On Wed, Apr 03, 2019 at 11:56:26AM +0100, Andrew Murray wrote: > ARMv8.5 builds upon the ARMv8.2 DC CVAP instruction by introducing a DC > CVADP instruction which cleans the data cache to the point of deep > persistence. Let's expose this support via the arm64 ELF hwcaps. > > Signed-off-by: Andrew Murray <andrew.murray@xxxxxxx> Reviewed-by: Dave Martin <Dave.Martin@xxxxxxx> > --- > Documentation/arm64/elf_hwcaps.txt | 4 ++++ > arch/arm64/include/asm/hwcap.h | 1 + > arch/arm64/include/uapi/asm/hwcap.h | 5 +++++ > arch/arm64/kernel/cpufeature.c | 1 + > arch/arm64/kernel/cpuinfo.c | 1 + > 5 files changed, 12 insertions(+) > > diff --git a/Documentation/arm64/elf_hwcaps.txt b/Documentation/arm64/elf_hwcaps.txt > index c04f8e87bab8..7b591c1dcb53 100644 > --- a/Documentation/arm64/elf_hwcaps.txt > +++ b/Documentation/arm64/elf_hwcaps.txt > @@ -135,6 +135,10 @@ HWCAP_DCPOP > > Functionality implied by ID_AA64ISAR1_EL1.DPB == 0b0001. > > +HWCAP2_DCPODP > + > + Functionality implied by ID_AA64ISAR1_EL1.DPB == 0b0010. > + > HWCAP_SHA3 > > Functionality implied by ID_AA64ISAR0_EL1.SHA3 == 0b0001. > diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h > index 509ee0d2fa0f..732bdd7286c8 100644 > --- a/arch/arm64/include/asm/hwcap.h > +++ b/arch/arm64/include/asm/hwcap.h > @@ -85,6 +85,7 @@ > #define KERNEL_HWCAP_PACG __khwcap_feature(PACG) > > #define __khwcap2_feature(x) (ilog2(HWCAP2_ ## x) + 32) > +#define KERNEL_HWCAP_DCPODP __khwcap2_feature(DCPODP) > > #ifndef __ASSEMBLY__ > > diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h > index 453b45af80b7..d64af3913a9e 100644 > --- a/arch/arm64/include/uapi/asm/hwcap.h > +++ b/arch/arm64/include/uapi/asm/hwcap.h > @@ -53,4 +53,9 @@ > #define HWCAP_PACA (1 << 30) > #define HWCAP_PACG (1UL << 31) > > +/* > + * HWCAP2 flags - for AT_HWCAP2 > + */ > +#define HWCAP2_DCPODP (1 << 0) > + > #endif /* _UAPI__ASM_HWCAP_H */ > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index a655d1bb1186..f8b682a3a9f4 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -1591,6 +1591,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { > HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ASIMDHP), > HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_DIT_SHIFT, FTR_SIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DIT), > HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DCPOP), > + HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DPB_SHIFT, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_DCPODP), > HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_JSCVT_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_JSCVT), > HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FCMA_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FCMA), > HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_LRCPC_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_LRCPC), > diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c > index 810db95f293f..093ca53ce1d1 100644 > --- a/arch/arm64/kernel/cpuinfo.c > +++ b/arch/arm64/kernel/cpuinfo.c > @@ -85,6 +85,7 @@ static const char *const hwcap_str[] = { > "sb", > "paca", > "pacg", > + "dcpodp", > NULL > }; > > -- > 2.21.0 >