RDMA/iw_cxgb4: Low resource fixes for Memory registration

Pre-allocate buffers for deregistering memory region and memory window
during RDMA connection close, when system is running out of memory.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
index ce42d09..e94ec0d 100644 (file)
--- a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
+++ b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
@@ -384,6 +384,7 @@ struct c4iw_mr {
        struct ib_mr ibmr;
        struct ib_umem *umem;
        struct c4iw_dev *rhp;
+       struct sk_buff *dereg_skb;
        u64 kva;
        struct tpt_attributes attr;
        u64 *mpl;
@@ -400,6 +401,7 @@ static inline struct c4iw_mr *to_c4iw_mr(struct ib_mr *ibmr)
 struct c4iw_mw {
        struct ib_mw ibmw;
        struct c4iw_dev *rhp;
+       struct sk_buff *dereg_skb;
        u64 kva;
        struct tpt_attributes attr;
 };

diff --git a/drivers/infiniband/hw/cxgb4/mem.c b/drivers/infiniband/hw/cxgb4/mem.c
index 55d0651..5d0aa55 100644 (file)
--- a/drivers/infiniband/hw/cxgb4/mem.c
+++ b/drivers/infiniband/hw/cxgb4/mem.c
@@ -59,9 +59,9 @@ static int mr_exceeds_hw_limits(struct c4iw_dev *dev, u64 length)
 }
 
 static int _c4iw_write_mem_dma_aligned(struct c4iw_rdev *rdev, u32 addr,
-                                      u32 len, dma_addr_t data, int wait)
+                                      u32 len, dma_addr_t data,
+                                      int wait, struct sk_buff *skb)
 {
-       struct sk_buff *skb;
        struct ulp_mem_io *req;
        struct ulptx_sgl *sgl;
        u8 wr_len;
@@ -74,9 +74,11 @@ static int _c4iw_write_mem_dma_aligned(struct c4iw_rdev *rdev, u32 addr,
                c4iw_init_wr_wait(&wr_wait);
        wr_len = roundup(sizeof(*req) + sizeof(*sgl), 16);
 
-       skb = alloc_skb(wr_len, GFP_KERNEL);
-       if (!skb)
-               return -ENOMEM;
+       if (!skb) {
+               skb = alloc_skb(wr_len, GFP_KERNEL | __GFP_NOFAIL);
+               if (!skb)
+                       return -ENOMEM;
+       }
        set_wr_txq(skb, CPL_PRIORITY_CONTROL, 0);
 
        req = (struct ulp_mem_io *)__skb_put(skb, wr_len);
@@ -108,9 +110,8 @@ static int _c4iw_write_mem_dma_aligned(struct c4iw_rdev *rdev, u32 addr,
 }
 
 static int _c4iw_write_mem_inline(struct c4iw_rdev *rdev, u32 addr, u32 len,
-                                 void *data)
+                                 void *data, struct sk_buff *skb)
 {
-       struct sk_buff *skb;
        struct ulp_mem_io *req;
        struct ulptx_idata *sc;
        u8 wr_len, *to_dp, *from_dp;
@@ -134,9 +135,11 @@ static int _c4iw_write_mem_inline(struct c4iw_rdev *rdev, u32 addr, u32 len,
                wr_len = roundup(sizeof *req + sizeof *sc +
                                 roundup(copy_len, T4_ULPTX_MIN_IO), 16);
 
-               skb = alloc_skb(wr_len, GFP_KERNEL);
-               if (!skb)
-                       return -ENOMEM;
+               if (!skb) {
+                       skb = alloc_skb(wr_len, GFP_KERNEL | __GFP_NOFAIL);
+                       if (!skb)
+                               return -ENOMEM;
+               }
                set_wr_txq(skb, CPL_PRIORITY_CONTROL, 0);
 
                req = (struct ulp_mem_io *)__skb_put(skb, wr_len);
@@ -173,6 +176,7 @@ static int _c4iw_write_mem_inline(struct c4iw_rdev *rdev, u32 addr, u32 len,
                        memset(to_dp + copy_len, 0, T4_ULPTX_MIN_IO -
                               (copy_len % T4_ULPTX_MIN_IO));
                ret = c4iw_ofld_send(rdev, skb);
+               skb = NULL;
                if (ret)
                        return ret;
                len -= C4IW_MAX_INLINE_SIZE;
@@ -182,7 +186,8 @@ static int _c4iw_write_mem_inline(struct c4iw_rdev *rdev, u32 addr, u32 len,
        return ret;
 }
 
