Re: [PATCH for-next 2/4] RDMA/hns: Add IOMMU enable support in hip08

From: Leon Romanovsky
Date: Sat Sep 30 2017 - 12:10:32 EST

On Sat, Sep 30, 2017 at 05:28:59PM +0800, Wei Hu (Xavier) wrote:
> If the IOMMU is enabled, the length of sg obtained from
> __iommu_map_sg_attrs is not 4kB. When the IOVA is set with the sg
> dma address, the IOVA will not be page continuous. and the VA
> returned from dma_alloc_coherent is a vmalloc address. However,
> the VA obtained by the page_address is a discontinuous VA. Under
> these circumstances, the IOVA should be calculated based on the
> sg length, and record the VA returned from dma_alloc_coherent
> in the struct of hem.
>
> Signed-off-by: Wei Hu (Xavier) <xavier.huwei@xxxxxxxxxx>
> Signed-off-by: Shaobo Xu <xushaobo2@xxxxxxxxxx>
> Signed-off-by: Lijun Ou <oulijun@xxxxxxxxxx>
> ---

Doug,

I didn't invest time in reviewing it, but having "is_vmalloc_addr" in
driver code to deal with dma_alloc_coherent is most probably wrong.

Thanks


> drivers/infiniband/hw/hns/hns_roce_alloc.c | 5 ++++-
> drivers/infiniband/hw/hns/hns_roce_hem.c | 30 +++++++++++++++++++++++++++---
> drivers/infiniband/hw/hns/hns_roce_hem.h | 6 ++++++
> drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 22 +++++++++++++++-------
> 4 files changed, 52 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/infiniband/hw/hns/hns_roce_alloc.c b/drivers/infiniband/hw/hns/hns_roce_alloc.c
> index 3e4c525..a69cd4b 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_alloc.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_alloc.c
> @@ -243,7 +243,10 @@ int hns_roce_buf_alloc(struct hns_roce_dev *hr_dev, u32 size, u32 max_direct,
> goto err_free;
>
> for (i = 0; i < buf->nbufs; ++i)
> - pages[i] = virt_to_page(buf->page_list[i].buf);
> + pages[i] =
> + is_vmalloc_addr(buf->page_list[i].buf) ?
> + vmalloc_to_page(buf->page_list[i].buf) :
> + virt_to_page(buf->page_list[i].buf);
>
> buf->direct.buf = vmap(pages, buf->nbufs, VM_MAP,
> PAGE_KERNEL);
> diff --git a/drivers/infiniband/hw/hns/hns_roce_hem.c b/drivers/infiniband/hw/hns/hns_roce_hem.c
> index 8388ae2..4a3d1d4 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_hem.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_hem.c
> @@ -200,6 +200,7 @@ static struct hns_roce_hem *hns_roce_alloc_hem(struct hns_roce_dev *hr_dev,
> gfp_t gfp_mask)
> {
> struct hns_roce_hem_chunk *chunk = NULL;
> + struct hns_roce_vmalloc *vmalloc;
> struct hns_roce_hem *hem;
> struct scatterlist *mem;
> int order;
> @@ -227,6 +228,7 @@ static struct hns_roce_hem *hns_roce_alloc_hem(struct hns_roce_dev *hr_dev,
> sg_init_table(chunk->mem, HNS_ROCE_HEM_CHUNK_LEN);
> chunk->npages = 0;
> chunk->nsg = 0;
> + memset(chunk->vmalloc, 0, sizeof(chunk->vmalloc));
> list_add_tail(&chunk->list, &hem->chunk_list);
> }
>
> @@ -243,7 +245,15 @@ static struct hns_roce_hem *hns_roce_alloc_hem(struct hns_roce_dev *hr_dev,
> if (!buf)
> goto fail;
>
> - sg_set_buf(mem, buf, PAGE_SIZE << order);
> + if (is_vmalloc_addr(buf)) {
> + vmalloc = &chunk->vmalloc[chunk->npages];
> + vmalloc->is_vmalloc_addr = true;
> + vmalloc->vmalloc_addr = buf;
> + sg_set_page(mem, vmalloc_to_page(buf),
> + PAGE_SIZE << order, offset_in_page(buf));
> + } else {
> + sg_set_buf(mem, buf, PAGE_SIZE << order);
