Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754074AbbDMMWZ (ORCPT ); Mon, 13 Apr 2015 08:22:25 -0400 Received: from mail-wi0-f176.google.com ([209.85.212.176]:35918 "EHLO mail-wi0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753014AbbDMMWW (ORCPT ); Mon, 13 Apr 2015 08:22:22 -0400 Message-ID: <552BB4FA.5000109@profitbricks.com> Date: Mon, 13 Apr 2015 14:22:18 +0200 From: Michael Wang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Roland Dreier , Sean Hefty , Hal Rosenstock , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org CC: Tom Tucker , Steve Wise , Hoang-Nam Nguyen , Christoph Raisch , Mike Marciniszyn , Eli Cohen , Faisal Latif , Jack Morgenstein , Or Gerlitz , Haggai Eran , Ira Weiny , Tom Talpey , Jason Gunthorpe , Doug Ledford , Michael Wang Subject: [PATCH v3 01/28] IB/Verbs: Implement new callback query_transport() References: <552BB470.4090407@profitbricks.com> In-Reply-To: <552BB470.4090407@profitbricks.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 18642 Lines: 473 Add new callback query_transport() and implement for each HW. Mapping List: node-type link-layer old-transport new-transport nes RNIC ETH IWARP IWARP amso1100 RNIC ETH IWARP IWARP cxgb3 RNIC ETH IWARP IWARP cxgb4 RNIC ETH IWARP IWARP usnic USNIC_UDP ETH USNIC_UDP USNIC_UDP ocrdma IB_CA ETH IB IBOE mlx4 IB_CA IB/ETH IB IB/IBOE mlx5 IB_CA IB IB IB ehca IB_CA IB IB IB ipath IB_CA IB IB IB mthca IB_CA IB IB IB qib IB_CA IB IB IB Cc: Steve Wise Cc: Tom Talpey Cc: Jason Gunthorpe Cc: Doug Ledford Cc: Ira Weiny Cc: Sean Hefty Signed-off-by: Michael Wang --- drivers/infiniband/core/device.c | 1 + drivers/infiniband/core/verbs.c | 4 +++- drivers/infiniband/hw/amso1100/c2_provider.c | 7 +++++++ drivers/infiniband/hw/cxgb3/iwch_provider.c | 7 +++++++ drivers/infiniband/hw/cxgb4/provider.c | 7 +++++++ drivers/infiniband/hw/ehca/ehca_hca.c | 6 ++++++ drivers/infiniband/hw/ehca/ehca_iverbs.h | 3 +++ drivers/infiniband/hw/ehca/ehca_main.c | 1 + drivers/infiniband/hw/ipath/ipath_verbs.c | 7 +++++++ drivers/infiniband/hw/mlx4/main.c | 10 ++++++++++ drivers/infiniband/hw/mlx5/main.c | 7 +++++++ drivers/infiniband/hw/mthca/mthca_provider.c | 7 +++++++ drivers/infiniband/hw/nes/nes_verbs.c | 6 ++++++ drivers/infiniband/hw/ocrdma/ocrdma_main.c | 1 + drivers/infiniband/hw/ocrdma/ocrdma_verbs.c | 6 ++++++ drivers/infiniband/hw/ocrdma/ocrdma_verbs.h | 3 +++ drivers/infiniband/hw/qib/qib_verbs.c | 7 +++++++ drivers/infiniband/hw/usnic/usnic_ib_main.c | 1 + drivers/infiniband/hw/usnic/usnic_ib_verbs.c | 6 ++++++ drivers/infiniband/hw/usnic/usnic_ib_verbs.h | 2 ++ include/rdma/ib_verbs.h | 7 ++++++- 21 files changed, 104 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c index 18c1ece..a9587c4 100644 --- a/drivers/infiniband/core/device.c +++ b/drivers/infiniband/core/device.c @@ -76,6 +76,7 @@ static int ib_device_check_mandatory(struct ib_device *device) } mandatory_table[] = { IB_MANDATORY_FUNC(query_device), IB_MANDATORY_FUNC(query_port), + IB_MANDATORY_FUNC(query_transport), IB_MANDATORY_FUNC(query_pkey), IB_MANDATORY_FUNC(query_gid), IB_MANDATORY_FUNC(alloc_pd), diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c