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2019-08-05NTB/msi: remove incorrect MODULE definesLogan Gunthorpe1-5/+0
msi.c is not a module on its own right and should not have the MODULE_[LICENSE|VERSION|AUTHOR|DESCRIPTION] definitions. This caused a regression noticed by lkp with the following back trace: WARNING: CPU: 0 PID: 1 at kernel/params.c:861 param_sysfs_init+0xb1/0x20a Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc1-00018-g26b3a37b928457 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 RIP: 0010:param_sysfs_init+0xb1/0x20a Code: 24 38 e8 ec 17 2e fd 49 8b 7c 24 38 e8 76 fe ff ff 48 85 c0 48 89 c5 74 25 31 d2 4c 89 e6 48 89 c7 e8 6d 6f 3c fd 85 c0 74 02 <0f> 0b 48 89 ef 31 f6 e8 5d 70 a7 fe 48 89 ef e8 95 52 a7 fe 48 83 RSP: 0000:ffff88806b0ffe30 EFLAGS: 00010282 RAX: 00000000ffffffef RBX: ffffffff83774220 RCX: ffff88806a85e880 RDX: 00000000ffffffef RSI: ffff88806b000400 RDI: ffff88806a8608c0 RBP: ffff88806b392000 R08: ffffed100d61ff59 R09: ffffed100d61ff59 R10: 0000000000000001 R11: ffffed100d61ff58 R12: ffffffff83974bc0 R13: 0000000000000004 R14: 0000000000000028 R15: 00000000000003b9 FS: 0000000000000000(0000) GS:ffff88806b800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000000380e000 CR4: 00000000000406b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? file_caps_disable+0x10/0x10 ? locate_module_kobject+0xf2/0xf2 do_one_initcall+0x47/0x1f0 kernel_init_freeable+0x1b1/0x243 ? rest_init+0xd0/0xd0 kernel_init+0xa/0x130 ? calculate_sigpending+0x63/0x80 ? rest_init+0xd0/0xd0 ret_from_fork+0x1f/0x30 ---[ end trace 78201497ae74cc91 ]--- Reported-by: kernel test robot <lkp@intel.com> Fixes: 26b3a37b9284 ("NTB: Introduce MSI library") Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2019-06-13NTB: Introduce MSI libraryLogan Gunthorpe1-0/+415
The NTB MSI library allows passing MSI interrupts across a memory window. This offers similar functionality to doorbells or messages except will often have much better latency and the client can potentially use significantly more remote interrupts than typical hardware provides for doorbells. (Which can be important in high-multiport setups.) The library utilizes one memory window per peer and uses the highest index memory windows. Before any ntb_msi function may be used, the user must call ntb_msi_init(). It may then setup and tear down the memory windows when the link state changes using ntb_msi_setup_mws() and ntb_msi_clear_mws(). The peer which receives the interrupt must call ntb_msim_request_irq() to assign the interrupt handler (this function is functionally similar to devm_request_irq()) and the returned descriptor must be transferred to the peer which can use it to trigger the interrupt. The triggering peer, once having received the descriptor, can trigger the interrupt by calling ntb_msi_peer_trigger(). Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Allen Hubbe <allenbh@gmail.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>