> + }
> WARN_ON(mem->offset);
> sg_dma_len(mem) = PAGE_SIZE << order;
>
> @@ -262,17 +272,25 @@ static struct hns_roce_hem *hns_roce_alloc_hem(struct hns_roce_dev *hr_dev,
> void hns_roce_free_hem(struct hns_roce_dev *hr_dev, struct hns_roce_hem *hem)
> {
> struct hns_roce_hem_chunk *chunk, *tmp;
> + void *cpu_addr;
> int i;
>
> if (!hem)
> return;
>
> list_for_each_entry_safe(chunk, tmp, &hem->chunk_list, list) {
> - for (i = 0; i < chunk->npages; ++i)
> + for (i = 0; i < chunk->npages; ++i) {
> + if (chunk->vmalloc[i].is_vmalloc_addr)
> + cpu_addr = chunk->vmalloc[i].vmalloc_addr;
> + else
> + cpu_addr =
> + lowmem_page_address(sg_page(&chunk->mem[i]));
> +
> dma_free_coherent(hr_dev->dev,
> chunk->mem[i].length,
> - lowmem_page_address(sg_page(&chunk->mem[i])),
> + cpu_addr,
> sg_dma_address(&chunk->mem[i]));
> + }
> kfree(chunk);
> }
>
> @@ -774,6 +792,12 @@ void *hns_roce_table_find(struct hns_roce_dev *hr_dev,
>
> if (chunk->mem[i].length > (u32)offset) {
> page = sg_page(&chunk->mem[i]);
> + if (chunk->vmalloc[i].is_vmalloc_addr) {
> + mutex_unlock(&table->mutex);
> + return page ?
> + chunk->vmalloc[i].vmalloc_addr
> + + offset : NULL;
> + }
> goto out;
> }
> offset -= chunk->mem[i].length;
> diff --git a/drivers/infiniband/hw/hns/hns_roce_hem.h b/drivers/infiniband/hw/hns/hns_roce_hem.h
> index af28bbf..62d712a 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_hem.h
> +++ b/drivers/infiniband/hw/hns/hns_roce_hem.h
> @@ -72,11 +72,17 @@ enum {
> HNS_ROCE_HEM_PAGE_SIZE = 1 << HNS_ROCE_HEM_PAGE_SHIFT,
> };
>
> +struct hns_roce_vmalloc {
> + bool is_vmalloc_addr;
> + void *vmalloc_addr;
> +};
> +
> struct hns_roce_hem_chunk {
> struct list_head list;
> int npages;
> int nsg;
> struct scatterlist mem[HNS_ROCE_HEM_CHUNK_LEN];
> + struct hns_roce_vmalloc vmalloc[HNS_ROCE_HEM_CHUNK_LEN];
> };
>
> struct hns_roce_hem {
> diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
> index b99d70a..9e19bf1 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
> @@ -1093,9 +1093,11 @@ static int hns_roce_v2_write_mtpt(void *mb_buf, struct hns_roce_mr *mr,
> {
> struct hns_roce_v2_mpt_entry *mpt_entry;
> struct scatterlist *sg;
> + u64 page_addr = 0;
> u64 *pages;
> + int i = 0, j = 0;
> + int len = 0;
> int entry;
> - int i;
>
> mpt_entry = mb_buf;
> memset(mpt_entry, 0, sizeof(*mpt_entry));
> @@ -1153,14 +1155,20 @@ static int hns_roce_v2_write_mtpt(void *mb_buf, struct hns_roce_mr *mr,
>
> i = 0;
> for_each_sg(mr->umem->sg_head.sgl, sg, mr->umem->nmap, entry) {
> - pages[i] = ((u64)sg_dma_address(sg)) >> 6;
> -
> - /* Record the first 2 entry directly to MTPT table */
> - if (i >= HNS_ROCE_V2_MAX_INNER_MTPT_NUM - 1)
> - break;
> - i++;
> + len = sg_dma_len(sg) >> PAGE_SHIFT;
> + for (j = 0; j < len; ++j) {
> + page_addr = sg_dma_address(sg) +
> + (j << mr->umem->page_shift);
> + pages[i] = page_addr >> 6;
> +
> + /* Record the first 2 entry directly to MTPT table */
> + if (i >= HNS_ROCE_V2_MAX_INNER_MTPT_NUM - 1)
> + goto found;
> + i++;
> + }
> }
>
> +found:
> mpt_entry->pa0_l = cpu_to_le32(lower_32_bits(pages[0]));
> roce_set_field(mpt_entry->byte_56_pa0_h, V2_MPT_BYTE_56_PA0_H_M,
> V2_MPT_BYTE_56_PA0_H_S,
> --
> 1.9.1
>

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