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[IA64] Annotate __kernel_syscall_via_epc() with McKinley dispatch info.

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Two other very minor changes: use "mov.i" instead of "mov" for reading
ar.pfs (for clarity; doesn't affect the code at all).  Also, predicate
the load of r14 for consistency.

Signed-off-by: David Mosberger-Tang <davidm@hpl.hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
David Mosberger-Tang 2005-04-27 21:20:11 -07:00 committed by Tony Luck
parent 70929a57cf
commit 21bc4f9b34
1 changed files with 22 additions and 22 deletions
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44
arch/ia64/kernel/gate.S
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@ -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
;;