2007-10-22 01:03:40 +00:00
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/* Virtio ring implementation.
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*
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* Copyright 2007 Rusty Russell IBM Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <linux/virtio.h>
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#include <linux/virtio_ring.h>
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2008-07-25 17:06:13 +00:00
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#include <linux/virtio_config.h>
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2007-10-22 01:03:40 +00:00
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#include <linux/device.h>
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include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
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#include <linux/slab.h>
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2011-07-03 20:20:30 +00:00
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#include <linux/module.h>
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2012-01-12 05:14:43 +00:00
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#include <linux/hrtimer.h>
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2014-02-13 04:33:46 +00:00
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#include <linux/kmemleak.h>
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2007-10-22 01:03:40 +00:00
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#ifdef DEBUG
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/* For development, we want to crash whenever the ring is screwed. */
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2009-06-13 04:16:35 +00:00
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#define BAD_RING(_vq, fmt, args...) \
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do { \
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dev_err(&(_vq)->vq.vdev->dev, \
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"%s:"fmt, (_vq)->vq.name, ##args); \
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BUG(); \
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} while (0)
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2009-03-31 03:55:22 +00:00
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/* Caller is supposed to guarantee no reentry. */
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#define START_USE(_vq) \
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do { \
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if ((_vq)->in_use) \
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2009-06-13 04:16:35 +00:00
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panic("%s:in_use = %i\n", \
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(_vq)->vq.name, (_vq)->in_use); \
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2009-03-31 03:55:22 +00:00
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(_vq)->in_use = __LINE__; \
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2009-06-13 04:16:35 +00:00
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} while (0)
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2009-01-22 15:42:57 +00:00
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#define END_USE(_vq) \
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2010-02-24 20:22:22 +00:00
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do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; } while(0)
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2007-10-22 01:03:40 +00:00
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#else
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2009-06-13 04:16:35 +00:00
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#define BAD_RING(_vq, fmt, args...) \
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do { \
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dev_err(&_vq->vq.vdev->dev, \
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"%s:"fmt, (_vq)->vq.name, ##args); \
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(_vq)->broken = true; \
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} while (0)
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2007-10-22 01:03:40 +00:00
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#define START_USE(vq)
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#define END_USE(vq)
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#endif
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struct vring_virtqueue
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{
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struct virtqueue vq;
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/* Actual memory layout for this queue */
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struct vring vring;
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2012-01-12 05:14:42 +00:00
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/* Can we use weak barriers? */
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bool weak_barriers;
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2007-10-22 01:03:40 +00:00
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/* Other side has made a mess, don't try any more. */
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bool broken;
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2009-05-11 17:11:45 +00:00
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/* Host supports indirect buffers */
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bool indirect;
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2011-05-19 23:10:44 +00:00
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/* Host publishes avail event idx */
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bool event;
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2007-10-22 01:03:40 +00:00
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/* Head of free buffer list. */
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unsigned int free_head;
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/* Number we've added since last sync. */
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unsigned int num_added;
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/* Last used index we've seen. */
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2007-11-07 21:49:24 +00:00
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u16 last_used_idx;
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2007-10-22 01:03:40 +00:00
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/* How to notify other side. FIXME: commonalize hcalls! */
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2013-10-28 23:08:50 +00:00
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bool (*notify)(struct virtqueue *vq);
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2007-10-22 01:03:40 +00:00
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#ifdef DEBUG
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/* They're supposed to lock for us. */
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unsigned int in_use;
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2012-01-12 05:14:43 +00:00
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/* Figure out if their kicks are too delayed. */
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bool last_add_time_valid;
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ktime_t last_add_time;
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2007-10-22 01:03:40 +00:00
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#endif
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/* Tokens for callbacks. */
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void *data[];
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};
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#define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq)
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2014-09-11 00:47:38 +00:00
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static struct vring_desc *alloc_indirect(unsigned int total_sg, gfp_t gfp)
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2009-05-11 17:11:45 +00:00
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{
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struct vring_desc *desc;
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2014-09-11 00:47:38 +00:00
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unsigned int i;
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2009-05-11 17:11:45 +00:00
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2012-10-19 13:03:33 +00:00
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/*
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* We require lowmem mappings for the descriptors because
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* otherwise virt_to_phys will give us bogus addresses in the
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* virtqueue.
