include/asm-sparc64/tsb.h - linux/kernel/git/torvalds/linux - Git at Google

 #ifndef _SPARC64_TSB_H
 #define _SPARC64_TSB_H

 /* The sparc64 TSB is similar to the powerpc hashtables.  It's a
  * power-of-2 sized table of TAG/PTE pairs.  The cpu precomputes
  * pointers into this table for 8K and 64K page sizes, and also a
  * comparison TAG based upon the virtual address and context which
  * faults.
  *
  * TLB miss trap handler software does the actual lookup via something
  * of the form:
  *
  * 	ldxa		[%g0] ASI_{D,I}MMU_TSB_8KB_PTR, %g1
  * 	ldxa		[%g0] ASI_{D,I}MMU, %g6
  *	sllx		%g6, 22, %g6
  *	srlx		%g6, 22, %g6
  * 	ldda		[%g1] ASI_NUCLEUS_QUAD_LDD, %g4
  * 	cmp		%g4, %g6
  * 	bne,pn	%xcc, tsb_miss_{d,i}tlb
  * 	 mov		FAULT_CODE_{D,I}TLB, %g3
  * 	stxa		%g5, [%g0] ASI_{D,I}TLB_DATA_IN
  * 	retry
  *
  *
  * Each 16-byte slot of the TSB is the 8-byte tag and then the 8-byte
  * PTE.  The TAG is of the same layout as the TLB TAG TARGET mmu
  * register which is:
  *
  * -------------------------------------------------
  * |  -  |  CONTEXT |  -  |    VADDR bits 63:22    |
  * -------------------------------------------------
  *  63 61 60      48 47 42 41                     0
  *
  * But actually, since we use per-mm TSB's, we zero out the CONTEXT
  * field.
  *
  * Like the powerpc hashtables we need to use locking in order to
  * synchronize while we update the entries.  PTE updates need locking
  * as well.
  *
  * We need to carefully choose a lock bits for the TSB entry.  We
  * choose to use bit 47 in the tag.  Also, since we never map anything
  * at page zero in context zero, we use zero as an invalid tag entry.
  * When the lock bit is set, this forces a tag comparison failure.
  */

 #define TSB_TAG_LOCK_BIT	47
 #define TSB_TAG_LOCK_HIGH	(1 << (TSB_TAG_LOCK_BIT - 32))

 #define TSB_TAG_INVALID_BIT	46
 #define TSB_TAG_INVALID_HIGH	(1 << (TSB_TAG_INVALID_BIT - 32))

 #define TSB_MEMBAR	membar	#StoreStore

 /* Some cpus support physical address quad loads.  We want to use
  * those if possible so we don't need to hard-lock the TSB mapping
  * into the TLB.  We encode some instruction patching in order to
  * support this.
  *
  * The kernel TSB is locked into the TLB by virtue of being in the
  * kernel image, so we don't play these games for swapper_tsb access.
  */
 #ifndef __ASSEMBLY__
 struct tsb_ldquad_phys_patch_entry {
 	unsigned int	addr;
 	unsigned int	sun4u_insn;
 	unsigned int	sun4v_insn;
 };
 extern struct tsb_ldquad_phys_patch_entry __tsb_ldquad_phys_patch,
 	__tsb_ldquad_phys_patch_end;

 struct tsb_phys_patch_entry {
 	unsigned int	addr;
 	unsigned int	insn;
 };
 extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;
 #endif
 #define TSB_LOAD_QUAD(TSB, REG)	\
 661:	ldda		[TSB] ASI_NUCLEUS_QUAD_LDD, REG; \
 	.section	.tsb_ldquad_phys_patch, "ax"; \
 	.word		661b; \
 	ldda		[TSB] ASI_QUAD_LDD_PHYS, REG; \
 	ldda		[TSB] ASI_QUAD_LDD_PHYS_4V, REG; \
 	.previous

 #define TSB_LOAD_TAG_HIGH(TSB, REG) \
 661:	lduwa		[TSB] ASI_N, REG; \
 	.section	.tsb_phys_patch, "ax"; \
 	.word		661b; \
 	lduwa		[TSB] ASI_PHYS_USE_EC, REG; \
 	.previous

 #define TSB_LOAD_TAG(TSB, REG) \
 661:	ldxa		[TSB] ASI_N, REG; \
 	.section	.tsb_phys_patch, "ax"; \
 	.word		661b; \
 	ldxa		[TSB] ASI_PHYS_USE_EC, REG; \
 	.previous

