Remove rproc_get_by_name() and rproc_put(), and the associated
remoteproc infrastructure that supports it (i.e. klist and friends),
because:

1. No one uses them
2. Using them is highly discouraged, and any potential user
   will be deeply scrutinized and encouraged to move.

If a user, that absolutely can't live with the direct boot/shutdown
model, does show up one day, then bringing this functionality back
is going to be trivial.

At this point though, keeping this functionality around is way too
much of a maintenance burden.

Cc: Sjur Brændeland <sjur.brandeland@stericsson.com>
Cc: Loic Pallardy <loic.pallardy@stericsson.com>
Cc: Ludovic BARRE <ludovic.barre@stericsson.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Fernando Guzman Lugo <fernando.lugo@ti.com>
Cc: Suman Anna <s-anna@ti.com>
Cc: Mark Grosen <mgrosen@ti.com>
Acked-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>

Now that every rproc instance contains a device, we don't need a
kref anymore to maintain the refcount of the rproc instances:
that's what device are good with!

This patch removes the now-redundant kref, and switches to
{get, put}_device instead of kref_{get, put}.

We also don't need the kref's release function anymore, and instead,
we just utilize the class's release handler (which is now responsible
for all memory de-allocations).

Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Fernando Guzman Lugo <fernando.lugo@ti.com>
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>

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: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>

Remove the hardcoded vring alignment of 4096 bytes,
and instead utilize tha vring alignment as specified in
the resource table.

This is needed for remote processors that have rigid
memory requirement, and which have found the alignment of
4096 bytes to be excessively big.
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>
Cc: Brian Swetland <swetland@google.com>
Cc: Iliyan Malchev <malchev@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Mark Grosen <mgrosen@ti.com>
Cc: John Williams <john.williams@petalogix.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Loic PALLARDY <loic.pallardy@stericsson.com>
Cc: Ludovic BARRE <ludovic.barre@stericsson.com>
Cc: Omar Ramirez Luna <omar.luna@linaro.org>
Cc: Guzman Lugo Fernando <fernando.lugo@ti.com>
Cc: Anna Suman <s-anna@ti.com>
Cc: Clark Rob <rob@ti.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: David Brown <davidb@codeaurora.org>
Cc: Kieran Bingham <kieranbingham@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>

Now that the resource table supports publishing a virtio device
in a single resource entry, firmware images can start supporting
more than a single vdev.

This patch removes the single vdev limitation of the remoteproc
framework so multi-vdev firmwares can be leveraged: VDEV resource
entries are parsed when the rproc is registered, and as a result
their vrings are set up and the virtio devices are registered
(and they go away when the rproc goes away).

Moreover, we no longer only support VIRTIO_ID_RPMSG vdevs; any
virtio device type goes now. As a result, there's no more any
rpmsg-specific APIs or code in remoteproc: it all becomes generic
virtio handling.
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>
Cc: Brian Swetland <swetland@google.com>
Cc: Iliyan Malchev <malchev@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Mark Grosen <mgrosen@ti.com>
Cc: John Williams <john.williams@petalogix.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Loic PALLARDY <loic.pallardy@stericsson.com>
Cc: Ludovic BARRE <ludovic.barre@stericsson.com>
Cc: Omar Ramirez Luna <omar.luna@linaro.org>
Cc: Guzman Lugo Fernando <fernando.lugo@ti.com>
Cc: Anna Suman <s-anna@ti.com>
Cc: Clark Rob <rob@ti.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: David Brown <davidb@codeaurora.org>
Cc: Kieran Bingham <kieranbingham@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>

The resource table is an array of 'struct fw_resource' members, where
each resource entry is expressed as a single member of that array.

This approach got us this far, but it has a few drawbacks:

1. Different resource entries end up overloading the same members of 'struct
   fw_resource' with different meanings. The resulting code is error prone
   and hard to read and maintain.

2. It's impossible to extend 'struct fw_resource' without breaking the
   existing firmware images (and we already want to: we can't introduce the
   new virito device resource entry with the current scheme).

3. It doesn't scale: 'struct fw_resource' must be as big as the largest
   resource entry type. As a result, smaller resource entries end up
   utilizing only small part of it.

This is fixed by defining a dedicated structure for every resource type,
and then converting the resource table to a list of type-value members.
Instead of a rigid array of homogeneous structs, the resource table
is turned into a collection of heterogeneous structures.

This way:
1. Resource entries consume exactly the amount of bytes they need.
2. It's easy to extend: just create a new resource entry structure, and assign
   it a new type.
3. The code is easier to read and maintain: the structures' members names are
   meaningful.

While we're at it, this patch has several other resource table changes:
1. The resource table gains a simple header which contains the
   number of entries in the table and their offsets within the table. This
   makes the parsing code simpler and easier to read.
2. A version member is added to the resource table. Should we change the
   format again, we'll bump up this version to prevent breakage with
   existing firmware images.
3. The VRING and VIRTIO_DEV resource entries are combined to a single
   VDEV entry. This paves the way to supporting multiple VDEV entries.
4. Since we don't really support 64-bit rprocs yet, convert two stray u64
   members to u32.
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>
Cc: Brian Swetland <swetland@google.com>
Cc: Iliyan Malchev <malchev@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Mark Grosen <mgrosen@ti.com>
Cc: John Williams <john.williams@petalogix.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Loic PALLARDY <loic.pallardy@stericsson.com>
Cc: Ludovic BARRE <ludovic.barre@stericsson.com>
Cc: Omar Ramirez Luna <omar.luna@linaro.org>
Cc: Guzman Lugo Fernando <fernando.lugo@ti.com>
Cc: Anna Suman <s-anna@ti.com>
Cc: Clark Rob <rob@ti.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Saravana Kannan <skannan@codeaurora.org>
Cc: David Brown <davidb@codeaurora.org>
Cc: Kieran Bingham <kieranbingham@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>

A lookup table would be easier to extend, and the resulting
code is a bit cleaner.
Reported-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>

RSC_VIRTIO_CFG isn't being used, so remove it.

Originally it was introduced to overcome a resource table limitation
that prevented describing a virtio device in a single resource table
entry.

The plan though is to describe resource table entries in a TLV fashion,
where each entry will consume the amount of space it requires,
so the original limitation is anyway temporary.
Reported-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>

Modern SoCs typically employ a central symmetric multiprocessing (SMP)
application processor running Linux, with several other asymmetric
multiprocessing (AMP) heterogeneous processors running different instances
of operating system, whether Linux or any other flavor of real-time OS.

Booting a remote processor in an AMP configuration typically involves:
- Loading a firmware which contains the OS image
- Allocating and providing it required system resources (e.g. memory)
- Programming an IOMMU (when relevant)
- Powering on the device

This patch introduces a generic framework that allows drivers to do
that. In the future, this framework will also include runtime power
management and error recovery.

Based on (but now quite far from) work done by Fernando Guzman Lugo
<fernando.lugo@ti.com>.

ELF loader was written by Mark Grosen <mgrosen@ti.com>, based on
msm's Peripheral Image Loader (PIL) by Stephen Boyd <sboyd@codeaurora.org>.

Designed with Brian Swetland <swetland@google.com>.
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Brian Swetland <swetland@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg KH <greg@kroah.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>