include/asm/cpufeature.h

1 /* SPDX-License-Identifier: GPL-2.0-only */
28  * between the values, the features are classified into 3 types - LOWER_SAFE,
67  * @arm64_ftr_reg - Feature register
115  *     c) SCOPE_BOOT_CPU: Check only on the primary boot CPU to detect the
125  *    actions if any. Usually, this is done, after all the boot-time
129  *    boot by the primary boot CPU. (e.g, running the kernel at EL2 with
134  *    referred to as "Late CPU" w.r.t the capability. e.g, all secondary
135  *    CPUs are treated "late CPUs" for capabilities determined by the boot
139  *      a) Boot CPU scope capabilities - Finalised by primary boot CPU via
141  *      b) Everything except (a) - Run via setup_system_capabilities().
148  *	secondary_start_kernel()-> check_local_cpu_capabilities()
156  *	except for the primary boot CPU.
159  *	user after the kernel boot are verified against the capability.
181  *	  check_local_cpu_capabilities() -> verify_local_cpu_capabilities()
186  *		x-----------------------------x
188  *		|-----------------------------|
190  *		|-----------------------------|
192  *		x-----------------------------x
196  *		ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU - Case(a) is allowed
197  *		ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU - Case(b) is allowed
204  *     during boot if any CPU in the system requires it in order to run
208  *     In some non-typical cases either both (a) and (b), or neither,
220  * On any local CPU vs System wide vs the primary boot CPU
225  * The capabilitiy is detected on the Boot CPU and is used by kernel
226  * during early boot. i.e, the capability should be "detected" and
251  * CPU errata workarounds that need to be enabled at boot time if one or
253  * has been enabled, it is safe to allow any CPU to boot that doesn't
260  * CPU feature detected at boot time based on system-wide value of a
269  * CPU feature detected at boot time based on feature of one or more CPUs.
280  * CPU feature detected at boot time, on one or more CPUs. A late CPU
289  * CPU feature used early in the boot based on the boot CPU. All secondary
290  * CPUs must match the state of the capability as detected by the boot CPU. In
297  * CPU feature used early in the boot based on the boot CPU. It is safe for a
298  * late CPU to have this feature even though the boot CPU hasn't enabled it,
299  * although the feature will not be used by Linux in this case. If the boot CPU
359 	return cap->type & ARM64_CPUCAP_SCOPE_MASK;  in cpucap_default_scope()
373 	for (caps = entry->match_list; caps->matches; caps++)  in cpucap_multi_entry_cap_matches()
374 		if (caps->matches(caps, scope))  in cpucap_multi_entry_cap_matches()
440  * @num must be a compile-time constant.
455  * @num must be a compile-time constant.
466  * Test for a capability, possibly with a runtime check for non-hyp code.
470  * For non-hyp code:
474  * @num must be a compile-time constant.
499 	return (s64)(features << (64 - width - field)) >> (64 - width);  in cpuid_feature_extract_signed_field_width()
511 	return (u64)(features << (64 - width - field)) >> (64 - width);  in cpuid_feature_extract_unsigned_field_width()
522  * not follow the standard ID scheme. See ARM DDI 0487E.a page D13-2825,
545 	return (u64)GENMASK(ftrp->shift + ftrp->width - 1, ftrp->shift);  in arm64_ftr_mask()
548 static inline u64 arm64_ftr_reg_user_value(const struct arm64_ftr_reg *reg)  in arm64_ftr_reg_user_value()  argument
550 	return (reg->user_val | (reg->sys_val & reg->user_mask));  in arm64_ftr_reg_user_value()
569 	return (s64)cpuid_feature_extract_field_width(val, ftrp->shift, ftrp->width, ftrp->sign);  in arm64_ftr_value()