Linux-2.6.33.2/arch/sparc/include/asm/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))
/* 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; \
#define TSB_WRITE(TSB, TTE, TAG) \
add TSB, 0x8, TSB; \
TSB_STORE(TSB, TTE); \
sub TSB, 0x8, TSB; \
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; \
#define KTSB_WRITE(TSB, TTE, TAG) \
add TSB, 0x8, TSB; \
stxa TTE, [TSB] ASI_N; \
sub TSB, 0x8, TSB; \
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;
#ifndef CONFIG_DEBUG_PAGEALLOC
/* 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_TSB4M_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
#endif /* !(_SPARC64_TSB_H) */