 #define TSB_CAS_TAG_HIGH(TSB, REG1, REG2) \
 661:	casa		[TSB] ASI_N, REG1, REG2; \
 	.section	.tsb_phys_patch, "ax"; \
 	.word		661b; \
 	casa		[TSB] ASI_PHYS_USE_EC, REG1, REG2; \
 	.previous

 #define TSB_CAS_TAG(TSB, REG1, REG2) \
 661:	casxa		[TSB] ASI_N, REG1, REG2; \
 	.section	.tsb_phys_patch, "ax"; \
 	.word		661b; \
 	casxa		[TSB] ASI_PHYS_USE_EC, REG1, REG2; \
 	.previous

 #define TSB_STORE(ADDR, VAL) \
 661:	stxa		VAL, [ADDR] ASI_N; \
 	.section	.tsb_phys_patch, "ax"; \
 	.word		661b; \
 	stxa		VAL, [ADDR] ASI_PHYS_USE_EC; \
 	.previous

 #define TSB_LOCK_TAG(TSB, REG1, REG2)	\
 99:	TSB_LOAD_TAG_HIGH(TSB, REG1);	\
 	sethi	%hi(TSB_TAG_LOCK_HIGH), REG2;\
 	andcc	REG1, REG2, %g0;	\
 	bne,pn	%icc, 99b;		\
 	 nop;				\
 	TSB_CAS_TAG_HIGH(TSB, REG1, REG2);	\
 	cmp	REG1, REG2;		\
 	bne,pn	%icc, 99b;		\
 	 nop;				\
 	TSB_MEMBAR

 #define TSB_WRITE(TSB, TTE, TAG) \
 	add	TSB, 0x8, TSB;   \
 	TSB_STORE(TSB, TTE);     \
 	sub	TSB, 0x8, TSB;   \
 	TSB_MEMBAR;              \
 	TSB_STORE(TSB, TAG);

 #define KTSB_LOAD_QUAD(TSB, REG) \
 	ldda		[TSB] ASI_NUCLEUS_QUAD_LDD, REG;

 #define KTSB_STORE(ADDR, VAL) \
 	stxa		VAL, [ADDR] ASI_N;

 #define KTSB_LOCK_TAG(TSB, REG1, REG2)	\
 99:	lduwa	[TSB] ASI_N, REG1;	\
 	sethi	%hi(TSB_TAG_LOCK_HIGH), REG2;\
 	andcc	REG1, REG2, %g0;	\
 	bne,pn	%icc, 99b;		\
 	 nop;				\
 	casa	[TSB] ASI_N, REG1, REG2;\
 	cmp	REG1, REG2;		\
 	bne,pn	%icc, 99b;		\
 	 nop;				\
 	TSB_MEMBAR

 #define KTSB_WRITE(TSB, TTE, TAG) \
 	add	TSB, 0x8, TSB;   \
 	stxa	TTE, [TSB] ASI_N;     \
 	sub	TSB, 0x8, TSB;   \
 	TSB_MEMBAR;              \
 	stxa	TAG, [TSB] ASI_N;

 	/* Do a kernel page table walk.  Leaves physical PTE pointer in
 	 * REG1.  Jumps to FAIL_LABEL on early page table walk termination.
 	 * VADDR will not be clobbered, but REG2 will.
 	 */
 #define KERN_PGTABLE_WALK(VADDR, REG1, REG2, FAIL_LABEL)	\
 	sethi		%hi(swapper_pg_dir), REG1; \
 	or		REG1, %lo(swapper_pg_dir), REG1; \
 	sllx		VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
 	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
 	andn		REG2, 0x3, REG2; \
 	lduw		[REG1 + REG2], REG1; \
 	brz,pn		REG1, FAIL_LABEL; \
 	 sllx		VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
 	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
 	sllx		REG1, 11, REG1; \
 	andn		REG2, 0x3, REG2; \
 	lduwa		[REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
 	brz,pn		REG1, FAIL_LABEL; \
 	 sllx		VADDR, 64 - PMD_SHIFT, REG2; \
 	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
 	sllx		REG1, 11, REG1; \
 	andn		REG2, 0x7, REG2; \
 	add		REG1, REG2, REG1;

