On a functioning FSI link there is not need to retry a write when doing
a scom in the driver.
Allow the higher layers (eg. userspace) to attempt a retry if they want,
or to accept that the address they are talking to is not accessible.
By removing the retries we can separate the error handling from retry
logic. In particular -EBUSY was used to force the get/put scom logic to
retry.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20210527070109.225198-1-joel@jms.id.au
Signed-off-by: Joel Stanley <joel@jms.id.au>
The error bits in the FSI2PIB status are only cleared by a reset. So
the driver needs to perform a reset after seeing any of the FSI2PIB
errors, otherwise subsequent operations will also look like failures.
Fixes: 6b293258cd ("fsi: scom: Major overhaul")
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20210329151344.14246-1-eajames@linux.ibm.com
Signed-off-by: Joel Stanley <joel@jms.id.au>
The only usage of scom_ids is to assign its address to the id_table
field in the fsi_driver struct, which is a const pointer, so make it
const to allow the compiler to put it in read-only memory
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
The scom driver currently fails out of operations if certain system
errors are flagged in the status register; system checkstop, special
attention, or recoverable error. These errors won't impact the ability
of the scom engine to perform operations, so the driver should continue
under these conditions.
Also, don't do a PIB reset for these conditions, since it won't help.
Fixes: 6b293258cd ("fsi: scom: Major overhaul")
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20190827041249.13381-1-jk@ozlabs.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of mergchantability or
fitness for a particular purpose see the gnu general public license
for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 2 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081202.997941624@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove linux/cdev.h which is included more than once
Signed-off-by: Brajeswar Ghosh <brajeswar.linux@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The chardev conversion forgot to copy the fsi_dev,
silly mistake, compounded by a testing mistake on
my side, this specific driver wasn't being tested
properly.
Fixes: d8f4587655 "fsi: scom: Convert to use the new chardev"
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This converts FSI scom to use the new fsi-core controlled
chardev allocator and use a real cdev instead of a miscdev.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This was too hard to split ... this adds a number of features
to the SCOM user interface:
- Support for indirect SCOMs
- read()/write() interface now handle errors and retries
- New ioctl() "raw" interface for use by debuggers
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Eddie James <eajames@linux.vnet.ibm.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Add a few more register and bit definitions, also define and use
SCOM_READ_CMD (which is 0 but it makes the code clearer)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Eddie James <eajames@linux.vnet.ibm.com>
Use the proper annotated type __be32 and fixup the
accessor used for get_scom()
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Eddie James <eajames@linux.vnet.ibm.com>
Otherwise, multiple clients can open the driver and attempt
to access the PIB at the same time, thus clobbering each other
in the process.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Eddie James <eajames@linux.vnet.ibm.com>
The PIB reset causes problems for the running P9 chip. The reset
shouldn't be performed by this driver.
Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Joel Stanley <joel@jms.id.au>
Reset causes problems for operations requiring multiple scoms (e.g. i2c
over scom). Instead, reset scom engine during probe.
Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Create a simple SCOM engine device driver that reads and writes
its control registers via an FSI bus.
Includes changes from Edward A. James <eajames@us.ibm.com>.
Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Joel Stanley