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Russell King authored
SWP is deprecated in ARMv6 and ARMv7 CPUs, but more importantly, when running on a SMP system, SWP doesn't guarantee atomicity. This means it can't really be used (by userspace) for locking purposes in a SMP environment. Currently, many configurations leave the SWP emulation disabled, which means we never know if userspace executes this instruction on ARMv7 hardware. Rectify this by enabling SWP emulation for ARMv7 with SMP (where we can trap the instruction.) Tested-by: Tony Lindgren <tony@atomide.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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