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-rw-r--r--arch/sparc/include/asm/tsb.h283
1 files changed, 283 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/tsb.h b/arch/sparc/include/asm/tsb.h
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+++ b/arch/sparc/include/asm/tsb.h
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+#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;
+
+#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) */