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crypto: tegra - Fix CMAC intermediate result handling
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Saving and restoring of the intermediate results are needed if there is
context switch caused by another ongoing request on the same engine.
This is therefore not only to support import/export functionality.
Hence, save and restore the intermediate result for every non-first task.

Fixes: 0880bb3 ("crypto: tegra - Add Tegra Security Engine driver")
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Akhil R authored and Herbert Xu committed Mar 8, 2025
1 parent ff4b7df commit ce390d6
Showing 1 changed file with 9 additions and 9 deletions.
18 changes: 9 additions & 9 deletions drivers/crypto/tegra/tegra-se-aes.c
Original file line number Diff line number Diff line change
Expand Up @@ -1547,23 +1547,16 @@ static int tegra_cmac_do_update(struct ahash_request *req)
rctx->residue.size = nresidue;

/*
* If this is not the first 'update' call, paste the previous copied
* If this is not the first task, paste the previous copied
* intermediate results to the registers so that it gets picked up.
* This is to support the import/export functionality.
*/
if (!(rctx->task & SHA_FIRST))
tegra_cmac_paste_result(ctx->se, rctx);

cmdlen = tegra_cmac_prep_cmd(ctx, rctx);
ret = tegra_se_host1x_submit(se, se->cmdbuf, cmdlen);

/*
* If this is not the final update, copy the intermediate results
* from the registers so that it can be used in the next 'update'
* call. This is to support the import/export functionality.
*/
if (!(rctx->task & SHA_FINAL))
tegra_cmac_copy_result(ctx->se, rctx);
tegra_cmac_copy_result(ctx->se, rctx);

dma_free_coherent(ctx->se->dev, rctx->datbuf.size,
rctx->datbuf.buf, rctx->datbuf.addr);
Expand Down Expand Up @@ -1600,6 +1593,13 @@ static int tegra_cmac_do_final(struct ahash_request *req)
rctx->total_len += rctx->residue.size;
rctx->config = tegra234_aes_cfg(SE_ALG_CMAC, 0);

/*
* If this is not the first task, paste the previous copied
* intermediate results to the registers so that it gets picked up.
*/
if (!(rctx->task & SHA_FIRST))
tegra_cmac_paste_result(ctx->se, rctx);

/* Prepare command and submit */
cmdlen = tegra_cmac_prep_cmd(ctx, rctx);
ret = tegra_se_host1x_submit(se, se->cmdbuf, cmdlen);
Expand Down

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