740 lines
18 KiB
ArmAsm
740 lines
18 KiB
ArmAsm
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/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Unified implementation of memcpy, memmove and the __copy_user backend.
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*
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* Copyright (C) 1998, 99, 2000, 01, 2002 Ralf Baechle (ralf@gnu.org)
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* Copyright (C) 1999, 2000, 01, 2002 Silicon Graphics, Inc.
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* Copyright (C) 2002 Broadcom, Inc.
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* memcpy/copy_user author: Mark Vandevoorde
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* Copyright (C) 2007 Maciej W. Rozycki
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* Copyright (C) 2014 Imagination Technologies Ltd.
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*
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* Mnemonic names for arguments to memcpy/__copy_user
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*/
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/*
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* Hack to resolve longstanding prefetch issue
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*
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* Prefetching may be fatal on some systems if we're prefetching beyond the
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* end of memory on some systems. It's also a seriously bad idea on non
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* dma-coherent systems.
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*/
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#ifdef CONFIG_DMA_NONCOHERENT
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#undef CONFIG_CPU_HAS_PREFETCH
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#endif
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#ifdef CONFIG_MIPS_MALTA
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#undef CONFIG_CPU_HAS_PREFETCH
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#endif
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#include <asm/asm.h>
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#include <asm/asm-offsets.h>
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#include <asm/regdef.h>
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#define dst a0
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#define src a1
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#define len a2
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/*
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* Spec
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*
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* memcpy copies len bytes from src to dst and sets v0 to dst.
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* It assumes that
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* - src and dst don't overlap
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* - src is readable
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* - dst is writable
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* memcpy uses the standard calling convention
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*
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* __copy_user copies up to len bytes from src to dst and sets a2 (len) to
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* the number of uncopied bytes due to an exception caused by a read or write.
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* __copy_user assumes that src and dst don't overlap, and that the call is
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* implementing one of the following:
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* copy_to_user
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* - src is readable (no exceptions when reading src)
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* copy_from_user
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* - dst is writable (no exceptions when writing dst)
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* __copy_user uses a non-standard calling convention; see
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* include/asm-mips/uaccess.h
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*
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* When an exception happens on a load, the handler must
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# ensure that all of the destination buffer is overwritten to prevent
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* leaking information to user mode programs.
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*/
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/*
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* Implementation
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*/
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/*
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* The exception handler for loads requires that:
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* 1- AT contain the address of the byte just past the end of the source
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* of the copy,
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* 2- src_entry <= src < AT, and
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* 3- (dst - src) == (dst_entry - src_entry),
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* The _entry suffix denotes values when __copy_user was called.
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*
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* (1) is set up up by uaccess.h and maintained by not writing AT in copy_user
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* (2) is met by incrementing src by the number of bytes copied
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* (3) is met by not doing loads between a pair of increments of dst and src
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*
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* The exception handlers for stores adjust len (if necessary) and return.
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* These handlers do not need to overwrite any data.
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*
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* For __rmemcpy and memmove an exception is always a kernel bug, therefore
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* they're not protected.
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*/
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/* Instruction type */
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#define LD_INSN 1
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#define ST_INSN 2
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/* Pretech type */
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#define SRC_PREFETCH 1
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#define DST_PREFETCH 2
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#define LEGACY_MODE 1
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#define EVA_MODE 2
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#define USEROP 1
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#define KERNELOP 2
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/*
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* Wrapper to add an entry in the exception table
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* in case the insn causes a memory exception.
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* Arguments:
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* insn : Load/store instruction
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* type : Instruction type
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* reg : Register
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* addr : Address
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* handler : Exception handler
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*/
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#define EXC(insn, type, reg, addr, handler) \
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.if \mode == LEGACY_MODE; \
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9: insn reg, addr; \
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.section __ex_table,"a"; \
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PTR 9b, handler; \
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.previous; \
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/* This is assembled in EVA mode */ \
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.else; \
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/* If loading from user or storing to user */ \
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.if ((\from == USEROP) && (type == LD_INSN)) || \
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((\to == USEROP) && (type == ST_INSN)); \
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9: __BUILD_EVA_INSN(insn##e, reg, addr); \
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.section __ex_table,"a"; \
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PTR 9b, handler; \
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.previous; \
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.else; \
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/* \
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* Still in EVA, but no need for \
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* exception handler or EVA insn \
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*/ \
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insn reg, addr; \
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.endif; \
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.endif
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/*
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* Only on the 64-bit kernel we can made use of 64-bit registers.
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*/
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#ifdef CONFIG_64BIT
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#define USE_DOUBLE
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#endif
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#ifdef USE_DOUBLE
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#define LOADK ld /* No exception */
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#define LOAD(reg, addr, handler) EXC(ld, LD_INSN, reg, addr, handler)
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#define LOADL(reg, addr, handler) EXC(ldl, LD_INSN, reg, addr, handler)
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#define LOADR(reg, addr, handler) EXC(ldr, LD_INSN, reg, addr, handler)
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#define STOREL(reg, addr, handler) EXC(sdl, ST_INSN, reg, addr, handler)
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#define STORER(reg, addr, handler) EXC(sdr, ST_INSN, reg, addr, handler)
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#define STORE(reg, addr, handler) EXC(sd, ST_INSN, reg, addr, handler)
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#define ADD daddu
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#define SUB dsubu
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#define SRL dsrl
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#define SRA dsra
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#define SLL dsll
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#define SLLV dsllv
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#define SRLV dsrlv
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#define NBYTES 8
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#define LOG_NBYTES 3
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/*
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* As we are sharing code base with the mips32 tree (which use the o32 ABI
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* register definitions). We need to redefine the register definitions from
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* the n64 ABI register naming to the o32 ABI register naming.
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*/
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#undef t0
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#undef t1
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#undef t2
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#undef t3
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#define t0 $8
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#define t1 $9
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#define t2 $10
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#define t3 $11
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#define t4 $12
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#define t5 $13
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#define t6 $14
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#define t7 $15
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#else
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#define LOADK lw /* No exception */
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#define LOAD(reg, addr, handler) EXC(lw, LD_INSN, reg, addr, handler)
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#define LOADL(reg, addr, handler) EXC(lwl, LD_INSN, reg, addr, handler)
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#define LOADR(reg, addr, handler) EXC(lwr, LD_INSN, reg, addr, handler)
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#define STOREL(reg, addr, handler) EXC(swl, ST_INSN, reg, addr, handler)
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#define STORER(reg, addr, handler) EXC(swr, ST_INSN, reg, addr, handler)
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#define STORE(reg, addr, handler) EXC(sw, ST_INSN, reg, addr, handler)
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#define ADD addu
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#define SUB subu
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#define SRL srl
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#define SLL sll
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#define SRA sra
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#define SLLV sllv
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#define SRLV srlv
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#define NBYTES 4
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#define LOG_NBYTES 2
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#endif /* USE_DOUBLE */
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#define LOADB(reg, addr, handler) EXC(lb, LD_INSN, reg, addr, handler)
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#define STOREB(reg, addr, handler) EXC(sb, ST_INSN, reg, addr, handler)
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#define _PREF(hint, addr, type) \
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.if \mode == LEGACY_MODE; \
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PREF(hint, addr); \
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.else; \
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.if ((\from == USEROP) && (type == SRC_PREFETCH)) || \
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((\to == USEROP) && (type == DST_PREFETCH)); \
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/* \
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* PREFE has only 9 bits for the offset \
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* compared to PREF which has 16, so it may \
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* need to use the $at register but this \
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* register should remain intact because it's \
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* used later on. Therefore use $v1. \
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*/ \
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.set at=v1; \
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PREFE(hint, addr); \
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.set noat; \
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.else; \
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PREF(hint, addr); \
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.endif; \
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.endif
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#define PREFS(hint, addr) _PREF(hint, addr, SRC_PREFETCH)
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#define PREFD(hint, addr) _PREF(hint, addr, DST_PREFETCH)
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#ifdef CONFIG_CPU_LITTLE_ENDIAN
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#define LDFIRST LOADR
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#define LDREST LOADL
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#define STFIRST STORER
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#define STREST STOREL
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#define SHIFT_DISCARD SLLV
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#else
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#define LDFIRST LOADL
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#define LDREST LOADR
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#define STFIRST STOREL
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#define STREST STORER
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#define SHIFT_DISCARD SRLV
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#endif
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#define FIRST(unit) ((unit)*NBYTES)
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#define REST(unit) (FIRST(unit)+NBYTES-1)
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#define UNIT(unit) FIRST(unit)
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#define ADDRMASK (NBYTES-1)
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.text
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.set noreorder
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#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
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.set noat
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#else
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.set at=v1
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#endif
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.align 5
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/*
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* Macro to build the __copy_user common code
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* Arguments:
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* mode : LEGACY_MODE or EVA_MODE
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* from : Source operand. USEROP or KERNELOP
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* to : Destination operand. USEROP or KERNELOP
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*/
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.macro __BUILD_COPY_USER mode, from, to
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/* initialize __memcpy if this the first time we execute this macro */
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.ifnotdef __memcpy
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.set __memcpy, 1
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.hidden __memcpy /* make sure it does not leak */
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.endif
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/*
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* Note: dst & src may be unaligned, len may be 0
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* Temps
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*/
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#define rem t8
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R10KCBARRIER(0(ra))
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/*
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* The "issue break"s below are very approximate.
