mirror of
https://github.com/torvalds/linux.git
synced 2024-12-15 23:51:46 +00:00
24d559cac4
The manual says that it is required and we actually have crash reports where loads see stale data due to not having membars here. In one case the networking does: memset(skb, 0, offsetof(struct sk_buff, truesize)); and then some code later checks skb->nohdr for zero, but it's still the value that was there before the memset(). Note that arch/sparc64/lib/xor.S already got this right. Signed-off-by: David S. Miller <davem@davemloft.net>
165 lines
3.4 KiB
ArmAsm
165 lines
3.4 KiB
ArmAsm
/* NGbzero.S: Niagara optimized memset/clear_user.
|
|
*
|
|
* Copyright (C) 2006 David S. Miller (davem@davemloft.net)
|
|
*/
|
|
#include <asm/asi.h>
|
|
|
|
#define EX_ST(x,y) \
|
|
98: x,y; \
|
|
.section .fixup; \
|
|
.align 4; \
|
|
99: retl; \
|
|
mov %o1, %o0; \
|
|
.section __ex_table; \
|
|
.align 4; \
|
|
.word 98b, 99b; \
|
|
.text; \
|
|
.align 4;
|
|
|
|
.text
|
|
|
|
.globl NGmemset
|
|
.type NGmemset, #function
|
|
NGmemset: /* %o0=buf, %o1=pat, %o2=len */
|
|
and %o1, 0xff, %o3
|
|
mov %o2, %o1
|
|
sllx %o3, 8, %g1
|
|
or %g1, %o3, %o2
|
|
sllx %o2, 16, %g1
|
|
or %g1, %o2, %o2
|
|
sllx %o2, 32, %g1
|
|
ba,pt %xcc, 1f
|
|
or %g1, %o2, %o2
|
|
|
|
.globl NGbzero
|
|
.type NGbzero, #function
|
|
NGbzero:
|
|
clr %o2
|
|
1: brz,pn %o1, NGbzero_return
|
|
mov %o0, %o3
|
|
|
|
/* %o5: saved %asi, restored at NGbzero_done
|
|
* %g7: store-init %asi to use
|
|
* %o4: non-store-init %asi to use
|
|
*/
|
|
rd %asi, %o5
|
|
mov ASI_BLK_INIT_QUAD_LDD_P, %g7
|
|
mov ASI_P, %o4
|
|
wr %o4, 0x0, %asi
|
|
|
|
NGbzero_from_clear_user:
|
|
cmp %o1, 15
|
|
bl,pn %icc, NGbzero_tiny
|
|
andcc %o0, 0x7, %g1
|
|
be,pt %xcc, 2f
|
|
mov 8, %g2
|
|
sub %g2, %g1, %g1
|
|
sub %o1, %g1, %o1
|
|
1: EX_ST(stba %o2, [%o0 + 0x00] %asi)
|
|
subcc %g1, 1, %g1
|
|
bne,pt %xcc, 1b
|
|
add %o0, 1, %o0
|
|
2: cmp %o1, 128
|
|
bl,pn %icc, NGbzero_medium
|
|
andcc %o0, (64 - 1), %g1
|
|
be,pt %xcc, NGbzero_pre_loop
|
|
mov 64, %g2
|
|
sub %g2, %g1, %g1
|
|
sub %o1, %g1, %o1
|
|
1: EX_ST(stxa %o2, [%o0 + 0x00] %asi)
|
|
subcc %g1, 8, %g1
|
|
bne,pt %xcc, 1b
|
|
add %o0, 8, %o0
|
|
|
|
NGbzero_pre_loop:
|
|
wr %g7, 0x0, %asi
|
|
andn %o1, (64 - 1), %g1
