[IA64] Annotate __kernel_syscall_via_epc() with McKinley dispatch info. (21bc4f9b) · Commits · 戴 / test

arch/ia64/kernel/gate.S

+22 −22

Original line number	Diff line number	Diff line
		@@ -72,41 +72,41 @@ GLOBAL_ENTRY(__kernel_syscall_via_epc)
		* bundle get executed. The remaining code must be safe even if
		* they do not get executed.
		*/
		adds r17=-1024,r15
		mov r10=0 // default to successful syscall execution
		epc
		adds r17=-1024,r15 // A
		mov r10=0 // A default to successful syscall execution
		epc // B causes split-issue
		}
		;;
		rsm psr.be // note: on McKinley "rsm psr.be/srlz.d" is slightly faster than "rum psr.be"
		LOAD_FSYSCALL_TABLE(r14)
		rsm psr.be // M2 (5 cyc to srlz.d)
		LOAD_FSYSCALL_TABLE(r14) // X
		;;
		mov r16=IA64_KR(CURRENT) // 12 cycle read latency
		shladd r18=r17,3,r14
		mov r19=NR_syscalls-1
		mov r16=IA64_KR(CURRENT) // M2 (12 cyc)
		shladd r18=r17,3,r14 // A
		mov r19=NR_syscalls-1 // A
		;;
		lfetch [r18] // M0\|1
		mov r29=psr // read psr (12 cyc load latency)
		/* Note: if r17 is a NaT, p6 will be set to zero. */
		cmp.geu p6,p7=r19,r17 // (syscall > 0 && syscall < 1024+NR_syscalls)?
		mov r29=psr // M2 (12 cyc)
		// If r17 is a NaT, p6 will be zero
		cmp.geu p6,p7=r19,r17 // A (sysnr > 0 && sysnr < 1024+NR_syscalls)?
		;;
		mov r21=ar.fpsr
		tnat.nz p10,p9=r15
		mov r26=ar.pfs
		mov r21=ar.fpsr // M2 (12 cyc)
		tnat.nz p10,p9=r15 // I0
		mov.i r26=ar.pfs // I0 (would stall anyhow due to srlz.d...)
		;;
		srlz.d
		(p6) ld8 r18=[r18]
		srlz.d // M0 (forces split-issue) ensure PSR.BE==0
		(p6) ld8 r18=[r18] // M0\|1
		nop.i 0
		;;
		nop.m 0
		(p6) mov b7=r18
		(p6) tbit.z.unc p8,p0=r18,0
		(p6) mov b7=r18 // I0
		(p6) tbit.z.unc p8,p0=r18,0 // I0 (dual-issues with "mov b7=r18"!)

		nop.m 0
		nop.i 0
		(p8) br.dptk.many b7
		(p8) br.dptk.many b7 // B

		mov r27=ar.rsc
		(p6) rsm psr.i
		mov r27=ar.rsc // M2 (12 cyc)
		(p6) rsm psr.i // M2
		/*
		* brl.cond doesn't work as intended because the linker would convert this branch
		* into a branch to a PLT. Perhaps there will be a way to avoid this with some
		@@ -114,7 +114,7 @@ GLOBAL_ENTRY(__kernel_syscall_via_epc)
		* instead.
		*/
		#ifdef CONFIG_ITANIUM
		add r14=-8,r14 // r14 <- addr of fsys_bubble_down entry
		(p6) add r14=-8,r14 // r14 <- addr of fsys_bubble_down entry
		;;
		(p6) ld8 r14=[r14] // r14 <- fsys_bubble_down
		;;

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