Commit 41c76690 authored by Nicolas Toromanoff's avatar Nicolas Toromanoff Committed by Herbert Xu
Browse files

crypto: stm32/cryp - fix CTR counter carry 



STM32 CRYP hardware doesn't manage CTR counter bigger than max U32, as
a workaround, at each block the current IV is saved, if the saved IV
lower u32 is 0xFFFFFFFF, the full IV is manually incremented, and set
in hardware.
Fixes: bbb28326 ("crypto: stm32 - Fix sparse warnings")

Signed-off-by: default avatarNicolas Toromanoff <nicolas.toromanoff@foss.st.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 029812ae

drivers/crypto/stm32/stm32-cryp.c

+13 −14
Original line number Diff line number Diff line
@@ -163,7 +163,7 @@ struct stm32_cryp { 
	struct scatter_walk     in_walk;

	struct scatter_walk     out_walk;



	u32                     last_ctr[4];

	__be32                  last_ctr[4];

	u32                     gcm_ctr;

};
@@ -1217,27 +1217,26 @@ static void stm32_cryp_check_ctr_counter(struct stm32_cryp *cryp) 
{

	u32 cr;



	if (unlikely(cryp->last_ctr[3] == 0xFFFFFFFF)) {

		cryp->last_ctr[3] = 0;

		cryp->last_ctr[2]++;

		if (!cryp->last_ctr[2]) {

			cryp->last_ctr[1]++;

			if (!cryp->last_ctr[1])

				cryp->last_ctr[0]++;

		}

	if (unlikely(cryp->last_ctr[3] == cpu_to_be32(0xFFFFFFFF))) {

		/*

		 * In this case, we need to increment manually the ctr counter,

		 * as HW doesn't handle the U32 carry.

		 */

		crypto_inc((u8 *)cryp->last_ctr, sizeof(cryp->last_ctr));



		cr = stm32_cryp_read(cryp, CRYP_CR);

		stm32_cryp_write(cryp, CRYP_CR, cr & ~CR_CRYPEN);



		stm32_cryp_hw_write_iv(cryp, (__be32 *)cryp->last_ctr);

		stm32_cryp_hw_write_iv(cryp, cryp->last_ctr);



		stm32_cryp_write(cryp, CRYP_CR, cr);

	}



	cryp->last_ctr[0] = stm32_cryp_read(cryp, CRYP_IV0LR);

	cryp->last_ctr[1] = stm32_cryp_read(cryp, CRYP_IV0RR);

	cryp->last_ctr[2] = stm32_cryp_read(cryp, CRYP_IV1LR);

	cryp->last_ctr[3] = stm32_cryp_read(cryp, CRYP_IV1RR);

	/* The IV registers are BE  */

	cryp->last_ctr[0] = cpu_to_be32(stm32_cryp_read(cryp, CRYP_IV0LR));

	cryp->last_ctr[1] = cpu_to_be32(stm32_cryp_read(cryp, CRYP_IV0RR));

	cryp->last_ctr[2] = cpu_to_be32(stm32_cryp_read(cryp, CRYP_IV1LR));

	cryp->last_ctr[3] = cpu_to_be32(stm32_cryp_read(cryp, CRYP_IV1RR));

}



static bool stm32_cryp_irq_read_data(struct stm32_cryp *cryp)