kernel/linux.git/drivers/misc/sram.c, branch v4.11.5

misc: sram: Integrate protect-exec reserved sram area type

2017-01-25T10:48:03+00:00

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 Acked-by: Tony Lindgren Signed-off-by: Greg Kroah-Hartman

misc: sram: Split sram data structures into local header

2017-01-25T10:48:03+00:00

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 Acked-by: Tony Lindgren Signed-off-by: Greg Kroah-Hartman

misc: set error code when devm_kstrdup fails

2017-01-10T20:46:41+00:00

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 Signed-off-by: Greg Kroah-Hartman

misc: sram: remove useless #ifdef

2016-11-30T14:43:25+00:00

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: 2ae2e28852f2 ("misc: sram: add Atmel securam support") Reviewed-by: Vladimir Zapolskiy Signed-off-by: Arnd Bergmann

misc: sram: add Atmel securam support

2016-11-07T22:43:28+00:00

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 Acked-by: Greg Kroah-Hartman

misc: sram: fix check of devm_ioremap*() return value

2016-04-30T21:15:56+00:00

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: 0ab163ad1ea0 ("misc: sram: switch to ioremap_wc from ioremap") Signed-off-by: Vladimir Zapolskiy Signed-off-by: Greg Kroah-Hartman

misc: sram: add optional ioremap without write combining

2016-03-14T16:19:45+00:00

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 Signed-off-by: David S. Miller

misc: sram: partition base address belongs to __iomem space

2015-10-19T02:00:36+00:00

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] * Signed-off-by: Vladimir Zapolskiy Signed-off-by: Greg Kroah-Hartman

misc: sram: extend usage of reserved partitions

2015-10-18T04:51:47+00:00

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 Signed-off-by: Greg Kroah-Hartman

genalloc: add name arg to gen_pool_get() and devm_gen_pool_create()

2015-09-04T23:54:41+00:00

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 Cc: Philipp Zabel Cc: Greg Kroah-Hartman Cc: Russell King Cc: Nicolas Ferre Cc: Alexandre Belloni Cc: Jean-Christophe Plagniol-Villard Cc: Shawn Guo Cc: Sascha Hauer Cc: Mauro Carvalho Chehab Cc: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds