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@linaro.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/0-v2-05ea785520ed+10-ib_virt_page_jgg@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
index 1e17f80..0e538fa 100644 (file)
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c
@@ -210,10 +210,10 @@ err1:
        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 4e2db7c..1281915 100644 (file)
--- 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 fd721cc..58bbf73 100644 (file)
--- 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 6bb9e9e..4b292e0 100644 (file)
--- 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 906fde1..398ec13 100644 (file)
--- 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 949cf4f..1e7774a 100644 (file)
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -4036,6 +4036,31 @@ static inline bool ib_dma_pci_p2p_dma_supported(struct ib_device *dev)
 }
 
 /**
+ * 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
  * @dma_addr: The DMA address to check