-static int _c4iw_write_mem_dma(struct c4iw_rdev *rdev, u32 addr, u32 len, void *data)
+static int _c4iw_write_mem_dma(struct c4iw_rdev *rdev, u32 addr, u32 len,
+                              void *data, struct sk_buff *skb)
 {
        u32 remain = len;
        u32 dmalen;
@@ -205,7 +210,7 @@ static int _c4iw_write_mem_dma(struct c4iw_rdev *rdev, u32 addr, u32 len, void *
                        dmalen = T4_ULPTX_MAX_DMA;
                remain -= dmalen;
                ret = _c4iw_write_mem_dma_aligned(rdev, addr, dmalen, daddr,
-                                                !remain);
+                                                !remain, skb);
                if (ret)
                        goto out;
                addr += dmalen >> 5;
@@ -213,7 +218,7 @@ static int _c4iw_write_mem_dma(struct c4iw_rdev *rdev, u32 addr, u32 len, void *
                daddr += dmalen;
        }
        if (remain)
-               ret = _c4iw_write_mem_inline(rdev, addr, remain, data);
+               ret = _c4iw_write_mem_inline(rdev, addr, remain, data, skb);
 out:
        dma_unmap_single(&rdev->lldi.pdev->dev, save, len, DMA_TO_DEVICE);
        return ret;
@@ -224,23 +229,25 @@ out:
  * If data is NULL, clear len byte of memory to zero.
  */
 static int write_adapter_mem(struct c4iw_rdev *rdev, u32 addr, u32 len,
-                            void *data)
+                            void *data, struct sk_buff *skb)
 {
        if (is_t5(rdev->lldi.adapter_type) && use_dsgl) {
                if (len > inline_threshold) {
-                       if (_c4iw_write_mem_dma(rdev, addr, len, data)) {
+                       if (_c4iw_write_mem_dma(rdev, addr, len, data, skb)) {
                                printk_ratelimited(KERN_WARNING
                                                   "%s: dma map"
                                                   " failure (non fatal)\n",
                                                   pci_name(rdev->lldi.pdev));
                                return _c4iw_write_mem_inline(rdev, addr, len,
-                                                             data);
-                       } else
+                                                             data, skb);
+                       } else {
                                return 0;
+                       }
                } else
-                       return _c4iw_write_mem_inline(rdev, addr, len, data);
+                       return _c4iw_write_mem_inline(rdev, addr,
+                                                     len, data, skb);
        } else
-               return _c4iw_write_mem_inline(rdev, addr, len, data);
+               return _c4iw_write_mem_inline(rdev, addr, len, data, skb);
 }
 
 /*
@@ -253,7 +260,8 @@ static int write_tpt_entry(struct c4iw_rdev *rdev, u32 reset_tpt_entry,
                           u32 *stag, u8 stag_state, u32 pdid,
                           enum fw_ri_stag_type type, enum fw_ri_mem_perms perm,
                           int bind_enabled, u32 zbva, u64 to,
-                          u64 len, u8 page_size, u32 pbl_size, u32 pbl_addr)
+                          u64 len, u8 page_size, u32 pbl_size, u32 pbl_addr,
+                          struct sk_buff *skb)
 {
        int err;
        struct fw_ri_tpte tpt;
@@ -307,7 +315,7 @@ static int write_tpt_entry(struct c4iw_rdev *rdev, u32 reset_tpt_entry,
        }
        err = write_adapter_mem(rdev, stag_idx +
                                (rdev->lldi.vr->stag.start >> 5),
-                               sizeof(tpt), &tpt);
+                               sizeof(tpt), &tpt, skb);
 
        if (reset_tpt_entry) {
                c4iw_put_resource(&rdev->resource.tpt_table, stag_idx);
@@ -327,28 +335,29 @@ static int write_pbl(struct c4iw_rdev *rdev, __be64 *pbl,
             __func__, pbl_addr, rdev->lldi.vr->pbl.start,
             pbl_size);
 
-       err = write_adapter_mem(rdev, pbl_addr >> 5, pbl_size << 3, pbl);
+       err = write_adapter_mem(rdev, pbl_addr >> 5, pbl_size << 3, pbl, NULL);
        return err;
 }
 
 static int dereg_mem(struct c4iw_rdev *rdev, u32 stag, u32 pbl_size,
-                    u32 pbl_addr)
+                    u32 pbl_addr, struct sk_buff *skb)
 {
        return write_tpt_entry(rdev, 1, &stag, 0, 0, 0, 0, 0, 0, 0UL, 0, 0,
-                              pbl_size, pbl_addr);
+                              pbl_size, pbl_addr, skb);
 }
 
 static int allocate_window(struct c4iw_rdev *rdev, u32 * stag, u32 pdid)
 {
        *stag = T4_STAG_UNSET;
        return write_tpt_entry(rdev, 0, stag, 0, pdid, FW_RI_STAG_MW, 0, 0, 0,
-                              0UL, 0, 0, 0, 0);
+                              0UL, 0, 0, 0, 0, NULL);
 }
 
-static int deallocate_window(struct c4iw_rdev *rdev, u32 stag)
+static int deallocate_window(struct c4iw_rdev *rdev, u32 stag,
+                            struct sk_buff *skb)
 {
        return write_tpt_entry(rdev, 1, &stag, 0, 0, 0, 0, 0, 0, 0UL, 0, 0, 0,
-                              0);
+                              0, skb);
 }
 
 static int allocate_stag(struct c4iw_rdev *rdev, u32 *stag, u32 pdid,
@@ -356,7 +365,7 @@ static int allocate_stag(struct c4iw_rdev *rdev, u32 *stag, u32 pdid,
 {
        *stag = T4_STAG_UNSET;
        return write_tpt_entry(rdev, 0, stag, 0, pdid, FW_RI_STAG_NSMR, 0, 0, 0,
-                              0UL, 0, 0, pbl_size, pbl_addr);
+                              0UL, 0, 0, pbl_size, pbl_addr, NULL);
 }
 
 static int finish_mem_reg(struct c4iw_mr *mhp, u32 stag)
@@ -383,14 +392,16 @@ static int register_mem(struct c4iw_dev *rhp, struct c4iw_pd *php,
                              mhp->attr.mw_bind_enable, mhp->attr.zbva,
                              mhp->attr.va_fbo, mhp->attr.len ?
                              mhp->attr.len : -1, shift - 12,
-                             mhp->attr.pbl_size, mhp->attr.pbl_addr);
+                             mhp->attr.pbl_size, mhp->attr.pbl_addr, NULL);
        if (ret)
                return ret;
 
        ret = finish_mem_reg(mhp, stag);
-       if (ret)
+       if (ret) {
                dereg_mem(&rhp->rdev, mhp->attr.stag, mhp->attr.pbl_size,
-                      mhp->attr.pbl_addr);
+                         mhp->attr.pbl_addr, mhp->dereg_skb);
+               mhp->dereg_skb = NULL;
+       }
        return ret;
 }
 
@@ -423,6 +434,12 @@ struct ib_mr *c4iw_get_dma_mr(struct ib_pd *pd, int acc)
        if (!mhp)
                return ERR_PTR(-ENOMEM);
 
+       mhp->dereg_skb = alloc_skb(SGE_MAX_WR_LEN, GFP_KERNEL);
+       if (!mhp->dereg_skb) {
+               ret = -ENOMEM;
+               goto err0;
+       }
+
        mhp->rhp = rhp;
        mhp->attr.pdid = php->pdid;
        mhp->attr.perms = c4iw_ib_to_tpt_access(acc);
@@ -435,7 +452,8 @@ struct ib_mr *c4iw_get_dma_mr(struct ib_pd *pd, int acc)
 
        ret = write_tpt_entry(&rhp->rdev, 0, &stag, 1, php->pdid,
                              FW_RI_STAG_NSMR, mhp->attr.perms,
-                             mhp->attr.mw_bind_enable, 0, 0, ~0ULL, 0, 0, 0);
+                             mhp->attr.mw_bind_enable, 0, 0, ~0ULL, 0, 0, 0,
+                             NULL);
        if (ret)
                goto err1;
 
@@ -445,8 +463,10 @@ struct ib_mr *c4iw_get_dma_mr(struct ib_pd *pd, int acc)
        return &mhp->ibmr;
 err2:
        dereg_mem(&rhp->rdev, mhp->attr.stag, mhp->attr.pbl_size,
-                 mhp->attr.pbl_addr);
+                 mhp->attr.pbl_addr, mhp->dereg_skb);
 err1:
+       kfree_skb(mhp->dereg_skb);
+err0:
        kfree(mhp);
        return ERR_PTR(ret);
 }
@@ -481,11 +501,18 @@ struct ib_mr *c4iw_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
        if (!mhp)
                return ERR_PTR(-ENOMEM);
 