|
|
sub %o1, %g1, %o1
|
|
NGbzero_loop:
|
|
EX_ST(stxa %o2, [%o0 + 0x00] %asi)
|
|
EX_ST(stxa %o2, [%o0 + 0x08] %asi)
|
|
EX_ST(stxa %o2, [%o0 + 0x10] %asi)
|
|
EX_ST(stxa %o2, [%o0 + 0x18] %asi)
|
|
EX_ST(stxa %o2, [%o0 + 0x20] %asi)
|
|
EX_ST(stxa %o2, [%o0 + 0x28] %asi)
|
|
EX_ST(stxa %o2, [%o0 + 0x30] %asi)
|
|
EX_ST(stxa %o2, [%o0 + 0x38] %asi)
|
|
subcc %g1, 64, %g1
|
|
bne,pt %xcc, NGbzero_loop
|
|
add %o0, 64, %o0
|
|
|
|
membar #Sync
|
|
wr %o4, 0x0, %asi
|
|
brz,pn %o1, NGbzero_done
|
|
NGbzero_medium:
|
|
andncc %o1, 0x7, %g1
|
|
be,pn %xcc, 2f
|
|
sub %o1, %g1, %o1
|
|
1: EX_ST(stxa %o2, [%o0 + 0x00] %asi)
|
|
subcc %g1, 8, %g1
|
|
bne,pt %xcc, 1b
|
|
add %o0, 8, %o0
|
|
2: brz,pt %o1, NGbzero_done
|
|
nop
|
|
|
|
NGbzero_tiny:
|
|
1: EX_ST(stba %o2, [%o0 + 0x00] %asi)
|
|
subcc %o1, 1, %o1
|
|
bne,pt %icc, 1b
|
|
add %o0, 1, %o0
|
|
|
|
/* fallthrough */
|
|
|
|
NGbzero_done:
|
|
wr %o5, 0x0, %asi
|
|
|
|
NGbzero_return:
|
|
retl
|
|
mov %o3, %o0
|
|
.size NGbzero, .-NGbzero
|
|
.size NGmemset, .-NGmemset
|
|
|
|
.globl NGclear_user
|
|
.type NGclear_user, #function
|
|
NGclear_user: /* %o0=buf, %o1=len */
|
|
rd %asi, %o5
|
|
brz,pn %o1, NGbzero_done
|
|
clr %o3
|
|
cmp %o5, ASI_AIUS
|
|
bne,pn %icc, NGbzero
|
|
clr %o2
|
|
mov ASI_BLK_INIT_QUAD_LDD_AIUS, %g7
|
|
ba,pt %xcc, NGbzero_from_clear_user
|
|
mov ASI_AIUS, %o4
|
|
.size NGclear_user, .-NGclear_user
|
|
|
|
#define BRANCH_ALWAYS 0x10680000
|
|
#define NOP 0x01000000
|
|
#define NG_DO_PATCH(OLD, NEW) \
|
|
sethi %hi(NEW), %g1; \
|
|
or %g1, %lo(NEW), %g1; \
|
|
sethi %hi(OLD), %g2; \
|
|
or %g2, %lo(OLD), %g2; \
|
|
sub %g1, %g2, %g1; \
|
|
sethi %hi(BRANCH_ALWAYS), %g3; \
|
|
sll %g1, 11, %g1; \
|
|
srl %g1, 11 + 2, %g1; \
|
|
or %g3, %lo(BRANCH_ALWAYS), %g3; \
|
|
or %g3, %g1, %g3; \
|
|
stw %g3, [%g2]; \
|
|
sethi %hi(NOP), %g3; \
|
|
or %g3, %lo(NOP), %g3; \
|
|
stw %g3, [%g2 + 0x4]; \
|
|
flush %g2;
|
|
|
|
.globl niagara_patch_bzero
|
|
.type niagara_patch_bzero,#function
|
|
niagara_patch_bzero:
|
|
NG_DO_PATCH(memset, NGmemset)
|
|
NG_DO_PATCH(__bzero, NGbzero)
|
|
NG_DO_PATCH(__clear_user, NGclear_user)
|
|
NG_DO_PATCH(tsb_init, NGtsb_init)
|
|
retl
|
|
nop
|
|
.size niagara_patch_bzero,.-niagara_patch_bzero
|