index f93eb8d..626c9cf 100644 --- a/drivers/infiniband/core/verbs.c +++ b/drivers/infiniband/core/verbs.c @@ -133,14 +133,16 @@ enum rdma_link_layer rdma_port_get_link_layer(struct ib_device *device, u8 port_ if (device->get_link_layer) return device->get_link_layer(device, port_num); - switch (rdma_node_get_transport(device->node_type)) { + switch (device->query_transport(device, port_num)) { case RDMA_TRANSPORT_IB: return IB_LINK_LAYER_INFINIBAND; + case RDMA_TRANSPORT_IBOE: case RDMA_TRANSPORT_IWARP: case RDMA_TRANSPORT_USNIC: case RDMA_TRANSPORT_USNIC_UDP: return IB_LINK_LAYER_ETHERNET; default: + BUG(); return IB_LINK_LAYER_UNSPECIFIED; } } diff --git a/drivers/infiniband/hw/amso1100/c2_provider.c b/drivers/infiniband/hw/amso1100/c2_provider.c index bdf3507..d46bbb0 100644 --- a/drivers/infiniband/hw/amso1100/c2_provider.c +++ b/drivers/infiniband/hw/amso1100/c2_provider.c @@ -99,6 +99,12 @@ static int c2_query_port(struct ib_device *ibdev, return 0; } +static enum rdma_transport_type +c2_query_transport(struct ib_device *device, u8 port_num) +{ + return RDMA_TRANSPORT_IWARP; +} + static int c2_query_pkey(struct ib_device *ibdev, u8 port, u16 index, u16 * pkey) { @@ -801,6 +807,7 @@ int c2_register_device(struct c2_dev *dev) dev->ibdev.dma_device = &dev->pcidev->dev; dev->ibdev.query_device = c2_query_device; dev->ibdev.query_port = c2_query_port; + dev->ibdev.query_transport = c2_query_transport; dev->ibdev.query_pkey = c2_query_pkey; dev->ibdev.query_gid = c2_query_gid; dev->ibdev.alloc_ucontext = c2_alloc_ucontext; diff --git a/drivers/infiniband/hw/cxgb3/iwch_provider.c b/drivers/infiniband/hw/cxgb3/iwch_provider.c index 811b24a..09682e9e 100644 --- a/drivers/infiniband/hw/cxgb3/iwch_provider.c +++ b/drivers/infiniband/hw/cxgb3/iwch_provider.c @@ -1232,6 +1232,12 @@ static int iwch_query_port(struct ib_device *ibdev, return 0; } +static enum rdma_transport_type +iwch_query_transport(struct ib_device *device, u8 port_num) +{ + return RDMA_TRANSPORT_IWARP; +} + static ssize_t show_rev(struct device *dev, struct device_attribute *attr, char *buf) { @@ -1385,6 +1391,7 @@ int iwch_register_device(struct iwch_dev *dev) dev->ibdev.dma_device = &(dev->rdev.rnic_info.pdev->dev); dev->ibdev.query_device = iwch_query_device; dev->ibdev.query_port = iwch_query_port; + dev->ibdev.query_transport = iwch_query_transport; dev->ibdev.query_pkey = iwch_query_pkey; dev->ibdev.query_gid = iwch_query_gid; dev->ibdev.alloc_ucontext = iwch_alloc_ucontext; diff --git a/drivers/infiniband/hw/cxgb4/provider.c b/drivers/infiniband/hw/cxgb4/provider.c index 66bd6a2..a445e0d 100644 --- a/drivers/infiniband/hw/cxgb4/provider.c +++ b/drivers/infiniband/hw/cxgb4/provider.c @@ -390,6 +390,12 @@ static int c4iw_query_port(struct ib_device *ibdev, u8 port, return 0; } +static enum rdma_transport_type +c4iw_query_transport(struct ib_device *device, u8 port_num) +{ + return RDMA_TRANSPORT_IWARP; +} + static