arm64: Generate cpucaps.h

The arm64 code allocates an internal constant to every CPU feature it can
detect, distinct from the public hwcap numbers we use to expose some
features to userspace. Currently this is maintained manually which is an
irritating source of conflicts when working on new features, to avoid this
replace the header with a simple text file listing the names we've assigned
and sort it to minimise conflicts.

As part of doing this we also do the Kbuild hookup required to hook up
an arch tools directory and to generate header files in there.

This will result in a renumbering and reordering of the existing constants,
since they are all internal only the values should not be important. The
reordering will impact the order in which some steps in enumeration handle
features but the algorithm is not intended to depend on this and I haven't
seen any issues when testing. Due to the UAO cpucap having been removed in
the past we end up with ARM64_NCAPS being 1 smaller than it was before.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210428121231.11219-1-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/Makefile

@@ -175,6 +175,9 @@ vdso_install:
 	$(if $(CONFIG_COMPAT_VDSO), \
 		$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso32 $@)
 
+archprepare:
+	$(Q)$(MAKE) $(build)=arch/arm64/tools kapi
+
 # We use MRPROPER_FILES and CLEAN_FILES now
 archclean:
 	$(Q)$(MAKE) $(clean)=$(boot)

arch/arm64/include/asm/Kbuild

@@ -5,3 +5,5 @@ generic-y += qrwlock.h
 generic-y += qspinlock.h
 generic-y += set_memory.h
 generic-y += user.h
+
+generated-y += cpucaps.h

arch/arm64/include/asm/cpucaps.h

-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * arch/arm64/include/asm/cpucaps.h
- *
- * Copyright (C) 2016 ARM Ltd.
- */
-#ifndef __ASM_CPUCAPS_H
-#define __ASM_CPUCAPS_H
-
-#define ARM64_WORKAROUND_CLEAN_CACHE		0
-#define ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE	1
-#define ARM64_WORKAROUND_845719			2
-#define ARM64_HAS_SYSREG_GIC_CPUIF		3
-#define ARM64_HAS_PAN				4
-#define ARM64_HAS_LSE_ATOMICS			5
-#define ARM64_WORKAROUND_CAVIUM_23154		6
-#define ARM64_WORKAROUND_834220			7
-#define ARM64_HAS_NO_HW_PREFETCH		8
-#define ARM64_HAS_VIRT_HOST_EXTN		11
-#define ARM64_WORKAROUND_CAVIUM_27456		12
-#define ARM64_HAS_32BIT_EL0			13
-#define ARM64_SPECTRE_V3A			14
-#define ARM64_HAS_CNP				15
-#define ARM64_HAS_NO_FPSIMD			16
-#define ARM64_WORKAROUND_REPEAT_TLBI		17
-#define ARM64_WORKAROUND_QCOM_FALKOR_E1003	18
-#define ARM64_WORKAROUND_858921			19
-#define ARM64_WORKAROUND_CAVIUM_30115		20
-#define ARM64_HAS_DCPOP				21
-#define ARM64_SVE				22
-#define ARM64_UNMAP_KERNEL_AT_EL0		23
-#define ARM64_SPECTRE_V2			24
-#define ARM64_HAS_RAS_EXTN			25
-#define ARM64_WORKAROUND_843419			26
-#define ARM64_HAS_CACHE_IDC			27
-#define ARM64_HAS_CACHE_DIC			28
-#define ARM64_HW_DBM				29
-#define ARM64_SPECTRE_V4			30
-#define ARM64_MISMATCHED_CACHE_TYPE		31
-#define ARM64_HAS_STAGE2_FWB			32
-#define ARM64_HAS_CRC32				33
-#define ARM64_SSBS				34
-#define ARM64_WORKAROUND_1418040		35
-#define ARM64_HAS_SB				36
-#define ARM64_WORKAROUND_SPECULATIVE_AT		37
-#define ARM64_HAS_ADDRESS_AUTH_ARCH		38
-#define ARM64_HAS_ADDRESS_AUTH_IMP_DEF		39
-#define ARM64_HAS_GENERIC_AUTH_ARCH		40
-#define ARM64_HAS_GENERIC_AUTH_IMP_DEF		41
-#define ARM64_HAS_IRQ_PRIO_MASKING		42
-#define ARM64_HAS_DCPODP			43
-#define ARM64_WORKAROUND_1463225		44
-#define ARM64_WORKAROUND_CAVIUM_TX2_219_TVM	45
-#define ARM64_WORKAROUND_CAVIUM_TX2_219_PRFM	46
-#define ARM64_WORKAROUND_1542419		47
-#define ARM64_HAS_E0PD				48
-#define ARM64_HAS_RNG				49
-#define ARM64_HAS_AMU_EXTN			50
-#define ARM64_HAS_ADDRESS_AUTH			51
-#define ARM64_HAS_GENERIC_AUTH			52
-#define ARM64_HAS_32BIT_EL1			53
-#define ARM64_BTI				54
-#define ARM64_HAS_ARMv8_4_TTL			55
-#define ARM64_HAS_TLB_RANGE			56
-#define ARM64_MTE				57
-#define ARM64_WORKAROUND_1508412		58
-#define ARM64_HAS_LDAPR				59
-#define ARM64_KVM_PROTECTED_MODE		60
-#define ARM64_WORKAROUND_NVIDIA_CARMEL_CNP	61
-#define ARM64_HAS_EPAN				62
-
-#define ARM64_NCAPS				63
-
-#endif /* __ASM_CPUCAPS_H */

