2021-07-01 19:06:06

by Sean Anderson

[permalink] [raw]
Subject: [PATCH v2 1/2] crypto: mxs-dcp: Check for DMA mapping errors

After calling dma_map_single(), we must also call dma_mapping_error().
This fixes the following warning when compiling with CONFIG_DMA_API_DEBUG:

[ 311.241478] WARNING: CPU: 0 PID: 428 at kernel/dma/debug.c:1027 check_unmap+0x79c/0x96c
[ 311.249547] DMA-API: mxs-dcp 2280000.crypto: device driver failed to check map error[device address=0x00000000860cb080] [size=32 bytes] [mapped as single]

Signed-off-by: Sean Anderson <[email protected]>
---

(no changes since v1)

drivers/crypto/mxs-dcp.c | 45 +++++++++++++++++++++++++++++++---------
1 file changed, 35 insertions(+), 10 deletions(-)

diff --git a/drivers/crypto/mxs-dcp.c b/drivers/crypto/mxs-dcp.c
index d6a7784d2988..f397cc5bf102 100644
--- a/drivers/crypto/mxs-dcp.c
+++ b/drivers/crypto/mxs-dcp.c
@@ -170,15 +170,19 @@ static struct dcp *global_sdcp;

static int mxs_dcp_start_dma(struct dcp_async_ctx *actx)
{
+ int dma_err;
struct dcp *sdcp = global_sdcp;
const int chan = actx->chan;
uint32_t stat;
unsigned long ret;
struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
-
dma_addr_t desc_phys = dma_map_single(sdcp->dev, desc, sizeof(*desc),
DMA_TO_DEVICE);

+ dma_err = dma_mapping_error(sdcp->dev, desc_phys);
+ if (dma_err)
+ return dma_err;
+
reinit_completion(&sdcp->completion[chan]);

/* Clear status register. */
@@ -216,18 +220,29 @@ static int mxs_dcp_start_dma(struct dcp_async_ctx *actx)
static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
struct skcipher_request *req, int init)
{
+ dma_addr_t key_phys, src_phys, dst_phys;
struct dcp *sdcp = global_sdcp;
struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
int ret;

- dma_addr_t key_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_key,
- 2 * AES_KEYSIZE_128,
- DMA_TO_DEVICE);
- dma_addr_t src_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_in_buf,
- DCP_BUF_SZ, DMA_TO_DEVICE);
- dma_addr_t dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
- DCP_BUF_SZ, DMA_FROM_DEVICE);
+ key_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_key,
+ 2 * AES_KEYSIZE_128, DMA_TO_DEVICE);
+ ret = dma_mapping_error(sdcp->dev, key_phys);
+ if (ret)
+ return ret;
+
+ src_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_in_buf,
+ DCP_BUF_SZ, DMA_TO_DEVICE);
+ ret = dma_mapping_error(sdcp->dev, src_phys);
+ if (ret)
+ goto err_src;
+
+ dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
+ DCP_BUF_SZ, DMA_FROM_DEVICE);
+ ret = dma_mapping_error(sdcp->dev, dst_phys);
+ if (ret)
+ goto err_dst;

if (actx->fill % AES_BLOCK_SIZE) {
dev_err(sdcp->dev, "Invalid block size!\n");
@@ -265,10 +280,12 @@ static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
ret = mxs_dcp_start_dma(actx);

aes_done_run:
+ dma_unmap_single(sdcp->dev, dst_phys, DCP_BUF_SZ, DMA_FROM_DEVICE);
+err_dst:
+ dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
+err_src:
dma_unmap_single(sdcp->dev, key_phys, 2 * AES_KEYSIZE_128,
DMA_TO_DEVICE);
- dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
- dma_unmap_single(sdcp->dev, dst_phys, DCP_BUF_SZ, DMA_FROM_DEVICE);

return ret;
}
@@ -557,6 +574,10 @@ static int mxs_dcp_run_sha(struct ahash_request *req)
dma_addr_t buf_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_in_buf,
DCP_BUF_SZ, DMA_TO_DEVICE);

+ ret = dma_mapping_error(sdcp->dev, buf_phys);
+ if (ret)
+ return ret;
+
/* Fill in the DMA descriptor. */
desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
MXS_DCP_CONTROL0_INTERRUPT |
@@ -589,6 +610,10 @@ static int mxs_dcp_run_sha(struct ahash_request *req)
if (rctx->fini) {
digest_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_out_buf,
DCP_SHA_PAY_SZ, DMA_FROM_DEVICE);
+ ret = dma_mapping_error(sdcp->dev, digest_phys);
+ if (ret)
+ goto done_run;
+
desc->control0 |= MXS_DCP_CONTROL0_HASH_TERM;
desc->payload = digest_phys;
}
--
2.25.1


2021-07-01 20:00:04

by Richard Weinberger

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] crypto: mxs-dcp: Check for DMA mapping errors

----- Ursprüngliche Mail -----
> Von: "Sean Anderson" <[email protected]>
> An: "Linux Crypto Mailing List" <[email protected]>, "Herbert Xu" <[email protected]>, "davem"
> <[email protected]>
> CC: "horia geanta" <[email protected]>, "aymen sghaier" <[email protected]>, "richard" <[email protected]>,
> "linux-arm-kernel" <[email protected]>, "Marek Vasut" <[email protected]>, "Sean Anderson"
> <[email protected]>
> Gesendet: Donnerstag, 1. Juli 2021 20:56:37
> Betreff: [PATCH v2 1/2] crypto: mxs-dcp: Check for DMA mapping errors