 	/* Do a user page table walk in MMU globals.  Leaves physical PTE
 	 * pointer in REG1.  Jumps to FAIL_LABEL on early page table walk
 	 * termination.  Physical base of page tables is in PHYS_PGD which
 	 * will not be modified.
 	 *
 	 * VADDR will not be clobbered, but REG1 and REG2 will.
 	 */
 #define USER_PGTABLE_WALK_TL1(VADDR, PHYS_PGD, REG1, REG2, FAIL_LABEL)	\
 	sllx		VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
 	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
 	andn		REG2, 0x3, REG2; \
 	lduwa		[PHYS_PGD + REG2] ASI_PHYS_USE_EC, REG1; \
 	brz,pn		REG1, FAIL_LABEL; \
 	 sllx		VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
 	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
 	sllx		REG1, 11, REG1; \
 	andn		REG2, 0x3, REG2; \
 	lduwa		[REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
 	brz,pn		REG1, FAIL_LABEL; \
 	 sllx		VADDR, 64 - PMD_SHIFT, REG2; \
 	srlx		REG2, 64 - PAGE_SHIFT, REG2; \
 	sllx		REG1, 11, REG1; \
 	andn		REG2, 0x7, REG2; \
 	add		REG1, REG2, REG1;

 /* Lookup a OBP mapping on VADDR in the prom_trans[] table at TL>0.
  * If no entry is found, FAIL_LABEL will be branched to.  On success
  * the resulting PTE value will be left in REG1.  VADDR is preserved
  * by this routine.
  */
 #define OBP_TRANS_LOOKUP(VADDR, REG1, REG2, REG3, FAIL_LABEL) \
 	sethi		%hi(prom_trans), REG1; \
 	or		REG1, %lo(prom_trans), REG1; \
 97:	ldx		[REG1 + 0x00], REG2; \
 	brz,pn		REG2, FAIL_LABEL; \
 	 nop; \
 	ldx		[REG1 + 0x08], REG3; \
 	add		REG2, REG3, REG3; \
 	cmp		REG2, VADDR; \
 	bgu,pt		%xcc, 98f; \
 	 cmp		VADDR, REG3; \
 	bgeu,pt		%xcc, 98f; \
 	 ldx		[REG1 + 0x10], REG3; \
 	sub		VADDR, REG2, REG2; \
 	ba,pt		%xcc, 99f; \
 	 add		REG3, REG2, REG1; \
 98:	ba,pt		%xcc, 97b; \
 	 add		REG1, (3 * 8), REG1; \
 99:

 	/* We use a 32K TSB for the whole kernel, this allows to
 	 * handle about 16MB of modules and vmalloc mappings without
 	 * incurring many hash conflicts.
 	 */
 #define KERNEL_TSB_SIZE_BYTES	(32 * 1024)
 #define KERNEL_TSB_NENTRIES	\
 	(KERNEL_TSB_SIZE_BYTES / 16)
 #define KERNEL_TSB4M_NENTRIES	4096

 	/* Do a kernel TSB lookup at tl>0 on VADDR+TAG, branch to OK_LABEL
 	 * on TSB hit.  REG1, REG2, REG3, and REG4 are used as temporaries
 	 * and the found TTE will be left in REG1.  REG3 and REG4 must
 	 * be an even/odd pair of registers.
 	 *
 	 * VADDR and TAG will be preserved and not clobbered by this macro.
 	 */
 #define KERN_TSB_LOOKUP_TL1(VADDR, TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
 	sethi		%hi(swapper_tsb), REG1; \
 	or		REG1, %lo(swapper_tsb), REG1; \
 	srlx		VADDR, PAGE_SHIFT, REG2; \
 	and		REG2, (KERNEL_TSB_NENTRIES - 1), REG2; \
 	sllx		REG2, 4, REG2; \
 	add		REG1, REG2, REG2; \
 	KTSB_LOAD_QUAD(REG2, REG3); \
 	cmp		REG3, TAG; \
 	be,a,pt		%xcc, OK_LABEL; \
 	 mov		REG4, REG1;

 	/* This version uses a trick, the TAG is already (VADDR >> 22) so
 	 * we can make use of that for the index computation.
 	 */
 #define KERN_TSB4M_LOOKUP_TL1(TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
 	sethi		%hi(swapper_4m_tsb), REG1; \
 	or		REG1, %lo(swapper_4m_tsb), REG1; \
 	and		TAG, (KERNEL_TSB_NENTRIES - 1), REG2; \
 	sllx		REG2, 4, REG2; \
 	add		REG1, REG2, REG2; \
 	KTSB_LOAD_QUAD(REG2, REG3); \
 	cmp		REG3, TAG; \
 	be,a,pt		%xcc, OK_LABEL; \
 	 mov		REG4, REG1;

