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68b34588e2
System call entry and particularly exit code is beyond the limit of what is reasonable to implement in asm. This conversion moves all conditional branches out of the asm code, except for the case that all GPRs should be restored at exit. Null syscall test is about 5% faster after this patch, because the exit work is handled under local_irq_disable, and the hard mask and pending interrupt replay is handled after that, which avoids games with MSR. mpe: Includes subsequent fixes from Nick: This fixes 4 issues caught by TM selftests. First was a tm-syscall bug that hit due to tabort_syscall being called after interrupts were reconciled (in a subsequent patch), which led to interrupts being enabled before tabort_syscall was called. Rather than going through an un-reconciling interrupts for the return, I just go back to putting the test early in asm, the C-ification of that wasn't a big win anyway. Second is the syscall return _TIF_USER_WORK_MASK check would go into an infinite loop if _TIF_RESTORE_TM became set. The asm code uses _TIF_USER_WORK_MASK to brach to slowpath which includes restore_tm_state. Third is system call return was not calling restore_tm_state, I missed this completely (alhtough it's in the return from interrupt C conversion because when the asm syscall code encountered problems it would branch to the interrupt return code. Fourth is MSR_VEC missing from restore_math, which was caught by tm-unavailable selftest taking an unexpected facility unavailable interrupt when testing VSX unavailble exception with MSR.FP=1 MSR.VEC=1. Fourth case also has a fixup in a subsequent patch. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200225173541.1549955-26-npiggin@gmail.com
37 lines
860 B
ArmAsm
37 lines
860 B
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* This file contains the table of syscall-handling functions.
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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*
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* Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
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* and Paul Mackerras.
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*
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* Adapted for iSeries by Mike Corrigan (mikejc@us.ibm.com)
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* PPC64 updates by Dave Engebretsen (engebret@us.ibm.com)
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*/
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#include <asm/ppc_asm.h>
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.section .rodata,"a"
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#ifdef CONFIG_PPC64
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.p2align 3
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#define __SYSCALL(nr, entry) .8byte entry
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#else
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#define __SYSCALL(nr, entry) .long entry
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#endif
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.globl sys_call_table
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sys_call_table:
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#ifdef CONFIG_PPC64
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#include <asm/syscall_table_64.h>
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#else
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#include <asm/syscall_table_32.h>
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#endif
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#ifdef CONFIG_COMPAT
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.globl compat_sys_call_table
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compat_sys_call_table:
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#define compat_sys_sigsuspend sys_sigsuspend
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#include <asm/syscall_table_c32.h>
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#endif
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