> After calling dma_map_single(), we must also call dma_mapping_error().
> This fixes the following warning when compiling with CONFIG_DMA_API_DEBUG:
>
> [ 311.241478] WARNING: CPU: 0 PID: 428 at kernel/dma/debug.c:1027
> check_unmap+0x79c/0x96c
> [ 311.249547] DMA-API: mxs-dcp 2280000.crypto: device driver failed to check
> map error[device address=0x00000000860cb080] [size=32 bytes] [mapped as single]
>
> Signed-off-by: Sean Anderson <[email protected]>
> ---
>
> (no changes since v1)
>
> drivers/crypto/mxs-dcp.c | 45 +++++++++++++++++++++++++++++++---------
> 1 file changed, 35 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/crypto/mxs-dcp.c b/drivers/crypto/mxs-dcp.c
> index d6a7784d2988..f397cc5bf102 100644
> --- a/drivers/crypto/mxs-dcp.c
> +++ b/drivers/crypto/mxs-dcp.c
> @@ -170,15 +170,19 @@ static struct dcp *global_sdcp;
>
> static int mxs_dcp_start_dma(struct dcp_async_ctx *actx)
> {
> + int dma_err;
> struct dcp *sdcp = global_sdcp;
> const int chan = actx->chan;
> uint32_t stat;
> unsigned long ret;
> struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
> -
> dma_addr_t desc_phys = dma_map_single(sdcp->dev, desc, sizeof(*desc),
> DMA_TO_DEVICE);
>
> + dma_err = dma_mapping_error(sdcp->dev, desc_phys);
> + if (dma_err)
> + return dma_err;
> +

Minor nit, you don't need to propagate the return code from dma_mapping_error().
It just returns 0 for success and -ENOMEM on failure.
So treating it as boolean function is fine, IMHO and keeps the code simpler.
But it is a matter of taste. :-)

> reinit_completion(&sdcp->completion[chan]);
>
> /* Clear status register. */
> @@ -216,18 +220,29 @@ static int mxs_dcp_start_dma(struct dcp_async_ctx *actx)
> static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
> struct skcipher_request *req, int init)
> {
> + dma_addr_t key_phys, src_phys, dst_phys;
> struct dcp *sdcp = global_sdcp;
> struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
> struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
> int ret;
>
> - dma_addr_t key_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_key,
> - 2 * AES_KEYSIZE_128,
> - DMA_TO_DEVICE);
> - dma_addr_t src_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_in_buf,
> - DCP_BUF_SZ, DMA_TO_DEVICE);
> - dma_addr_t dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
> - DCP_BUF_SZ, DMA_FROM_DEVICE);
> + key_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_key,
> + 2 * AES_KEYSIZE_128, DMA_TO_DEVICE);
> + ret = dma_mapping_error(sdcp->dev, key_phys);
> + if (ret)
> + return ret;
> +
> + src_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_in_buf,
> + DCP_BUF_SZ, DMA_TO_DEVICE);
> + ret = dma_mapping_error(sdcp->dev, src_phys);
> + if (ret)
> + goto err_src;
> +
> + dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
> + DCP_BUF_SZ, DMA_FROM_DEVICE);
> + ret = dma_mapping_error(sdcp->dev, dst_phys);
> + if (ret)
> + goto err_dst;
>
> if (actx->fill % AES_BLOCK_SIZE) {
> dev_err(sdcp->dev, "Invalid block size!\n");
> @@ -265,10 +280,12 @@ static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
> ret = mxs_dcp_start_dma(actx);
>
> aes_done_run:
> + dma_unmap_single(sdcp->dev, dst_phys, DCP_BUF_SZ, DMA_FROM_DEVICE);
> +err_dst:
> + dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
> +err_src:
> dma_unmap_single(sdcp->dev, key_phys, 2 * AES_KEYSIZE_128,
> DMA_TO_DEVICE);
> - dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
> - dma_unmap_single(sdcp->dev, dst_phys, DCP_BUF_SZ, DMA_FROM_DEVICE);
>
> return ret;
> }
> @@ -557,6 +574,10 @@ static int mxs_dcp_run_sha(struct ahash_request *req)
> dma_addr_t buf_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_in_buf,
> DCP_BUF_SZ, DMA_TO_DEVICE);
>
> + ret = dma_mapping_error(sdcp->dev, buf_phys);
> + if (ret)
> + return ret;
> +
> /* Fill in the DMA descriptor. */
> desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
> MXS_DCP_CONTROL0_INTERRUPT |
> @@ -589,6 +610,10 @@ static int mxs_dcp_run_sha(struct ahash_request *req)
> if (rctx->fini) {
> digest_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_out_buf,
> DCP_SHA_PAY_SZ, DMA_FROM_DEVICE);
> + ret = dma_mapping_error(sdcp->dev, digest_phys);
> + if (ret)
> + goto done_run;
> +
> desc->control0 |= MXS_DCP_CONTROL0_HASH_TERM;
> desc->payload = digest_phys;
> }

Reviewed-by: Richard Weinberger <[email protected]>

Thanks,
//richard