RDMA/cxgb4: Save the correct map length for fast_reg_page_lists

We cannot save the mapped length using the rdma max_page_list_len field
of the ib_fast_reg_page_list struct because the core code uses it.  This
results in an incorrect unmap of the page list in c4iw_free_fastreg_pbl().

I found this with dma mapping debugging enabled in the kernel.  The
fix is to save the length in the c4iw_fr_page_list struct.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

diff --git a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
index b810d2a..a1e8f13 100644 (file)
--- a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
+++ b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
@@ -369,6 +369,7 @@ struct c4iw_fr_page_list {
        DEFINE_DMA_UNMAP_ADDR(mapping);
        dma_addr_t dma_addr;
        struct c4iw_dev *dev;
+       int pll_len;
 };
 
 static inline struct c4iw_fr_page_list *to_c4iw_fr_page_list(

diff --git a/drivers/infiniband/hw/cxgb4/mem.c b/drivers/infiniband/hw/cxgb4/mem.c
index 41b1195..22a2e3e 100644 (file)
--- a/drivers/infiniband/hw/cxgb4/mem.c
+++ b/drivers/infiniband/hw/cxgb4/mem.c
@@ -903,7 +903,11 @@ struct ib_fast_reg_page_list *c4iw_alloc_fastreg_pbl(struct ib_device *device,
        dma_unmap_addr_set(c4pl, mapping, dma_addr);
        c4pl->dma_addr = dma_addr;
        c4pl->dev = dev;
-       c4pl->ibpl.max_page_list_len = pll_len;
+       c4pl->pll_len = pll_len;
+
+       PDBG("%s c4pl %p pll_len %u page_list %p dma_addr %pad\n",
+            __func__, c4pl, c4pl->pll_len, c4pl->ibpl.page_list,
+            &c4pl->dma_addr);
 
        return &c4pl->ibpl;
 }
@@ -912,8 +916,12 @@ void c4iw_free_fastreg_pbl(struct ib_fast_reg_page_list *ibpl)
 {
        struct c4iw_fr_page_list *c4pl = to_c4iw_fr_page_list(ibpl);
 
+       PDBG("%s c4pl %p pll_len %u page_list %p dma_addr %pad\n",
+            __func__, c4pl, c4pl->pll_len, c4pl->ibpl.page_list,
+            &c4pl->dma_addr);
+
        dma_free_coherent(&c4pl->dev->rdev.lldi.pdev->dev,
-                         c4pl->ibpl.max_page_list_len,
+                         c4pl->pll_len,
                          c4pl->ibpl.page_list, dma_unmap_addr(c4pl, mapping));
        kfree(c4pl);
 }