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*/
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gfp &= ~(__GFP_HIGHMEM | __GFP_HIGH);
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2013-03-20 05:07:09 +00:00
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desc = kmalloc(total_sg * sizeof(struct vring_desc), gfp);
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2009-05-11 17:11:45 +00:00
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if (!desc)
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2014-09-11 00:47:38 +00:00
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return NULL;
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2009-05-11 17:11:45 +00:00
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2014-09-11 00:47:38 +00:00
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for (i = 0; i < total_sg; i++)
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desc[i].next = i+1;
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return desc;
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2009-05-11 17:11:45 +00:00
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}
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2013-03-20 05:07:09 +00:00
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static inline int virtqueue_add(struct virtqueue *_vq,
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struct scatterlist *sgs[],
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2014-09-11 00:47:37 +00:00
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unsigned int total_sg,
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2013-03-20 05:07:09 +00:00
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unsigned int out_sgs,
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unsigned int in_sgs,
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void *data,
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gfp_t gfp)
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2007-10-22 01:03:40 +00:00
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{
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struct vring_virtqueue *vq = to_vvq(_vq);
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2013-03-20 05:07:09 +00:00
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struct scatterlist *sg;
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2014-09-11 00:47:38 +00:00
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struct vring_desc *desc;
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unsigned int i, n, avail, descs_used, uninitialized_var(prev);
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2010-07-26 07:25:30 +00:00
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int head;
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2014-09-11 00:47:38 +00:00
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bool indirect;
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2007-10-22 01:03:40 +00:00
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2009-05-11 17:11:45 +00:00
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START_USE(vq);
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2007-10-22 01:03:40 +00:00
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BUG_ON(data == NULL);
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2009-05-11 17:11:45 +00:00
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2014-03-13 00:53:40 +00:00
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if (unlikely(vq->broken)) {
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END_USE(vq);
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return -EIO;
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}
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2012-01-12 05:14:43 +00:00
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#ifdef DEBUG
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{
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ktime_t now = ktime_get();
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/* No kick or get, with .1 second between? Warn. */
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if (vq->last_add_time_valid)
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WARN_ON(ktime_to_ms(ktime_sub(now, vq->last_add_time))
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> 100);
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vq->last_add_time = now;
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vq->last_add_time_valid = true;
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}
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#endif
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2014-09-11 00:47:38 +00:00
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BUG_ON(total_sg > vq->vring.num);
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BUG_ON(total_sg == 0);
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head = vq->free_head;
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2009-05-11 17:11:45 +00:00
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/* If the host supports indirect descriptor tables, and we have multiple
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* buffers, then go indirect. FIXME: tune this threshold */
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2014-09-11 00:47:38 +00:00
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if (vq->indirect && total_sg > 1 && vq->vq.num_free)
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desc = alloc_indirect(total_sg, gfp);
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else
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desc = NULL;
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if (desc) {
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/* Use a single buffer which doesn't continue */
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vq->vring.desc[head].flags = VRING_DESC_F_INDIRECT;
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vq->vring.desc[head].addr = virt_to_phys(desc);
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/* avoid kmemleak false positive (hidden by virt_to_phys) */
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kmemleak_ignore(desc);
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vq->vring.desc[head].len = total_sg * sizeof(struct vring_desc);
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/* Set up rest to use this indirect table. */
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i = 0;
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descs_used = 1;
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indirect = true;
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} else {
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desc = vq->vring.desc;
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i = head;
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descs_used = total_sg;
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indirect = false;
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2009-05-11 17:11:45 +00:00
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}
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2014-09-11 00:47:38 +00:00
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if (vq->vq.num_free < descs_used) {
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2007-10-22 01:03:40 +00:00
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pr_debug("Can't add buf len %i - avail = %i\n",
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2014-09-11 00:47:38 +00:00
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descs_used, vq->vq.num_free);
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2008-07-25 17:06:04 +00:00
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/* FIXME: for historical reasons, we force a notify here if
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* there are outgoing parts to the buffer. Presumably the
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* host should service the ring ASAP. */
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2013-03-20 05:07:09 +00:00
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if (out_sgs)
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2008-07-25 17:06:04 +00:00
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vq->notify(&vq->vq);
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2007-10-22 01:03:40 +00:00
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END_USE(vq);
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return -ENOSPC;
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}
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/* We're about to use some buffers from the free list. */
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2014-09-11 00:47:38 +00:00
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vq->vq.num_free -= descs_used;
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2013-03-20 05:07:09 +00:00
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for (n = 0; n < out_sgs; n++) {
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2014-09-11 00:47:37 +00:00
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for (sg = sgs[n]; sg; sg = sg_next(sg)) {
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2014-09-11 00:47:38 +00:00
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desc[i].flags = VRING_DESC_F_NEXT;
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desc[i].addr = sg_phys(sg);
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desc[i].len = sg->length;
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2013-03-20 05:07:09 +00:00
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prev = i;
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2014-09-11 00:47:38 +00:00
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i = desc[i].next;
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2013-03-20 05:07:09 +00:00
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}
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2007-10-22 01:03:40 +00:00
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}
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2013-03-20 05:07:09 +00:00
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for (; n < (out_sgs + in_sgs); n++) {
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2014-09-11 00:47:37 +00:00
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for (sg = sgs[n]; sg; sg = sg_next(sg)) {
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2014-09-11 00:47:38 +00:00
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desc[i].flags = VRING_DESC_F_NEXT|VRING_DESC_F_WRITE;
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desc[i].addr = sg_phys(sg);
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desc[i].len = sg->length;
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2013-03-20 05:07:09 +00:00
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prev = i;
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2014-09-11 00:47:38 +00:00
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i = desc[i].next;
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2013-03-20 05:07:09 +00:00
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}
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2007-10-22 01:03:40 +00:00
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}
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/* Last one doesn't continue. */
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2014-09-11 00:47:38 +00:00
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desc[prev].flags &= ~VRING_DESC_F_NEXT;
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2007-10-22 01:03:40 +00:00
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/* Update free pointer */
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2014-09-11 00:47:38 +00:00
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if (indirect)
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vq->free_head = vq->vring.desc[head].next;
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else
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vq->free_head = i;
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2007-10-22 01:03:40 +00:00
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/* Set token. */
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vq->data[head] = data;
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/* Put entry in available array (but don't update avail->idx until they
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2012-01-12 05:14:43 +00:00
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* do sync). */
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2012-01-12 05:14:43 +00:00
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avail = (vq->vring.avail->idx & (vq->vring.num-1));
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2007-10-22 01:03:40 +00:00
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vq->vring.avail->ring[avail] = head;
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2012-01-12 05:14:43 +00:00
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/* Descriptors and available array need to be set before we expose the
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* new available array entries. */
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2013-03-18 02:52:19 +00:00
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virtio_wmb(vq->weak_barriers);
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2012-01-12 05:14:43 +00:00
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vq->vring.avail->idx++;
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vq->num_added++;
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/* This is very unlikely, but theoretically possible. Kick
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* just in case. */
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if (unlikely(vq->num_added == (1 << 16) - 1))
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virtqueue_kick(_vq);
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2007-10-22 01:03:40 +00:00
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pr_debug("Added buffer head %i to %p\n", head, vq);
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END_USE(vq);
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2009-09-24 04:26:31 +00:00
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2012-10-16 13:26:15 +00:00
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return 0;
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2007-10-22 01:03:40 +00:00
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}
|
2013-03-20 05:07:09 +00:00
|
|
|
|
|
|
|
/**
|
|
|
|
* virtqueue_add_sgs - expose buffers to other end
|
|
|
|
* @vq: the struct virtqueue we're talking about.