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* Issue delays for dcache fills will perturb the schedule, as will
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* load queue full replay traps, etc.
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*
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* If len < NBYTES use byte operations.
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*/
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PREFS( 0, 0(src) )
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PREFD( 1, 0(dst) )
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sltu t2, len, NBYTES
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and t1, dst, ADDRMASK
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PREFS( 0, 1*32(src) )
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PREFD( 1, 1*32(dst) )
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bnez t2, .Lcopy_bytes_checklen\@
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and t0, src, ADDRMASK
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PREFS( 0, 2*32(src) )
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PREFD( 1, 2*32(dst) )
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#ifndef CONFIG_CPU_MIPSR6
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bnez t1, .Ldst_unaligned\@
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nop
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bnez t0, .Lsrc_unaligned_dst_aligned\@
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#else
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or t0, t0, t1
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bnez t0, .Lcopy_unaligned_bytes\@
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#endif
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/*
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* use delay slot for fall-through
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* src and dst are aligned; need to compute rem
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*/
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.Lboth_aligned\@:
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SRL t0, len, LOG_NBYTES+3 # +3 for 8 units/iter
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beqz t0, .Lcleanup_both_aligned\@ # len < 8*NBYTES
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and rem, len, (8*NBYTES-1) # rem = len % (8*NBYTES)
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PREFS( 0, 3*32(src) )
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PREFD( 1, 3*32(dst) )
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.align 4
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1:
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R10KCBARRIER(0(ra))
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LOAD(t0, UNIT(0)(src), .Ll_exc\@)
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LOAD(t1, UNIT(1)(src), .Ll_exc_copy\@)
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LOAD(t2, UNIT(2)(src), .Ll_exc_copy\@)
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LOAD(t3, UNIT(3)(src), .Ll_exc_copy\@)
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SUB len, len, 8*NBYTES
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LOAD(t4, UNIT(4)(src), .Ll_exc_copy\@)
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LOAD(t7, UNIT(5)(src), .Ll_exc_copy\@)
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STORE(t0, UNIT(0)(dst), .Ls_exc_p8u\@)
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STORE(t1, UNIT(1)(dst), .Ls_exc_p7u\@)
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LOAD(t0, UNIT(6)(src), .Ll_exc_copy\@)
