powerpc/powernv/flash: Check OPAL flash calls exist before using

Currently only FSP based powernv systems supports firmware update
interfaces. Hence check that the token OPAL_FLASH_VALIDATE exists
before initalising the flash driver.

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210914101630.30613-1-hegdevasant@linux.vnet.ibm.com

powerpc: declare unmodified attribute_group usages const

Inspired by (bd75b4ef4977: Constify static attribute_group structs),
accepted by linux-next, reported:
https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20220210202805.7750-4-rikard.falkeborn@gmail.com/

Nearly all singletons of type struct attribute_group are never modified,
and so are candidates for being const. Declare them as const.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220307231414.86560-1-rmclure@linux.ibm.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

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 as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

powerpc/powernv: Always stop secondaries before reboot/shutdown

Currently powernv reboot and shutdown requests just leave secondaries
to do their own things. This is undesirable because they can trigger
any number of watchdogs while waiting for reboot, but also we don't
know what else they might be doing -- they might be causing trouble,
trampling memory, etc.

The opal scheduled flash update code already ran into watchdog problems
due to flashing taking a long time, and it was fixed with 2196c6f1ed
("powerpc/powernv: Return secondary CPUs to firmware before FW update"),
which returns secondaries to opal. It's been found that regular reboots
can take over 10 seconds, which can result in the hard lockup watchdog
firing,

reboot: Restarting system
[ 360.038896709,5] OPAL: Reboot request...
Watchdog CPU:0 Hard LOCKUP
Watchdog CPU:44 detected Hard LOCKUP other CPUS:16
Watchdog CPU:16 Hard LOCKUP
watchdog: BUG: soft lockup - CPU#16 stuck for 3s! [swapper/16:0]

This patch removes the special case for flash update, and calls
smp_send_stop in all cases before calling reboot/shutdown.

smp_send_stop could return CPUs to OPAL, the main reason not to is
that the request could come from a NMI that interrupts OPAL code,
so re-entry to OPAL can cause a number of problems. Putting
secondaries into simple spin loops improves the chances of a
successful reboot.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc: Use sizeof(*foo) rather than sizeof(struct foo)

It's slightly less error prone to use sizeof(*foo) rather than
specifying the type.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
[mpe: Consolidate into one patch, rewrite change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc: Add const to bin_attribute structures

Declare bin_attribute structures as const as they are only passed as an
argument to the function sysfs_create_bin_file. This argument is of
type const, so declare the structure as const.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/powernv: Add interfaces for flash device access

This change adds the OPAL interface definitions to allow Linux to read,
write and erase from system flash devices. We register platform devices
for the flash devices exported by firmware.

We clash with the existing opal_flash_init function, which is really for
the FSP flash update functionality, so we rename that initcall to
opal_flash_update_init().

A future change will add an mtd driver that uses this interface.

Changes from Joel Stanley and Jeremy Kerr.

Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/powernv: Check image loaded or not before calling flash

Present code checks for update_flash_data in opal_flash_term_callback().
update_flash_data has been statically initialized to zero, and that
is the value of FLASH_IMG_READY. Also code update initialization happens
during subsys init.

So if reboot is issued before the subsys init stage then we endup displaying
"Flashing new firmware" message.. which may confuse end user.

This patch fixes above described issue by initializes update_flash status
to invalid state.

Reported-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc/powernv: Pass buffer size to OPAL validate flash call

We pass actual buffer size to opal_validate_flash() OPAL API call
and in return it contains output buffer size.

Commit cc146d1d (Fix little endian issues) missed to set the size
param before making OPAL call. So firmware image validation fails.

This patch sets size variable before making OPAL call.

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Tested-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc/powernv: Return secondary CPUs to firmware before FW update

Firmware update on PowerNV platform takes several minutes. During
this time one CPU is stuck in FW and the kernel complains about "soft
lockups".

This patch returns all secondary CPUs to firmware before starting
firmware update process.

[ Reworked a bit and cleaned up -- BenH ]

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc/powernv: Create OPAL sglist helper functions and fix endian issues

We have two copies of code that creates an OPAL sg list. Consolidate
these into a common set of helpers and fix the endian issues.

The flash interface embedded a version number in the num_entries
field, whereas the dump interface did did not. Since versioning
wasn't added to the flash interface and it is impossible to add
this in a backwards compatible way, just remove it.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc/powernv: Fix little endian issues in OPAL flash code

With this patch I was able to update firmware on an LE kernel.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc/powernv: Increase candidate fw image size

At present we assume candidate image is <= 256MB. But in P8,
candidate image size can go up to 750MB. Hence increasing
candidate image max size to 1GB.

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

treewide: fix comments and printk msgs

This patch fixed several typo in printk from various
part of kernel source.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

powerpc/powernv: Move SG list structure to header file

Move SG list and entry structure to header file so that
it can be used in other places as well.

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc/powernv: Code update interface

Code update interface for powernv platform. This provides
sysfs interface to pass new image, validate, update and
commit images.

This patch includes:
- Below OPAL APIs for code update
- opal_validate_flash()
- opal_manage_flash()
- opal_update_flash()

- Create below sysfs files under /sys/firmware/opal
- image : Interface to pass new FW image
- validate_flash : Validate candidate image
- manage_flash : Commit/Reject operations
- update_flash : Flash new candidate image

Updating Image:
"update_flash" is an interface to indicate flash new FW.
It just passes image SG list to FW. Actual flashing is done
during system reboot time.

Note:
- SG entry format:
I have kept version number to keep this list similar to what
PAPR is defined.

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>