Re: [PATCH 3/4 v3] crypto: octeontx2: Fix address alignment on CN10K A0/A1 and OcteonTX2

On Wed, May 21, 2025 at 03:34:46PM +0530, Bharat Bhushan wrote:

@@ -429,22 +431,51 @@ otx2_sg_info_create(struct pci_dev *pdev, struct otx2_cpt_req_info *req, return NULL; }

• g_sz_bytes = ((req->in_cnt + 3) / 4) *

•       sizeof(struct otx2_cpt_sglist_component);
  

• s_sz_bytes = ((req->out_cnt + 3) / 4) *

•       sizeof(struct otx2_cpt_sglist_component);
  

• /* Allocate memory to meet below alignment requirement:

• *  ----------------------------------
  

• * |    struct otx2_cpt_inst_info     |
  

• * |    (No alignment required)       |
  

• * |     -----------------------------|
  

• * |    | padding for 8B alignment    |
  

• * |----------------------------------|
  

This should be updated to show that everything following this is on an 128-byte boundary.

• * |    SG List Gather/Input memory   |
  

• * |    Length = multiple of 32Bytes  |
  

• * |    Alignment = 8Byte             |
  

• * |----------------------------------|
  

• * |    SG List Scatter/Output memory |
  

• * |    Length = multiple of 32Bytes  |
  

• * |    Alignment = 8Byte             |
  

• * |    (padding for below alignment) |
  

• * |     -----------------------------|
  

• * |    | padding for 32B alignment   |
  

• * |----------------------------------|
  

• * |    Result response memory        |
  

• *  ----------------------------------
  

• */
  

• dlen = g_sz_bytes + s_sz_bytes + SG_LIST_HDR_SIZE;
• align_dlen = ALIGN(dlen, align);
• info_len = ALIGN(sizeof(*info), align);
• total_mem_len = align_dlen + info_len + sizeof(union otx2_cpt_res_s);

• info_len = sizeof(*info);
• g_len = ((req->in_cnt + 3) / 4) *

•  sizeof(struct otx2_cpt_sglist_component);
  

• s_len = ((req->out_cnt + 3) / 4) *

•  sizeof(struct otx2_cpt_sglist_component);
  

• dlen = g_len + s_len + SG_LIST_HDR_SIZE;
• /* Allocate extra memory for SG and response address alignment */
• total_mem_len = ALIGN(info_len, ARCH_DMA_MINALIGN) + dlen;
• total_mem_len = ALIGN(total_mem_len, OTX2_CPT_DPTR_RPTR_ALIGN);
• total_mem_len += (OTX2_CPT_RES_ADDR_ALIGN - 1) &

• 	  ~(OTX2_CPT_DPTR_RPTR_ALIGN - 1);
  

• total_mem_len += sizeof(union otx2_cpt_res_s);

This calculation is wrong again. It should be:

total_mem_len = ALIGN(info_len, OTX2_CPT_DPTR_RPTR_ALIGN); total_mem_len += (ARCH_DMA_MINALIGN - 1) & ~(OTX2_CPT_DPTR_RPTR_ALIGN - 1); total_mem_len += ALIGN(dlen, OTX2_CPT_RES_ADDR_ALIGN); total_mem_len += sizeof(union otx2_cpt_res_s);

Remember ALIGN may not actually give you extra memory. So if you need to add memory for alignment padding, you will need to do it by hand.

Cheers,