> -----Original Message-----
> From: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Sent: Friday, 14 April 2023 15:58
> To: Bernard Metzler <BMT@xxxxxxxxxxxxxx>; Leon Romanovsky
> <leon@xxxxxxxxxx>; linux-rdma@xxxxxxxxxxxxxxx; Zhu Yanjun
> <zyjzyj2000@xxxxxxxxx>
> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
> Subject: [EXTERNAL] [PATCH v2] RDMA: Add ib_virt_dma_to_page()
>
> Make it clearer what is going on by adding a function to go back from the
> "virtual" dma_addr to a kva and another to a struct page. This is used in
> the
> ib_uses_virt_dma() style drivers (siw, rxe, hfi, qib).
>
> Call them instead of a naked casting and virt_to_page() when working with
> dma_addr
> values encoded by the various ib_map functions.
>
> This also fixes the virt_to_page() casting problem Linus Walleij has been
> chasing.
>
> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> ---
> drivers/infiniband/sw/rxe/rxe_mr.c | 16 ++++++++--------
> drivers/infiniband/sw/rxe/rxe_verbs.c | 2 +-
> drivers/infiniband/sw/siw/siw_qp_rx.c | 6 +++---
> drivers/infiniband/sw/siw/siw_qp_tx.c | 19 ++++++-------------
> drivers/infiniband/sw/siw/siw_verbs.c | 4 ++--
> include/rdma/ib_verbs.h | 25 +++++++++++++++++++++++++
> 6 files changed, 45 insertions(+), 27 deletions(-)
>
> v2:
> - Add ib_virt_dma_to_ptr() as well to solve the compilation warning
> problem on 32 bit.
> v1: INVALID URI REMOVED
> 3A__lore.kernel.org_r_0-2Dv1-2D789ba72d2950-2B2e-2Dib-5Fvirt-5Fpage-5Fjgg-
> 40nvidia.com_&d=DwIDAg&c=jf_iaSHvJObTbx-siA1ZOg&r=2TaYXQ0T-
> r8ZO1PP1alNwU_QJcRRLfmYTAgd3QCvqSc&m=x0pyaJvLFc1vj23NB1Tod-
> R4uo7IlVzFtfaXh8o37pWvab8JylJjtJi2c1qVOtGK&s=u1W6B9A0tPmxsjYk77UUbVaa0x2Gf2
> ukNNzN-cWsNkA&e=
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c
> b/drivers/infiniband/sw/rxe/rxe_mr.c
> index 1e17f8086d59a8..0e538fafcc20ff 100644
> --- a/drivers/infiniband/sw/rxe/rxe_mr.c
> +++ b/drivers/infiniband/sw/rxe/rxe_mr.c
> @@ -210,10 +210,10 @@ int rxe_mr_init_fast(int max_pages, struct rxe_mr
> *mr)
> return err;
> }
>
> -static int rxe_set_page(struct ib_mr *ibmr, u64 iova)
> +static int rxe_set_page(struct ib_mr *ibmr, u64 dma_addr)
> {
> struct rxe_mr *mr = to_rmr(ibmr);
> - struct page *page = virt_to_page(iova & mr->page_mask);
> + struct page *page = ib_virt_dma_to_page(dma_addr);
> bool persistent = !!(mr->access & IB_ACCESS_FLUSH_PERSISTENT);
> int err;
>
> @@ -279,16 +279,16 @@ static int rxe_mr_copy_xarray(struct rxe_mr *mr, u64
> iova, void *addr,
> return 0;
> }
>
> -static void rxe_mr_copy_dma(struct rxe_mr *mr, u64 iova, void *addr,
> +static void rxe_mr_copy_dma(struct rxe_mr *mr, u64 dma_addr, void *addr,
> unsigned int length, enum rxe_mr_copy_dir dir)
> {
> - unsigned int page_offset = iova & (PAGE_SIZE - 1);
> + unsigned int page_offset = dma_addr & (PAGE_SIZE - 1);
> unsigned int bytes;
> struct page *page;
> u8 *va;
>
> while (length) {
> - page = virt_to_page(iova & mr->page_mask);
> + page = ib_virt_dma_to_page(dma_addr);
> bytes = min_t(unsigned int, length,
> PAGE_SIZE - page_offset);
> va = kmap_local_page(page);
> @@ -300,7 +300,7 @@ static void rxe_mr_copy_dma(struct rxe_mr *mr, u64
> iova, void *addr,
>
> kunmap_local(va);
> page_offset = 0;
> - iova += bytes;
> + dma_addr += bytes;
> addr += bytes;
> length -= bytes;
> }
> @@ -488,7 +488,7 @@ int rxe_mr_do_atomic_op(struct rxe_mr *mr, u64 iova,
> int opcode,
>
> if (mr->ibmr.type == IB_MR_TYPE_DMA) {
> page_offset = iova & (PAGE_SIZE - 1);
