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>
Most of the included header files are already included as
dependencies.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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>
Since some space in SRAM may be reserved, report the left free space
in the allocated memory pool instead of total physical size of the
SRAM device.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Report an error level message to a user, if the driver is unbound
while there are still some pool allocations.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A pointer device node reference should be decremented on manual exit
from for_each_available_child_of_node() loop.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If devm_gen_pool_create() fails, the previously enabled sram->clk is
not disabled on probe() exit.
Because reserved block logic relies only on information from device tree,
there is no need to get and enable device clock in advance, especially
because not provided clock is not considered as an error, so it is
safe to place devm_clk_get() at the end of probe(). No functional
change.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, the SRAM allocator returns device memory via ioremap.
This causes issues on ARM64 when the internal SoC SRAM allocated by
the generic sram driver is used for audio playback. The destination
buffer address (which is ioremapped SRAM) is not 64-bit aligned for
certain streams (e.g. 44.1k sampling rate). In such cases we get
unhandled alignment faults. Use ioremap_wc in place of ioremap which
gives us normal non-cacheable memory instead of device memory.
Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
of_device_id is always used as const.
(See driver.of_match_table and open firmware functions)
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This implements support for defining reserved areas as subnodes,
to keep the genpool from using these.
Suggested-by: Rob Herring <robherring2@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Ulrich Prinz <ulrich.prinz@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since the devm_gen_pool_create() is used, so the gen_pool_destroy()
here is redundant.
Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The pool is created thru devm_gen_pool_create, so the call to
gen_pool_destroy is not necessary.
Instead the sram-clock must be turned off again if it exists.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Ulrich Prinz <ulrich.prinz@googlemail.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Patch removes unneeded check for resource since
devm_ioremap_resource do all for us.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Replace a call to deprecated devm_request_and_ioremap by devm_ioremap_resource.
Found with coccicheck and this semantic patch:
scripts/coccinelle/api/devm_request_and_ioremap.cocci.
Signed-off-by: Laurent Navet <laurent.navet@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This driver requests and remaps a memory region as configured in the
device tree. It serves memory from this region via the genalloc API. It
optionally enables the SRAM clock.
Other drivers can retrieve the genalloc pool from a phandle pointing to
this drivers' device node in the device tree.
The allocation granularity is hard-coded to 32 bytes for now, to make the
SRAM driver useful for the 6502 remoteproc driver. There is overhead for
bigger SRAMs, where only a much coarser allocation granularity is needed:
At 32 bytes minimum allocation size, a 256 KiB SRAM needs a 1 KiB bitmap
to track allocations.
[akpm@linux-foundation.org: fix Kconfig text, make sram_init static]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Michal Simek <monstr@monstr.eu>
Cc: Dong Aisheng <dong.aisheng@linaro.org>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Huang Shijie <shijie8@gmail.com>
Cc: Javier Martin <javier.martin@vista-silicon.com>
Cc: Matt Porter <mporter@ti.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