arch/arm64/tools/Makefile

+# SPDX-License-Identifier: GPL-2.0
+
+gen := arch/$(ARCH)/include/generated
+kapi := $(gen)/asm
+
+kapi-hdrs-y := $(kapi)/cpucaps.h
+
+targets += $(addprefix ../../../,$(gen-y) $(kapi-hdrs-y))
+
+PHONY += kapi
+
+kapi:   $(kapi-hdrs-y) $(gen-y)
+
+# Create output directory if not already present
+_dummy := $(shell [ -d '$(kapi)' ] || mkdir -p '$(kapi)')
+
+quiet_cmd_gen_cpucaps = GEN     $@
+      cmd_gen_cpucaps = mkdir -p $(dir $@) && \
+                     $(AWK) -f $(filter-out $(PHONY),$^) > $@
+
+$(kapi)/cpucaps.h: $(src)/gen-cpucaps.awk $(src)/cpucaps FORCE
+	$(call if_changed,gen_cpucaps)

arch/arm64/tools/cpucaps

+# SPDX-License-Identifier: GPL-2.0
+#
+# Internal CPU capabilities constants, keep this list sorted
+
+BTI
+HAS_32BIT_EL0
+HAS_32BIT_EL1
+HAS_ADDRESS_AUTH
+HAS_ADDRESS_AUTH_ARCH
+HAS_ADDRESS_AUTH_IMP_DEF
+HAS_AMU_EXTN
+HAS_ARMv8_4_TTL
+HAS_CACHE_DIC
+HAS_CACHE_IDC
+HAS_CNP
+HAS_CRC32
+HAS_DCPODP
+HAS_DCPOP
+HAS_E0PD
+HAS_EPAN
+HAS_GENERIC_AUTH
+HAS_GENERIC_AUTH_ARCH
+HAS_GENERIC_AUTH_IMP_DEF
+HAS_IRQ_PRIO_MASKING
+HAS_LDAPR
+HAS_LSE_ATOMICS
+HAS_NO_FPSIMD
+HAS_NO_HW_PREFETCH
+HAS_PAN
+HAS_RAS_EXTN
+HAS_RNG
+HAS_SB
+HAS_STAGE2_FWB
+HAS_SYSREG_GIC_CPUIF
+HAS_TLB_RANGE
+HAS_VIRT_HOST_EXTN
+HW_DBM
+KVM_PROTECTED_MODE
+MISMATCHED_CACHE_TYPE
+MTE
+SPECTRE_V2
+SPECTRE_V3A
+SPECTRE_V4
+SSBS
+SVE
+UNMAP_KERNEL_AT_EL0
+WORKAROUND_834220
+WORKAROUND_843419
+WORKAROUND_845719
+WORKAROUND_858921
+WORKAROUND_1418040
+WORKAROUND_1463225
+WORKAROUND_1508412
+WORKAROUND_1542419
+WORKAROUND_CAVIUM_23154
+WORKAROUND_CAVIUM_27456
+WORKAROUND_CAVIUM_30115
+WORKAROUND_CAVIUM_TX2_219_PRFM
+WORKAROUND_CAVIUM_TX2_219_TVM
+WORKAROUND_CLEAN_CACHE
+WORKAROUND_DEVICE_LOAD_ACQUIRE
+WORKAROUND_NVIDIA_CARMEL_CNP
+WORKAROUND_QCOM_FALKOR_E1003
+WORKAROUND_REPEAT_TLBI
+WORKAROUND_SPECULATIVE_AT

arch/arm64/tools/gen-cpucaps.awk

+#!/bin/awk -f
+# SPDX-License-Identifier: GPL-2.0
+# gen-cpucaps.awk: arm64 cpucaps header generator
+#
+# Usage: awk -f gen-cpucaps.awk cpucaps.txt
+
+# Log an error and terminate
+function fatal(msg) {
+	print "Error at line " NR ": " msg > "/dev/stderr"
+	exit 1
+}
+
+# skip blank lines and comment lines
+/^$/ { next }
+/^#/ { next }
+
+BEGIN {
+	print "#ifndef __ASM_CPUCAPS_H"
+	print "#define __ASM_CPUCAPS_H"
+	print ""
+	print "/* Generated file - do not edit */"
+	cap_num = 0
+	print ""
+}
+
+/^[vA-Z0-9_]+$/ {
+	printf("#define ARM64_%-30s\t%d\n", $0, cap_num++)
+	next
+}
+
+END {
+	printf("#define ARM64_NCAPS\t\t\t\t%d\n", cap_num)
+	print ""
+	print "#endif"
+}
+
+# Any lines not handled by previous rules are unexpected
+{
+	fatal("unhandled statement")
+}