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![Jimi Xenidis](/assets/img/avatar_default.png)
There is a race where a thread causes a coprocessor type to be valid in its own ACOP _and_ in the current context, but it does not propagate to the ACOP register of other threads in time for them to use it. The original code tries to solve this by sending an IPI to all threads on the system, which is heavy handed, but unfortunately still provides a window where the icswx is issued by other threads and the ACOP is not up to date. This patch detects that the ACOP DSI fault was a "false positive" and syncs the ACOP and causes the icswx to be replayed. Signed-off-by: Jimi Xenidis <jimix@pobox.com> Cc: Anton Blanchard <anton@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
68 lines
2 KiB
C
68 lines
2 KiB
C
#ifndef _ARCH_POWERPC_MM_ICSWX_H_
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#define _ARCH_POWERPC_MM_ICSWX_H_
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/*
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* ICSWX and ACOP Management
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*
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* Copyright (C) 2011 Anton Blanchard, IBM Corp. <anton@samba.org>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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*/
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#include <asm/mmu_context.h>
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/* also used to denote that PIDs are not used */
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#define COP_PID_NONE 0
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static inline void sync_cop(void *arg)
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{
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struct mm_struct *mm = arg;
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if (mm == current->active_mm)
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switch_cop(current->active_mm);
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}
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#ifdef CONFIG_PPC_ICSWX_PID
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extern int get_cop_pid(struct mm_struct *mm);
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extern int disable_cop_pid(struct mm_struct *mm);
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extern void free_cop_pid(int free_pid);
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#else
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#define get_cop_pid(m) (COP_PID_NONE)
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#define disable_cop_pid(m) (COP_PID_NONE)
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#define free_cop_pid(p)
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#endif
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/*
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* These are implementation bits for architected registers. If this
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* ever becomes architecture the should be moved to reg.h et. al.
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*/
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/* UCT is the same bit for Server and Embedded */
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#define ICSWX_DSI_UCT 0x00004000 /* Unavailable Coprocessor Type */
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#ifdef CONFIG_PPC_BOOK3E
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/* Embedded implementation gives us no hints as to what the CT is */
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#define ICSWX_GET_CT_HINT(x) (-1)
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#else
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/* Server implementation contains the CT value in the DSISR */
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#define ICSWX_DSISR_CTMASK 0x00003f00
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#define ICSWX_GET_CT_HINT(x) (((x) & ICSWX_DSISR_CTMASK) >> 8)
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#endif
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#define ICSWX_RC_STARTED 0x8 /* The request has been started */
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#define ICSWX_RC_NOT_IDLE 0x4 /* No coprocessor found idle */
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#define ICSWX_RC_NOT_FOUND 0x2 /* No coprocessor found */
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#define ICSWX_RC_UNDEFINED 0x1 /* Reserved */
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extern int acop_handle_fault(struct pt_regs *regs, unsigned long address,
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unsigned long error_code);
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static inline u64 acop_copro_type_bit(unsigned int type)
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{
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return 1ULL << (63 - type);
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}
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#endif /* !_ARCH_POWERPC_MM_ICSWX_H_ */
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