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2016-05-06rpmsg: add THIS_MODULE to rpmsg_driver in rpmsg coreAndrew F. Davis1-3/+5
Add register_rpmsg_driver helper macro that adds THIS_MODULE to rpmsg_driver for the registering driver. We rename and modify the existing register_rpmsg_driver to enable this. Signed-off-by: Andrew F. Davis <afd@ti.com> Acked-by: Suman Anna <s-anna@ti.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2016-01-12virtio: make find_vqs() checkpatch.pl-friendlyStefan Hajnoczi1-1/+1
checkpatch.pl wants arrays of strings declared as follows: static const char * const names[] = { "vq-1", "vq-2", "vq-3" }; Currently the find_vqs() function takes a const char *names[] argument so passing checkpatch.pl's const char * const names[] results in a compiler error due to losing the second const. This patch adjusts the find_vqs() prototype and updates all virtio transports. This makes it possible for virtio_balloon.c, virtio_input.c, virtgpu_kms.c, and virtio_rpmsg_bus.c to use the checkpatch.pl-friendly type. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
2015-03-13virtio_rpmsg: set DRIVER_OK before using deviceMichael S. Tsirkin1-1/+16
virtio spec requires that all drivers set DRIVER_OK before using devices. While rpmsg isn't yet included in the virtio 1 spec, previous spec versions also required this. virtio rpmsg violates this rule: is calls kick before setting DRIVER_OK. The fix isn't trivial since simply calling virtio_device_ready earlier would mean we might get an interrupt in parallel with adding buffers. Instead, split kick out to prepare+notify calls. prepare before virtio_device_ready - when we know we won't get interrupts. notify right afterwards. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Ohad Ben-Cohen <ohad@wizery.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-11-26rpmsg: use less buffers when vrings are smallSuman Anna1-14/+30
Adjust the number of rpmsg buffers to rely on the size of the vring, instead of using the hard coded value of 512 (256 per direction). This is needed when small vrings are being used, where 256 buffers are too much to fit in a vring. While considering the vring size, keep using the 512 hard coded value as an upper limit to avoid wacky resource tables consuming unreasonable amount of memory. NOTE: The number of buffers is already assumed to be symmetrical in each direction, and that logic is unchanged. Signed-off-by: Suman Anna <s-anna@ti.com> [edit commit message, small code and comment simplification] Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2013-05-07Merge tag 'rpmsg-3.10' of ↵Linus Torvalds2-14/+36
git://git.kernel.org/pub/scm/linux/kernel/git/ohad/rpmsg Pull rpmsg changes from Ohad Ben-Cohen: "A small pull request consisting of: - Make rpmsg process all pending messages instead of just one, from Robert Tivy - Fix Kconfig dependency on VIRTUALIZATION, from Suman. Note: this was submitted late during the 3.9 rc cycle and it seemed appropriate to wait with it for the merge window. - Belated addition of an rpmsg entry to the MAINTAINERS file. People seem to look for this" * tag 'rpmsg-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/rpmsg: rpmsg: fix kconfig dependencies for VIRTIO MAINTAINERS: add rpmsg entry rpmsg: process _all_ pending messages in rpmsg_recv_done
2013-05-02Merge tag 'virtio-next-for-linus' of ↵Linus Torvalds1-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull virtio & lguest updates from Rusty Russell: "Lots of virtio work which wasn't quite ready for last merge window. Plus I dived into lguest again, reworking the pagetable code so we can move the switcher page: our fixmaps sometimes take more than 2MB now..." Ugh. Annoying conflicts with the tcm_vhost -> vhost_scsi rename. Hopefully correctly resolved. * tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (57 commits) caif_virtio: Remove bouncing email addresses lguest: improve code readability in lg_cpu_start. virtio-net: fill only rx queues which are being used lguest: map Switcher below fixmap. lguest: cache last cpu we ran on. lguest: map Switcher text whenever we allocate a new pagetable. lguest: don't share Switcher PTE pages between guests. lguest: expost switcher_pages array (as lg_switcher_pages). lguest: extract shadow PTE walking / allocating. lguest: make check_gpte et. al return bool. lguest: assume Switcher text is a single page. lguest: rename switcher_page to switcher_pages. lguest: remove RESERVE_MEM constant. lguest: check vaddr not pgd for Switcher protection. lguest: prepare to make SWITCHER_ADDR a variable. virtio: console: replace EMFILE with EBUSY for already-open port virtio-scsi: reset virtqueue affinity when doing cpu hotplug virtio-scsi: introduce multiqueue support virtio-scsi: push vq lock/unlock into virtscsi_vq_done virtio-scsi: pass struct virtio_scsi to virtqueue completion function ...
