Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946045Ab2JaWst (ORCPT ); Wed, 31 Oct 2012 18:48:49 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:54318 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760954Ab2JaWrD (ORCPT ); Wed, 31 Oct 2012 18:47:03 -0400 From: =?UTF-8?q?Sjur=20Br=C3=A6ndeland?= To: Rusty Russell Cc: "Michael S. Tsirkin" , Linus Walleij , Ohad Ben-Cohen , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, sjur@brendeland.net, dmitry.tarnyagin@stericsson.com, =?UTF-8?q?Sjur=20Br=C3=A6ndeland?= Subject: [RFC virtio-next 1/4] virtio: Move definitions to header file vring.h Date: Wed, 31 Oct 2012 23:46:51 +0100 Message-Id: <1351723614-4145-2-git-send-email-sjur@brendeland.net> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1351723614-4145-1-git-send-email-sjur@brendeland.net> References: <1351723614-4145-1-git-send-email-sjur@brendeland.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8169 Lines: 259 From: Sjur Brændeland Move the vring_virtqueue structure, memory barrier and debug macros out from virtio_ring.c to the new header file vring.h. This is done in order to allow other kernel modules to access the virtio internal data-structures. Signed-off-by: Sjur Brændeland --- Tis patch triggers a couple of checkpatch warnings, but I've chosen to do a clean copy and not do any corrections. drivers/virtio/virtio_ring.c | 96 +-------------------------------- drivers/virtio/vring.h | 121 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 122 insertions(+), 95 deletions(-) create mode 100644 drivers/virtio/vring.h diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index ffd7e7d..9027af6 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -23,101 +23,7 @@ #include #include #include - -/* virtio guest is communicating with a virtual "device" that actually runs on - * a host processor. Memory barriers are used to control SMP effects. */ -#ifdef CONFIG_SMP -/* Where possible, use SMP barriers which are more lightweight than mandatory - * barriers, because mandatory barriers control MMIO effects on accesses - * through relaxed memory I/O windows (which virtio-pci does not use). */ -#define virtio_mb(vq) \ - do { if ((vq)->weak_barriers) smp_mb(); else mb(); } while(0) -#define virtio_rmb(vq) \ - do { if ((vq)->weak_barriers) smp_rmb(); else rmb(); } while(0) -#define virtio_wmb(vq) \ - do { if ((vq)->weak_barriers) smp_wmb(); else wmb(); } while(0) -#else -/* We must force memory ordering even if guest is UP since host could be - * running on another CPU, but SMP barriers are defined to barrier() in that - * configuration. So fall back to mandatory barriers instead. */ -#define virtio_mb(vq) mb() -#define virtio_rmb(vq) rmb() -#define virtio_wmb(vq) wmb() -#endif - -#ifdef DEBUG -/* For development, we want to crash whenever the ring is screwed. */ -#define BAD_RING(_vq, fmt, args...) \ - do { \ - dev_err(&(_vq)->vq.vdev->dev, \ - "%s:"fmt, (_vq)->vq.name, ##args); \ - BUG(); \ - } while (0) -/* Caller is supposed to guarantee no reentry. */ -#define START_USE(_vq) \ - do { \ - if ((_vq)->in_use) \ - panic("%s:in_use = %i\n", \ - (_vq)->vq.name, (_vq)->in_use); \ - (_vq)->in_use = __LINE__; \ - } while (0) -#define END_USE(_vq) \ - do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; } while(0) -#else -#define BAD_RING(_vq, fmt, args...) \ - do { \ - dev_err(&_vq->vq.vdev->dev, \ - "%s:"fmt, (_vq)->vq.name, ##args); \ - (_vq)->broken = true; \ - } while (0) -#define START_USE(vq) -#define END_USE(vq) -#endif - -struct vring_virtqueue -{ - struct virtqueue vq; - - /* Actual memory layout for this queue */ - struct vring vring; - - /* Can we use weak barriers? */ - bool weak_barriers; - - /* Other side has made a mess, don't try any more. */ - bool broken; - - /* Host supports indirect buffers */ - bool indirect; - - /* Host publishes avail event idx */ - bool event; - - /* Head of free buffer list. */ - unsigned int