The kernel always executes in the TSO memory model now, so none of this stuff is necessary any more. With helpful feedback from Nick Piggin. Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			277 lines
		
	
	
	
		
			8.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			277 lines
		
	
	
	
		
			8.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef _SPARC64_TSB_H
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#define _SPARC64_TSB_H
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/* The sparc64 TSB is similar to the powerpc hashtables.  It's a
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 * power-of-2 sized table of TAG/PTE pairs.  The cpu precomputes
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 * pointers into this table for 8K and 64K page sizes, and also a
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 * comparison TAG based upon the virtual address and context which
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 * faults.
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 *
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 * TLB miss trap handler software does the actual lookup via something
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 * of the form:
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 *
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 * 	ldxa		[%g0] ASI_{D,I}MMU_TSB_8KB_PTR, %g1
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 * 	ldxa		[%g0] ASI_{D,I}MMU, %g6
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 *	sllx		%g6, 22, %g6
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 *	srlx		%g6, 22, %g6
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 * 	ldda		[%g1] ASI_NUCLEUS_QUAD_LDD, %g4
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 * 	cmp		%g4, %g6
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 * 	bne,pn	%xcc, tsb_miss_{d,i}tlb
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 * 	 mov		FAULT_CODE_{D,I}TLB, %g3
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 * 	stxa		%g5, [%g0] ASI_{D,I}TLB_DATA_IN
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 * 	retry
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 *
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 *
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 * Each 16-byte slot of the TSB is the 8-byte tag and then the 8-byte
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 * PTE.  The TAG is of the same layout as the TLB TAG TARGET mmu
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 * register which is:
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 *
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 * -------------------------------------------------
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 * |  -  |  CONTEXT |  -  |    VADDR bits 63:22    |
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 * -------------------------------------------------
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 *  63 61 60      48 47 42 41                     0
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 *
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 * But actually, since we use per-mm TSB's, we zero out the CONTEXT
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 * field.
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 *
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 * Like the powerpc hashtables we need to use locking in order to
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 * synchronize while we update the entries.  PTE updates need locking
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 * as well.
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 *
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 * We need to carefully choose a lock bits for the TSB entry.  We
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 * choose to use bit 47 in the tag.  Also, since we never map anything
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 * at page zero in context zero, we use zero as an invalid tag entry.
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 * When the lock bit is set, this forces a tag comparison failure.
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 */
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#define TSB_TAG_LOCK_BIT	47
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#define TSB_TAG_LOCK_HIGH	(1 << (TSB_TAG_LOCK_BIT - 32))
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#define TSB_TAG_INVALID_BIT	46
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#define TSB_TAG_INVALID_HIGH	(1 << (TSB_TAG_INVALID_BIT - 32))
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/* Some cpus support physical address quad loads.  We want to use
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 * those if possible so we don't need to hard-lock the TSB mapping
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 * into the TLB.  We encode some instruction patching in order to
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 * support this.
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 *
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 * The kernel TSB is locked into the TLB by virtue of being in the
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 * kernel image, so we don't play these games for swapper_tsb access.
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 */
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#ifndef __ASSEMBLY__
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struct tsb_ldquad_phys_patch_entry {
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	unsigned int	addr;
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	unsigned int	sun4u_insn;
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	unsigned int	sun4v_insn;
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};
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extern struct tsb_ldquad_phys_patch_entry __tsb_ldquad_phys_patch,
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	__tsb_ldquad_phys_patch_end;
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struct tsb_phys_patch_entry {
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	unsigned int	addr;
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	unsigned int	insn;
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};
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extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;
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#endif
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#define TSB_LOAD_QUAD(TSB, REG)	\
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661:	ldda		[TSB] ASI_NUCLEUS_QUAD_LDD, REG; \
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	.section	.tsb_ldquad_phys_patch, "ax"; \
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	.word		661b; \
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	ldda		[TSB] ASI_QUAD_LDD_PHYS, REG; \
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	ldda		[TSB] ASI_QUAD_LDD_PHYS_4V, REG; \
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	.previous
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#define TSB_LOAD_TAG_HIGH(TSB, REG) \
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661:	lduwa		[TSB] ASI_N, REG; \
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	.section	.tsb_phys_patch, "ax"; \
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	.word		661b; \
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	lduwa		[TSB] ASI_PHYS_USE_EC, REG; \
