From f7c6a7b5d59980b076abbf2ceeb8735591290285 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Sun, 4 Mar 2007 16:15:11 -0800 Subject: IB/uverbs: Export ib_umem_get()/ib_umem_release() to modules Export ib_umem_get()/ib_umem_release() and put low-level drivers in control of when to call ib_umem_get() to pin and DMA map userspace, rather than always calling it in ib_uverbs_reg_mr() before calling the low-level driver's reg_user_mr method. Also move these functions to be in the ib_core module instead of ib_uverbs, so that driver modules using them do not depend on ib_uverbs. This has a number of advantages: - It is better design from the standpoint of making generic code a library that can be used or overridden by device-specific code as the details of specific devices dictate. - Drivers that do not need to pin userspace memory regions do not need to take the performance hit of calling ib_mem_get(). For example, although I have not tried to implement it in this patch, the ipath driver should be able to avoid pinning memory and just use copy_{to,from}_user() to access userspace memory regions. - Buffers that need special mapping treatment can be identified by the low-level driver. For example, it may be possible to solve some Altix-specific memory ordering issues with mthca CQs in userspace by mapping CQ buffers with extra flags. - Drivers that need to pin and DMA map userspace memory for things other than memory regions can use ib_umem_get() directly, instead of hacks using extra parameters to their reg_phys_mr method. For example, the mlx4 driver that is pending being merged needs to pin and DMA map QP and CQ buffers, but it does not need to create a memory key for these buffers. So the cleanest solution is for mlx4 to call ib_umem_get() in the create_qp and create_cq methods. Signed-off-by: Roland Dreier --- drivers/infiniband/hw/mthca/mthca_provider.c | 38 ++++++++++++++++++++-------- 1 file changed, 28 insertions(+), 10 deletions(-) (limited to 'drivers/infiniband/hw/mthca/mthca_provider.c') diff --git a/drivers/infiniband/hw/mthca/mthca_provider.c b/drivers/infiniband/hw/mthca/mthca_provider.c index 1c05486c3c68..6bcde1cb9688 100644 --- a/drivers/infiniband/hw/mthca/mthca_provider.c +++ b/drivers/infiniband/hw/mthca/mthca_provider.c @@ -37,6 +37,7 @@ */ #include +#include #include #include @@ -908,6 +909,8 @@ static struct ib_mr *mthca_get_dma_mr(struct ib_pd *pd, int acc) return ERR_PTR(err); } + mr->umem = NULL; + return &mr->ibmr; } @@ -1003,11 +1006,13 @@ static struct ib_mr *mthca_reg_phys_mr(struct ib_pd *pd, } kfree(page_list); + mr->umem = NULL; + return &mr->ibmr; } -static struct ib_mr *mthca_reg_user_mr(struct ib_pd *pd, struct ib_umem *region, - int acc, struct ib_udata *udata) +static struct ib_mr *mthca_reg_user_mr(struct ib_pd *pd, u64 start, u64 length, + u64 virt, int acc, struct ib_udata *udata) { struct mthca_dev *dev = to_mdev(pd->device); struct ib_umem_chunk *chunk; @@ -1018,20 +1023,26 @@ static struct ib_mr *mthca_reg_user_mr(struct ib_pd *pd, struct ib_umem *region, int err = 0; int write_mtt_size; - shift = ffs(region->page_size) - 1; - mr = kmalloc(sizeof *mr, GFP_KERNEL); if (!mr) return ERR_PTR(-ENOMEM); + mr->umem = ib_umem_get(pd->uobject->context, start, length, acc); + if (IS_ERR(mr->umem)) { + err = PTR_ERR(mr->umem); + goto err; + } + + shift = ffs(mr->umem->page_size) - 1; + n = 0; - list_for_each_entry(chunk, ®ion->chunk_list, list) + list_for_each_entry(chunk, &mr->umem->chunk_list, list) n += chunk->nents; mr->mtt = mthca_alloc_mtt(dev, n); if (IS_ERR(mr->mtt)) { err = PTR_ERR(mr->mtt); - goto err; + goto err_umem; } pages = (u64 *) __get_free_page(GFP_KERNEL); @@ -1044,12 +1055,12 @@ static struct ib_mr *mthca_reg_user_mr(struct ib_pd *pd, struct ib_umem *region, write_mtt_size = min(mthca_write_mtt_size(dev), (int) (PAGE_SIZE / sizeof *pages)); - list_for_each_entry(chunk, ®ion->chunk_list, list) + list_for_each_entry(chunk, &mr->umem->chunk_list, list) for (j = 0; j < chunk->nmap; ++j) { len = sg_dma_len(&chunk->page_list[j]) >> shift; for (k = 0; k < len; ++k) { pages[i++] = sg_dma_address(&chunk->page_list[j]) + - region->page_size * k; + mr->umem->page_size * k; /* * Be friendly to write_mtt and pass it chunks * of appropriate size. @@ -1071,8 +1082,8 @@ mtt_done: if (err) goto err_mtt; - err = mthca_mr_alloc(dev, to_mpd(pd)->pd_num, shift, region->virt_base, - region->length, convert_access(acc), mr); + err = mthca_mr_alloc(dev, to_mpd(pd)->pd_num, shift, virt, length, + convert_access(acc), mr); if (err) goto err_mtt; @@ -1082,6 +1093,9 @@ mtt_done: err_mtt: mthca_free_mtt(dev, mr->mtt); +err_umem: + ib_umem_release(mr->umem); + err: kfree(mr); return ERR_PTR(err); @@ -1090,8 +1104,12 @@ err: static int mthca_dereg_mr(struct ib_mr *mr) { struct mthca_mr *mmr = to_mmr(mr); + mthca_free_mr(to_mdev(mr->device), mmr); + if (mmr->umem) + ib_umem_release(mmr->umem); kfree(mmr); + return 0; } -- cgit v1.2.3-59-g8ed1b