linux/arch/powerpc/lib/mem_64.S
Li Zhong 6f5405bc2e powerpc: use _GLOBAL_TOC for memmove
memmove may be called from module code copy_pages(btrfs), and it may
call memcpy, which may call back to C code, so it needs to use
_GLOBAL_TOC to set up r2 correctly.

This fixes following error when I tried to boot an le guest:

Vector: 300 (Data Access) at [c000000073f97210]
    pc: c000000000015004: enable_kernel_altivec+0x24/0x80
    lr: c000000000058fbc: enter_vmx_copy+0x3c/0x60
    sp: c000000073f97490
   msr: 8000000002009033
   dar: d000000001d50170
 dsisr: 40000000
  current = 0xc0000000734c0000
  paca    = 0xc00000000fff0000	 softe: 0	 irq_happened: 0x01
    pid   = 815, comm = mktemp
enter ? for help
[c000000073f974f0] c000000000058fbc enter_vmx_copy+0x3c/0x60
[c000000073f97510] c000000000057d34 memcpy_power7+0x274/0x840
[c000000073f97610] d000000001c3179c copy_pages+0xfc/0x110 [btrfs]
[c000000073f97660] d000000001c3c248 memcpy_extent_buffer+0xe8/0x160 [btrfs]
[c000000073f97700] d000000001be4be8 setup_items_for_insert+0x208/0x4a0 [btrfs]
[c000000073f97820] d000000001be50b4 btrfs_insert_empty_items+0xf4/0x140 [btrfs]
[c000000073f97890] d000000001bfed30 insert_with_overflow+0x70/0x180 [btrfs]
[c000000073f97900] d000000001bff174 btrfs_insert_dir_item+0x114/0x2f0 [btrfs]
[c000000073f979a0] d000000001c1f92c btrfs_add_link+0x10c/0x370 [btrfs]
[c000000073f97a40] d000000001c20e94 btrfs_create+0x204/0x270 [btrfs]
[c000000073f97b00] c00000000026d438 vfs_create+0x178/0x210
[c000000073f97b50] c000000000270a70 do_last+0x9f0/0xe90
[c000000073f97c20] c000000000271010 path_openat+0x100/0x810
[c000000073f97ce0] c000000000272ea8 do_filp_open+0x58/0xd0
[c000000073f97dc0] c00000000025ade8 do_sys_open+0x1b8/0x300
[c000000073f97e30] c00000000000a008 syscall_exit+0x0/0x7c

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-07-22 15:56:04 +10:00

120 lines
1.9 KiB
ArmAsm

/*
* String handling functions for PowerPC.
*
* Copyright (C) 1996 Paul Mackerras.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <asm/processor.h>
#include <asm/errno.h>
#include <asm/ppc_asm.h>
_GLOBAL(memset)
neg r0,r3
rlwimi r4,r4,8,16,23
andi. r0,r0,7 /* # bytes to be 8-byte aligned */
rlwimi r4,r4,16,0,15
cmplw cr1,r5,r0 /* do we get that far? */
rldimi r4,r4,32,0
PPC_MTOCRF(1,r0)
mr r6,r3
blt cr1,8f
beq+ 3f /* if already 8-byte aligned */
subf r5,r0,r5
bf 31,1f
stb r4,0(r6)
addi r6,r6,1
1: bf 30,2f
sth r4,0(r6)
addi r6,r6,2
2: bf 29,3f
stw r4,0(r6)
addi r6,r6,4
3: srdi. r0,r5,6
clrldi r5,r5,58
mtctr r0
beq 5f
4: std r4,0(r6)
std r4,8(r6)
std r4,16(r6)
std r4,24(r6)
std r4,32(r6)
std r4,40(r6)
std r4,48(r6)
std r4,56(r6)
addi r6,r6,64
bdnz 4b
5: srwi. r0,r5,3
clrlwi r5,r5,29
PPC_MTOCRF(1,r0)
beq 8f
bf 29,6f
std r4,0(r6)
std r4,8(r6)
std r4,16(r6)
std r4,24(r6)
addi r6,r6,32
6: bf 30,7f
std r4,0(r6)
std r4,8(r6)
addi r6,r6,16
7: bf 31,8f
std r4,0(r6)
addi r6,r6,8
8: cmpwi r5,0
PPC_MTOCRF(1,r5)
beqlr+
bf 29,9f
stw r4,0(r6)
addi r6,r6,4
9: bf 30,10f
sth r4,0(r6)
addi r6,r6,2
10: bflr 31
stb r4,0(r6)
blr
_GLOBAL_TOC(memmove)
cmplw 0,r3,r4
bgt backwards_memcpy
b memcpy
_GLOBAL(backwards_memcpy)
rlwinm. r7,r5,32-3,3,31 /* r0 = r5 >> 3 */
add r6,r3,r5
add r4,r4,r5
beq 2f
andi. r0,r6,3
mtctr r7
bne 5f
1: lwz r7,-4(r4)
lwzu r8,-8(r4)
stw r7,-4(r6)
stwu r8,-8(r6)
bdnz 1b
andi. r5,r5,7
2: cmplwi 0,r5,4
blt 3f
lwzu r0,-4(r4)
subi r5,r5,4
stwu r0,-4(r6)
3: cmpwi 0,r5,0
beqlr
mtctr r5
4: lbzu r0,-1(r4)
stbu r0,-1(r6)
bdnz 4b
blr
5: mtctr r0
6: lbzu r7,-1(r4)
stbu r7,-1(r6)
bdnz 6b
subf r5,r0,r5
rlwinm. r7,r5,32-3,3,31
beq 2b
mtctr r7
b 1b