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	.previous
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#define TSB_LOAD_TAG(TSB, REG) \
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661:	ldxa		[TSB] ASI_N, REG; \
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	.section	.tsb_phys_patch, "ax"; \
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	.word		661b; \
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	ldxa		[TSB] ASI_PHYS_USE_EC, REG; \
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	.previous
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#define TSB_CAS_TAG_HIGH(TSB, REG1, REG2) \
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661:	casa		[TSB] ASI_N, REG1, REG2; \
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	.section	.tsb_phys_patch, "ax"; \
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	.word		661b; \
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	casa		[TSB] ASI_PHYS_USE_EC, REG1, REG2; \
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	.previous
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#define TSB_CAS_TAG(TSB, REG1, REG2) \
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661:	casxa		[TSB] ASI_N, REG1, REG2; \
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	.section	.tsb_phys_patch, "ax"; \
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	.word		661b; \
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	casxa		[TSB] ASI_PHYS_USE_EC, REG1, REG2; \
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	.previous
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#define TSB_STORE(ADDR, VAL) \
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661:	stxa		VAL, [ADDR] ASI_N; \
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	.section	.tsb_phys_patch, "ax"; \
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	.word		661b; \
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	stxa		VAL, [ADDR] ASI_PHYS_USE_EC; \
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	.previous
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#define TSB_LOCK_TAG(TSB, REG1, REG2)	\
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99:	TSB_LOAD_TAG_HIGH(TSB, REG1);	\
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	sethi	%hi(TSB_TAG_LOCK_HIGH), REG2;\
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	andcc	REG1, REG2, %g0;	\
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	bne,pn	%icc, 99b;		\
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	 nop;				\
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	TSB_CAS_TAG_HIGH(TSB, REG1, REG2);	\
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	cmp	REG1, REG2;		\
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	bne,pn	%icc, 99b;		\
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	 nop;				\
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#define TSB_WRITE(TSB, TTE, TAG) \
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	add	TSB, 0x8, TSB;   \
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	TSB_STORE(TSB, TTE);     \
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	sub	TSB, 0x8, TSB;   \
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	TSB_STORE(TSB, TAG);
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#define KTSB_LOAD_QUAD(TSB, REG) \
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	ldda		[TSB] ASI_NUCLEUS_QUAD_LDD, REG;
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#define KTSB_STORE(ADDR, VAL) \
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	stxa		VAL, [ADDR] ASI_N;
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#define KTSB_LOCK_TAG(TSB, REG1, REG2)	\
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99:	lduwa	[TSB] ASI_N, REG1;	\
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	sethi	%hi(TSB_TAG_LOCK_HIGH), REG2;\
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	andcc	REG1, REG2, %g0;	\
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	bne,pn	%icc, 99b;		\
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	 nop;				\
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	casa	[TSB] ASI_N, REG1, REG2;\
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	cmp	REG1, REG2;		\
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	bne,pn	%icc, 99b;		\
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	 nop;				\
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#define KTSB_WRITE(TSB, TTE, TAG) \
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	add	TSB, 0x8, TSB;   \
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	stxa	TTE, [TSB] ASI_N;     \
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	sub	TSB, 0x8, TSB;   \
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	stxa	TAG, [TSB] ASI_N;
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	/* Do a kernel page table walk.  Leaves physical PTE pointer in
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	 * REG1.  Jumps to FAIL_LABEL on early page table walk termination.
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	 * VADDR will not be clobbered, but REG2 will.
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	 */
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#define KERN_PGTABLE_WALK(VADDR, REG1, REG2, FAIL_LABEL)	\
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	sethi		%hi(swapper_pg_dir), REG1; \
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	or		REG1, %lo(swapper_pg_dir), REG1; \
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	sllx		VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
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	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
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	andn		REG2, 0x3, REG2; \
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	lduw		[REG1 + REG2], REG1; \
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	brz,pn		REG1, FAIL_LABEL; \
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	 sllx		VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
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	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
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	sllx		REG1, 11, REG1; \
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	andn		REG2, 0x3, REG2; \
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	lduwa		[REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
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	brz,pn		REG1, FAIL_LABEL; \
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	 sllx		VADDR, 64 - PMD_SHIFT, REG2; \
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	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
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	sllx		REG1, 11, REG1; \
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	andn		REG2, 0x7, REG2; \
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	add		REG1, REG2, REG1;
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	/* Do a user page table walk in MMU globals.  Leaves physical PTE
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	 * pointer in REG1.  Jumps to FAIL_LABEL on early page table walk
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	 * termination.  Physical base of page tables is in PHYS_PGD which
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	 * will not be modified.
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	 *
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	 * VADDR will not be clobbered, but REG1 and REG2 will.
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	 */
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#define USER_PGTABLE_WALK_TL1(VADDR, PHYS_PGD, REG1, REG2, FAIL_LABEL)	\
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	sllx		VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
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	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
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	andn		REG2, 0x3, REG2; \
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	lduwa		[PHYS_PGD + REG2] ASI_PHYS_USE_EC, REG1; \
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	brz,pn		REG1, FAIL_LABEL; \
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	 sllx		VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
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	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
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	sllx		REG1, 11, REG1; \
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	andn		REG2, 0x3, REG2; \
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	lduwa		[REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
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	brz,pn		REG1, FAIL_LABEL; \
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	 sllx		VADDR, 64 - PMD_SHIFT, REG2; \
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	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
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	sllx		REG1, 11, REG1; \
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	andn		REG2, 0x7, REG2; \
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	add		REG1, REG2, REG1;
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/* Lookup a OBP mapping on VADDR in the prom_trans[] table at TL>0.
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 * If no entry is found, FAIL_LABEL will be branched to.  On success
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 * the resulting PTE value will be left in REG1.  VADDR is preserved
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 * by this routine.
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 */
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#define OBP_TRANS_LOOKUP(VADDR, REG1, REG2, REG3, FAIL_LABEL) \
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	sethi		%hi(prom_trans), REG1; \
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	or		REG1, %lo(prom_trans), REG1; \
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97:	ldx		[REG1 + 0x00], REG2; \
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	brz,pn		REG2, FAIL_LABEL; \
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	 nop; \
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	ldx		[REG1 + 0x08], REG3; \
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	add		REG2, REG3, REG3; \
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	cmp		REG2, VADDR; \
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	bgu,pt		%xcc, 98f; \
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	 cmp		VADDR, REG3; \
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	bgeu,pt		%xcc, 98f; \
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	 ldx		[REG1 + 0x10], REG3; \
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	sub		VADDR, REG2, REG2; \
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	ba,pt		%xcc, 99f; \
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	 add		REG3, REG2, REG1; \
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98:	ba,pt		%xcc, 97b; \
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	 add		REG1, (3 * 8), REG1; \
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99:
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	/* We use a 32K TSB for the whole kernel, this allows to
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	 * handle about 16MB of modules and vmalloc mappings without
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	 * incurring many hash conflicts.
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	 */
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#define KERNEL_TSB_SIZE_BYTES	(32 * 1024)
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#define KERNEL_TSB_NENTRIES	\
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	(KERNEL_TSB_SIZE_BYTES / 16)
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#define KERNEL_TSB4M_NENTRIES	4096
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	/* Do a kernel TSB lookup at tl>0 on VADDR+TAG, branch to OK_LABEL
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	 * on TSB hit.  REG1, REG2, REG3, and REG4 are used as temporaries
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	 * and the found TTE will be left in REG1.  REG3 and REG4 must
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	 * be an even/odd pair of registers.
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	 *
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	 * VADDR and TAG will be preserved and not clobbered by this macro.
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	 */
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#define KERN_TSB_LOOKUP_TL1(VADDR, TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
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	sethi		%hi(swapper_tsb), REG1; \
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	or		REG1, %lo(swapper_tsb), REG1; \
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	srlx		VADDR, PAGE_SHIFT, REG2; \
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	and		REG2, (KERNEL_TSB_NENTRIES - 1), REG2; \
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	sllx		REG2, 4, REG2; \
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	add		REG1, REG2, REG2; \
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	KTSB_LOAD_QUAD(REG2, REG3); \
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	cmp		REG3, TAG; \
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	be,a,pt		%xcc, OK_LABEL; \
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	 mov		REG4, REG1;
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#ifndef CONFIG_DEBUG_PAGEALLOC
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	/* This version uses a trick, the TAG is already (VADDR >> 22) so
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	 * we can make use of that for the index computation.
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	 */
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#define KERN_TSB4M_LOOKUP_TL1(TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
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	sethi		%hi(swapper_4m_tsb), REG1; \
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	or		REG1, %lo(swapper_4m_tsb), REG1; \
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	and		TAG, (KERNEL_TSB4M_NENTRIES - 1), REG2; \
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	sllx		REG2, 4, REG2; \
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	add		REG1, REG2, REG2; \
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	KTSB_LOAD_QUAD(REG2, REG3); \
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	cmp		REG3, TAG; \
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	be,a,pt		%xcc, OK_LABEL; \
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	 mov		REG4, REG1;
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#endif
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#endif /* !(_SPARC64_TSB_H) */
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