2013-04-29drivers/rpmsg/virtio_rpmsg_bus.c: fix error return code in rpmsg_probe()Wei Yongjun1-1/+3
Return a negative error code from the error handling case instead of 0, as returned elsewhere in this function. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: Ohad Ben-Cohen <ohad@wizery.com> Cc: Tejun Heo <tj@kernel.org> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-21rpmsg: fix kconfig dependencies for VIRTIOSuman Anna1-0/+1
Fix this: warning: (VIRTIO_PCI && VIRTIO_MMIO && REMOTEPROC && RPMSG) selects VIRTIO which has unmet direct dependencies (VIRTUALIZATION) Cc: stable@vger.kernel.org Signed-off-by: Suman Anna <s-anna@ti.com> [edit commit log] Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2013-04-15rpmsg: process _all_ pending messages in rpmsg_recv_doneRobert Tivy1-14/+35
Change virtqueue callback function rpmsg_recv_done() to process all available messages instead of just one message. Signed-off-by: Robert Tivy <rtivy@ti.com> [split _recv function instead of adding indentation] Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2013-03-20virtio_rpmsg_bus: use simplified virtqueue accessors.Rusty Russell1-4/+4
We never add buffers with input and output parts, so use the new accessors. Cc: Ohad Ben-Cohen <ohad@wizery.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-02-27rpmsg: convert to idr_alloc()Tejun Heo1-18/+12
Convert to the much saner new idr interface. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ohad Ben-Cohen <ohad@wizery.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27rpmsg: don't use idr_remove_all()Tejun Heo1-1/+0
idr_destroy() can destroy idr by itself and idr_remove_all() is being deprecated. Drop its usage. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ohad Ben-Cohen <ohad@wizery.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-21Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree from Jiri Kosina: "Assorted tiny fixes queued in trivial tree" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (22 commits) DocBook: update EXPORT_SYMBOL entry to point at export.h Documentation: update top level 00-INDEX file with new additions ARM: at91/ide: remove unsused at91-ide Kconfig entry percpu_counter.h: comment code for better readability x86, efi: fix comment typo in head_32.S IB: cxgb3: delay freeing mem untill entirely done with it net: mvneta: remove unneeded version.h include time: x86: report_lost_ticks doesn't exist any more pcmcia: avoid static analysis complaint about use-after-free fs/jfs: Fix typo in comment : 'how may' -> 'how many' of: add missing documentation for of_platform_populate() btrfs: remove unnecessary cur_trans set before goto loop in join_transaction sound: soc: Fix typo in sound/codecs treewide: Fix typo in various drivers btrfs: fix comment typos Update ibmvscsi module name in Kconfig. powerpc: fix typo (utilties -> utilities) of: fix spelling mistake in comment h8300: Fix home page URL in h8300/README xtensa: Fix home page URL in Kconfig ...
2013-01-29Merge branch 'master' into for-nextJiri Kosina1-6/+4
Conflicts: drivers/devfreq/exynos4_bus.c Sync with Linus' tree to be able to apply patches that are against newer code (mvneta).
