Commit c00c6ce6 authored by Marc Zyngier's avatar Marc Zyngier Committed by Kunkun Jiang
Browse files

arm64: Add HWCAP advertising FEAT_WFXT 

mainline inclusion
from mainline-v5.19-rc1
commit 69bb02eb
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I6YAMV
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=69bb02ebc38ace438c9cd7c5315cfe43862b51fe



-------------------------------

In order to allow userspace to enjoy WFET, add a new HWCAP that
advertises it when available.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419182755.601427-9-maz@kernel.org


Signed-off-by: default avatarKunkun Jiang <jiangkunkun@huawei.com>
parent da0fcf7a

Documentation/arm64/cpu-feature-registers.rst

+2 −0
Original line number Diff line number Diff line
@@ -290,6 +290,8 @@ infrastructure: 
     +------------------------------+---------+---------+

     | RPRES                        | [7-4]   |    y    |

     +------------------------------+---------+---------+

     | WFXT                         | [3-0]   |    y    |

     +------------------------------+---------+---------+





Appendix I: Example

Documentation/arm64/elf_hwcaps.rst

+4 −0
Original line number Diff line number Diff line
@@ -257,6 +257,10 @@ HWCAP2_RPRES 


    Functionality implied by ID_AA64ISAR2_EL1.RPRES == 0b0001.



HWCAP2_WFXT



    Functionality implied by ID_AA64ISAR2_EL1.WFXT == 0b0010.



4. Unused AT_HWCAP bits

-----------------------

arch/arm64/include/asm/cpucaps.h

+1 −0
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ 
#define ARM64_HAS_EPAN				65

#define ARM64_SPECTRE_BHB			66

#define ARM64_WORKAROUND_1742098	67

#define ARM64_HAS_WFXT				68



#define ARM64_NCAPS				80

arch/arm64/include/asm/hwcap.h

+1 −0
Original line number Diff line number Diff line
@@ -108,6 +108,7 @@ 
#define KERNEL_HWCAP_ECV		__khwcap2_feature(ECV)

#define KERNEL_HWCAP_AFP		__khwcap2_feature(AFP)

#define KERNEL_HWCAP_RPRES		__khwcap2_feature(RPRES)

#define KERNEL_HWCAP_WFXT		__khwcap2_feature(WFXT)



/*

 * This yields a mask that user programs can use to figure out what

arch/arm64/include/uapi/asm/hwcap.h

+1 −0
Original line number Diff line number Diff line
@@ -78,5 +78,6 @@ 
#define HWCAP2_ECV		(1 << 19)

#define HWCAP2_AFP		(1 << 20)

#define HWCAP2_RPRES		(1 << 21)

#define HWCAP2_WFXT		(1 << 23)



#endif /* _UAPI__ASM_HWCAP_H */