> - page = virt_to_page(iova & PAGE_MASK);
> + page = ib_virt_dma_to_page(iova);
> } else {
> unsigned long index;
> int err;
> @@ -545,7 +545,7 @@ int rxe_mr_do_atomic_write(struct rxe_mr *mr, u64 iova,
> u64 value)
>
> if (mr->ibmr.type == IB_MR_TYPE_DMA) {
> page_offset = iova & (PAGE_SIZE - 1);
> - page = virt_to_page(iova & PAGE_MASK);
> + page = ib_virt_dma_to_page(iova);
> } else {
> unsigned long index;
> int err;
> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c
> b/drivers/infiniband/sw/rxe/rxe_verbs.c
> index 4e2db7c2e4ed78..12819153bda769 100644
> --- a/drivers/infiniband/sw/rxe/rxe_verbs.c
> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
> @@ -760,7 +760,7 @@ static void copy_inline_data_to_wqe(struct rxe_send_wqe
> *wqe,
> int i;
>
> for (i = 0; i < ibwr->num_sge; i++, sge++) {
> - memcpy(p, (void *)(uintptr_t)sge->addr, sge->length);
> + memcpy(p, ib_virt_dma_to_page(sge->addr), sge->length);
> p += sge->length;
> }
> }
> diff --git a/drivers/infiniband/sw/siw/siw_qp_rx.c
> b/drivers/infiniband/sw/siw/siw_qp_rx.c
> index fd721cc19682eb..58bbf738e4e599 100644
> --- a/drivers/infiniband/sw/siw/siw_qp_rx.c
> +++ b/drivers/infiniband/sw/siw/siw_qp_rx.c
> @@ -139,7 +139,7 @@ static int siw_rx_pbl(struct siw_rx_stream *srx, int
> *pbl_idx,
> break;
>
> bytes = min(bytes, len);
> - if (siw_rx_kva(srx, (void *)(uintptr_t)buf_addr, bytes) ==
> + if (siw_rx_kva(srx, ib_virt_dma_to_ptr(buf_addr), bytes) ==
> bytes) {
> copied += bytes;
> offset += bytes;
> @@ -487,7 +487,7 @@ int siw_proc_send(struct siw_qp *qp)
> mem_p = *mem;
> if (mem_p->mem_obj == NULL)
> rv = siw_rx_kva(srx,
> - (void *)(uintptr_t)(sge->laddr + frx->sge_off),
> + ib_virt_dma_to_ptr(sge->laddr + frx->sge_off),
> sge_bytes);
> else if (!mem_p->is_pbl)
> rv = siw_rx_umem(srx, mem_p->umem,
> @@ -852,7 +852,7 @@ int siw_proc_rresp(struct siw_qp *qp)
>
> if (mem_p->mem_obj == NULL)
> rv = siw_rx_kva(srx,
> - (void *)(uintptr_t)(sge->laddr + wqe->processed),
> + ib_virt_dma_to_ptr(sge->laddr + wqe->processed),
> bytes);
> else if (!mem_p->is_pbl)
> rv = siw_rx_umem(srx, mem_p->umem, sge->laddr + wqe->processed,
> diff --git a/drivers/infiniband/sw/siw/siw_qp_tx.c
> b/drivers/infiniband/sw/siw/siw_qp_tx.c
> index 6bb9e9e81ff4ca..4b292e0504f1a1 100644
> --- a/drivers/infiniband/sw/siw/siw_qp_tx.c
> +++ b/drivers/infiniband/sw/siw/siw_qp_tx.c
> @@ -29,7 +29,7 @@ static struct page *siw_get_pblpage(struct siw_mem *mem,
> u64 addr, int *idx)
> dma_addr_t paddr = siw_pbl_get_buffer(pbl, offset, NULL, idx);
>
> if (paddr)
> - return virt_to_page((void *)(uintptr_t)paddr);
> + return ib_virt_dma_to_page(paddr);
>
> return NULL;
> }
> @@ -56,8 +56,7 @@ static int siw_try_1seg(struct siw_iwarp_tx *c_tx, void
> *paddr)
>
> if (!mem->mem_obj) {
> /* Kernel client using kva */
> - memcpy(paddr,
> - (const void *)(uintptr_t)sge->laddr, bytes);
> + memcpy(paddr, ib_virt_dma_to_ptr(sge->laddr), bytes);
> } else if (c_tx->in_syscall) {
> if (copy_from_user(paddr, u64_to_user_ptr(sge->laddr),
> bytes))
> @@ -477,7 +476,7 @@ static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct
> socket *s)
> * or memory region with assigned kernel buffer
> */
> iov[seg].iov_base =
> - (void *)(uintptr_t)(sge->laddr + sge_off);
> + ib_virt_dma_to_ptr(sge->laddr + sge_off);
> iov[seg].iov_len = sge_len;
>
> if (do_crc)
> @@ -537,19 +536,13 @@ static int siw_tx_hdt(struct siw_iwarp_tx *c_tx,
> struct socket *s)
> * Cast to an uintptr_t to preserve all 64 bits
> * in sge->laddr.