|
|
|
|
* @sgs: array of terminated scatterlists.
|
|
|
|
* @out_num: the number of scatterlists readable by other side
|
|
|
|
* @in_num: the number of scatterlists which are writable (after readable ones)
|
|
|
|
* @data: the token identifying the buffer.
|
|
|
|
* @gfp: how to do memory allocations (if necessary).
|
|
|
|
*
|
|
|
|
* Caller must ensure we don't call this with other virtqueue operations
|
|
|
|
* at the same time (except where noted).
|
|
|
|
*
|
2014-03-13 00:53:40 +00:00
|
|
|
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
|
2013-03-20 05:07:09 +00:00
|
|
|
*/
|
|
|
|
int virtqueue_add_sgs(struct virtqueue *_vq,
|
|
|
|
struct scatterlist *sgs[],
|
|
|
|
unsigned int out_sgs,
|
|
|
|
unsigned int in_sgs,
|
|
|
|
void *data,
|
|
|
|
gfp_t gfp)
|
|
|
|
{
|
2014-09-11 00:47:37 +00:00
|
|
|
unsigned int i, total_sg = 0;
|
2013-03-20 05:07:09 +00:00
|
|
|
|
|
|
|
/* Count them first. */
|
2014-09-11 00:47:37 +00:00
|
|
|
for (i = 0; i < out_sgs + in_sgs; i++) {
|
2013-03-20 05:07:09 +00:00
|
|
|
struct scatterlist *sg;
|
|
|
|
for (sg = sgs[i]; sg; sg = sg_next(sg))
|
2014-09-11 00:47:37 +00:00
|
|
|
total_sg++;
|
2013-03-20 05:07:09 +00:00
|
|
|
}
|
2014-09-11 00:47:37 +00:00
|
|
|
return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs, data, gfp);
|
2013-03-20 05:07:09 +00:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
|
|
|
|
|
2013-03-20 05:14:26 +00:00
|
|
|
/**
|
|
|
|
* virtqueue_add_outbuf - expose output buffers to other end
|
|
|
|
* @vq: the struct virtqueue we're talking about.
|
2014-09-11 00:47:37 +00:00
|
|
|
* @sg: scatterlist (must be well-formed and terminated!)
|
|
|
|
* @num: the number of entries in @sg readable by other side
|
2013-03-20 05:14:26 +00:00
|
|
|
* @data: the token identifying the buffer.
|
|
|
|
* @gfp: how to do memory allocations (if necessary).
|
|
|
|
*
|
|
|
|
* Caller must ensure we don't call this with other virtqueue operations
|
|
|
|
* at the same time (except where noted).
|
|
|
|
*
|
2014-03-13 00:53:40 +00:00
|
|
|
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
|
2013-03-20 05:14:26 +00:00
|
|
|
*/
|
|
|
|
int virtqueue_add_outbuf(struct virtqueue *vq,
|
2014-09-11 00:47:37 +00:00
|
|
|
struct scatterlist *sg, unsigned int num,
|
2013-03-20 05:14:26 +00:00
|
|
|
void *data,
|
|
|
|
gfp_t gfp)
|
|
|
|
{
|
2014-09-11 00:47:37 +00:00
|
|
|
return virtqueue_add(vq, &sg, num, 1, 0, data, gfp);
|
2013-03-20 05:14:26 +00:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_add_outbuf);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* virtqueue_add_inbuf - expose input buffers to other end
|
|
|
|
* @vq: the struct virtqueue we're talking about.
|
2014-09-11 00:47:37 +00:00
|
|
|
* @sg: scatterlist (must be well-formed and terminated!)
|
|
|
|
* @num: the number of entries in @sg writable by other side
|
2013-03-20 05:14:26 +00:00
|
|
|
* @data: the token identifying the buffer.
|
|
|
|
* @gfp: how to do memory allocations (if necessary).
|
|
|
|
*
|
|
|
|
* Caller must ensure we don't call this with other virtqueue operations
|
|
|
|
* at the same time (except where noted).
|
|
|
|
*
|
2014-03-13 00:53:40 +00:00
|
|
|
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
|
2013-03-20 05:14:26 +00:00
|
|
|
*/
|
|
|
|
int virtqueue_add_inbuf(struct virtqueue *vq,
|
2014-09-11 00:47:37 +00:00
|
|
|
struct scatterlist *sg, unsigned int num,
|
2013-03-20 05:14:26 +00:00
|
|
|
void *data,
|
|
|
|
gfp_t gfp)
|
|
|
|
{
|
2014-09-11 00:47:37 +00:00
|
|
|
return virtqueue_add(vq, &sg, num, 0, 1, data, gfp);
|
2013-03-20 05:14:26 +00:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_add_inbuf);
|
|
|
|
|
2012-01-12 05:14:42 +00:00
|
|
|
/**
|
2012-01-12 05:14:43 +00:00
|
|
|
* virtqueue_kick_prepare - first half of split virtqueue_kick call.
