mailbox: bcm-pdc: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: Use device_get_match_data()

Use preferred device_get_match_data() instead of of_match_device() to
get the driver match data. With this, adjust the includes to explicitly
include the correct headers.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: Fix some kernel-doc comments

Fix some kernel-doc comments to silence the warnings:

drivers/mailbox/bcm-pdc-mailbox.c:707: warning: Function parameter or member 'pdcs' not described in 'pdc_tx_list_sg_add'
drivers/mailbox/bcm-pdc-mailbox.c:707: warning: Excess function parameter 'spu_idx' description in 'pdc_tx_list_sg_add'
drivers/mailbox/bcm-pdc-mailbox.c:875: warning: Function parameter or member 'pdcs' not described in 'pdc_rx_list_sg_add'
drivers/mailbox/bcm-pdc-mailbox.c:875: warning: Excess function parameter 'spu_idx' description in 'pdc_rx_list_sg_add'
drivers/mailbox/bcm-pdc-mailbox.c:966: warning: Function parameter or member 't' not described in 'pdc_tasklet_cb'
drivers/mailbox/bcm-pdc-mailbox.c:966: warning: Excess function parameter 'data' description in 'pdc_tasklet_cb'

Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: Use devm_platform_get_and_ioremap_resource()

Convert platform_get_resource(), devm_ioremap_resource() to a single
call to devm_platform_get_and_ioremap_resource(), as this is exactly
what this function does.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: drop of_match_ptr for ID table

The driver can match only via the DT table so the table should be always
used and the of_match_ptr does not have any sense (this also allows ACPI
matching via PRP0001, even though it might not be relevant here).

drivers/mailbox/bcm-pdc-mailbox.c:1474:34: error: ‘pdc_mbox_of_match’ defined but not used [-Werror=unused-const-variable=]

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: Remove redundant error printing in pdc_probe()

When devm_ioremap_resource() fails, a clear enough error message will be
printed by its subfunction __devm_ioremap_resource(). The error
information contains the device name, failure cause, and possibly resource
information.

Therefore, remove the error printing here to simplify code and reduce the
binary size.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm: convert tasklets to use new tasklet_setup() API

In preparation for unconditionally passing the
struct tasklet_struct pointer to all tasklet
callbacks, switch to using the new tasklet_setup()
and from_tasklet() to pass the tasklet pointer explicitly.

Signed-off-by: Romain Perier <romain.perier@gmail.com>
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

iomap: constify ioreadX() iomem argument (as in generic implementation)

Patch series "iomap: Constify ioreadX() iomem argument", v3.

The ioread8/16/32() and others have inconsistent interface among the
architectures: some taking address as const, some not.

It seems there is nothing really stopping all of them to take pointer to
const.

This patch (of 4):

The ioreadX() and ioreadX_rep() helpers have inconsistent interface. On
some architectures void *__iomem address argument is a pointer to const,
on some not.

Implementations of ioreadX() do not modify the memory under the address so
they can be converted to a "const" version for const-safety and
consistency among architectures.

[krzk@kernel.org: sh: clk: fix assignment from incompatible pointer type for ioreadX()]
Link: http://lkml.kernel.org/r/20200723082017.24053-1-krzk@kernel.org
[akpm@linux-foundation.org: fix drivers/mailbox/bcm-pdc-mailbox.c]
Link: http://lkml.kernel.org/r/202007132209.Rxmv4QyS%25lkp@intel.com

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Allen Hubbe <allenbh@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Link: http://lkml.kernel.org/r/20200709072837.5869-1-krzk@kernel.org
Link: http://lkml.kernel.org/r/20200709072837.5869-2-krzk@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mailbox: bcm-pdc: Use scnprintf() for avoiding potential buffer overflow

Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit. Fix it by replacing with scnprintf().

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 459

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation the gpl this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
version 2 gplv2 for more details you should have received a copy of
the gnu general public license version 2 gplv2 along with this
source code

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 16 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081201.771169395@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mailbox: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.

Cc: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mailbox: bcm-pdc: Use device-managed registration API

Get rid of some boilerplate driver removal code by using the newly added
device-managed registration API.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: Add Northstar Plus support to PDC driver

Adds support for Northstar Plus (NS+) products to the PDC mailbox
driver. The PDC driver was originally written to support the PDC
ring manager in the Northstar2 (64-bit) device. The NS+ (32 bit
device) uses an almost identical ring manager, though with a
different name. We just need to check for the type of hardware in
use, in order to write the appropriate interrupt configuration register.
Also updated DMA width to be correct for both NS+ and NS2.

Tested on NS+ and NS2.

Signed-off-by: Steve Lin <steven.lin1@broadcom.com>
Acked-by: Jon Mason <jon.mason@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: Remove unnecessary void* casts

Remove unnecessary void* casts in register writes. Fix two other
minor formatting issues.

Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Reviewed-by: Jon Mason <jon.mason@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: Simplify interrupt handler logic

Earlier versions of the PDC driver registered for both
transmit and receive interrupts. The hard IRQ handler had to
communicate to the soft handler which interrupt(s) had occurred.
The PDC driver no longer registers for tx interrupts. So there is
no reason to save the intstatus. So remove the intstatus member
of the PDC state.

Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: Performance improvements

Three changes to improve performance in the PDC driver:
- disable and reenable interrupts while the interrupt handler is
running
- update rxin and txin descriptor indexes more efficiently
- group receive descriptor context into a structure and keep
context in a single array rather than five to improve locality
of reference

Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: Don't use iowrite32 to write DMA descriptors

In PDC driver, it is not necessary to use iowrite32()
when writing DMA descriptors to the transmit and receive rings.
The ring memory is in host memory. So convert to normal
assignment statements.

Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: Convert from threaded IRQ to tasklet

Previously used threaded IRQs in the PDC driver to defer
processing the rx DMA ring after getting an rx done interrupt.
Instead, use a tasklet at normal priority for deferred processing.

Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: Try to improve branch prediction

Use likely/unlikely directives to improve branch prediction.

Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: streamline rx code

Remove the unnecessary rmb() from the receive path.

If the rx ring has multiple messages ready, avoid reading
last_rx_curr multiple times from the register.

Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: Convert from interrupts to poll for tx done

The PDC driver is a mailbox controller. A mailbox controller
can report that a mailbox message has been "transmitted" either when
a tx interrupt fires or by having the mailbox framework poll. This
commit converts the PDC driver to the poll method. We found that the
tx interrupt happens when the descriptors are read by the SPU hw. Thus,
the interrupt method does not allow more than one tx message in the PDC
tx DMA ring at a time. To keep the SPU hw busy, we would like to keep
the tx ring full under heavy load.

With the poll method, the PDC driver responds that the previous message
has been transmitted if the tx ring has space for another message.
SPU request messages take a variable number of descriptors. If 15
descriptors are available, there is a good chance another message will
fit. Also increased the ring size from 128 to 512 descriptors.

With this change, I found the PDC driver hangs on its spinlock under
heavy load. The PDC spinlock is not required; so I removed it. Calls
to pdc_send_data() are already synchronized because of the channel
spinlock in the mailbox framework. Other references to ring indexes
should not require locking because they only written on either the
tx or rx side.

Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: PDC driver leaves debugfs files after removal

Minor fix to ensure that debugfs stats pseudo-files are
removed when driver module is unloaded. Previously, the call to
debugfs_remove_recursive() was never being called since the
directory was not empty, and a seg fault would occur if another
process tried to access these leftover files.

Signed-off-by: Steve Lin <steven.lin1@broadcom.com>
Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: Changes so mbox client can be removed / re-inserted

Ensure that DMA is disabled, and pointers reset, when changing
DMA base addresses in pdc_ring_init(). This allows a mailbox client
to be re-inserted after being removed. Otherwise, the DMA doesn't
restart so the client hangs while being reinserted.

Signed-off-by: Steve Lin <steven.lin1@broadcom.com>
Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: Use octal permissions rather than symbolic

When creating the debugfs files for the PDC driver, use
octal file permissions rather than symbolic file permissions.

Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

fix:mailbox:bcm-pdc-mailbox:mark symbols static where possible

We get 2 warnings when biuld kernel with W=1:
drivers/mailbox/bcm-pdc-mailbox.c:472:6: warning: no previous prototype for 'pdc_setup_debugfs' [-Wmissing-prototypes]
drivers/mailbox/bcm-pdc-mailbox.c:488:6: warning: no previous prototype for 'pdc_free_debugfs' [-Wmissing-prototypes]

In fact, these functions are only used in the file in which they are
declared and don't need a declaration, but can be made static.
so this patch marks these functions with 'static'.

Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: bcm-pdc: potential NULL dereference in pdc_shutdown()

We can't pass NULL pointers to pdc_ring_free() so I moved the check for
NULL.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: Fix format and type mismatches in Broadcom PDC driver

Fix format and type mismatches in a couple debug prints in the
Broadcom PDC driver. Use %pad for dma_addr_t and %pa for
resource_size_t.

Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: Add Broadcom PDC mailbox driver

The Broadcom PDC mailbox driver is a mailbox controller that
manages data transfers to and from one or more offload engines.

Signed-off-by: Rob Rice <rob.rice@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>