> */
> - uintptr_t va = (uintptr_t)(sge->laddr + sge_off);
> + u64 va = sge->laddr + sge_off;
>
> - /*
> - * virt_to_page() takes a (void *) pointer
> - * so cast to a (void *) meaning it will be 64
> - * bits on a 64 bit platform and 32 bits on a
> - * 32 bit platform.
> - */
> - page_array[seg] = virt_to_page((void *)(va &
> PAGE_MASK));
> + page_array[seg] = ib_virt_dma_to_page(va);
> if (do_crc)
> crypto_shash_update(
> c_tx->mpa_crc_hd,
> - (void *)va,
> + ib_virt_dma_to_ptr(va),
> plen);
> }
>
> diff --git a/drivers/infiniband/sw/siw/siw_verbs.c
> b/drivers/infiniband/sw/siw/siw_verbs.c
> index 906fde1a2a0de2..398ec13db62481 100644
> --- a/drivers/infiniband/sw/siw/siw_verbs.c
> +++ b/drivers/infiniband/sw/siw/siw_verbs.c
> @@ -660,7 +660,7 @@ static int siw_copy_inline_sgl(const struct ib_send_wr
> *core_wr,
> bytes = -EINVAL;
> break;
> }
> - memcpy(kbuf, (void *)(uintptr_t)core_sge->addr,
> + memcpy(kbuf, ib_virt_dma_to_ptr(core_sge->addr),
> core_sge->length);
>
> kbuf += core_sge->length;
> @@ -1523,7 +1523,7 @@ int siw_map_mr_sg(struct ib_mr *base_mr, struct
> scatterlist *sl, int num_sle,
> }
> siw_dbg_mem(mem,
> "sge[%d], size %u, addr 0x%p, total %lu\n",
> - i, pble->size, (void *)(uintptr_t)pble->addr,
> + i, pble->size, ib_virt_dma_to_ptr(pble->addr),
> pbl_size);
> }
> rv = ib_sg_to_pages(base_mr, sl, num_sle, sg_off, siw_set_pbl_page);
> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
> index 949cf4ffc536c5..1e7774ac808f08 100644
> --- a/include/rdma/ib_verbs.h
> +++ b/include/rdma/ib_verbs.h
> @@ -4035,6 +4035,31 @@ static inline bool
> ib_dma_pci_p2p_dma_supported(struct ib_device *dev)
> return dma_pci_p2pdma_supported(dev->dma_device);
> }
>
> +/**
> + * ib_virt_dma_to_ptr - Convert a dma_addr to a kernel pointer
> + * @dma_addr: The DMA address
> + *
> + * Used by ib_uses_virt_dma() devices to get back to the kernel pointer
> after
> + * going through the dma_addr marshalling.
> + */
> +static inline void *ib_virt_dma_to_ptr(u64 dma_addr)
> +{
> + /* virt_dma mode maps the kvs's directly into the dma addr */
> + return (void *)(uintptr_t)dma_addr;
> +}
> +
> +/**
> + * ib_virt_dma_to_page - Convert a dma_addr to a struct page
> + * @dma_addr: The DMA address
> + *
> + * Used by ib_uses_virt_dma() device to get back to the struct page after
> going
> + * through the dma_addr marshalling.
> + */
> +static inline struct page *ib_virt_dma_to_page(u64 dma_addr)
> +{
> + return virt_to_page(ib_virt_dma_to_ptr(dma_addr));
> +}
> +
> /**
> * ib_dma_mapping_error - check a DMA addr for error
> * @dev: The device for which the dma_addr was created
>
> base-commit: a2e20b29cf9ce6d2070a6e36666e2239f7f9625b
> --
> 2.40.0
Thank you Jason. Looks cleaner than all that explicit casting!