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LOAD(t1, UNIT(7)(src), .Ll_exc_copy\@)
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ADD src, src, 8*NBYTES
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ADD dst, dst, 8*NBYTES
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STORE(t2, UNIT(-6)(dst), .Ls_exc_p6u\@)
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STORE(t3, UNIT(-5)(dst), .Ls_exc_p5u\@)
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STORE(t4, UNIT(-4)(dst), .Ls_exc_p4u\@)
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STORE(t7, UNIT(-3)(dst), .Ls_exc_p3u\@)
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STORE(t0, UNIT(-2)(dst), .Ls_exc_p2u\@)
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STORE(t1, UNIT(-1)(dst), .Ls_exc_p1u\@)
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PREFS( 0, 8*32(src) )
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PREFD( 1, 8*32(dst) )
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bne len, rem, 1b
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nop
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/*
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* len == rem == the number of bytes left to copy < 8*NBYTES
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*/
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.Lcleanup_both_aligned\@:
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beqz len, .Ldone\@
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sltu t0, len, 4*NBYTES
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bnez t0, .Lless_than_4units\@
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and rem, len, (NBYTES-1) # rem = len % NBYTES
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/*
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* len >= 4*NBYTES
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*/
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LOAD( t0, UNIT(0)(src), .Ll_exc\@)
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LOAD( t1, UNIT(1)(src), .Ll_exc_copy\@)
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LOAD( t2, UNIT(2)(src), .Ll_exc_copy\@)
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|
|
LOAD( t3, UNIT(3)(src), .Ll_exc_copy\@)
|
||
|
|
SUB len, len, 4*NBYTES
|
||
|
|
ADD src, src, 4*NBYTES
|
||
|
|
R10KCBARRIER(0(ra))
|
||
|
|
STORE(t0, UNIT(0)(dst), .Ls_exc_p4u\@)
|
||
|
|
STORE(t1, UNIT(1)(dst), .Ls_exc_p3u\@)
|
||
|
|
STORE(t2, UNIT(2)(dst), .Ls_exc_p2u\@)
|
||
|
|
STORE(t3, UNIT(3)(dst), .Ls_exc_p1u\@)
|
||
|
|
.set reorder /* DADDI_WAR */
|
||
|
|
ADD dst, dst, 4*NBYTES
|
||
|
|
beqz len, .Ldone\@
|
||
|
|
.set noreorder
|
||
|
|
.Lless_than_4units\@:
|
||
|
|
/*
|
||
|
|
* rem = len % NBYTES
|
||
|
|
*/
|
||
|
|
beq rem, len, .Lcopy_bytes\@
|
||
|
|
nop
|
||
|
|
1:
|
||
|
|
R10KCBARRIER(0(ra))
|
||
|
|
LOAD(t0, 0(src), .Ll_exc\@)
|
||
|
|
ADD src, src, NBYTES
|
||
|
|
SUB len, len, NBYTES
|
||
|
|
STORE(t0, 0(dst), .Ls_exc_p1u\@)
|
||
|
|
.set reorder /* DADDI_WAR */
|
||
|
|
ADD dst, dst, NBYTES
|
||
|
|
bne rem, len, 1b
|
||
|
|
.set noreorder
|
||
|
|
|
||
|
|
#ifndef CONFIG_CPU_MIPSR6
|
||
|
|
/*
|
||
|
|
* src and dst are aligned, need to copy rem bytes (rem < NBYTES)
|
||
|
|
* A loop would do only a byte at a time with possible branch
|
||
|
|
* mispredicts. Can't do an explicit LOAD dst,mask,or,STORE
|
||
|
|
* because can't assume read-access to dst. Instead, use
|
||
|
|
* STREST dst, which doesn't require read access to dst.
|
||
|
|
*
|
||
|
|
* This code should perform better than a simple loop on modern,
|
||
|
|
* wide-issue mips processors because the code has fewer branches and
|
||
|
|
* more instruction-level parallelism.