 #endif /* !(_SPARC64_TSB_H) */
	#ifndef _SPARC64_TSB_H
	#define _SPARC64_TSB_H

	/* The sparc64 TSB is similar to the powerpc hashtables. It's a
	* power-of-2 sized table of TAG/PTE pairs. The cpu precomputes
	* pointers into this table for 8K and 64K page sizes, and also a
	* comparison TAG based upon the virtual address and context which
	* faults.
	*
	* TLB miss trap handler software does the actual lookup via something
	* of the form:
	*
	* ldxa [%g0] ASI_{D,I}MMU_TSB_8KB_PTR, %g1
	* ldxa [%g0] ASI_{D,I}MMU, %g6
	* sllx %g6, 22, %g6
	* srlx %g6, 22, %g6
	* ldda [%g1] ASI_NUCLEUS_QUAD_LDD, %g4
	* cmp %g4, %g6
	* bne,pn %xcc, tsb_miss_{d,i}tlb
	* mov FAULT_CODE_{D,I}TLB, %g3
	* stxa %g5, [%g0] ASI_{D,I}TLB_DATA_IN
	* retry
	*
	*
	* Each 16-byte slot of the TSB is the 8-byte tag and then the 8-byte
	* PTE. The TAG is of the same layout as the TLB TAG TARGET mmu
	* register which is:
	*
	* -------------------------------------------------
	* \| - \| CONTEXT \| - \| VADDR bits 63:22 \|
	* -------------------------------------------------
	* 63 61 60 48 47 42 41 0
	*
	* But actually, since we use per-mm TSB's, we zero out the CONTEXT
	* field.
	*
	* Like the powerpc hashtables we need to use locking in order to
	* synchronize while we update the entries. PTE updates need locking
	* as well.
	*
	* We need to carefully choose a lock bits for the TSB entry. We
	* choose to use bit 47 in the tag. Also, since we never map anything
	* at page zero in context zero, we use zero as an invalid tag entry.
	* When the lock bit is set, this forces a tag comparison failure.
	*/

	#define TSB_TAG_LOCK_BIT 47
	#define TSB_TAG_LOCK_HIGH (1 << (TSB_TAG_LOCK_BIT - 32))

	#define TSB_TAG_INVALID_BIT 46
	#define TSB_TAG_INVALID_HIGH (1 << (TSB_TAG_INVALID_BIT - 32))

	#define TSB_MEMBAR membar #StoreStore

	/* Some cpus support physical address quad loads. We want to use
	* those if possible so we don't need to hard-lock the TSB mapping
	* into the TLB. We encode some instruction patching in order to
	* support this.
	*
	* The kernel TSB is locked into the TLB by virtue of being in the
	* kernel image, so we don't play these games for swapper_tsb access.
	*/
	#ifndef __ASSEMBLY__
	struct tsb_ldquad_phys_patch_entry {
	unsigned int addr;
	unsigned int sun4u_insn;
	unsigned int sun4v_insn;
	};
	extern struct tsb_ldquad_phys_patch_entry __tsb_ldquad_phys_patch,
	__tsb_ldquad_phys_patch_end;

	struct tsb_phys_patch_entry {
	unsigned int addr;
	unsigned int insn;
	};
	extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;
	#endif
	#define TSB_LOAD_QUAD(TSB, REG) \
	661: ldda [TSB] ASI_NUCLEUS_QUAD_LDD, REG; \
	.section .tsb_ldquad_phys_patch, "ax"; \
	.word 661b; \
	ldda [TSB] ASI_QUAD_LDD_PHYS, REG; \
	ldda [TSB] ASI_QUAD_LDD_PHYS_4V, REG; \
	.previous

	#define TSB_LOAD_TAG_HIGH(TSB, REG) \
	661: lduwa [TSB] ASI_N, REG; \
	.section .tsb_phys_patch, "ax"; \
	.word 661b; \
	lduwa [TSB] ASI_PHYS_USE_EC, REG; \
	.previous

	#define TSB_LOAD_TAG(TSB, REG) \
	661: ldxa [TSB] ASI_N, REG; \
	.section .tsb_phys_patch, "ax"; \
	.word 661b; \
	ldxa [TSB] ASI_PHYS_USE_EC, REG; \
	.previous