ssize_t show_rev(struct device *dev, struct device_attribute *attr, char *buf) { @@ -506,6 +512,7 @@ int c4iw_register_device(struct c4iw_dev *dev) dev->ibdev.dma_device = &(dev->rdev.lldi.pdev->dev); dev->ibdev.query_device = c4iw_query_device; dev->ibdev.query_port = c4iw_query_port; + dev->ibdev.query_transport = c4iw_query_transport; dev->ibdev.query_pkey = c4iw_query_pkey; dev->ibdev.query_gid = c4iw_query_gid; dev->ibdev.alloc_ucontext = c4iw_alloc_ucontext; diff --git a/drivers/infiniband/hw/ehca/ehca_hca.c b/drivers/infiniband/hw/ehca/ehca_hca.c index 9ed4d25..d5a34a6 100644 --- a/drivers/infiniband/hw/ehca/ehca_hca.c +++ b/drivers/infiniband/hw/ehca/ehca_hca.c @@ -242,6 +242,12 @@ query_port1: return ret; } +enum rdma_transport_type +ehca_query_transport(struct ib_device *device, u8 port_num) +{ + return RDMA_TRANSPORT_IB; +} + int ehca_query_sma_attr(struct ehca_shca *shca, u8 port, struct ehca_sma_attr *attr) { diff --git a/drivers/infiniband/hw/ehca/ehca_iverbs.h b/drivers/infiniband/hw/ehca/ehca_iverbs.h index 22f79af..cec945f 100644 --- a/drivers/infiniband/hw/ehca/ehca_iverbs.h +++ b/drivers/infiniband/hw/ehca/ehca_iverbs.h @@ -49,6 +49,9 @@ int ehca_query_device(struct ib_device *ibdev, struct ib_device_attr *props); int ehca_query_port(struct ib_device *ibdev, u8 port, struct ib_port_attr *props); +enum rdma_transport_type +ehca_query_transport(struct ib_device *device, u8 port_num); + int ehca_query_sma_attr(struct ehca_shca *shca, u8 port, struct ehca_sma_attr *attr); diff --git a/drivers/infiniband/hw/ehca/ehca_main.c b/drivers/infiniband/hw/ehca/ehca_main.c index cd8d290..60e0a09 100644 --- a/drivers/infiniband/hw/ehca/ehca_main.c +++ b/drivers/infiniband/hw/ehca/ehca_main.c @@ -467,6 +467,7 @@ static int ehca_init_device(struct ehca_shca *shca) shca->ib_device.dma_device = &shca->ofdev->dev; shca->ib_device.query_device = ehca_query_device; shca->ib_device.query_port = ehca_query_port; + shca->ib_device.query_transport = ehca_query_transport; shca->ib_device.query_gid = ehca_query_gid; shca->ib_device.query_pkey = ehca_query_pkey; /* shca->in_device.modify_device = ehca_modify_device */ diff --git a/drivers/infiniband/hw/ipath/ipath_verbs.c b/drivers/infiniband/hw/ipath/ipath_verbs.c index 44ea939..58d36e3 100644 --- a/drivers/infiniband/hw/ipath/ipath_verbs.c +++ b/drivers/infiniband/hw/ipath/ipath_verbs.c @@ -1638,6 +1638,12 @@ static int ipath_query_port(struct ib_device *ibdev, return 0; } +static enum rdma_transport_type +ipath_query_transport(struct ib_device *device, u8 port_num) +{ + return RDMA_TRANSPORT_IB; +} + static int ipath_modify_device(struct ib_device *device, int device_modify_mask, struct ib_device_modify *device_modify) @@ -2140,6 +2146,7 @@ int ipath_register_ib_device(struct ipath_devdata *dd) dev->query_device = ipath_query_device; dev->modify_device = ipath_modify_device; dev->query_port = ipath_query_port; + dev->query_transport = ipath_query_transport; dev->modify_port = ipath_modify_port; dev->query_pkey = ipath_query_pkey; dev->query_gid = ipath_query_gid; diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c index b972c0b..e1424ad 100644 --- a/drivers/infiniband/hw/mlx4/main.c +++ b/drivers/infiniband/hw/mlx4/main.c @@ -420,6 +420,15 @@ static int mlx4_ib_query_port(struct ib_device *ibdev, u8 port, return __mlx4_ib_query_port(ibdev, port, props, 0); } +static enum rdma_transport_type +mlx4_ib_query_transport(struct ib_device *device, u8 port_num) +{ + struct mlx4_dev *dev = to_mdev(device)->dev; + + return dev->caps.port_mask[port_num] == MLX4_PORT_TYPE_IB ? + RDMA_TRANSPORT_IB : RDMA_TRANSPORT_IBOE; +} + int __mlx4_ib_query_gid(struct ib_device *ibdev, u8 port, int index, union ib_gid *gid, int netw_view) { @@ -2201,6 +2210,7 @@ static void *mlx4_ib_add(struct mlx4_dev *dev) ibdev->ib_dev.query_device = mlx4_ib_query_device; ibdev->ib_dev.query_port = mlx4_ib_query_port; + ibdev->ib_dev.query_transport = mlx4_ib_query_transport; ibdev->ib_dev.get_link_layer = mlx4_ib_port_link_layer; ibdev->ib_dev.query_gid = mlx4_ib_query_gid; ibdev->ib_dev.query_pkey = mlx4_ib_query_pkey; diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index cc4ac1e..209c796 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -351,6 +351,12 @@ out: return err; } +static enum rdma_transport_type +mlx5_ib_query_transport(struct ib_device *device, u8 port_num) +{ + return RDMA_TRANSPORT_IB; +} + static int mlx5_ib_query_gid(struct ib_device *ibdev, u8 port, int index, union ib_gid *gid) { @@ -1336,6 +1342,7 @@ static void *mlx5_ib_add(struct mlx5_core_dev *mdev) dev->ib_dev.query_device = mlx5_ib_query_device; dev->ib_dev.query_port = mlx5_ib_query_port; + dev->ib_dev.query_transport = mlx5_ib_query_transport; dev->ib_dev.query_gid = mlx5_ib_query_gid; dev->ib_dev.query_pkey = mlx5_ib_query_pkey; dev->ib_dev.modify_device = mlx5_ib_modify_device; diff --git a/drivers/infiniband/hw/mthca/mthca_provider.c b/drivers/infiniband/hw/mthca/mthca_provider.c index 415f8e1..67ac6a4 100644 --- a/drivers/infiniband/hw/mthca/mthca_provider.c +++ b/drivers/infiniband/hw/mthca/mthca_provider.c @@ -179,6 +179,12 @@ static int mthca_query_port(struct ib_device *ibdev, return err; } +static enum rdma_transport_type +mthca_query_transport(struct ib_device *device, u8 port_num) +{ + return RDMA_TRANSPORT_IB; +} + static int mthca_modify_device(struct ib_device *ibdev, int mask, struct ib_device_modify *props) @@ -1281,6 +1287,7 @@ int mthca_register_device(struct mthca_dev *dev) dev->ib_dev.dma_device = &dev->pdev->dev; dev->ib_dev.query_device = mthca_query_device; dev->ib_dev.query_port = mthca_query_port; + dev->ib_dev.query_transport = mthca_query_transport; dev->ib_dev.modify_device = mthca_modify_device; dev->ib_dev.modify_port = mthca_modify_port; dev->ib_dev.query_pkey = mthca_query_pkey; diff --git a/drivers/infiniband/hw/nes/nes_verbs.c b/drivers/infiniband/hw/nes/nes_verbs.c index c0d0296..8df5b61 100644 --- a/drivers/infiniband/hw/nes/nes_verbs.c +++ b/drivers/infiniband/hw/nes/nes_verbs.c @@ -606,6 +606,11 @@ static int nes_query_port(struct