+       mhp->dereg_skb = alloc_skb(SGE_MAX_WR_LEN, GFP_KERNEL);
+       if (!mhp->dereg_skb) {
+               kfree(mhp);
+               return ERR_PTR(-ENOMEM);
+       }
+
        mhp->rhp = rhp;
 
        mhp->umem = ib_umem_get(pd->uobject->context, start, length, acc, 0);
        if (IS_ERR(mhp->umem)) {
                err = PTR_ERR(mhp->umem);
+               kfree_skb(mhp->dereg_skb);
                kfree(mhp);
                return ERR_PTR(err);
        }
@@ -550,6 +577,7 @@ err_pbl:
 
 err:
        ib_umem_release(mhp->umem);
+       kfree_skb(mhp->dereg_skb);
        kfree(mhp);
        return ERR_PTR(err);
 }
@@ -572,8 +600,16 @@ struct ib_mw *c4iw_alloc_mw(struct ib_pd *pd, enum ib_mw_type type,
        mhp = kzalloc(sizeof(*mhp), GFP_KERNEL);
        if (!mhp)
                return ERR_PTR(-ENOMEM);
+
+       mhp->dereg_skb = alloc_skb(SGE_MAX_WR_LEN, GFP_KERNEL);
+       if (!mhp->dereg_skb) {
+               kfree(mhp);
+               return ERR_PTR(-ENOMEM);
+       }
+
        ret = allocate_window(&rhp->rdev, &stag, php->pdid);
        if (ret) {
+               kfree(mhp->dereg_skb);
                kfree(mhp);
                return ERR_PTR(ret);
        }
@@ -584,7 +620,8 @@ struct ib_mw *c4iw_alloc_mw(struct ib_pd *pd, enum ib_mw_type type,
        mmid = (stag) >> 8;
        mhp->ibmw.rkey = stag;
        if (insert_handle(rhp, &rhp->mmidr, mhp, mmid)) {
-               deallocate_window(&rhp->rdev, mhp->attr.stag);
+               deallocate_window(&rhp->rdev, mhp->attr.stag, mhp->dereg_skb);
+               kfree(mhp->dereg_skb);
                kfree(mhp);
                return ERR_PTR(-ENOMEM);
        }
@@ -602,7 +639,7 @@ int c4iw_dealloc_mw(struct ib_mw *mw)
        rhp = mhp->rhp;
        mmid = (mw->rkey) >> 8;
        remove_handle(rhp, &rhp->mmidr, mmid);
-       deallocate_window(&rhp->rdev, mhp->attr.stag);
+       deallocate_window(&rhp->rdev, mhp->attr.stag, mhp->dereg_skb);
        kfree(mhp);
        PDBG("%s ib_mw %p mmid 0x%x ptr %p\n", __func__, mw, mmid, mhp);
        return 0;
@@ -666,7 +703,7 @@ struct ib_mr *c4iw_alloc_mr(struct ib_pd *pd,
        return &(mhp->ibmr);
 err3:
        dereg_mem(&rhp->rdev, stag, mhp->attr.pbl_size,
-                      mhp->attr.pbl_addr);
+                 mhp->attr.pbl_addr, mhp->dereg_skb);
 err2:
        c4iw_pblpool_free(&mhp->rhp->rdev, mhp->attr.pbl_addr,
                              mhp->attr.pbl_size << 3);
@@ -717,7 +754,7 @@ int c4iw_dereg_mr(struct ib_mr *ib_mr)
                dma_free_coherent(&mhp->rhp->rdev.lldi.pdev->dev,
                                  mhp->max_mpl_len, mhp->mpl, mhp->mpl_addr);
        dereg_mem(&rhp->rdev, mhp->attr.stag, mhp->attr.pbl_size,
-                      mhp->attr.pbl_addr);
+                 mhp->attr.pbl_addr, mhp->dereg_skb);
        if (mhp->attr.pbl_size)
                c4iw_pblpool_free(&mhp->rhp->rdev, mhp->attr.pbl_addr,
                                  mhp->attr.pbl_size << 3);