|
||
|
|
*/
|
||
|
|
#define bits t2
|
||
|
|
beqz len, .Ldone\@
|
||
|
|
ADD t1, dst, len # t1 is just past last byte of dst
|
||
|
|
li bits, 8*NBYTES
|
||
|
|
SLL rem, len, 3 # rem = number of bits to keep
|
||
|
|
LOAD(t0, 0(src), .Ll_exc\@)
|
||
|
|
SUB bits, bits, rem # bits = number of bits to discard
|
||
|
|
SHIFT_DISCARD t0, t0, bits
|
||
|
|
STREST(t0, -1(t1), .Ls_exc\@)
|
||
|
|
jr ra
|
||
|
|
move len, zero
|
||
|
|
.Ldst_unaligned\@:
|
||
|
|
/*
|
||
|
|
* dst is unaligned
|
||
|
|
* t0 = src & ADDRMASK
|
||
|
|
* t1 = dst & ADDRMASK; T1 > 0
|
||
|
|
* len >= NBYTES
|
||
|
|
*
|
||
|
|
* Copy enough bytes to align dst
|
||
|
|
* Set match = (src and dst have same alignment)
|
||
|
|
*/
|
||
|
|
#define match rem
|
||
|
|
LDFIRST(t3, FIRST(0)(src), .Ll_exc\@)
|
||
|
|
ADD t2, zero, NBYTES
|
||
|
|
LDREST(t3, REST(0)(src), .Ll_exc_copy\@)
|
||
|
|
SUB t2, t2, t1 # t2 = number of bytes copied
|
||
|
|
xor match, t0, t1
|
||
|
|
R10KCBARRIER(0(ra))
|
||
|
|
STFIRST(t3, FIRST(0)(dst), .Ls_exc\@)
|
||
|
|
beq len, t2, .Ldone\@
|
||
|
|
SUB len, len, t2
|
||
|
|
ADD dst, dst, t2
|
||
|
|
beqz match, .Lboth_aligned\@
|
||
|
|
ADD src, src, t2
|
||
|
|
|
||
|
|
.Lsrc_unaligned_dst_aligned\@:
|
||
|
|
SRL t0, len, LOG_NBYTES+2 # +2 for 4 units/iter
|
||
|
|
PREFS( 0, 3*32(src) )
|
||
|
|
beqz t0, .Lcleanup_src_unaligned\@
|
||
|
|
and rem, len, (4*NBYTES-1) # rem = len % 4*NBYTES
|
||
|
|
PREFD( 1, 3*32(dst) )
|
||
|
|
1:
|
||
|
|
/*
|
||
|
|
* Avoid consecutive LD*'s to the same register since some mips
|
||
|
|
* implementations can't issue them in the same cycle.
|
||
|
|
* It's OK to load FIRST(N+1) before REST(N) because the two addresses
|
||
|
|
* are to the same unit (unless src is aligned, but it's not).
|
||
|
|
*/
|
||
|
|
R10KCBARRIER(0(ra))
|
||
|
|
LDFIRST(t0, FIRST(0)(src), .Ll_exc\@)
|
||
|
|
LDFIRST(t1, FIRST(1)(src), .Ll_exc_copy\@)
|
||
|
|
SUB len, len, 4*NBYTES
|
||
|
|
LDREST(t0, REST(0)(src), .Ll_exc_copy\@)
|
||
|
|
LDREST(t1, REST(1)(src), .Ll_exc_copy\@)
|
||
|
|
LDFIRST(t2, FIRST(2)(src), .Ll_exc_copy\@)
|
||
|
|
LDFIRST(t3, FIRST(3)(src), .Ll_exc_copy\@)
|
||
|
|
LDREST(t2, REST(2)(src), .Ll_exc_copy\@)
|
||
|
|
LDREST(t3, REST(3)(src), .Ll_exc_copy\@)
|
||
|
|
PREFS( 0, 9*32(src) ) # 0 is PREF_LOAD (not streamed)
|
||
|
|
ADD src, src, 4*NBYTES
|
||
|
|
#ifdef CONFIG_CPU_SB1
|
||
|
|
nop # improves slotting
|
||
|
|
#endif
|
||
|
|
STORE(t0, UNIT(0)(dst), .Ls_exc_p4u\@)
|
||
|
|
STORE(t1, UNIT(1)(dst), .Ls_exc_p3u\@)
|
||
|
|
STORE(t2, UNIT(2)(dst), .Ls_exc_p2u\@)
|
||
|
|
STORE(t3, UNIT(3)(dst), .Ls_exc_p1u\@)
|
||
|
|
PREFD( 1, 9*32(dst) ) # 1 is PREF_STORE (not streamed)
|
||
|
|
.set reorder /* DADDI_WAR */
|
||
|
|
ADD dst, dst, 4*NBYTES
|
||
|
|
bne len, rem, 1b
|
||
|
|
.set noreorder
|
||
|
|
|
||
|
|
.Lcleanup_src_unaligned\@:
|
||
|
|
