl-/ :)
> 

ack, gonna fix this for v2.

>>
>>>   obj-$(CONFIG_DIGEST_SHA384_GENERIC)	+= sha4.o
>>>   obj-$(CONFIG_DIGEST_SHA512_GENERIC)	+= sha4.o
>>>   obj-y	+= memneq.o
>>> diff --git a/crypto/crc32.c b/crypto/crc32.c
>>> index 95cb2212db2b..284d39351682 100644
>>> --- a/crypto/crc32.c
>>> +++ b/crypto/crc32.c
>>> @@ -22,7 +22,7 @@
>>>   #define STATIC static inline
>>>   #endif
>>>   
>>> -#ifdef CONFIG_DYNAMIC_CRC_TABLE
>>> +#if defined(CONFIG_DYNAMIC_CRC_TABLE) && !defined(__PBL__)
>>
>> You could also replace the dynamic allocation with a static array initialized
>> to zero. That way you can have a dynamic crc table even in PBL without affecting
>> image size as the BSS is not part of the image.

ack. Is this ok?

#ifdef __PBL__
   static uint32_t _crc_table_memory[sizeof(uint32_t) * 256] = { 0 };
#endif

static void *alloc_crc_table() {
#ifdef __PBL__
	return _crc_table_memory;
#else
	return xmalloc(sizeof(uint32_t) * 256);
#endif
}

If so, I can change it for v2.

Best regards
Johannes


>>
>>>   
>>>   static uint32_t *crc_table;
>>>   
>>> @@ -145,7 +145,7 @@ STATIC uint32_t crc32(uint32_t crc, const void *_buf, unsigned int len)
>>>   {
>>>       const unsigned char *buf = _buf;
>>>   
>>> -#ifdef CONFIG_DYNAMIC_CRC_TABLE
>>> +#if defined(CONFIG_DYNAMIC_CRC_TABLE) && !defined(__PBL__)
>>>   	if (!crc_table)
>>>   		make_crc_table();
>>>   #endif
>>> @@ -171,7 +171,7 @@ STATIC uint32_t crc32_no_comp(uint32_t crc, const void *_buf, unsigned int len)
>>>   {
>>>      const unsigned char *buf = _buf;
>>>   
>>> -#ifdef CONFIG_DYNAMIC_CRC_TABLE
>>> +#if defined(CONFIG_DYNAMIC_CRC_TABLE) && !defined(__PBL__)
>>>   	if (!crc_table)
>>>   		make_crc_table();
>>>   #endif
>>>
>>> ---
>>> base-commit: bef38b18eeb5d2f1fac334fb8b831e47261e099c
>>> change-id: 20230829-crc32_in_pbl-4d824629d4e2
>>>
>>> Best regards,
>>
> 

-- 
Pengutronix e.K.                | Johannes Zink                  |
Steuerwalder Str. 21            | https://www.pengutronix.de/    |
31137 Hildesheim, Germany       | Phone: +49-5121-206917-0       |
Amtsgericht Hildesheim, HRA 2686| Fax:   +49-5121-206917-5555    |