ib_device *ibdev, u8 port, struct ib_port_attr return 0; } +static enum rdma_transport_type +nes_query_transport(struct ib_device *device, u8 port_num) +{ + return RDMA_TRANSPORT_IWARP; +} /** * nes_query_pkey @@ -3879,6 +3884,7 @@ struct nes_ib_device *nes_init_ofa_device(struct net_device *netdev) nesibdev->ibdev.dev.parent = &nesdev->pcidev->dev; nesibdev->ibdev.query_device = nes_query_device; nesibdev->ibdev.query_port = nes_query_port; + nesibdev->ibdev.query_transport = nes_query_transport; nesibdev->ibdev.query_pkey = nes_query_pkey; nesibdev->ibdev.query_gid = nes_query_gid; nesibdev->ibdev.alloc_ucontext = nes_alloc_ucontext; diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_main.c b/drivers/infiniband/hw/ocrdma/ocrdma_main.c index 7a2b59a..9f4d182 100644 --- a/drivers/infiniband/hw/ocrdma/ocrdma_main.c +++ b/drivers/infiniband/hw/ocrdma/ocrdma_main.c @@ -244,6 +244,7 @@ static int ocrdma_register_device(struct ocrdma_dev *dev) /* mandatory verbs. */ dev->ibdev.query_device = ocrdma_query_device; dev->ibdev.query_port = ocrdma_query_port; + dev->ibdev.query_transport = ocrdma_query_transport; dev->ibdev.modify_port = ocrdma_modify_port; dev->ibdev.query_gid = ocrdma_query_gid; dev->ibdev.get_link_layer = ocrdma_link_layer; diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c b/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c index 8771755..73bace4 100644 --- a/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c +++ b/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c @@ -187,6 +187,12 @@ int ocrdma_query_port(struct ib_device *ibdev, return 0; } +enum rdma_transport_type +ocrdma_query_transport(struct ib_device *device, u8 port_num) +{ + return RDMA_TRANSPORT_IBOE; +} + int ocrdma_modify_port(struct ib_device *ibdev, u8 port, int mask, struct ib_port_modify *props) { diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_verbs.h b/drivers/infiniband/hw/ocrdma/ocrdma_verbs.h index b8f7853..4a81b63 100644 --- a/drivers/infiniband/hw/ocrdma/ocrdma_verbs.h +++ b/drivers/infiniband/hw/ocrdma/ocrdma_verbs.h @@ -41,6 +41,9 @@ int ocrdma_query_port(struct ib_device *, u8 port, struct ib_port_attr *props); int ocrdma_modify_port(struct ib_device *, u8 port, int mask, struct ib_port_modify *props); +enum rdma_transport_type +ocrdma_query_transport(struct ib_device *device, u8 port_num); + void ocrdma_get_guid(struct ocrdma_dev *, u8 *guid); int ocrdma_query_gid(struct ib_device *, u8 port, int index, union ib_gid *gid); diff --git a/drivers/infiniband/hw/qib/qib_verbs.c b/drivers/infiniband/hw/qib/qib_verbs.c index 4a35998..caad665 100644 --- a/drivers/infiniband/hw/qib/qib_verbs.c +++ b/drivers/infiniband/hw/qib/qib_verbs.c @@ -1650,6 +1650,12 @@ static int qib_query_port(struct ib_device *ibdev, u8 port, return 0; } +static enum rdma_transport_type +qib_query_transport(struct ib_device *device, u8 port_num) +{ + return RDMA_TRANSPORT_IB; +} + static int qib_modify_device(struct ib_device *device, int device_modify_mask, struct ib_device_modify *device_modify) @@ -2184,6 +2190,7 @@ int qib_register_ib_device(struct qib_devdata *dd) ibdev->query_device = qib_query_device; ibdev->modify_device = qib_modify_device; ibdev->query_port = qib_query_port; + ibdev->query_transport = qib_query_transport; ibdev->modify_port = qib_modify_port; ibdev->query_pkey = qib_query_pkey; ibdev->query_gid = qib_query_gid; diff --git a/drivers/infiniband/hw/usnic/usnic_ib_main.c b/drivers/infiniband/hw/usnic/usnic_ib_main.c index 0d0f986..03ea9f3 100644 --- a/drivers/infiniband/hw/usnic/usnic_ib_main.c +++ b/drivers/infiniband/hw/usnic/usnic_ib_main.c @@ -360,6 +360,7 @@ static void *usnic_ib_device_add(struct pci_dev *dev) us_ibdev->ib_dev.query_device = usnic_ib_query_device; us_ibdev->ib_dev.query_port = usnic_ib_query_port; + us_ibdev->ib_dev.query_transport = usnic_ib_query_transport; us_ibdev->ib_dev.query_pkey = usnic_ib_query_pkey; us_ibdev->ib_dev.query_gid = usnic_ib_query_gid; us_ibdev->ib_dev.get_link_layer = usnic_ib_port_link_layer; diff --git a/drivers/infiniband/hw/usnic/usnic_ib_verbs.c b/drivers/infiniband/hw/usnic/usnic_ib_verbs.c index 53bd6a2..ff9a5f7 100644 --- a/drivers/infiniband/hw/usnic/usnic_ib_verbs.c +++ b/drivers/infiniband/hw/usnic/usnic_ib_verbs.c @@ -348,6 +348,12 @@ int usnic_ib_query_port(struct ib_device *ibdev, u8 port, return 0; } +enum rdma_transport_type +usnic_ib_query_transport(struct ib_device *device, u8 port_num) +{ + return RDMA_TRANSPORT_USNIC_UDP; +} + int usnic_ib_query_qp(struct ib_qp *qp, struct ib_qp_attr *qp_attr, int qp_attr_mask, struct ib_qp_init_attr *qp_init_attr) diff --git a/drivers/infiniband/hw/usnic/usnic_ib_verbs.h b/drivers/infiniband/hw/usnic/usnic_ib_verbs.h index bb864f5..0b1633b 100644 --- a/drivers/infiniband/hw/usnic/usnic_ib_verbs.h +++ b/drivers/infiniband/hw/usnic/usnic_ib_verbs.h @@ -27,6 +27,8 @@ int usnic_ib_query_device(struct ib_device *ibdev, struct ib_device_attr *props); int usnic_ib_query_port(struct ib_device *ibdev, u8 port, struct ib_port_attr *props); +enum rdma_transport_type +usnic_ib_query_transport(struct ib_device *device, u8 port_num); int usnic_ib_query_qp(struct ib_qp *qp, struct ib_qp_attr *qp_attr, int qp_attr_mask, struct ib_qp_init_attr *qp_init_attr); diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index 65994a1..d54f91e 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -75,10 +75,13 @@ enum rdma_node_type { }; enum rdma_transport_type { + /* legacy for users */ RDMA_TRANSPORT_IB, RDMA_TRANSPORT_IWARP, RDMA_TRANSPORT_USNIC, - RDMA_TRANSPORT_USNIC_UDP + RDMA_TRANSPORT_USNIC_UDP, + /* new transport */ + RDMA_TRANSPORT_IBOE, }; __attribute_const__ enum rdma_transport_type @@ -1501,6 +1504,8 @@ struct ib_device { int (*query_port)(struct ib_device *device, u8 port_num, struct ib_port_attr *port_attr); + enum rdma_transport_type (*query_transport)(struct ib_device *device, + u8 port_num); enum rdma_link_layer (*get_link_layer)(struct ib_device *device, u8 port_num); int (*query_gid)(struct ib_device *device, -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/