|
2012-01-12 05:14:42 +00:00
|
|
|
* @vq: the struct virtqueue
|
|
|
|
*
|
2012-01-12 05:14:43 +00:00
|
|
|
* Instead of virtqueue_kick(), you can do:
|
|
|
|
* if (virtqueue_kick_prepare(vq))
|
|
|
|
* virtqueue_notify(vq);
|
2012-01-12 05:14:42 +00:00
|
|
|
*
|
2012-01-12 05:14:43 +00:00
|
|
|
* This is sometimes useful because the virtqueue_kick_prepare() needs
|
|
|
|
* to be serialized, but the actual virtqueue_notify() call does not.
|
2012-01-12 05:14:42 +00:00
|
|
|
*/
|
2012-01-12 05:14:43 +00:00
|
|
|
bool virtqueue_kick_prepare(struct virtqueue *_vq)
|
2007-10-22 01:03:40 +00:00
|
|
|
{
|
|
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
2011-05-19 23:10:44 +00:00
|
|
|
u16 new, old;
|
2012-01-12 05:14:43 +00:00
|
|
|
bool needs_kick;
|
|
|
|
|
2007-10-22 01:03:40 +00:00
|
|
|
START_USE(vq);
|
2012-01-20 08:17:08 +00:00
|
|
|
/* We need to expose available array entries before checking avail
|
|
|
|
* event. */
|
2013-03-18 02:52:19 +00:00
|
|
|
virtio_mb(vq->weak_barriers);
|
2007-10-22 01:03:40 +00:00
|
|
|
|
2012-01-12 05:14:43 +00:00
|
|
|
old = vq->vring.avail->idx - vq->num_added;
|
|
|
|
new = vq->vring.avail->idx;
|
2007-10-22 01:03:40 +00:00
|
|
|
vq->num_added = 0;
|
|
|
|
|
2012-01-12 05:14:43 +00:00
|
|
|
#ifdef DEBUG
|
|
|
|
if (vq->last_add_time_valid) {
|
|
|
|
WARN_ON(ktime_to_ms(ktime_sub(ktime_get(),
|
|
|
|
vq->last_add_time)) > 100);
|
|
|
|
}
|
|
|
|
vq->last_add_time_valid = false;
|
|
|
|
#endif
|
|
|
|
|
2012-01-12 05:14:43 +00:00
|
|
|
if (vq->event) {
|
|
|
|
needs_kick = vring_need_event(vring_avail_event(&vq->vring),
|
|
|
|
new, old);
|
|
|
|
} else {
|
|
|
|
needs_kick = !(vq->vring.used->flags & VRING_USED_F_NO_NOTIFY);
|
|
|
|
}
|
2007-10-22 01:03:40 +00:00
|
|
|
END_USE(vq);
|
2012-01-12 05:14:43 +00:00
|
|
|
return needs_kick;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* virtqueue_notify - second half of split virtqueue_kick call.
|
|
|
|
* @vq: the struct virtqueue
|
|
|
|
*
|
|
|
|
* This does not need to be serialized.
|
2013-10-28 23:09:48 +00:00
|
|
|
*
|
|
|
|
* Returns false if host notify failed or queue is broken, otherwise true.
|
2012-01-12 05:14:43 +00:00
|
|
|
*/
|
2013-10-28 23:09:48 +00:00
|
|
|
bool virtqueue_notify(struct virtqueue *_vq)
|
2012-01-12 05:14:43 +00:00
|
|
|
{
|
|
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
|
2013-10-28 23:09:48 +00:00
|
|
|
if (unlikely(vq->broken))
|
|
|
|
return false;
|
|
|
|
|
2012-01-12 05:14:43 +00:00
|
|
|
/* Prod other side to tell it about changes. */
|
2013-11-05 10:50:27 +00:00
|
|
|
if (!vq->notify(_vq)) {
|
2013-10-28 23:09:48 +00:00
|
|
|
vq->broken = true;
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
return true;
|
2012-01-12 05:14:43 +00:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_notify);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* virtqueue_kick - update after add_buf
|
|
|
|
* @vq: the struct virtqueue
|
|
|
|
*
|
2013-05-20 02:45:44 +00:00
|
|
|
* After one or more virtqueue_add_* calls, invoke this to kick
|
2012-01-12 05:14:43 +00:00
|
|
|
* the other side.
|
|
|
|
*
|
|
|
|
* Caller must ensure we don't call this with other virtqueue
|
|
|
|
* operations at the same time (except where noted).
|
2013-10-28 23:09:48 +00:00
|
|
|
*
|
|
|
|
* Returns false if kick failed, otherwise true.
|
2012-01-12 05:14:43 +00:00
|
|
|
*/
|
2013-10-28 23:09:48 +00:00
|
|
|
bool virtqueue_kick(struct virtqueue *vq)
|
2012-01-12 05:14:43 +00:00
|
|
|
{
|
|
|
|
if (virtqueue_kick_prepare(vq))
|
2013-10-28 23:09:48 +00:00
|
|
|
return virtqueue_notify(vq);
|
|
|
|
return true;
|
2007-10-22 01:03:40 +00:00
|
|
|
}
|
2010-04-12 13:19:07 +00:00
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_kick);
|
2007-10-22 01:03:40 +00:00
|
|
|
|
|
|
|
static void detach_buf(struct vring_virtqueue *vq, unsigned int head)
|
|
|
|
{
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
/* Clear data ptr. */
|
|
|
|
vq->data[head] = NULL;
|
|
|
|
|
|
|
|
/* Put back on free list: find end */
|
|
|
|
i = head;
|
2009-05-11 17:11:45 +00:00
|
|
|
|
|
|
|
/* Free the indirect table */
|
|
|
|
if (vq->vring.desc[i].flags & VRING_DESC_F_INDIRECT)
|
|
|
|
kfree(phys_to_virt(vq->vring.desc[i].addr));
|
|
|
|
|
2007-10-22 01:03:40 +00:00
|
|
|
while (vq->vring.desc[i].flags & VRING_DESC_F_NEXT) {
|
|
|
|
i = vq->vring.desc[i].next;
|
2012-10-16 13:26:14 +00:00
|
|
|
vq->vq.num_free++;
|
2007-10-22 01:03:40 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
vq->vring.desc[i].next = vq->free_head;
|
|
|
|
vq->free_head = head;
|
|
|
|
/* Plus final descriptor */
|
2012-10-16 13:26:14 +00:00
|
|
|
vq->vq.num_free++;
|
2007-10-22 01:03:40 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
static inline bool more_used(const struct vring_virtqueue *vq)
|
|
|
|
{
|
|
|
|
return vq->last_used_idx != vq->vring.used->idx;
|
|
|
|
}
|
|
|
|
|
2012-01-12 05:14:42 +00:00
|
|
|
/**
|
|
|
|
* virtqueue_get_buf - get the next used buffer
|
|
|
|
* @vq: the struct virtqueue we're talking about.
|
|
|
|
* @len: the length written into the buffer
|
|
|
|
*
|
|
|
|
* If the driver wrote data into the buffer, @len will be set to the
|
|
|
|
* amount written. This means you don't need to clear the buffer
|
|
|
|
* beforehand to ensure there's no data leakage in the case of short
|
|
|
|
* writes.
|
|
|
|
*
|
|
|
|
* Caller must ensure we don't call this with other virtqueue
|
|
|
|
* operations at the same time (except where noted).
|
|
|
|
*
|
|
|
|
* Returns NULL if there are no used buffers, or the "data" token
|
2013-05-20 02:45:44 +00:00
|
|
|
* handed to virtqueue_add_*().
|
2012-01-12 05:14:42 +00:00
|
|
|
*/
|
2010-04-12 13:19:07 +00:00
|
|
|
void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
|
2007-10-22 01:03:40 +00:00
|
|
|
{
|
|
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
void *ret;
|
|
|
|
unsigned int i;
|
2012-01-12 05:14:43 +00:00
|
|
|
u16 last_used;
|
2007-10-22 01:03:40 +00:00
|
|
|
|
|
|
|
START_USE(vq);
|
|
|
|
|
2008-05-03 02:50:43 +00:00
|
|
|
if (unlikely(vq->broken)) {
|
|
|
|
END_USE(vq);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
2007-10-22 01:03:40 +00:00
|
|
|
if (!more_used(vq)) {
|
|
|
|
pr_debug("No more buffers in queue\n");
|
|
|
|
END_USE(vq);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
2009-10-25 13:28:53 +00:00
|
|
|
/* Only get used array entries after they have been exposed by host. */
|
2013-03-18 02:52:19 +00:00
|
|
|
virtio_rmb(vq->weak_barriers);
|
2009-10-25 13:28:53 +00:00
|
|
|
|
2012-01-12 05:14:43 +00:00
|
|
|
last_used = (vq->last_used_idx & (vq->vring.num - 1));
|
|
|
|
i = vq->vring.used->ring[last_used].id;
|
|
|
|
*len = vq->vring.used->ring[last_used].len;
|
2007-10-22 01:03:40 +00:00
|
|
|
|
|
|
|
if (unlikely(i >= vq->vring.num)) {
|
|
|
|
BAD_RING(vq, "id %u out of range\n", i);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
if (unlikely(!vq->data[i])) {
|
|
|
|
BAD_RING(vq, "id %u is not a head!\n", i);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* detach_buf clears data, so grab it now. */
|
|
|
|
ret = vq->data[i];
|
|
|
|
detach_buf(vq, i);
|
|
|
|
vq->last_used_idx++;
|
2011-05-19 23:10:44 +00:00
|
|
|
/* If we expect an interrupt for the next entry, tell host
|
|
|
|
* by writing event index and flush out the write before
|
|
|
|
* the read in the next get_buf call. */
|
|
|
|
if (!(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT)) {
|
|
|
|
vring_used_event(&vq->vring) = vq->last_used_idx;
|
2013-03-18 02:52:19 +00:00
|
|
|
virtio_mb(vq->weak_barriers);
|
2011-05-19 23:10:44 +00:00
|
|
|
}
|
|
|
|
|
2012-01-12 05:14:43 +00:00
|
|
|
#ifdef DEBUG
|
|
|
|
vq->last_add_time_valid = false;
|
|
|
|
#endif
|
|
|
|
|
2007-10-22 01:03:40 +00:00
|
|
|
END_USE(vq);
|
|
|
|
return ret;
|
|
|
|
}
|
2010-04-12 13:19:07 +00:00
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_get_buf);
|
2007-10-22 01:03:40 +00:00
|
|
|
|
2012-01-12 05:14:42 +00:00
|
|
|
/**
|
|
|
|
* virtqueue_disable_cb - disable callbacks
|
|
|
|
* @vq: the struct virtqueue we're talking about.