free_head; - /* Number we've added since last sync. */ - unsigned int num_added; - - /* Last used index we've seen. */ - u16 last_used_idx; - - /* How to notify other side. FIXME: commonalize hcalls! */ - void (*notify)(struct virtqueue *vq); - -#ifdef DEBUG - /* They're supposed to lock for us. */ - unsigned int in_use; - - /* Figure out if their kicks are too delayed. */ - bool last_add_time_valid; - ktime_t last_add_time; -#endif - - /* Tokens for callbacks. */ - void *data[]; -}; - -#define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq) +#include "vring.h" /* Set up an indirect table of descriptors and add it to the queue. */ static int vring_add_indirect(struct vring_virtqueue *vq, diff --git a/drivers/virtio/vring.h b/drivers/virtio/vring.h new file mode 100644 index 0000000..b997fc3 --- /dev/null +++ b/drivers/virtio/vring.h @@ -0,0 +1,121 @@ +/* Virtio ring implementation. + * + * Copyright 2007 Rusty Russell IBM Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ +#ifndef _LINUX_VIRTIO_RING_H_ +#define _LINUX_VIRTIO_RING_H_ + +#include +#include + +struct vring_virtqueue +{ + struct virtqueue vq; + + /* Actual memory layout for this queue */ + struct vring vring; + + /* Can we use weak barriers? */ + bool weak_barriers; + + /* Other side has made a mess, don't try any more. */ + bool broken; + + /* Host supports indirect buffers */ + bool indirect; + + /* Host publishes avail event idx */ + bool event; + + /* Number of free buffers */ + unsigned int num_free; + /* Head of free buffer list. */ + unsigned int free_head; + /* Number we've added since last sync. */ + unsigned int num_added; + + /* Last used index we've seen. */ + u16 last_used_idx; + + /* How to notify other side. FIXME: commonalize hcalls! */ + void (*notify)(struct virtqueue *vq); + +#ifdef DEBUG + /* They're supposed to lock for us. */ + unsigned int in_use; + + /* Figure out if their kicks are too delayed. */ + bool last_add_time_valid; + ktime_t last_add_time; +#endif + + /* Tokens for callbacks. */ + void *data[]; +}; +#define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq) + +/* virtio guest is communicating with a virtual "device" that actually runs on + * a host processor. Memory barriers are used to control SMP effects. */ +#ifdef CONFIG_SMP +/* Where possible, use SMP barriers which are more lightweight than mandatory + * barriers, because mandatory barriers control MMIO effects on accesses + * through relaxed memory I/O windows (which virtio-pci does not use). */ +#define virtio_mb(vq) \ + do { if ((vq)->weak_barriers) smp_mb(); else mb(); } while(0) +#define virtio_rmb(vq) \ + do { if ((vq)->weak_barriers) smp_rmb(); else rmb(); } while(0) +#define virtio_wmb(vq) \ + do { if ((vq)->weak_barriers) smp_wmb(); else wmb(); } while(0) +#else +/* We must force memory ordering even if guest is UP since host could be + * running on another CPU, but SMP barriers are defined to barrier() in that + * configuration. So fall back to mandatory barriers instead. */ +#define virtio_mb(vq) mb() +#define virtio_rmb(vq) rmb() +#define virtio_wmb(vq) wmb() +#endif + +#ifdef DEBUG +/* For development, we want to crash whenever the ring is screwed. */ +#define BAD_RING(_vq, fmt, args...) \ + do { \ + dev_err(&(_vq)->vq.vdev->dev, \ + "%s:"fmt, (_vq)->vq.name, ##args); \ + BUG(); \ + } while (0) +/* Caller is supposed to guarantee no reentry. */ +#define START_USE(_vq) \ + do { \ + if ((_vq)->in_use) \ + panic("%s:in_use = %i\n", \ + (_vq)->vq.name, (_vq)->in_use); \ + (_vq)->in_use = __LINE__; \ + } while (0) +#define END_USE(_vq) \ + do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; } while(0) +#else +#define BAD_RING(_vq, fmt, args...) \ + do { \ + dev_err(&_vq->vq.vdev->dev, \ + "%s:"fmt, (_vq)->vq.name, ##args); \ + (_vq)->broken = true; \ + } while (0) +#define START_USE(vq) +#define END_USE(vq) +#endif + +#endif -- 1.7.9.5 -- 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/