c467ea763f
Current context tracking symbols are designed to express living state. As such they are prefixed with "IN_": IN_USER, IN_KERNEL. Now we are going to use these symbols to also express state transitions such as context_tracking_enter(IN_USER) or context_tracking_exit(IN_USER). But while the "IN_" prefix works well to express entering a context, it's confusing to depict a context exit: context_tracking_exit(IN_USER) could mean two things: 1) We are exiting the current context to enter user context. 2) We are exiting the user context We want 2) but the reviewer may be confused and understand 1) So lets disambiguate these symbols and rename them to CONTEXT_USER and CONTEXT_KERNEL. Acked-by: Rik van Riel <riel@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will deacon <will.deacon@arm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
45 lines
1.1 KiB
C
45 lines
1.1 KiB
C
#ifndef _LINUX_CONTEXT_TRACKING_STATE_H
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#define _LINUX_CONTEXT_TRACKING_STATE_H
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#include <linux/percpu.h>
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#include <linux/static_key.h>
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struct context_tracking {
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/*
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* When active is false, probes are unset in order
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* to minimize overhead: TIF flags are cleared
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* and calls to user_enter/exit are ignored. This
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* may be further optimized using static keys.
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*/
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bool active;
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enum ctx_state {
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CONTEXT_KERNEL = 0,
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CONTEXT_USER,
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} state;
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};
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#ifdef CONFIG_CONTEXT_TRACKING
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extern struct static_key context_tracking_enabled;
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DECLARE_PER_CPU(struct context_tracking, context_tracking);
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static inline bool context_tracking_is_enabled(void)
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{
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return static_key_false(&context_tracking_enabled);
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}
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static inline bool context_tracking_cpu_is_enabled(void)
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{
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return __this_cpu_read(context_tracking.active);
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}
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static inline bool context_tracking_in_user(void)
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{
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return __this_cpu_read(context_tracking.state) == CONTEXT_USER;
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}
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#else
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static inline bool context_tracking_in_user(void) { return false; }
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static inline bool context_tracking_active(void) { return false; }
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#endif /* CONFIG_CONTEXT_TRACKING */
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#endif
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