|
|
|
|
*
|
|
|
|
* Note that this is not necessarily synchronous, hence unreliable and only
|
|
|
|
* useful as an optimization.
|
|
|
|
*
|
|
|
|
* Unlike other operations, this need not be serialized.
|
|
|
|
*/
|
2010-04-12 13:19:07 +00:00
|
|
|
void virtqueue_disable_cb(struct virtqueue *_vq)
|
2008-02-05 04:49:57 +00:00
|
|
|
{
|
|
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
|
|
|
|
vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
|
|
|
|
}
|
2010-04-12 13:19:07 +00:00
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
|
2008-02-05 04:49:57 +00:00
|
|
|
|
2012-01-12 05:14:42 +00:00
|
|
|
/**
|
2013-07-09 10:19:18 +00:00
|
|
|
* virtqueue_enable_cb_prepare - restart callbacks after disable_cb
|
2012-01-12 05:14:42 +00:00
|
|
|
* @vq: the struct virtqueue we're talking about.
|
|
|
|
*
|
2013-07-09 10:19:18 +00:00
|
|
|
* This re-enables callbacks; it returns current queue state
|
|
|
|
* in an opaque unsigned value. This value should be later tested by
|
|
|
|
* virtqueue_poll, to detect a possible race between the driver checking for
|
|
|
|
* more work, and enabling callbacks.
|
2012-01-12 05:14:42 +00:00
|
|
|
*
|
|
|
|
* Caller must ensure we don't call this with other virtqueue
|
|
|
|
* operations at the same time (except where noted).
|
|
|
|
*/
|
2013-07-09 10:19:18 +00:00
|
|
|
unsigned virtqueue_enable_cb_prepare(struct virtqueue *_vq)
|
2007-10-22 01:03:40 +00:00
|
|
|
{
|
|
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
2013-07-09 10:19:18 +00:00
|
|
|
u16 last_used_idx;
|
2007-10-22 01:03:40 +00:00
|
|
|
|
|
|
|
START_USE(vq);
|
|
|
|
|
|
|
|
/* We optimistically turn back on interrupts, then check if there was
|
|
|
|
* more to do. */
|
2011-05-19 23:10:44 +00:00
|
|
|
/* Depending on the VIRTIO_RING_F_EVENT_IDX feature, we need to
|
|
|
|
* either clear the flags bit or point the event index at the next
|
|
|
|
* entry. Always do both to keep code simple. */
|
2007-10-22 01:03:40 +00:00
|
|
|
vq->vring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
|
2013-07-09 10:19:18 +00:00
|
|
|
vring_used_event(&vq->vring) = last_used_idx = vq->last_used_idx;
|
|
|
|
END_USE(vq);
|
|
|
|
return last_used_idx;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* virtqueue_poll - query pending used buffers
|
|
|
|
* @vq: the struct virtqueue we're talking about.
|
|
|
|
* @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare).
|
|
|
|
*
|
|
|
|
* Returns "true" if there are pending used buffers in the queue.
|
|
|
|
*
|
|
|
|
* This does not need to be serialized.
|
|
|
|
*/
|
|
|
|
bool virtqueue_poll(struct virtqueue *_vq, unsigned last_used_idx)
|
|
|
|
{
|
|
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
|
2013-03-18 02:52:19 +00:00
|
|
|
virtio_mb(vq->weak_barriers);
|
2013-07-09 10:19:18 +00:00
|
|
|
return (u16)last_used_idx != vq->vring.used->idx;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_poll);
|
2007-10-22 01:03:40 +00:00
|
|
|
|
2013-07-09 10:19:18 +00:00
|
|
|
/**
|
|
|
|
* virtqueue_enable_cb - restart callbacks after disable_cb.
|
|
|
|
* @vq: the struct virtqueue we're talking about.
|
|
|
|
*
|
|
|
|
* This re-enables callbacks; it returns "false" if there are pending
|
|
|
|
* buffers in the queue, to detect a possible race between the driver
|
|
|
|
* checking for more work, and enabling callbacks.
|
|
|
|
*
|
|
|
|
* Caller must ensure we don't call this with other virtqueue
|
|
|
|
* operations at the same time (except where noted).
|
|
|
|
*/
|
|
|
|
bool virtqueue_enable_cb(struct virtqueue *_vq)
|
|
|
|
{
|
|
|
|
unsigned last_used_idx = virtqueue_enable_cb_prepare(_vq);
|
|
|
|
return !virtqueue_poll(_vq, last_used_idx);
|
2007-10-22 01:03:40 +00:00
|
|
|
}
|
2010-04-12 13:19:07 +00:00
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
|
2007-10-22 01:03:40 +00:00
|
|
|
|
2012-01-12 05:14:42 +00:00
|
|
|
/**
|
|
|
|
* virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
|
|
|
|
* @vq: the struct virtqueue we're talking about.
|
|
|
|
*
|
|
|
|
* This re-enables callbacks but hints to the other side to delay
|
|
|
|
* interrupts until most of the available buffers have been processed;
|
|
|
|
* it returns "false" if there are many pending buffers in the queue,
|
|
|
|
* to detect a possible race between the driver checking for more work,
|
|
|
|
* and enabling callbacks.
|
|
|
|
*
|
|
|
|
* Caller must ensure we don't call this with other virtqueue
|
|
|
|
* operations at the same time (except where noted).
