remoteproc: allocate vrings on demand, free when not needed

Dynamically allocate the vrings' DMA when the remote processor
is about to be powered on (i.e. when ->find_vqs() is invoked),
and release them as soon as it is powered off (i.e. when ->del_vqs()
is invoked).

The obvious and immediate benefit is better memory utilization, since
memory for the vrings is now only allocated when the relevant remote
processor is used.

Additionally, this approach also makes recovery of a (crashing)
remote processor easier: one just needs to remove the relevant
vdevs, and the entire vrings cleanup takes place automagically.

Tested-by: Fernando Guzman Lugo <fernando.lugo@ti.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
remoteproc: maintain a generic child device for each rproc

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>
remoteproc: remove the now-redundant kref

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: Ohad Ben-Cohen <ohad@wizery.com>
remoteproc: simplify unregister/free interfaces

Simplify the unregister/free interfaces, and make them easier
to understand and use, by moving to a symmetric and consistent
alloc() -> register() -> unregister() -> free() flow.

To create and register an rproc instance, one needed to invoke
rproc_alloc() followed by rproc_register().

To unregister and free an rproc instance, one now needs to invoke
rproc_unregister() followed by rproc_free().

Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
remoteproc: support non-iommu carveout assignment

Publish carveout addresses on non-iommu setups too.

Reported-and-acked-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
remoteproc: remove the get_by_name/put API

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: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
remoteproc: adopt the driver core's alloc/add/del/put naming

To make remoteproc's API more intuitive for developers, we adopt
the driver core's naming, i.e. alloc -> add -> del -> put. We'll also
add register/unregister when their first user shows up.

Otherwise - there's no functional change here.

Suggested by Russell King <linux@arm.linux.org.uk>.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Fernando Guzman Lugo <fernando.lugo@ti.com>
Cc: Sjur Brændeland <sjur.brandeland@stericsson.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
remoteproc: Pass struct fw to load_segments and find_rsc_table.

Prepare for introduction of custom firmware loaders by changing
the functions rproc_find_rcs_table() and rproc_load_segments()
to use struct firmware as parameter.

When the custom loader framework is introduced all calls into
the firmware specific function must use struct firmware as
parameter.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
remoteproc: Add function rproc_get_boot_addr

Prepare for introduction of custom firmware loaders by
moving the function operating on ELF data-structures into
separate functions. Move lookup of the boot_addr in the
ELF binary to the function rproc_get_boot_addr().

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
[rproc_get_boot_addr's kerneldoc: add missing @rproc line]
[rproc_get_boot_addr's kerneldoc: minor style changes]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
remoteproc: Move Elf related functions to separate file

Prepare for introduction of custom firmware loaders by
moving all ELF related handling into a separate file.

The functions: rproc_find_rsc_table(), rproc_fw_sanity_check(),
rproc_find_rsc_table() and rproc_get_boot_addr() are moved
to the new file remoteproc_elf_loader.c. The function
rproc_da_to_va() is made non-static and is declared in
remoteproc_internal.h

No functional changes are introduced in this patch.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
[ohad: rebase, fix kerneldoc, put prototypes in remoteproc_internal.h]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
remoteproc: Support custom firmware handlers

Firmware handling is made customizable.
This is done by creating a separate ops structure for the
firmware functions that depends on a particular firmware
format (such as ELF). The ELF functions are default used
unless the HW driver explicitly injects another firmware
handler by updating rproc->fw_ops.
The function rproc_da_to_va() is exported, as custom
firmware handlers may need to use this function.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
[ohad: namespace fixes, whitespace fixes, style fixes]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
MAINTAINERS: add remoteproc's git

Add remoteproc's git tree to the MAINTAINERS entry

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Merge tag 'remoteproc-for-3.6' of 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