beqz len, .Ldone\@
|
||
|
|
and rem, len, NBYTES-1 # rem = len % NBYTES
|
||
|
|
beq rem, len, .Lcopy_bytes\@
|
||
|
|
nop
|
||
|
|
1:
|
||
|
|
R10KCBARRIER(0(ra))
|
||
|
|
LDFIRST(t0, FIRST(0)(src), .Ll_exc\@)
|
||
|
|
LDREST(t0, REST(0)(src), .Ll_exc_copy\@)
|
||
|
|
ADD src, src, NBYTES
|
||
|
|
SUB len, len, NBYTES
|
||
|
|
STORE(t0, 0(dst), .Ls_exc_p1u\@)
|
||
|
|
.set reorder /* DADDI_WAR */
|
||
|
|
ADD dst, dst, NBYTES
|
||
|
|
bne len, rem, 1b
|
||
|
|
.set noreorder
|
||
|
|
|
||
|
|
#endif /* !CONFIG_CPU_MIPSR6 */
|
||
|
|
.Lcopy_bytes_checklen\@:
|
||
|
|
beqz len, .Ldone\@
|
||
|
|
nop
|
||
|
|
.Lcopy_bytes\@:
|
||
|
|
/* 0 < len < NBYTES */
|
||
|
|
R10KCBARRIER(0(ra))
|
||
|
|
#define COPY_BYTE(N) \
|
||
|
|
LOADB(t0, N(src), .Ll_exc\@); \
|
||
|
|
SUB len, len, 1; \
|
||
|
|
beqz len, .Ldone\@; \
|
||
|
|
STOREB(t0, N(dst), .Ls_exc_p1\@)
|
||
|
|
|
||
|
|
COPY_BYTE(0)
|
||
|
|
COPY_BYTE(1)
|
||
|
|
#ifdef USE_DOUBLE
|
||
|
|
COPY_BYTE(2)
|
||
|
|
COPY_BYTE(3)
|
||
|
|
COPY_BYTE(4)
|
||
|
|
COPY_BYTE(5)
|
||
|
|
#endif
|
||
|
|
LOADB(t0, NBYTES-2(src), .Ll_exc\@)
|
||
|
|
SUB len, len, 1
|
||
|
|
jr ra
|
||
|
|
STOREB(t0, NBYTES-2(dst), .Ls_exc_p1\@)
|
||
|
|
.Ldone\@:
|
||
|
|
jr ra
|
||
|
|
nop
|
||
|
|
|
||
|
|
#ifdef CONFIG_CPU_MIPSR6
|
||
|
|
.Lcopy_unaligned_bytes\@:
|
||
|
|
1:
|
||
|
|
COPY_BYTE(0)
|
||
|
|
COPY_BYTE(1)
|
||
|
|
COPY_BYTE(2)
|
||
|
|
COPY_BYTE(3)
|
||
|
|
COPY_BYTE(4)
|
||
|
|
COPY_BYTE(5)
|
||
|
|
COPY_BYTE(6)
|
||
|
|
COPY_BYTE(7)
|
||
|
|
ADD src, src, 8
|
||
|
|
b 1b
|
||
|
|
ADD dst, dst, 8
|
||
|
|
#endif /* CONFIG_CPU_MIPSR6 */
|
||
|
|
.if __memcpy == 1
|
||
|
|
END(memcpy)
|
||
|
|
.set __memcpy, 0
|
||
|
|
.hidden __memcpy
|
||
|
|
.endif
|
||
|
|
|
||
|
|
.Ll_exc_copy\@:
|
||
|
|
/*
|
||
|
|
* Copy bytes from src until faulting load address (or until a
|
||
|
|
* lb faults)
|
||
|
|
*
|
||
|
|
* When reached by a faulting LDFIRST/LDREST, THREAD_BUADDR($28)
|
||
|
|
* may be more than a byte beyond the last address.
|
||
|
|
* Hence, the lb below may get an exception.
|
||
|
|
*
|
||
|
|
* Assumes src < THREAD_BUADDR($28)
|
||
|
|
*/
|
||
|
|
LOADK t0, TI_TASK($28)
|
||
|
|
nop
|
||
|
|
LOADK t0, THREAD_BUADDR(t0)
|
||
|
|
1:
|
||
|
|
LOADB(t1, 0(src), .Ll_exc\@)
|
||
|
|
ADD src, src, 1
|
||
|
|
sb t1, 0(dst) # can't fault -- we're copy_from_user
|
||
|
|
.set reorder /* DADDI_WAR */
|
||
|
|
ADD dst, dst, 1
|
||
|
|
bne src, t0, 1b
|
||
|
|
.set noreorder
|
||
|
|
.Ll_exc\@:
|
||
|
|
LOADK t0, TI_TASK($28)
|
||
|
|
nop
|
||
|
|
LOADK t0, THREAD_BUADDR(t0) # t0 is just past last good address
|
||
|
|
nop
|
||
|
|
SUB len, AT, t0 # len number of uncopied bytes
|
||
|
|
bnez t6, .Ldone\@ /* Skip the zeroing part if inatomic */
|
||
|
|
/*
|
||
|
|
* Here's where we rely on src and dst being incremented in tandem,
|
||
|
|
* See (3) above.
