From 19b253fd1777694e2d2f7b0fb9fbc43a2ccf874b Mon Sep 17 00:00:00 2001 From: Michael Scire Date: Wed, 7 Apr 2021 10:09:35 -0700 Subject: [PATCH] kern: trivially optimize userspace io memory write --- .../source/arch/arm64/kern_userspace_memory_access_asm.s | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/libraries/libmesosphere/source/arch/arm64/kern_userspace_memory_access_asm.s b/libraries/libmesosphere/source/arch/arm64/kern_userspace_memory_access_asm.s index ebdec0c46..c9c04f7be 100644 --- a/libraries/libmesosphere/source/arch/arm64/kern_userspace_memory_access_asm.s +++ b/libraries/libmesosphere/source/arch/arm64/kern_userspace_memory_access_asm.s @@ -758,7 +758,6 @@ _ZN3ams4kern4arch5arm6415UserspaceAccess18WriteIoMemory32BitEPvPKvm: mov x8, x30 1: /* Read the word from normal memory. */ - mov x30, x8 ldtr w9, [x5] /* Set our return address so that on read failure we continue. */ @@ -769,7 +768,7 @@ _ZN3ams4kern4arch5arm6415UserspaceAccess18WriteIoMemory32BitEPvPKvm: dsb sy 2: /* Continue. */ - nop + mov x30, x8 /* Advance. */ add x4, x4, #4 @@ -801,7 +800,6 @@ _ZN3ams4kern4arch5arm6415UserspaceAccess18WriteIoMemory16BitEPvPKvm: mov x8, x30 1: /* Read the word from normal memory. */ - mov x30, x8 ldtrh w9, [x5] /* Set our return address so that on read failure we continue. */ @@ -812,7 +810,7 @@ _ZN3ams4kern4arch5arm6415UserspaceAccess18WriteIoMemory16BitEPvPKvm: dsb sy 2: /* Continue. */ - nop + mov x30, x8 /* Advance. */ add x4, x4, #2 @@ -844,7 +842,6 @@ _ZN3ams4kern4arch5arm6415UserspaceAccess17WriteIoMemory8BitEPvPKvm: mov x8, x30 1: /* Read the word from normal memory. */ - mov x30, x8 ldtrb w9, [x5] /* Set our return address so that on read failure we continue. */ @@ -855,7 +852,7 @@ _ZN3ams4kern4arch5arm6415UserspaceAccess17WriteIoMemory8BitEPvPKvm: dsb sy 2: /* Continue. */ - nop + mov x30, x8 /* Advance. */ add x4, x4, #1