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2016-02-08ARM: use virt_to_idmap() for soft_restart()Russell King
Code run via soft_restart() is run with the MMU disabled, so we need to pass the identity map physical address rather than the address obtained from virt_to_phys(). Therefore, replace virt_to_phys() with virt_to_idmap() for all callers of soft_restart(). Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-04-02ARM: move reboot code to arch/arm/kernel/reboot.cRussell King
Move shutdown and reboot related code to a separate file, out of process.c. This helps to avoid polluting process.c with non-process related code. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-04-02ARM: fix broken hibernationRussell King
Normally, when a CPU wants to clear a cache line to zero in the external L2 cache, it would generate bus cycles to write each word as it would do with any other data access. However, a Cortex A9 connected to a L2C-310 has a specific feature where the CPU can detect this operation, and signal that it wants to zero an entire cache line. This feature, known as Full Line of Zeros (FLZ), involves a non-standard AXI signalling mechanism which only the L2C-310 can properly interpret. There are separate enable bits in both the L2C-310 and the Cortex A9 - the L2C-310 needs to be enabled and have the FLZ enable bit set in the auxiliary control register before the Cortex A9 has this feature enabled. Unfortunately, the suspend code was not respecting this - it's not obvious from the code: swsusp_arch_suspend() cpu_suspend() /* saves the Cortex A9 auxiliary control register */ arch_save_image() soft_restart() /* turns off FLZ in Cortex A9, and disables L2C */ cpu_resume() /* restores the Cortex A9 registers, inc auxcr */ At this point, we end up with the L2C disabled, but the Cortex A9 with FLZ enabled - which means any memset() or zeroing of a full cache line will fail to take effect. A similar issue exists in the resume path, but it's slightly more complex: swsusp_arch_suspend() cpu_suspend() /* saves the Cortex A9 auxiliary control register */ arch_save_image() /* image with A9 auxcr saved */ ... swsusp_arch_resume() call_with_stack() arch_restore_image() /* restores image with A9 auxcr saved above */ soft_restart() /* turns off FLZ in Cortex A9, and disables L2C */ cpu_resume() /* restores the Cortex A9 registers, inc auxcr */ Again, here we end up with the L2C disabled, but Cortex A9 FLZ enabled. There's no need to turn off the L2C in either of these two paths; there are benefits from not doing so - for example, the page copies will be faster with the L2C enabled. Hence, fix this by providing a variant of soft_restart() which can be used without turning the L2 cache controller off, and use it in both of these paths to keep the L2C enabled across the respective resume transitions. Fixes: 8ef418c7178f ("ARM: l2c: trial at enabling some Cortex-A9 optimisations") Reported-by: Sean Cross <xobs@kosagi.com> Tested-by: Sean Cross <xobs@kosagi.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-10-09nosave: consolidate __nosave_{begin,end} in <asm/sections.h>Geert Uytterhoeven
The different architectures used their own (and different) declarations: extern __visible const void __nosave_begin, __nosave_end; extern const void __nosave_begin, __nosave_end; extern long __nosave_begin, __nosave_end; Consolidate them using the first variant in <asm/sections.h>. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-23ARM: 8011/1: ARM hibernation / suspend-to-diskSebastian Capella
Enable hibernation for ARM architectures and provide ARM architecture specific calls used during hibernation. The swsusp hibernation framework depends on the platform first having functional suspend/resume. Then, in order to enable hibernation on a given platform, a platform_hibernation_ops structure may need to be registered with the system in order to save/restore any SoC-specific / cpu specific state needing (re)init over a suspend-to-disk/resume-from-disk cycle. For example: - "secure" SoCs that have different sets of control registers and/or different CR reg access patterns. - SoCs with L2 caches as the activation sequence there is SoC-dependent; a full off-on cycle for L2 is not done by the hibernation support code. - SoCs requiring steps on wakeup _before_ the "generic" parts done by cpu_suspend / cpu_resume can work correctly. - SoCs having persistent state which is maintained during suspend and resume, but will be lost during the power off cycle after suspend-to-disk. This is a rebase/rework of Frank Hofmann's v5 hibernation patchset. Acked-by: Russ Dill <Russ.Dill@ti.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Sebastian Capella <sebastian.capella@linaro.org> Acked-by: Pavel Machek <pavel@ucw.cz> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> [fixed duplicate virt_to_pfn() definition --rmk] Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>