2013-01-11drivers/rpmsg: remove depends on CONFIG_EXPERIMENTALKees Cook1-2/+1
The CONFIG_EXPERIMENTAL config item has not carried much meaning for a while now and is almost always enabled by default. As agreed during the Linux kernel summit, remove it from any "depends on" lines in Kconfigs. CC: Ohad Ben-Cohen <ohad@wizery.com> CC: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au>
2013-01-09treewide: Fix typo in various driversMasanari Iida1-1/+1
Correct spelling typo in printk within various drivers. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-01-03Drivers: misc: remove __dev* attributes.Greg Kroah-Hartman1-2/+2
CONFIG_HOTPLUG is going away as an option. As a result, the __dev* markings need to be removed. This change removes the use of __devinit, __devexit_p, __devinitdata, __devinitconst, and __devexit from these drivers. Based on patches originally written by Bill Pemberton, but redone by me in order to handle some of the coding style issues better, by hand. Cc: Bill Pemberton <wfp5p@virginia.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-12-18virtio: rpmsg: make it clear that virtqueue_add_buf() no longer returns > 0Rusty Russell1-4/+2
We simplified virtqueue_add_buf(), make it clear in the callers. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-07Merge branch 'virtio-next' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull virtio changes from Rusty Russell: "New workflow: same git trees pulled by linux-next get sent straight to Linus. Git is awkward at shuffling patches compared with quilt or mq, but that doesn't happen often once things get into my -next branch." * 'virtio-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (24 commits) lguest: fix occasional crash in example launcher. virtio-blk: Disable callback in virtblk_done() virtio_mmio: Don't attempt to create empty virtqueues virtio_mmio: fix off by one error allocating queue drivers/virtio/virtio_pci.c: fix error return code virtio: don't crash when device is buggy virtio: remove CONFIG_VIRTIO_RING virtio: add help to CONFIG_VIRTIO option. virtio: support reserved vqs virtio: introduce an API to set affinity for a virtqueue virtio-ring: move queue_index to vring_virtqueue virtio_balloon: not EXPERIMENTAL any more. virtio-balloon: dependency fix virtio-blk: fix NULL checking in virtblk_alloc_req() virtio-blk: Add REQ_FLUSH and REQ_FUA support to bio path virtio-blk: Add bio-based IO path for virtio-blk virtio: console: fix error handling in init() function tools: Fix pthread flag for Makefile of trace-agent used by virtio-trace tools: Add guest trace agent as a user tool virtio/console: Allocate scatterlist according to the current pipe size ...
2012-09-28virtio: remove CONFIG_VIRTIO_RINGRusty Russell1-1/+0
Everyone who selects VIRTIO is also made to select VIRTIO_RING; just make them synonymous, since we removed the indirection layer some time ago. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-12rpmsg: fix dma_free_coherent dev parameterFernando Guzman Lugo1-3/+3
dma_alloc/free_coherent APIs requires the platform specific remoteproc device as the device parameter. We are passing vdev->dev.parent to the dma_free_coherent function which is the generic rproc device and it is wrong, it has to be vdev->dev.parent->parent instead, same as when we call dma_alloc_coherent function. Signed-off-by: Fernando Guzman Lugo <fernando.lugo@ti.com> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2012-07-26Merge tag 'remoteproc-for-3.6' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc Pull remoteproc update from Ohad Ben-Cohen: - custom binary format support from Sjur Brændeland - groundwork for recovery and runtime pm support - some cleanups and API simplifications Fix up conflicts in drivers/remoteproc/remoteproc_core.c due to clashes with earlier cleanups by Sjur Brændeland (with part of the cleanups moved into the new remoteproc_elf_loader.c file). * tag 'remoteproc-for-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc: MAINTAINERS: add remoteproc's git remoteproc: Support custom firmware handlers remoteproc: Move Elf related functions to separate file remoteproc: Add function rproc_get_boot_addr remoteproc: Pass struct fw to load_segments and find_rsc_table. remoteproc: adopt the driver core's alloc/add/del/put naming remoteproc: remove the get_by_name/put API remoteproc: support non-iommu carveout assignment remoteproc: simplify unregister/free interfaces remoteproc: remove the now-redundant kref remoteproc: maintain a generic child device for each rproc remoteproc: allocate vrings on demand, free when not needed
2012-07-17rpmsg: fix dependency on initialization orderFederico Fuga1-1/+1
When rpmsg drivers are built into the kernel, they must not initialize before the rpmsg bus does, otherwise they'd trigger a BUG() in drivers/base/driver.c line 169 (driver_register()). To fix that, and to stop depending on arbitrary linkage ordering of those built-in rpmsg drivers, we make the rpmsg bus initialize at subsys_initcall. Cc: stable <stable@vger.kernel.org> Signed-off-by: Federico Fuga <fuga@studiofuga.com> [ohad: rewrite the commit log] Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2012-07-06remoteproc: maintain a generic child device for each rprocOhad Ben-Cohen1-1/+2
For each registered rproc, maintain a generic remoteproc device whose parent is the low level platform-specific device (commonly a pdev, but it may certainly be any other type of device too). With this in hand, the resulting device hierarchy might then look like: omap-rproc.0 | - remoteproc0 <---- new ! | - virtio0 | - virtio1 | - rpmsg0 | - rpmsg1 | - rpmsg2 Where: - omap-rproc.0 is the low level device that's bound to the driver which invokes rproc_register() - remoteproc0 is the result of this patch, and will be added by the remoteproc framework when rproc_register() is invoked - virtio0 and virtio1 are vdevs that are registered by remoteproc when it realizes that they are supported by the firmware of the physical remote processor represented by omap-rproc.0 - rpmsg0, rpmsg1 and rpmsg2 are rpmsg devices that represent rpmsg channels, and are registerd by the rpmsg bus when it gets notified about their existence Technically, this patch: - changes 'struct rproc' to contain this generic remoteproc.x device - creates a new "remoteproc" type, to which this new generic remoteproc.x device belong to. - adds a super simple enumeration method for the indices of the remoteproc.x devices - updates all dev_* messaging to use the generic remoteproc.x device instead of the low level platform-specific device - updates all dma_* allocations to use the parent of remoteproc.x (where the platform-specific memory pools, most commonly CMA, are to be found) Adding this generic device has several merits: - we can now add remoteproc runtime PM support simply by hooking onto the new "remoteproc" type - all remoteproc log messages will now carry a common name prefix instead of having a platform-specific one - having a device as part of the rproc struct makes it possible to simplify refcounting (see subsequent patch) Thanks to Stephen Boyd <sboyd@codeaurora.org> for suggesting and discussing these ideas in one of the remoteproc review threads and to Fernando Guzman Lugo <fernando.lugo@ti.com> for trying them out with the (upcoming) runtime PM support for remoteproc. Cc: Fernando Guzman Lugo <fernando.lugo@ti.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2012-07-04rpmsg: make sure inflight messages don't invoke just-removed callbacksOhad Ben-Cohen1-6/+19
When inbound messages arrive, rpmsg core looks up their associated endpoint (by destination address) and then invokes their callback. We've made sure that endpoints will never be de-allocated after they were found by rpmsg core, but we also need to protect against the (rare) scenario where the rpmsg driver was just removed, and its callback function isn't available anymore. This is achieved by introducing a callback mutex, which must be taken before the callback is invoked, and, obviously, before it is removed. Cc: stable <stable@vger.kernel.org> Reported-by: Fernando Guzman Lugo <fernando.lugo@ti.com> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2012-07-04rpmsg: avoid premature deallocation of endpointsOhad Ben-Cohen1-2/+34
When an inbound message arrives, the rpmsg core looks up its associated endpoint and invokes the registered callback. If a message arrives while its endpoint is being removed (because the rpmsg driver was removed, or a recovery of a remote processor has kicked in) we must ensure atomicity, i.e.: - Either the ept is removed before it is found or - The ept is found but will not be freed until the callback returns This is achieved by maintaining a per-ept reference count, which, when drops to zero, will trigger deallocation of the ept. With this in hand, it is now forbidden to directly deallocate epts once they have been added to the endpoints idr. Cc: stable <stable@vger.kernel.org> Reported-by: Fernando Guzman Lugo <fernando.lugo@ti.com> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2012-03-04rpmsg: fix build warning when dma_addr_t is 64-bitMark Asselstine1-2/+2
dev_dbg() in rpmsg_probe() made use of the %x formatting that expects an 'unsigned int' which dma_addr_t is not in cases where dma_addr_t is 64-bit (CONFIG_ARCH_DMA_ADDR_T_64BIT). Casting to a 'unsigned long long' and using %llx will avoid this. Signed-off-by: Mark Asselstine <mark.asselstine@windriver.com> CC: Ohad Ben-Cohen <ohad@wizery.com> CC: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2012-02-28rpmsg: fix published buffer length in rpmsg_recv_doneOhad Ben-Cohen1-1/+2
After processing an incoming message, always publish the real size of its containing buffer when putting it back on the available rx ring. Using any different value might erroneously limit the remote processor (leading it to think the buffer is smaller than it really is). Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Mark Grosen <mgrosen@ti.com> Cc: Suman Anna <s-anna@ti.com> Cc: Fernando Guzman Lugo <fernando.lugo@ti.com> Cc: Rob Clark <rob@ti.com> Cc: Ludovic BARRE <ludovic.barre@stericsson.com> Cc: Loic PALLARDY <loic.pallardy@stericsson.com> Cc: Omar Ramirez Luna <omar.luna@linaro.org>
2012-02-28rpmsg: validate incoming message length before propagatingOhad Ben-Cohen1-0/+10
When an inbound message arrives, validate its reported length before propagating it, otherwise buggy (or malicious) remote processors might trick us into accessing memory which we really shouldn't. Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Mark Grosen <mgrosen@ti.com> Cc: Suman Anna <s-anna@ti.com> Cc: Fernando Guzman Lugo <fernando.lugo@ti.com> Cc: Rob Clark <rob@ti.com> Cc: Ludovic BARRE <ludovic.barre@stericsson.com> Cc: Loic PALLARDY <loic.pallardy@stericsson.com> Cc: Omar Ramirez Luna <omar.luna@linaro.org>
2012-02-28rpmsg: fix name service endpoint leakOhad Ben-Cohen1-6/+23
The name service endpoint wasn't destroyed, so fix it. This is achieved by introducing an internal __rpmsg_destroy_ept function which doesn't assume the given ept is bound to an rpmsg channel (much like the existing __rpmsg_create_ept). This is needed because the name service ept belongs to the rpmsg bus, and is never bound with a specific rpdev. Reported-by: Omar Ramirez Luna <omar.ramirez@ti.com> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Mark Grosen <mgrosen@ti.com> Cc: Suman Anna <s-anna@ti.com> Cc: Fernando Guzman Lugo <fernando.lugo@ti.com> Cc: Rob Clark <rob@ti.com> Cc: Ludovic BARRE <ludovic.barre@stericsson.com> Cc: Loic PALLARDY <loic.pallardy@stericsson.com> Cc: Omar Ramirez Luna <omar.ramirez@ti.com>
2012-02-22rpmsg: rename virtqueue_add_buf_gfp to virtqueue_add_bufAxel Lin1-4/+4
Since commit 7bb7aef2 "virtio: rename virtqueue_add_buf_gfp to virtqueue_add_buf", virtqueue_add_buf_gfp is already rename to virtqueue_add_buf now. This patch fixes below build error: CC [M] drivers/rpmsg/virtio_rpmsg_bus.o drivers/rpmsg/virtio_rpmsg_bus.c: In function 'rpmsg_send_offchannel_raw': drivers/rpmsg/virtio_rpmsg_bus.c:723: error: implicit declaration of function 'virtqueue_add_buf_gfp' make[2]: *** [drivers/rpmsg/virtio_rpmsg_bus.o] Error 1 make[1]: *** [drivers/rpmsg] Error 2 make: *** [drivers] Error 2 Signed-off-by: Axel Lin <axel.lin@gmail.com> Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2012-02-22rpmsg: depend on EXPERIMENTALOhad Ben-Cohen1-1/+2
There isn't any binary change in sight or evidence of any stability issue, but as we just begin to get traction we can't rule them out completely. To be on the safe side, let's mark rpmsg as EXPERIMENTAL, and remove it later on after we have several happy users. Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Rob Clark <rob@ti.com> Cc: Mark Grosen <mgrosen@ti.com> Cc: Ludovic BARRE <ludovic.barre@stericsson.com>
2012-02-08rpmsg: add Kconfig menuOhad Ben-Cohen1-0/+4
Add a dedicated Kconfig menu for the rpmsg drivers, so they don't show up in the main driver menu. Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
2012-02-08rpmsg: add virtio-based remote processor messaging busOhad Ben-Cohen3-0/+1032
Add a virtio-based inter-processor communication bus, which enables kernel drivers to communicate with entities, running on remote processors, over shared memory using a simple messaging protocol. Every pair of AMP processors share two vrings, which are used to send and receive the messages over shared memory. The header of every message sent on the rpmsg bus contains src and dst addresses, which make it possible to multiplex several rpmsg channels on the same vring. Every rpmsg channel is a device on this bus. When a channel is added, and an appropriate rpmsg driver is found and probed, it is also assigned a local rpmsg address, which is then bound to the driver's callback. When inbound messages carry the local address of a bound driver, its callback is invoked by the bus. This patch provides a kernel interface only; user space interfaces will be later exposed by kernel users of this rpmsg bus. Designed with Brian Swetland <swetland@google.com>. Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> (virtio_ids.h) Cc: Brian Swetland <swetland@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Tony Lindgren <tony@atomide.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg KH <greg@kroah.com> Cc: Stephen Boyd <sboyd@codeaurora.org>