From: Yicong Yang Date: Mon, 19 Jan 2026 02:29:25 +0000 (+0800) Subject: arm64: Provide basic EL2 setup for FEAT_{LS64, LS64_V} usage at EL0/1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dea58da4b6fede082d9f38ce069090fd6d43f4e2;p=thirdparty%2Fkernel%2Flinux.git arm64: Provide basic EL2 setup for FEAT_{LS64, LS64_V} usage at EL0/1 Instructions introduced by FEAT_{LS64, LS64_V} is controlled by HCRX_EL2.{EnALS, EnASR}. Configure all of these to allow usage at EL0/1. This doesn't mean these instructions are always available in EL0/1 if provided. The hypervisor still have the control at runtime. Acked-by: Will Deacon Acked-by: Arnd Bergmann Acked-by: Oliver Upton Signed-off-by: Yicong Yang Signed-off-by: Zhou Wang Signed-off-by: Will Deacon --- diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h index cacd20df1786e..9393220de0692 100644 --- a/arch/arm64/include/asm/el2_setup.h +++ b/arch/arm64/include/asm/el2_setup.h @@ -83,9 +83,19 @@ /* Enable GCS if supported */ mrs_s x1, SYS_ID_AA64PFR1_EL1 ubfx x1, x1, #ID_AA64PFR1_EL1_GCS_SHIFT, #4 - cbz x1, .Lset_hcrx_\@ + cbz x1, .Lskip_gcs_hcrx_\@ orr x0, x0, #HCRX_EL2_GCSEn +.Lskip_gcs_hcrx_\@: + /* Enable LS64, LS64_V if supported */ + mrs_s x1, SYS_ID_AA64ISAR1_EL1 + ubfx x1, x1, #ID_AA64ISAR1_EL1_LS64_SHIFT, #4 + cbz x1, .Lset_hcrx_\@ + orr x0, x0, #HCRX_EL2_EnALS + cmp x1, #ID_AA64ISAR1_EL1_LS64_LS64_V + b.lt .Lset_hcrx_\@ + orr x0, x0, #HCRX_EL2_EnASR + .Lset_hcrx_\@: msr_s SYS_HCRX_EL2, x0 .Lskip_hcrx_\@: