linux/arch/sparc64/lib/NGpage.S
David S. Miller 24d559cac4 [SPARC64]: store-init needs trailing membar.
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>
2007-03-19 13:27:33 -07:00

99 lines
2.6 KiB
ArmAsm

/* NGpage.S: Niagara optimize clear and copy page.
*
* Copyright (C) 2006 (davem@davemloft.net)
*/
#include <asm/asi.h>
#include <asm/page.h>
.text
.align 32
/* This is heavily simplified from the sun4u variants
* because Niagara does not have any D-cache aliasing issues
* and also we don't need to use the FPU in order to implement
* an optimal page copy/clear.
*/
NGcopy_user_page: /* %o0=dest, %o1=src, %o2=vaddr */
prefetch [%o1 + 0x00], #one_read
mov 8, %g1
mov 16, %g2
mov 24, %g3
set PAGE_SIZE, %g7
1: ldda [%o1 + %g0] ASI_BLK_INIT_QUAD_LDD_P, %o2
ldda [%o1 + %g2] ASI_BLK_INIT_QUAD_LDD_P, %o4
prefetch [%o1 + 0x40], #one_read
add %o1, 32, %o1
stxa %o2, [%o0 + %g0] ASI_BLK_INIT_QUAD_LDD_P
stxa %o3, [%o0 + %g1] ASI_BLK_INIT_QUAD_LDD_P
ldda [%o1 + %g0] ASI_BLK_INIT_QUAD_LDD_P, %o2
stxa %o4, [%o0 + %g2] ASI_BLK_INIT_QUAD_LDD_P
stxa %o5, [%o0 + %g3] ASI_BLK_INIT_QUAD_LDD_P
ldda [%o1 + %g2] ASI_BLK_INIT_QUAD_LDD_P, %o4
add %o1, 32, %o1
add %o0, 32, %o0
stxa %o2, [%o0 + %g0] ASI_BLK_INIT_QUAD_LDD_P
stxa %o3, [%o0 + %g1] ASI_BLK_INIT_QUAD_LDD_P
stxa %o4, [%o0 + %g2] ASI_BLK_INIT_QUAD_LDD_P
stxa %o5, [%o0 + %g3] ASI_BLK_INIT_QUAD_LDD_P
subcc %g7, 64, %g7
bne,pt %xcc, 1b
add %o0, 32, %o0
membar #Sync
retl
nop
NGclear_page: /* %o0=dest */
NGclear_user_page: /* %o0=dest, %o1=vaddr */
mov 8, %g1
mov 16, %g2
mov 24, %g3
set PAGE_SIZE, %g7
1: stxa %g0, [%o0 + %g0] ASI_BLK_INIT_QUAD_LDD_P
stxa %g0, [%o0 + %g1] ASI_BLK_INIT_QUAD_LDD_P
stxa %g0, [%o0 + %g2] ASI_BLK_INIT_QUAD_LDD_P
stxa %g0, [%o0 + %g3] ASI_BLK_INIT_QUAD_LDD_P
add %o0, 32, %o0
stxa %g0, [%o0 + %g0] ASI_BLK_INIT_QUAD_LDD_P
stxa %g0, [%o0 + %g1] ASI_BLK_INIT_QUAD_LDD_P
stxa %g0, [%o0 + %g2] ASI_BLK_INIT_QUAD_LDD_P
stxa %g0, [%o0 + %g3] ASI_BLK_INIT_QUAD_LDD_P
subcc %g7, 64, %g7
bne,pt %xcc, 1b
add %o0, 32, %o0
membar #Sync
retl
nop
#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_pageops
.type niagara_patch_pageops,#function
niagara_patch_pageops:
NG_DO_PATCH(copy_user_page, NGcopy_user_page)
NG_DO_PATCH(_clear_page, NGclear_page)
NG_DO_PATCH(clear_user_page, NGclear_user_page)
retl
nop
.size niagara_patch_pageops,.-niagara_patch_pageops