crypto: qat - add resubmit logic for decompression

The acomp API allows to send requests with a NULL destination buffer. In
this case, the algorithm implementation needs to allocate the
destination scatter list, perform the operation and return the buffer to
the user. For decompression, data is likely to expand and be bigger than
the allocated buffer.

This implements a re-submission mechanism for decompression requests
that is triggered if the destination buffer, allocated by the driver,
is not sufficiently big to store the output from decompression.

If an overflow is detected when processing the callback for a
decompression request with a NULL destination buffer, a workqueue is
scheduled. This allocates a new scatter list of size CRYPTO_ACOMP_DST_MAX,
now 128KB, creates a new firmware scatter list and resubmits the job to
the hardware accelerator.

Suggested-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 159 insertions, 0 deletions

diff --git a/drivers/crypto/qat/qat_common/qat_bl.c b/drivers/crypto/qat/qat_common/qat_bl.c
index 221a4eb610a3..2e89ff08041b 100644
--- a/drivers/crypto/qat/qat_common/qat_bl.c
+++ b/drivers/crypto/qat/qat_common/qat_bl.c
@@ -222,3 +222,162 @@ int qat_bl_sgl_to_bufl(struct adf_accel_dev *accel_dev,
 				    extra_dst_buff, sz_extra_dst_buff,
 				    flags);
 }
+
+static void qat_bl_sgl_unmap(struct adf_accel_dev *accel_dev,
+			     struct qat_alg_buf_list *bl)
+{
+	struct device *dev = &GET_DEV(accel_dev);
+	int n = bl->num_bufs;
+	int i;
+
+	for (i = 0; i < n; i++)
+		if (!dma_mapping_error(dev, bl->bufers[i].addr))
+			dma_unmap_single(dev, bl->bufers[i].addr,
+					 bl->bufers[i].len, DMA_FROM_DEVICE);
+}
+
+static int qat_bl_sgl_map(struct adf_accel_dev *accel_dev,
+			  struct scatterlist *sgl,
+			  struct qat_alg_buf_list **bl)
+{
+	struct device *dev = &GET_DEV(accel_dev);
+	struct qat_alg_buf_list *bufl;
+	int node = dev_to_node(dev);
+	struct scatterlist *sg;
+	int n, i, sg_nctr;
+	size_t sz;
+
+	n = sg_nents(sgl);
+	sz = struct_size(bufl, bufers, n);
+	bufl = kzalloc_node(sz, GFP_KERNEL, node);
+	if (unlikely(!bufl))
+		return -ENOMEM;
+
+	for (i = 0; i < n; i++)
+		bufl->bufers[i].addr = DMA_MAPPING_ERROR;
+
+	sg_nctr = 0;
+	for_each_sg(sgl, sg, n, i) {
+		int y = sg_nctr;
+
+		if (!sg->length)
+			continue;
+
+		bufl->bufers[y].addr = dma_map_single(dev, sg_virt(sg),
+						      sg->length,
+						      DMA_FROM_DEVICE);
+		bufl->bufers[y].len = sg->length;
+		if (unlikely(dma_mapping_error(dev, bufl->bufers[y].addr)))
+			goto err_map;
+		sg_nctr++;
+	}
+	bufl->num_bufs = sg_nctr;
+	bufl->num_mapped_bufs = sg_nctr;
+
+	*bl = bufl;
+
+	return 0;
+
+err_map:
+	for (i = 0; i < n; i++)
+		if (!dma_mapping_error(dev, bufl->bufers[i].addr))
+			dma_unmap_single(dev, bufl->bufers[i].addr,
+					 bufl->bufers[i].len,
+					 DMA_FROM_DEVICE);
+	kfree(bufl);
+	*bl = NULL;
+
+	return -ENOMEM;
+}
+
+static void qat_bl_sgl_free_unmap(struct adf_accel_dev *accel_dev,
+				  struct scatterlist *sgl,
+				  struct qat_alg_buf_list *bl,
+				  bool free_bl)
+{
+	if (bl) {
+		qat_bl_sgl_unmap(accel_dev, bl);
+
+		if (free_bl)
+			kfree(bl);
+	}
+	if (sgl)
+		sgl_free(sgl);
+}
+
+static int qat_bl_sgl_alloc_map(struct adf_accel_dev *accel_dev,
+				struct scatterlist **sgl,
+				struct qat_alg_buf_list **bl,
+				unsigned int dlen,
+				gfp_t gfp)
+{
+	struct scatterlist *dst;
+	int ret;
+
+	dst = sgl_alloc(dlen, gfp, NULL);
+	if (!dst) {
+		dev_err(&GET_DEV(accel_dev), "sg_alloc failed\n");
+		return -ENOMEM;
+	}
+
+	ret = qat_bl_sgl_map(accel_dev, dst, bl);
+	if (ret)
+		goto err;
+
+	*sgl = dst;
+
+	return 0;
+
+err:
+	sgl_free(dst);
+	*sgl = NULL;
+	return ret;
+}
+
+int qat_bl_realloc_map_new_dst(struct adf_accel_dev *accel_dev,
+			       struct scatterlist **sg,
+			       unsigned int dlen,
+			       struct qat_request_buffs *qat_bufs,
+			       gfp_t gfp)
+{
+	struct device *dev = &GET_DEV(accel_dev);
+	dma_addr_t new_blp = DMA_MAPPING_ERROR;
+	struct qat_alg_buf_list *new_bl;
+	struct scatterlist *new_sg;
+	size_t new_bl_size;
+	int ret;
+
+	ret = qat_bl_sgl_alloc_map(accel_dev, &new_sg, &new_bl, dlen, gfp);
+	if (ret)
+		return ret;
+
+	new_bl_size = struct_size(new_bl, bufers, new_bl->num_bufs);
+
+	/* Map new firmware SGL descriptor */
+	new_blp = dma_map_single(dev, new_bl, new_bl_size, DMA_TO_DEVICE);
+	if (unlikely(dma_mapping_error(dev, new_blp)))
+		goto err;
+
+	/* Unmap old firmware SGL descriptor */
+	dma_unmap_single(dev, qat_bufs->bloutp, qat_bufs->sz_out, DMA_TO_DEVICE);
+
+	/* Free and unmap old scatterlist */
+	qat_bl_sgl_free_unmap(accel_dev, *sg, qat_bufs->blout,
+			      !qat_bufs->sgl_dst_valid);
+
+	qat_bufs->sgl_dst_valid = false;
+	qat_bufs->blout = new_bl;
+	qat_bufs->bloutp = new_blp;
+	qat_bufs->sz_out = new_bl_size;
+
+	*sg = new_sg;
+
+	return 0;
+err:
+	qat_bl_sgl_free_unmap(accel_dev, new_sg, new_bl, true);
+
+	if (!dma_mapping_error(dev, new_blp))
+		dma_unmap_single(dev, new_blp, new_bl_size, DMA_TO_DEVICE);
+
+	return -ENOMEM;
+}