	#define TSB_CAS_TAG_HIGH(TSB, REG1, REG2) \
	661: casa [TSB] ASI_N, REG1, REG2; \
	.section .tsb_phys_patch, "ax"; \
	.word 661b; \
	casa [TSB] ASI_PHYS_USE_EC, REG1, REG2; \
	.previous

	#define TSB_CAS_TAG(TSB, REG1, REG2) \
	661: casxa [TSB] ASI_N, REG1, REG2; \
	.section .tsb_phys_patch, "ax"; \
	.word 661b; \
	casxa [TSB] ASI_PHYS_USE_EC, REG1, REG2; \
	.previous

	#define TSB_STORE(ADDR, VAL) \
	661: stxa VAL, [ADDR] ASI_N; \
	.section .tsb_phys_patch, "ax"; \
	.word 661b; \
	stxa VAL, [ADDR] ASI_PHYS_USE_EC; \
	.previous

	#define TSB_LOCK_TAG(TSB, REG1, REG2) \
	99: TSB_LOAD_TAG_HIGH(TSB, REG1); \
	sethi %hi(TSB_TAG_LOCK_HIGH), REG2;\
	andcc REG1, REG2, %g0; \
	bne,pn %icc, 99b; \
	nop; \
	TSB_CAS_TAG_HIGH(TSB, REG1, REG2); \
	cmp REG1, REG2; \
	bne,pn %icc, 99b; \
	nop; \
	TSB_MEMBAR

	#define TSB_WRITE(TSB, TTE, TAG) \
	add TSB, 0x8, TSB; \
	TSB_STORE(TSB, TTE); \
	sub TSB, 0x8, TSB; \
	TSB_MEMBAR; \
	TSB_STORE(TSB, TAG);

	#define KTSB_LOAD_QUAD(TSB, REG) \
	ldda [TSB] ASI_NUCLEUS_QUAD_LDD, REG;

	#define KTSB_STORE(ADDR, VAL) \
	stxa VAL, [ADDR] ASI_N;

	#define KTSB_LOCK_TAG(TSB, REG1, REG2) \
	99: lduwa [TSB] ASI_N, REG1; \
	sethi %hi(TSB_TAG_LOCK_HIGH), REG2;\
	andcc REG1, REG2, %g0; \
	bne,pn %icc, 99b; \
	nop; \
	casa [TSB] ASI_N, REG1, REG2;\
	cmp REG1, REG2; \
	bne,pn %icc, 99b; \
	nop; \
	TSB_MEMBAR

	#define KTSB_WRITE(TSB, TTE, TAG) \
	add TSB, 0x8, TSB; \
	stxa TTE, [TSB] ASI_N; \
	sub TSB, 0x8, TSB; \
	TSB_MEMBAR; \
	stxa TAG, [TSB] ASI_N;

	/* Do a kernel page table walk. Leaves physical PTE pointer in
	* REG1. Jumps to FAIL_LABEL on early page table walk termination.
	* VADDR will not be clobbered, but REG2 will.
	*/
	#define KERN_PGTABLE_WALK(VADDR, REG1, REG2, FAIL_LABEL) \
	sethi %hi(swapper_pg_dir), REG1; \
	or REG1, %lo(swapper_pg_dir), REG1; \
	sllx VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
	srlx REG2, 64 - PAGE_SHIFT, REG2; \
	andn REG2, 0x3, REG2; \
	lduw [REG1 + REG2], REG1; \
	brz,pn REG1, FAIL_LABEL; \
	sllx VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
	srlx REG2, 64 - PAGE_SHIFT, REG2; \
	sllx REG1, 11, REG1; \
	andn REG2, 0x3, REG2; \
	lduwa [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
	brz,pn REG1, FAIL_LABEL; \
	sllx VADDR, 64 - PMD_SHIFT, REG2; \
	srlx REG2, 64 - PAGE_SHIFT, REG2; \
	sllx REG1, 11, REG1; \
	andn REG2, 0x7, REG2; \
	add REG1, REG2, REG1;

