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

["Wei Hu (Xavier)" <xavier.huwei@huawei.com>]

On 2017/10/1 0:10, Leon Romanovsky wrote:
> 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@huawei.com>
>> Signed-off-by: Shaobo Xu <xushaobo2@huawei.com>
>> Signed-off-by: Lijun Ou <oulijun@huawei.com>
>> ---
> 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
Hi,  Leon & Doug
     We refered the function named __ttm_dma_alloc_page in the kernel 
code as below:
     And there are similar methods in bch_bio_map and mem_to_page 
functions in current 4.14-rcx.

         static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool)
         {
             struct dma_page *d_page;

             d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL);
             if (!d_page)
                 return NULL;

             d_page->vaddr = dma_alloc_coherent(pool->dev, pool->size,
                                &d_page->dma,
                                    pool->gfp_flags);
             if (d_page->vaddr) {
                 if (is_vmalloc_addr(d_page->vaddr))
                     d_page->p = vmalloc_to_page(d_page->vaddr);
                 else
                     d_page->p = virt_to_page(d_page->vaddr);
             } else {
                 kfree(d_page);
                 d_page = NULL;
             }
             return d_page;
         }

     Regards
Wei Hu
>
>>   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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