Commit c5bd50a9 authored by David S. Miller's avatar David S. Miller
Browse files

[SPARC64]: Simplify Spitfire D-cache page flush. 



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: default avatarDavid S. Miller <davem@davemloft.net>
parent 80dc0d6b

arch/sparc64/mm/ultra.S

+23 −46
Original line number Diff line number Diff line
@@ -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.
@@ -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
@@ -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
@@ -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 */

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