	/* Do a user page table walk in MMU globals. Leaves physical PTE
	* pointer in REG1. Jumps to FAIL_LABEL on early page table walk
	* termination. Physical base of page tables is in PHYS_PGD which
	* will not be modified.
	*
	* VADDR will not be clobbered, but REG1 and REG2 will.
	*/
	#define USER_PGTABLE_WALK_TL1(VADDR, PHYS_PGD, REG1, REG2, FAIL_LABEL) \
	sllx VADDR, 64 - (PGDIR_SHIFT + PGDIR_BITS), REG2; \
	srlx REG2, 64 - PAGE_SHIFT, REG2; \
	andn REG2, 0x3, REG2; \
	lduwa [PHYS_PGD + REG2] ASI_PHYS_USE_EC, REG1; \
	brz,pn REG1, FAIL_LABEL; \
	sllx VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
	srlx REG2, 64 - PAGE_SHIFT, REG2; \
	sllx REG1, 11, REG1; \
	andn REG2, 0x3, REG2; \
	lduwa [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
	brz,pn REG1, FAIL_LABEL; \
	sllx VADDR, 64 - PMD_SHIFT, REG2; \
	srlx REG2, 64 - PAGE_SHIFT, REG2; \
	sllx REG1, 11, REG1; \
	andn REG2, 0x7, REG2; \
	add REG1, REG2, REG1;

	/* Lookup a OBP mapping on VADDR in the prom_trans[] table at TL>0.
	* If no entry is found, FAIL_LABEL will be branched to. On success
	* the resulting PTE value will be left in REG1. VADDR is preserved
	* by this routine.
	*/
	#define OBP_TRANS_LOOKUP(VADDR, REG1, REG2, REG3, FAIL_LABEL) \
	sethi %hi(prom_trans), REG1; \
	or REG1, %lo(prom_trans), REG1; \
	97: ldx [REG1 + 0x00], REG2; \
	brz,pn REG2, FAIL_LABEL; \
	nop; \
	ldx [REG1 + 0x08], REG3; \
	add REG2, REG3, REG3; \
	cmp REG2, VADDR; \
	bgu,pt %xcc, 98f; \
	cmp VADDR, REG3; \
	bgeu,pt %xcc, 98f; \
	ldx [REG1 + 0x10], REG3; \
	sub VADDR, REG2, REG2; \
	ba,pt %xcc, 99f; \
	add REG3, REG2, REG1; \
	98: ba,pt %xcc, 97b; \
	add REG1, (3 * 8), REG1; \
	99:

	/* We use a 32K TSB for the whole kernel, this allows to
	* handle about 16MB of modules and vmalloc mappings without
	* incurring many hash conflicts.
	*/
	#define KERNEL_TSB_SIZE_BYTES (32 * 1024)
	#define KERNEL_TSB_NENTRIES \
	(KERNEL_TSB_SIZE_BYTES / 16)
	#define KERNEL_TSB4M_NENTRIES 4096

	/* Do a kernel TSB lookup at tl>0 on VADDR+TAG, branch to OK_LABEL
	* on TSB hit. REG1, REG2, REG3, and REG4 are used as temporaries
	* and the found TTE will be left in REG1. REG3 and REG4 must
	* be an even/odd pair of registers.
	*
	* VADDR and TAG will be preserved and not clobbered by this macro.
	*/
	#define KERN_TSB_LOOKUP_TL1(VADDR, TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
	sethi %hi(swapper_tsb), REG1; \
	or REG1, %lo(swapper_tsb), REG1; \
	srlx VADDR, PAGE_SHIFT, REG2; \
	and REG2, (KERNEL_TSB_NENTRIES - 1), REG2; \
	sllx REG2, 4, REG2; \
	add REG1, REG2, REG2; \
	KTSB_LOAD_QUAD(REG2, REG3); \
	cmp REG3, TAG; \
	be,a,pt %xcc, OK_LABEL; \
	mov REG4, REG1;

	/* This version uses a trick, the TAG is already (VADDR >> 22) so
	* we can make use of that for the index computation.
	*/
	#define KERN_TSB4M_LOOKUP_TL1(TAG, REG1, REG2, REG3, REG4, OK_LABEL) \
	sethi %hi(swapper_4m_tsb), REG1; \
	or REG1, %lo(swapper_4m_tsb), REG1; \
	and TAG, (KERNEL_TSB_NENTRIES - 1), REG2; \
	sllx REG2, 4, REG2; \
	add REG1, REG2, REG2; \
	KTSB_LOAD_QUAD(REG2, REG3); \
	cmp REG3, TAG; \
	be,a,pt %xcc, OK_LABEL; \
	mov REG4, REG1;

	#endif /* !(_SPARC64_TSB_H) */