|
||
|
|
* dst += (fault addr - src) to put dst at first byte to clear
|
||
|
|
*/
|
||
|
|
ADD dst, t0 # compute start address in a1
|
||
|
|
SUB dst, src
|
||
|
|
/*
|
||
|
|
* Clear len bytes starting at dst. Can't call __bzero because it
|
||
|
|
* might modify len. An inefficient loop for these rare times...
|
||
|
|
*/
|
||
|
|
.set reorder /* DADDI_WAR */
|
||
|
|
SUB src, len, 1
|
||
|
|
beqz len, .Ldone\@
|
||
|
|
.set noreorder
|
||
|
|
1: sb zero, 0(dst)
|
||
|
|
ADD dst, dst, 1
|
||
|
|
#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
|
||
|
|
bnez src, 1b
|
||
|
|
SUB src, src, 1
|
||
|
|
#else
|
||
|
|
.set push
|
||
|
|
.set noat
|
||
|
|
li v1, 1
|
||
|
|
bnez src, 1b
|
||
|
|
SUB src, src, v1
|
||
|
|
.set pop
|
||
|
|
#endif
|
||
|
|
jr ra
|
||
|
|
nop
|
||
|
|
|
||
|
|
|
||
|
|
#define SEXC(n) \
|
||
|
|
.set reorder; /* DADDI_WAR */ \
|
||
|
|
.Ls_exc_p ## n ## u\@: \
|
||
|
|
ADD len, len, n*NBYTES; \
|
||
|
|
jr ra; \
|
||
|
|
.set noreorder
|
||
|
|
|
||
|
|
SEXC(8)
|
||
|
|
SEXC(7)
|
||
|
|
SEXC(6)
|
||
|
|
SEXC(5)
|
||
|
|
SEXC(4)
|
||
|
|
SEXC(3)
|
||
|
|
SEXC(2)
|
||
|
|
SEXC(1)
|
||
|
|
|
||
|
|
.Ls_exc_p1\@:
|
||
|
|
.set reorder /* DADDI_WAR */
|
||
|
|
ADD len, len, 1
|
||
|
|
jr ra
|
||
|
|
.set noreorder
|
||
|
|
.Ls_exc\@:
|
||
|
|
jr ra
|
||
|
|
nop
|
||
|
|
.endm
|
||
|
|
|
||
|
|
.align 5
|
||
|
|
LEAF(memmove)
|
||
|
|
ADD t0, a0, a2
|
||
|
|
ADD t1, a1, a2
|
||
|
|
sltu t0, a1, t0 # dst + len <= src -> memcpy
|
||
|
|
sltu t1, a0, t1 # dst >= src + len -> memcpy
|
||
|
|
and t0, t1
|
||
|
|
beqz t0, .L__memcpy
|
||
|
|
move v0, a0 /* return value */
|
||
|
|
beqz a2, .Lr_out
|
||
|
|
END(memmove)
|
||
|
|
|
||
|
|
/* fall through to __rmemcpy */
|
||
|
|
LEAF(__rmemcpy) /* a0=dst a1=src a2=len */
|
||
|
|
sltu t0, a1, a0
|
||
|
|
beqz t0, .Lr_end_bytes_up # src >= dst
|
||
|
|
nop
|
||
|
|
ADD a0, a2 # dst = dst + len
|
||
|
|
ADD a1, a2 # src = src + len
|
||
|
|
|
||
|
|
.Lr_end_bytes:
|
||
|
|
R10KCBARRIER(0(ra))
|
||
|
|
lb t0, -1(a1)
|
||
|
|
SUB a2, a2, 0x1
|
||
|
|
sb t0, -1(a0)
|
||
|
|
SUB a1, a1, 0x1
|
||
|
|
.set reorder /* DADDI_WAR */
|
||
|
|
SUB a0, a0, 0x1
|
||
|
|
bnez a2, .Lr_end_bytes
|
||
|
|
.set noreorder
|
||
|
|
|
||
|
|
.Lr_out:
|
||
|
|
jr ra
|
||
|
|
move a2, zero
|
||
