a7b9403f0e
Now that we have 64-bits for PMDs we can stop using special encodings for the huge PMD values, and just put real PTEs in there. We allocate a _PAGE_PMD_HUGE bit to distinguish between plain PMDs and huge ones. It is the same for both 4U and 4V PTE layouts. We also use _PAGE_SPECIAL to indicate the splitting state, since a huge PMD cannot also be special. All of the PMD --> PTE translation code disappears, and most of the huge PMD bit modifications and tests just degenerate into the PTE operations. In particular USER_PGTABLE_CHECK_PMD_HUGE becomes trivial. As a side effect, normal PMDs don't shift the physical address around. This also speeds up the page table walks in the TLB miss paths since they don't have to do the shifts any more. Another non-trivial aspect is that pte_modify() has to be changed to preserve the _PAGE_PMD_HUGE bits as well as the page size field of the pte. Signed-off-by: David S. Miller <davem@davemloft.net>
303 lines
9.4 KiB
C
303 lines
9.4 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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/* 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, 0x7, REG2; \
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ldx [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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andn REG2, 0x7, REG2; \
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ldxa [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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andn REG2, 0x7, REG2; \
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add REG1, REG2, REG1;
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/* PMD has been loaded into REG1, interpret the value, seeing
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* if it is a HUGE PMD or a normal one. If it is not valid
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* then jump to FAIL_LABEL. If it is a HUGE PMD, and it
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* translates to a valid PTE, branch to PTE_LABEL.
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*
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* We have to propagate the 4MB bit of the virtual address
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* because we are fabricating 8MB pages using 4MB hw pages.
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*/
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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#define USER_PGTABLE_CHECK_PMD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, PTE_LABEL) \
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brz,pn REG1, FAIL_LABEL; \
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sethi %uhi(_PAGE_PMD_HUGE), REG2; \
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sllx REG2, 32, REG2; \
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andcc REG1, REG2, %g0; \
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be,pt %xcc, 700f; \
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sethi %hi(4 * 1024 * 1024), REG2; \
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andn REG1, REG2, REG1; \
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and VADDR, REG2, REG2; \
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brlz,pt REG1, PTE_LABEL; \
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or REG1, REG2, REG1; \
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700:
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#else
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#define USER_PGTABLE_CHECK_PMD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, PTE_LABEL) \
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brz,pn REG1, FAIL_LABEL; \
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nop;
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#endif
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/* Do a user page table walk in MMU globals. Leaves final,
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* valid, PTE value in REG1. Jumps to FAIL_LABEL on early
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* page table walk termination or if the PTE is not valid.
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*
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* Physical base of page tables is in PHYS_PGD which will not
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* 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, 0x7, REG2; \
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ldxa [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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andn REG2, 0x7, REG2; \
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ldxa [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
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USER_PGTABLE_CHECK_PMD_HUGE(VADDR, REG1, REG2, FAIL_LABEL, 800f) \
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sllx VADDR, 64 - PMD_SHIFT, REG2; \
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srlx REG2, 64 - PAGE_SHIFT, REG2; \
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andn REG2, 0x7, REG2; \
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add REG1, REG2, REG1; \
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ldxa [REG1] ASI_PHYS_USE_EC, REG1; \
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brgez,pn REG1, FAIL_LABEL; \
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nop; \
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800:
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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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#define KTSB_PHYS_SHIFT 15
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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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661: sethi %hi(swapper_tsb), REG1; \
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or REG1, %lo(swapper_tsb), REG1; \
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.section .swapper_tsb_phys_patch, "ax"; \
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.word 661b; \
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.previous; \
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661: nop; \
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.section .tsb_ldquad_phys_patch, "ax"; \
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.word 661b; \
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sllx REG1, KTSB_PHYS_SHIFT, REG1; \
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sllx REG1, KTSB_PHYS_SHIFT, REG1; \
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.previous; \
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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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TSB_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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661: sethi %hi(swapper_4m_tsb), REG1; \
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or REG1, %lo(swapper_4m_tsb), REG1; \
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.section .swapper_4m_tsb_phys_patch, "ax"; \
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.word 661b; \
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.previous; \
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661: nop; \
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.section .tsb_ldquad_phys_patch, "ax"; \
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.word 661b; \
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sllx REG1, KTSB_PHYS_SHIFT, REG1; \
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sllx REG1, KTSB_PHYS_SHIFT, REG1; \
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.previous; \
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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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TSB_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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