|
|
|
|
*/
|
2011-05-19 23:11:14 +00:00
|
|
|
bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
|
|
|
|
{
|
|
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
u16 bufs;
|
|
|
|
|
|
|
|
START_USE(vq);
|
|
|
|
|
|
|
|
/* We optimistically turn back on interrupts, then check if there was
|
|
|
|
* more to do. */
|
|
|
|
/* Depending on the VIRTIO_RING_F_USED_EVENT_IDX feature, we need to
|
|
|
|
* either clear the flags bit or point the event index at the next
|
|
|
|
* entry. Always do both to keep code simple. */
|
|
|
|
vq->vring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
|
|
|
|
/* TODO: tune this threshold */
|
|
|
|
bufs = (u16)(vq->vring.avail->idx - vq->last_used_idx) * 3 / 4;
|
|
|
|
vring_used_event(&vq->vring) = vq->last_used_idx + bufs;
|
2013-03-18 02:52:19 +00:00
|
|
|
virtio_mb(vq->weak_barriers);
|
2011-05-19 23:11:14 +00:00
|
|
|
if (unlikely((u16)(vq->vring.used->idx - vq->last_used_idx) > bufs)) {
|
|
|
|
END_USE(vq);
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
END_USE(vq);
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
|
|
|
|
|
2012-01-12 05:14:42 +00:00
|
|
|
/**
|
|
|
|
* virtqueue_detach_unused_buf - detach first unused buffer
|
|
|
|
* @vq: the struct virtqueue we're talking about.
|
|
|
|
*
|
2013-05-20 02:45:44 +00:00
|
|
|
* Returns NULL or the "data" token handed to virtqueue_add_*().
|
2012-01-12 05:14:42 +00:00
|
|
|
* This is not valid on an active queue; it is useful only for device
|
|
|
|
* shutdown.
|
|
|
|
*/
|
2010-04-12 13:19:07 +00:00
|
|
|
void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
|
2010-01-18 13:45:23 +00:00
|
|
|
{
|
|
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
unsigned int i;
|
|
|
|
void *buf;
|
|
|
|
|
|
|
|
START_USE(vq);
|
|
|
|
|
|
|
|
for (i = 0; i < vq->vring.num; i++) {
|
|
|
|
if (!vq->data[i])
|
|
|
|
continue;
|
|
|
|
/* detach_buf clears data, so grab it now. */
|
|
|
|
buf = vq->data[i];
|
|
|
|
detach_buf(vq, i);
|
2011-03-16 13:42:10 +00:00
|
|
|
vq->vring.avail->idx--;
|
2010-01-18 13:45:23 +00:00
|
|
|
END_USE(vq);
|
|
|
|
return buf;
|
|
|
|
}
|
|
|
|
/* That should have freed everything. */
|
2012-10-16 13:26:14 +00:00
|
|
|
BUG_ON(vq->vq.num_free != vq->vring.num);
|
2010-01-18 13:45:23 +00:00
|
|
|
|
|
|
|
END_USE(vq);
|
|
|
|
return NULL;
|
|
|
|
}
|
2010-04-12 13:19:07 +00:00
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf);
|
2010-01-18 13:45:23 +00:00
|
|
|
|
2007-10-22 01:03:40 +00:00
|
|
|
irqreturn_t vring_interrupt(int irq, void *_vq)
|
|
|
|
{
|
|
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
|
|
|
|
if (!more_used(vq)) {
|
|
|
|
pr_debug("virtqueue interrupt with no work for %p\n", vq);
|
|
|
|
return IRQ_NONE;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (unlikely(vq->broken))
|
|
|
|
return IRQ_HANDLED;
|
|
|
|
|
|
|
|
pr_debug("virtqueue callback for %p (%p)\n", vq, vq->vq.callback);
|
2008-02-05 04:49:57 +00:00
|
|
|
if (vq->vq.callback)
|
|
|
|
vq->vq.callback(&vq->vq);
|
2007-10-22 01:03:40 +00:00
|
|
|
|
|
|
|
return IRQ_HANDLED;
|
|
|
|
}
|
2008-02-05 04:50:05 +00:00
|
|
|
EXPORT_SYMBOL_GPL(vring_interrupt);
|
2007-10-22 01:03:40 +00:00
|
|
|
|
2012-08-28 11:54:13 +00:00
|
|
|
struct virtqueue *vring_new_virtqueue(unsigned int index,
|
|
|
|
unsigned int num,
|
2008-12-30 15:26:03 +00:00
|
|
|
unsigned int vring_align,
|
2007-10-22 01:03:40 +00:00
|
|
|
struct virtio_device *vdev,
|
2012-01-12 05:14:42 +00:00
|
|
|
bool weak_barriers,
|
2007-10-22 01:03:40 +00:00
|
|
|
void *pages,
|
2013-10-28 23:08:50 +00:00
|
|
|
bool (*notify)(struct virtqueue *),
|
2009-06-13 04:16:35 +00:00
|
|
|
void (*callback)(struct virtqueue *),
|
|
|
|
const char *name)
|
2007-10-22 01:03:40 +00:00
|
|
|
{
|
|
|
|
struct vring_virtqueue *vq;
|
|
|
|
unsigned int i;
|
|
|
|
|
2007-11-12 02:39:18 +00:00
|
|
|
/* We assume num is a power of 2. */
|
|
|
|
if (num & (num - 1)) {
|
|
|
|
dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
2007-10-22 01:03:40 +00:00
|
|
|
vq = kmalloc(sizeof(*vq) + sizeof(void *)*num, GFP_KERNEL);
|
|
|
|
if (!vq)
|
|
|
|
return NULL;
|
|
|
|
|
2008-12-30 15:26:03 +00:00