|
|
|
||
|
|
.Lr_end_bytes_up:
|
||
|
|
R10KCBARRIER(0(ra))
|
||
|
|
lb t0, (a1)
|
||
|
|
SUB a2, a2, 0x1
|
||
|
|
sb t0, (a0)
|
||
|
|
ADD a1, a1, 0x1
|
||
|
|
.set reorder /* DADDI_WAR */
|
||
|
|
ADD a0, a0, 0x1
|
||
|
|
bnez a2, .Lr_end_bytes_up
|
||
|
|
.set noreorder
|
||
|
|
|
||
|
|
jr ra
|
||
|
|
move a2, zero
|
||
|
|
END(__rmemcpy)
|
||
|
|
|
||
|
|
/*
|
||
|
|
* t6 is used as a flag to note inatomic mode.
|
||
|
|
*/
|
||
|
|
LEAF(__copy_user_inatomic)
|
||
|
|
b __copy_user_common
|
||
|
|
li t6, 1
|
||
|
|
END(__copy_user_inatomic)
|
||
|
|
|
||
|
|
/*
|
||
|
|
* A combined memcpy/__copy_user
|
||
|
|
* __copy_user sets len to 0 for success; else to an upper bound of
|
||
|
|
* the number of uncopied bytes.
|
||
|
|
* memcpy sets v0 to dst.
|
||
|
|
*/
|
||
|
|
.align 5
|
||
|
|
LEAF(memcpy) /* a0=dst a1=src a2=len */
|
||
|
|
move v0, dst /* return value */
|
||
|
|
.L__memcpy:
|
||
|
|
FEXPORT(__copy_user)
|
||
|
|
li t6, 0 /* not inatomic */
|
||
|
|
__copy_user_common:
|
||
|
|
/* Legacy Mode, user <-> user */
|
||
|
|
__BUILD_COPY_USER LEGACY_MODE USEROP USEROP
|
||
|
|
|
||
|
|
#ifdef CONFIG_EVA
|
||
|
|
|
||
|
|
/*
|
||
|
|
* For EVA we need distinct symbols for reading and writing to user space.
|
||
|
|
* This is because we need to use specific EVA instructions to perform the
|
||
|
|
* virtual <-> physical translation when a virtual address is actually in user
|
||
|
|
* space
|
||
|
|
*/
|
||
|
|
|
||
|
|
LEAF(__copy_user_inatomic_eva)
|
||
|
|
b __copy_from_user_common
|
||
|
|
li t6, 1
|
||
|
|
END(__copy_user_inatomic_eva)
|
||
|
|
|
||
|
|
/*
|
||
|
|
* __copy_from_user (EVA)
|
||
|
|
*/
|
||
|
|
|
||
|
|
LEAF(__copy_from_user_eva)
|
||
|
|
li t6, 0 /* not inatomic */
|
||
|
|
__copy_from_user_common:
|
||
|
|
__BUILD_COPY_USER EVA_MODE USEROP KERNELOP
|
||
|
|
END(__copy_from_user_eva)
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* __copy_to_user (EVA)
|
||
|
|
*/
|
||
|
|
|
||
|
|
LEAF(__copy_to_user_eva)
|
||
|
|
__BUILD_COPY_USER EVA_MODE KERNELOP USEROP
|
||
|
|
END(__copy_to_user_eva)
|
||
|
|
|
||
|
|
/*
|
||
|
|
* __copy_in_user (EVA)
|
||
|
|
*/
|
||
|
|
|
||
|
|
LEAF(__copy_in_user_eva)
|
||
|
|
__BUILD_COPY_USER EVA_MODE USEROP USEROP
|
||
|
|
END(__copy_in_user_eva)
|
||
|
|
|
||
|
|
#endif
|