include/asm/cpufeature.h

123  * Each capability has the following list of attributes :
125  * 1) Scope of Detection : The system detects a given capability by
128  *    model. The capability provides a call back ( @matches() ) to
135  *        capability is finalised. (See section 2 below)
139  *        system decides to finalise the state of the capability. If the
140  *        capability relies on a field in one of the CPU ID feature
149  *    The process of detection is usually denoted by "update" capability
153  *    capability at some point during its execution and take necessary
160  *    changes to the state of a capability once it finalises the capability
162  *    safely. A CPU brought up after a capability is "finalised" is
163  *    referred to as "Late CPU" w.r.t the capability. e.g, all secondary
184  *	a) SCOPE_BOOT_CPU : All CPUs are verified against the capability
188  *	user after the kernel boot are verified against the capability.
193  *    capability, if it has not been finalised already. See section 5
197  *    detected capability, on all CPUs on the system. Appropriate actions
201  *    point. The actions are always initiated only after the capability
202  *    is finalised. This is usally denoted by "enabling" the capability.
204  *	a) Action is triggered on all online CPUs, after the capability is
212  * 5) Conflicts: Based on the state of the capability on a late CPU vs.
228  *     Case (a) is not permitted for a capability that the system requires
229  *     all CPUs to have in order for the capability to be enabled. This is
232  *     Case (b) is not permitted for a capability that must be enabled
235  *     enabled after the corresponding capability is finalised.
239  *     or both flags in the capability's type field.
242  *     ARM64_CPUCAP_PANIC_ON_CONFLICT flag is specified for the capability,
248  * Decide how the capability is detected.
255  * during early boot. i.e, the capability should be "detected" and
270  * Is it permitted for a late CPU to have this capability when system
274 /* Is it safe for a late CPU to miss this capability when system has it */
301  * capability to be advertised by cpus_have_*cap()!
310  * is not allowed to have the capability when the system doesn't have it.
319  * CPUs must match the state of the capability as detected by the boot CPU. In
336 	u16 capability;
340 	 * Take the appropriate actions to configure this capability
341 	 * for this CPU. If the capability is detected by the kernel
344 	 * capability is available on that specific CPU. This is
348 	 * is required only if the CPU has the capability, then the
376 	 * "capability" of the same "type" as described by the parent.
396  * of call backs, sharing the same capability bit.
456  * Test for a capability with a runtime check.
458  * Before the capability is detected, this returns false.
470  * Test for a capability without a runtime check.
487  * Test for a capability without a runtime check.