On Tegra186 and later, a portion of the SYSRAM may be reserved for use
by TZ. Non-TZ memory accesses to this portion, including speculative
accesses, trigger SErrors that bring down the system. This does also
happen in practice occasionally (due to speculative accesses).
To fix the issue, add a flag to the SRAM driver to only map the
device tree-specified reserved areas depending on a flag set
based on the compatibility string. This would not affect non-Tegra
systems that rely on the entire thing being memory mapped.
If 64K pages are being used, we cannot exactly map the 4K regions
that are placed in SYSRAM - ioremap code instead aligns to closest
64K pages. However, since in practice the non-accessible memory area
is 64K aligned, these mappings do not overlap with the non-accessible
memory area and things work out.
Reviewed-by: Mian Yousaf Kaukab <ykaukab@suse.de>
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Link: https://lore.kernel.org/r/20210715103423.1811101-1-mperttunen@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since the macro was introduced in 2019 (commit bb6243b4f7 ("drivers:
platform: provide devm_platform_ioremap_resource_wc()") there is only a
single user which hardly justifies the function for the small task it
provides.
So drop the helper and open-code it in the only user. Adapt the non-wc
case accordingly.
For a all-mod-config build on amd64 this change introduces the following
changes according to bloat-o-meter:
add/remove: 0/1 grow/shrink: 1/0 up/down: 20/-252 (-232)
Function old new delta
devm_platform_ioremap_resource_wc 252 - -252
sram_probe 796 816 +20
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210525103711.956438-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 2 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 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 for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
51 franklin street fifth floor boston ma 02110 1301 usa
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 [no]_[pad]_[ctrl] any later version 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
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 51 franklin street fifth floor boston ma
02110 1301 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 176 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190519154040.652910950@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
of_node_put has taken the null pinter check into account. So it is
safe to remove the duplicated check before of_node_put.
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure to enable the clock before registering regions and exporting
partitions to user space at which point we must be prepared for I/O.
Fixes: ee895ccdf7 ("misc: sram: fix enabled clock leak on error path")
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure to disable clocks and deregister any exported partitions
before returning on late probe errors.
Note that since commit ee895ccdf7 ("misc: sram: fix enabled clock leak
on error path"), partitions are deliberately exported before enabling
the clock so we stick to that logic here. A follow up patch will address
this.
Fixes: 2ae2e28852 ("misc: sram: add Atmel securam support")
Cc: stable <stable@vger.kernel.org> # 4.9
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce a new "protect-exec" reserved sram area type which is
makes use of the the existing functionality provided for the "pool"
sram region type for use with the genalloc framework and with the
added requirement that it be maintained as read-only and executable
while allowing for an arbitrary number of drivers to share the space.
This introduces a common way to maintain a region of sram as read-only
and executable and also introduces a helper function, sram_exec_copy,
which allows for copying data to this protected region while maintaining
locking to avoid conflicts between multiple users of the same space. A
region of memory that is marked with the "protect-exec" flag in the
device tree also has the requirement of providing a page aligned block
of memory so that the page attribute manipulation does not affect
surrounding regions.
Also, selectively enable this only for builds that support set_memory_*
calls, for now just ARM, through the use of Kconfig.
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation of a coming file split of the sram driver, move the
common data structures into a local header file that can be shared
between files related to the sram driver.
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In function sram_reserve_regions(), the value of return variable ret
should be negative on failures. However, the value of ret may be 0 even
if the call to devm_kstrdup() returns a NULL pointer. This patch
explicitly assigns "-ENOMEM" to ret on the path that devm_kstrdup()
fails.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188651
Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A recent patch added a new function that is now unused whenever
CONFIG_OF is disabled:
drivers/misc/sram.c:342:12: error: 'atmel_securam_wait' defined but not used [-Werror=unused-function]
There is actually no reason for the #ifdef, because the driver
currently cannot be used in a meaningful way without CONFIG_OF,
and there is no compile-time dependency.
Removing that #ifdef and the respective of_match_ptr() avoids the
warning and simplifies the driver slightly.
Fixes: 2ae2e28852 ("misc: sram: add Atmel securam support")
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The Atmel secure SRAM is connected to a security module and may be erased
automatically under certain conditions. For that reason, it is necessary to
wait for the security module to flag that SRAM accesses are allowed before
accessing it.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Both devm_ioremap() and devm_ioremap_wc() functions return either
a pointer to valid iomem region or NULL, check for IS_ERR() is improper
and may result in oops on error path. Now on error -ENOMEM is returned.
Fixes: 0ab163ad1e ("misc: sram: switch to ioremap_wc from ioremap")
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some SRAM users may require non-bufferable access to the memory, which is
impossible, because devm_ioremap_wc() is used for setting sram->virt_base.
This commit adds optional flag 'no-memory-wc', which allow to choose remap
method, using DT property. Documentation is updated accordingly.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The change fixes a warning found by sparse:
drivers/misc/sram.c:134:20: warning: incorrect type in assignment (different address spaces)
drivers/misc/sram.c:134:20: expected void *base
drivers/misc/sram.c:134:20: got void [noderef] <asn:2>*
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This change adds functionality to operate on reserved SRAM partitions
described in device tree file. Two partition properties are added,
"pool" and "export", the first one allows to share a specific partition
for usage by a kernel consumer in the same manner as it is done for
the whole SRAM device, and "export" property provides access to some
SRAM area from userspace over sysfs interface. Practically it is
possible to specify both properties for an SRAM partition, however
simultaneous access from a kernel consumer and from userspace is not
serialized, but still the combination may be useful for debugging
purpose.
The change opens the following scenarios of SRAM usage:
* updates in a particular SRAM area specified by offset and size are
done by bootloader, then this information is utilized by the kernel,
* a particular SRAM area is rw accessed from userspace, the stored
data is persistent on soft reboots,
* a device driver secures SRAM area for its purposes,
* etc.
Note, strictly speaking the added optional properties describe policy
of SRAM usage, rather than hardware, but here the policy mostly
resembles flash partitions in devicetree, which is undoubtedly
a very popular option but it does not describe hardware.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This change modifies gen_pool_get() and devm_gen_pool_create() client
interfaces adding one more argument "name" of a gen_pool object.
Due to implementation gen_pool_get() is capable to retrieve only one
gen_pool associated with a device even if multiple gen_pools are created,
fortunately right at the moment it is sufficient for the clients, hence
provide NULL as a valid argument on both producer devm_gen_pool_create()
and consumer gen_pool_get() sides.
Because only one created gen_pool per device is addressable, explicitly
add a restriction to devm_gen_pool_create() to create only one gen_pool
per device, this implies two possible error codes returned by the
function, account it on client side (only misc/sram). This completes
client side changes related to genalloc updates.
[akpm@linux-foundation.org: gen_pool_get() cleanup]
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
No functional change, but now previously overloaded sram_probe() is
greatly simplified and perceptible, reserved regions logic also has
its own space.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No functional change, this is a preceding change to simplify
separation of reserved partition handling logic from probe()
function.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
