Subject: Re: [PATCH v10 08/22] IB/hns: Add icm support

From: Leon Romanovsky <[email-masked]>
Date: Mon, 20 Jun 2016 09:06:14 +0300

On Mon, Jun 20, 2016 at 12:37:40PM +0800, Wei Hu (Xavier) wrote:
> 
> 
> On 2016/6/17 17:58, Leon Romanovsky wrote:
> >On Thu, Jun 16, 2016 at 10:35:16PM +0800, Lijun Ou wrote:
> >>This patch mainly added icm support for RoCE. It initializes icm
> >>which managers the relative memory blocks for RoCE. The data
> >>structures of RoCE will be located in it. For example, CQ table,
> >>QP table and MTPT table so on.
> >>
> >>Signed-off-by: Wei Hu <[email-masked]>
> >>Signed-off-by: Nenglong Zhao <zhaonenglong-C8/M+/[email-masked]>
> >>Signed-off-by: Lijun Ou <[email-masked]>
> >>---
> ><...>
> >
> >>+
> >>+static int hns_roce_alloc_icm_pages(struct scatterlist *mem, int order,
> >>+				    gfp_t gfp_mask)
> >>+{
> >>+	struct page *page;
> >>+
> >>+	page = alloc_pages(gfp_mask, order);
> >>+	if (!page)
> >>+		return -ENOMEM;
> >>+
> >>+	sg_set_page(mem, page, PAGE_SIZE << order, 0);
> >>+
> >>+	return 0;
> >>+}
> >>+
> >>+static int hns_roce_alloc_icm_coherent(struct device *dev,
> >>+				       struct scatterlist *mem, int order,
> >>+				       gfp_t gfp_mask)
> >>+{
> >>+	void *buf = dma_alloc_coherent(dev, PAGE_SIZE << order,
> >>+				       &sg_dma_address(mem), gfp_mask);
> >>+	if (!buf)
> >>+		return -ENOMEM;
> >>+
> >>+	sg_set_buf(mem, buf, PAGE_SIZE << order);
> >>+	WARN_ON(mem->offset);
> >>+	sg_dma_len(mem) = PAGE_SIZE << order;
> >>+	return 0;
> >>+}
> >>+
> ><...>
> >
> >>+
> >>+static void hns_roce_free_icm_pages(struct hns_roce_dev *hr_dev,
> >>+				    struct hns_roce_icm_chunk *chunk)
> >>+{
> >>+	int i;
> >>+
> >>+	if (chunk->nsg > 0)
> >>+		dma_unmap_sg(&hr_dev->pdev->dev, chunk->mem, chunk->npages,
> >>+			     DMA_BIDIRECTIONAL);
> >>+
> >>+	for (i = 0; i < chunk->npages; ++i)
> >>+		__free_pages(sg_page(&chunk->mem[i]),
> >>+			     get_order(chunk->mem[i].length));
> >You used alloc_pages for this allocation, so why are you using
> >__free_pages instead of free_pages?
> Hi, Leon
>     The function prototype of these functions as below：
>         static inline struct page * alloc_pages(gfp_t gfp_mask, unsigned int
> order);
>         void free_pages(unsigned long addr, unsigned int order);
>         void __free_pages(struct page *page, unsigned int order);
> 
>     The type of the first parameter of free_pages is same with the type of
> return value of alloc_pages.
>     Maybe it is better to call __free_pages to release memory that allocated
> by calling alloc_pages.

OK, I see.

Another question which you didn't answer [1].

"I wonder if you have the same needs for ICM as it is in mlx4 device.
Do you have firmware?"

[1] http://marc.info/?l=linux-rdma&m=146545553104913&w=2

> Regards
> Wei Hu