|
|
|
vring_init(&vq->vring, num, pages, vring_align);
|
2007-10-22 01:03:40 +00:00
|
|
|
vq->vq.callback = callback;
|
|
|
|
vq->vq.vdev = vdev;
|
2009-06-13 04:16:35 +00:00
|
|
|
vq->vq.name = name;
|
2012-10-16 13:26:14 +00:00
|
|
|
vq->vq.num_free = num;
|
|
|
|
vq->vq.index = index;
|
2007-10-22 01:03:40 +00:00
|
|
|
vq->notify = notify;
|
2012-01-12 05:14:42 +00:00
|
|
|
vq->weak_barriers = weak_barriers;
|
2007-10-22 01:03:40 +00:00
|
|
|
vq->broken = false;
|
|
|
|
vq->last_used_idx = 0;
|
|
|
|
vq->num_added = 0;
|
2009-06-13 04:16:35 +00:00
|
|
|
list_add_tail(&vq->vq.list, &vdev->vqs);
|
2007-10-22 01:03:40 +00:00
|
|
|
#ifdef DEBUG
|
|
|
|
vq->in_use = false;
|
2012-01-12 05:14:43 +00:00
|
|
|
vq->last_add_time_valid = false;
|
2007-10-22 01:03:40 +00:00
|
|
|
#endif
|
|
|
|
|
2009-05-11 17:11:45 +00:00
|
|
|
vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC);
|
2011-05-19 23:10:44 +00:00
|
|
|
vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
|
2009-05-11 17:11:45 +00:00
|
|
|
|
2007-10-22 01:03:40 +00:00
|
|
|
/* No callback? Tell other side not to bother us. */
|
|
|
|
if (!callback)
|
|
|
|
vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
|
|
|
|
|
|
|
|
/* Put everything in free lists. */
|
|
|
|
vq->free_head = 0;
|
2010-02-12 05:02:14 +00:00
|
|
|
for (i = 0; i < num-1; i++) {
|
2007-10-22 01:03:40 +00:00
|
|
|
vq->vring.desc[i].next = i+1;
|
2010-02-12 05:02:14 +00:00
|
|
|
vq->data[i] = NULL;
|
|
|
|
}
|
|
|
|
vq->data[i] = NULL;
|
2007-10-22 01:03:40 +00:00
|
|
|
|
|
|
|
return &vq->vq;
|
|
|
|
}
|
2008-02-05 04:50:05 +00:00
|
|
|
EXPORT_SYMBOL_GPL(vring_new_virtqueue);
|
2007-10-22 01:03:40 +00:00
|
|
|
|
|
|
|
void vring_del_virtqueue(struct virtqueue *vq)
|
|
|
|
{
|
2009-06-13 04:16:35 +00:00
|
|
|
list_del(&vq->list);
|
2007-10-22 01:03:40 +00:00
|
|
|
kfree(to_vvq(vq));
|
|
|
|
}
|
2008-02-05 04:50:05 +00:00
|
|
|
EXPORT_SYMBOL_GPL(vring_del_virtqueue);
|
2007-10-22 01:03:40 +00:00
|
|
|
|
2008-07-25 17:06:13 +00:00
|
|
|
/* Manipulates transport-specific feature bits. */
|
|
|
|
void vring_transport_features(struct virtio_device *vdev)
|
|
|
|
{
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) {
|
|
|
|
switch (i) {
|
2009-05-11 17:11:45 +00:00
|
|
|
case VIRTIO_RING_F_INDIRECT_DESC:
|
|
|
|
break;
|
2011-05-19 23:10:44 +00:00
|
|
|
case VIRTIO_RING_F_EVENT_IDX:
|
|
|
|
break;
|
2008-07-25 17:06:13 +00:00
|
|
|
default:
|
|
|
|
/* We don't understand this bit. */
|
2014-10-07 14:39:42 +00:00
|
|
|
__virtio_clear_bit(vdev, i);
|
2008-07-25 17:06:13 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(vring_transport_features);
|
|
|
|
|
2012-01-12 05:14:42 +00:00
|
|
|
/**
|
|
|
|
* virtqueue_get_vring_size - return the size of the virtqueue's vring
|
|
|
|
* @vq: the struct virtqueue containing the vring of interest.
|
|
|
|
*
|
|
|
|
* Returns the size of the vring. This is mainly used for boasting to
|
|
|
|
* userspace. Unlike other operations, this need not be serialized.
|
|
|
|
*/
|
2011-10-19 08:10:59 +00:00
|
|
|
unsigned int virtqueue_get_vring_size(struct virtqueue *_vq)
|
|
|
|
{
|
|
|
|
|
|
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
|
|
|
|
return vq->vring.num;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);
|
|
|
|
|
2013-10-28 23:10:19 +00:00
|
|
|
bool virtqueue_is_broken(struct virtqueue *_vq)
|
|
|
|
{
|
|
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
|
|
|
|
return vq->broken;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(virtqueue_is_broken);
|
|
|
|
|
2014-04-28 01:45:08 +00:00
|
|
|
/*
|
|
|
|
* This should prevent the device from being used, allowing drivers to
|
|
|
|
* recover. You may need to grab appropriate locks to flush.
|
|
|
|
*/
|
|
|
|
void virtio_break_device(struct virtio_device *dev)
|
|
|
|
{
|
|
|
|
struct virtqueue *_vq;
|
|
|
|
|
|
|
|
list_for_each_entry(_vq, &dev->vqs, list) {
|
|
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
vq->broken = true;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(virtio_break_device);
|
|
|
|
|
2008-02-05 04:50:05 +00:00
|
|
|
MODULE_LICENSE("GPL");
|