From b1c158350968d6717ec1889f07ea3a89432e8574 Mon Sep 17 00:00:00 2001 From: "Wei Hu\\(Xavier\\)" Date: Tue, 28 Nov 2017 15:10:27 +0800 Subject: [PATCH] RDMA/hns: Get rid of virt_to_page and vmap calls after dma_alloc_coherent In general dma_alloc_coherent() returns a CPU virtual address and a DMA address, and we have no guarantee that the virtual address is either in the linear map or vmalloc. It could be in some other special place. We have no guarantee that the underlying memory even has an associated struct page at all. In current code, there are incorrect usage as below: dma_alloc_coherent + virt_to_page + vmap. There will probably introduce coherency problem. This patch fixes it to get rid of virt_to_page and vmap calls at Leon's suggestion. The related link: https://lkml.org/lkml/2017/11/7/34 Fixes: 9a44353("IB/hns: Add driver files for hns RoCE driver") Signed-off-by: Wei Hu (Xavier) Signed-off-by: Shaobo Xu Signed-off-by: Lijun Ou Signed-off-by: Yixian Liu Signed-off-by: Xiping Zhang (Francis) Signed-off-by: Jason Gunthorpe --- drivers/infiniband/hw/hns/hns_roce_alloc.c | 23 --------------------- drivers/infiniband/hw/hns/hns_roce_device.h | 4 +--- 2 files changed, 1 insertion(+), 26 deletions(-) diff --git a/drivers/infiniband/hw/hns/hns_roce_alloc.c b/drivers/infiniband/hw/hns/hns_roce_alloc.c index 3e4c5253ab5c..a40ec939ece5 100644 --- a/drivers/infiniband/hw/hns/hns_roce_alloc.c +++ b/drivers/infiniband/hw/hns/hns_roce_alloc.c @@ -162,14 +162,10 @@ void hns_roce_buf_free(struct hns_roce_dev *hr_dev, u32 size, { int i; struct device *dev = hr_dev->dev; - u32 bits_per_long = BITS_PER_LONG; if (buf->nbufs == 1) { dma_free_coherent(dev, size, buf->direct.buf, buf->direct.map); } else { - if (bits_per_long == 64 && buf->page_shift == PAGE_SHIFT) - vunmap(buf->direct.buf); - for (i = 0; i < buf->nbufs; ++i) if (buf->page_list[i].buf) dma_free_coherent(dev, 1 << buf->page_shift, @@ -185,9 +181,7 @@ int hns_roce_buf_alloc(struct hns_roce_dev *hr_dev, u32 size, u32 max_direct, { int i = 0; dma_addr_t t; - struct page **pages; struct device *dev = hr_dev->dev; - u32 bits_per_long = BITS_PER_LONG; u32 page_size = 1 << page_shift; u32 order; @@ -236,23 +230,6 @@ int hns_roce_buf_alloc(struct hns_roce_dev *hr_dev, u32 size, u32 max_direct, buf->page_list[i].map = t; memset(buf->page_list[i].buf, 0, page_size); } - if (bits_per_long == 64 && page_shift == PAGE_SHIFT) { - pages = kmalloc_array(buf->nbufs, sizeof(*pages), - GFP_KERNEL); - if (!pages) - goto err_free; - - for (i = 0; i < buf->nbufs; ++i) - pages[i] = virt_to_page(buf->page_list[i].buf); - - buf->direct.buf = vmap(pages, buf->nbufs, VM_MAP, - PAGE_KERNEL); - kfree(pages); - if (!buf->direct.buf) - goto err_free; - } else { - buf->direct.buf = NULL; - } } return 0; diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h b/drivers/infiniband/hw/hns/hns_roce_device.h index 01d3d695cbba..b154ce40cded 100644 --- a/drivers/infiniband/hw/hns/hns_roce_device.h +++ b/drivers/infiniband/hw/hns/hns_roce_device.h @@ -726,11 +726,9 @@ static inline struct hns_roce_qp static inline void *hns_roce_buf_offset(struct hns_roce_buf *buf, int offset) { - u32 bits_per_long_val = BITS_PER_LONG; u32 page_size = 1 << buf->page_shift; - if ((bits_per_long_val == 64 && buf->page_shift == PAGE_SHIFT) || - buf->nbufs == 1) + if (buf->nbufs == 1) return (char *)(buf->direct.buf) + offset; else return (char *)(buf->page_list[offset >> buf->page_shift].buf) + -- GitLab