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[SPARC64]: Simplify Spitfire D-cache page flush.
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It tries to batch up the tag loads and comparisons, and
then the stores.  And this is just complicated instead
of efficient.

Also, make the symbol of the Cheetah version more grepable.

Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller committed Sep 26, 2005
1 parent 80dc0d6 commit c5bd50a
Showing 1 changed file with 23 additions and 46 deletions.
69 changes: 23 additions & 46 deletions arch/sparc64/mm/ultra.S
Original file line number Diff line number Diff line change
Expand Up @@ -144,42 +144,29 @@ __flush_icache_page: /* %o0 = phys_page */

#define DTAG_MASK 0x3

/* This routine is Spitfire specific so the hardcoded
* D-cache size and line-size are OK.
*/
.align 64
.globl __flush_dcache_page
__flush_dcache_page: /* %o0=kaddr, %o1=flush_icache */
sethi %uhi(PAGE_OFFSET), %g1
sllx %g1, 32, %g1
sub %o0, %g1, %o0
clr %o4
srlx %o0, 11, %o0
sethi %hi(1 << 14), %o2
1: ldxa [%o4] ASI_DCACHE_TAG, %o3 ! LSU Group
add %o4, (1 << 5), %o4 ! IEU0
ldxa [%o4] ASI_DCACHE_TAG, %g1 ! LSU Group
add %o4, (1 << 5), %o4 ! IEU0
ldxa [%o4] ASI_DCACHE_TAG, %g2 ! LSU Group o3 available
add %o4, (1 << 5), %o4 ! IEU0
andn %o3, DTAG_MASK, %o3 ! IEU1
ldxa [%o4] ASI_DCACHE_TAG, %g3 ! LSU Group
add %o4, (1 << 5), %o4 ! IEU0
andn %g1, DTAG_MASK, %g1 ! IEU1
cmp %o0, %o3 ! IEU1 Group
be,a,pn %xcc, dflush1 ! CTI
sub %o4, (4 << 5), %o4 ! IEU0 (Group)
cmp %o0, %g1 ! IEU1 Group
andn %g2, DTAG_MASK, %g2 ! IEU0
be,a,pn %xcc, dflush2 ! CTI
sub %o4, (3 << 5), %o4 ! IEU0 (Group)
cmp %o0, %g2 ! IEU1 Group
andn %g3, DTAG_MASK, %g3 ! IEU0
be,a,pn %xcc, dflush3 ! CTI
sub %o4, (2 << 5), %o4 ! IEU0 (Group)
cmp %o0, %g3 ! IEU1 Group
be,a,pn %xcc, dflush4 ! CTI
sub %o4, (1 << 5), %o4 ! IEU0
2: cmp %o4, %o2 ! IEU1 Group
bne,pt %xcc, 1b ! CTI
nop ! IEU0
sub %o0, %g1, %o0 ! physical address
srlx %o0, 11, %o0 ! make D-cache TAG
sethi %hi(1 << 14), %o2 ! D-cache size
sub %o2, (1 << 5), %o2 ! D-cache line size
1: ldxa [%o2] ASI_DCACHE_TAG, %o3 ! load D-cache TAG
andcc %o3, DTAG_MASK, %g0 ! Valid?
be,pn %xcc, 2f ! Nope, branch
andn %o3, DTAG_MASK, %o3 ! Clear valid bits
cmp %o3, %o0 ! TAG match?
bne,pt %xcc, 2f ! Nope, branch
nop
stxa %g0, [%o2] ASI_DCACHE_TAG ! Invalidate TAG
membar #Sync
2: brnz,pt %o2, 1b
sub %o2, (1 << 5), %o2 ! D-cache line size

/* The I-cache does not snoop local stores so we
* better flush that too when necessary.
Expand All @@ -189,20 +176,10 @@ __flush_dcache_page: /* %o0=kaddr, %o1=flush_icache */
retl
nop

dflush1:stxa %g0, [%o4] ASI_DCACHE_TAG
add %o4, (1 << 5), %o4
dflush2:stxa %g0, [%o4] ASI_DCACHE_TAG
add %o4, (1 << 5), %o4
dflush3:stxa %g0, [%o4] ASI_DCACHE_TAG
add %o4, (1 << 5), %o4
dflush4:stxa %g0, [%o4] ASI_DCACHE_TAG
add %o4, (1 << 5), %o4
membar #Sync
ba,pt %xcc, 2b
nop
#endif /* DCACHE_ALIASING_POSSIBLE */

.previous .text
.previous

.align 32
__prefill_dtlb:
rdpr %pstate, %g7
Expand Down Expand Up @@ -283,7 +260,7 @@ __cheetah_flush_tlb_pending: /* 26 insns */
wrpr %g7, 0x0, %pstate

#ifdef DCACHE_ALIASING_POSSIBLE
flush_dcpage_cheetah: /* 11 insns */
__cheetah_flush_dcache_page: /* 11 insns */
sethi %uhi(PAGE_OFFSET), %g1
sllx %g1, 32, %g1
sub %o0, %g1, %o0
Expand Down Expand Up @@ -329,8 +306,8 @@ cheetah_patch_cachetlbops:
#ifdef DCACHE_ALIASING_POSSIBLE
sethi %hi(__flush_dcache_page), %o0
or %o0, %lo(__flush_dcache_page), %o0
sethi %hi(flush_dcpage_cheetah), %o1
or %o1, %lo(flush_dcpage_cheetah), %o1
sethi %hi(__cheetah_flush_dcache_page), %o1
or %o1, %lo(__cheetah_flush_dcache_page), %o1
call cheetah_patch_one
mov 11, %o2
#endif /* DCACHE_ALIASING_POSSIBLE */
Expand Down

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