From 338a835f40a849cd89b993e342bd9fbd5684825c Mon Sep 17 00:00:00 2001 From: Joey Gouly Date: Tue, 19 Sep 2023 17:27:56 +0100 Subject: [PATCH 1/2] arm64: add FEAT_LRCPC3 HWCAP FEAT_LRCPC3 adds more instructions to support the Release Consistency model. Add a HWCAP so that userspace can make decisions about instructions it can use. Signed-off-by: Joey Gouly Cc: Will Deacon Link: https://lore.kernel.org/r/20230919162757.2707023-2-joey.gouly@arm.com [catalin.marinas@arm.com: change the HWCAP number] Signed-off-by: Catalin Marinas --- Documentation/arch/arm64/elf_hwcaps.rst | 3 +++ arch/arm64/include/asm/hwcap.h | 1 + arch/arm64/include/uapi/asm/hwcap.h | 1 + arch/arm64/kernel/cpufeature.c | 1 + arch/arm64/kernel/cpuinfo.c | 1 + arch/arm64/tools/sysreg | 1 + 6 files changed, 8 insertions(+) diff --git a/Documentation/arch/arm64/elf_hwcaps.rst b/Documentation/arch/arm64/elf_hwcaps.rst index 2ad0a369d96a..a453f8430f7f 100644 --- a/Documentation/arch/arm64/elf_hwcaps.rst +++ b/Documentation/arch/arm64/elf_hwcaps.rst @@ -311,6 +311,9 @@ HWCAP2_HBC HWCAP2_SVE_B16B16 Functionality implied by ID_AA64ZFR0_EL1.B16B16 == 0b0001. +HWCAP2_LRCPC3 + Functionality implied by ID_AA64ISAR1_EL1.LRCPC == 0b0011. + 4. Unused AT_HWCAP bits ----------------------- diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index 210a41f8b10a..1c65f10619a0 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -140,6 +140,7 @@ #define KERNEL_HWCAP_MOPS __khwcap2_feature(MOPS) #define KERNEL_HWCAP_HBC __khwcap2_feature(HBC) #define KERNEL_HWCAP_SVE_B16B16 __khwcap2_feature(SVE_B16B16) +#define KERNEL_HWCAP_LRCPC3 __khwcap2_feature(LRCPC3) /* * This yields a mask that user programs can use to figure out what diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h index 6faf549077c5..0f37944e98b6 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -105,5 +105,6 @@ #define HWCAP2_MOPS (1UL << 43) #define HWCAP2_HBC (1UL << 44) #define HWCAP2_SVE_B16B16 (1UL << 45) +#define HWCAP2_LRCPC3 (1UL << 46) #endif /* _UAPI__ASM_HWCAP_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index a013dfd5b6e9..a83934291037 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2809,6 +2809,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { HWCAP_CAP(ID_AA64ISAR1_EL1, FCMA, IMP, CAP_HWCAP, KERNEL_HWCAP_FCMA), HWCAP_CAP(ID_AA64ISAR1_EL1, LRCPC, IMP, CAP_HWCAP, KERNEL_HWCAP_LRCPC), HWCAP_CAP(ID_AA64ISAR1_EL1, LRCPC, LRCPC2, CAP_HWCAP, KERNEL_HWCAP_ILRCPC), + HWCAP_CAP(ID_AA64ISAR1_EL1, LRCPC, LRCPC3, CAP_HWCAP, KERNEL_HWCAP_LRCPC3), HWCAP_CAP(ID_AA64ISAR1_EL1, FRINTTS, IMP, CAP_HWCAP, KERNEL_HWCAP_FRINT), HWCAP_CAP(ID_AA64ISAR1_EL1, SB, IMP, CAP_HWCAP, KERNEL_HWCAP_SB), HWCAP_CAP(ID_AA64ISAR1_EL1, BF16, IMP, CAP_HWCAP, KERNEL_HWCAP_BF16), diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index ea2a31988103..0ba7e6cd8fee 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -128,6 +128,7 @@ static const char *const hwcap_str[] = { [KERNEL_HWCAP_MOPS] = "mops", [KERNEL_HWCAP_HBC] = "hbc", [KERNEL_HWCAP_SVE_B16B16] = "sveb16b16", + [KERNEL_HWCAP_LRCPC3] = "lrcpc3", }; #ifdef CONFIG_COMPAT diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg index bb69ab34202b..4794556e67e9 100644 --- a/arch/arm64/tools/sysreg +++ b/arch/arm64/tools/sysreg @@ -1309,6 +1309,7 @@ UnsignedEnum 23:20 LRCPC 0b0000 NI 0b0001 IMP 0b0010 LRCPC2 + 0b0011 LRCPC3 EndEnum UnsignedEnum 19:16 FCMA 0b0000 NI From 80652cc0c0485da593c1639a6355dcdab95364e6 Mon Sep 17 00:00:00 2001 From: Joey Gouly Date: Tue, 19 Sep 2023 17:27:57 +0100 Subject: [PATCH 2/2] selftests/arm64: add HWCAP2_LRCPC3 test Add a test for the newly added HWCAP2_LRCPC3. Signed-off-by: Joey Gouly Cc: Will Deacon Link: https://lore.kernel.org/r/20230919162757.2707023-3-joey.gouly@arm.com Signed-off-by: Catalin Marinas --- tools/testing/selftests/arm64/abi/hwcap.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/tools/testing/selftests/arm64/abi/hwcap.c b/tools/testing/selftests/arm64/abi/hwcap.c index d8a144213d04..a60f23794944 100644 --- a/tools/testing/selftests/arm64/abi/hwcap.c +++ b/tools/testing/selftests/arm64/abi/hwcap.c @@ -295,6 +295,19 @@ static void uscat_sigbus(void) asm volatile(".inst 0xb820003f" : : : ); } +static void lrcpc3_sigill(void) +{ + int data[2] = { 1, 2 }; + + register int *src asm ("x0") = data; + register int data0 asm ("w2") = 0; + register int data1 asm ("w3") = 0; + + /* LDIAPP w2, w3, [x0] */ + asm volatile(".inst 0x99431802" + : "=r" (data0), "=r" (data1) : "r" (src) :); +} + static const struct hwcap_data { const char *name; unsigned long at_hwcap; @@ -354,6 +367,13 @@ static const struct hwcap_data { .cpuinfo = "ilrcpc", .sigill_fn = ilrcpc_sigill, }, + { + .name = "LRCPC3", + .at_hwcap = AT_HWCAP2, + .hwcap_bit = HWCAP2_LRCPC3, + .cpuinfo = "lrcpc3", + .sigill_fn = lrcpc3_sigill, + }, { .name = "LSE", .at_hwcap = AT_HWCAP,