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-rw-r--r--arch/sparc/kernel/ktlb.S270
1 files changed, 270 insertions, 0 deletions
diff --git a/arch/sparc/kernel/ktlb.S b/arch/sparc/kernel/ktlb.S
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+/* SPDX-License-Identifier: GPL-2.0 */
+/* arch/sparc64/kernel/ktlb.S: Kernel mapping TLB miss handling.
+ *
+ * Copyright (C) 1995, 1997, 2005, 2008 David S. Miller <davem@davemloft.net>
+ * Copyright (C) 1996 Eddie C. Dost (ecd@brainaid.de)
+ * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
+ * Copyright (C) 1996,98,99 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
+ */
+
+#include <linux/pgtable.h>
+#include <asm/head.h>
+#include <asm/asi.h>
+#include <asm/page.h>
+#include <asm/tsb.h>
+
+ .text
+ .align 32
+
+kvmap_itlb:
+ /* g6: TAG TARGET */
+ mov TLB_TAG_ACCESS, %g4
+ ldxa [%g4] ASI_IMMU, %g4
+
+ /* The kernel executes in context zero, therefore we do not
+ * need to clear the context ID bits out of %g4 here.
+ */
+
+ /* sun4v_itlb_miss branches here with the missing virtual
+ * address already loaded into %g4
+ */
+kvmap_itlb_4v:
+
+ /* Catch kernel NULL pointer calls. */
+ sethi %hi(PAGE_SIZE), %g5
+ cmp %g4, %g5
+ blu,pn %xcc, kvmap_itlb_longpath
+ nop
+
+ KERN_TSB_LOOKUP_TL1(%g4, %g6, %g5, %g1, %g2, %g3, kvmap_itlb_load)
+
+kvmap_itlb_tsb_miss:
+ sethi %hi(LOW_OBP_ADDRESS), %g5
+ cmp %g4, %g5
+ blu,pn %xcc, kvmap_itlb_vmalloc_addr
+ mov 0x1, %g5
+ sllx %g5, 32, %g5
+ cmp %g4, %g5
+ blu,pn %xcc, kvmap_itlb_obp
+ nop
+
+kvmap_itlb_vmalloc_addr:
+ KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_itlb_longpath)
+
+ TSB_LOCK_TAG(%g1, %g2, %g7)
+ TSB_WRITE(%g1, %g5, %g6)
+
+ /* fallthrough to TLB load */
+
+kvmap_itlb_load:
+
+661: stxa %g5, [%g0] ASI_ITLB_DATA_IN
+ retry
+ .section .sun4v_2insn_patch, "ax"
+ .word 661b
+ nop
+ nop
+ .previous
+
+ /* For sun4v the ASI_ITLB_DATA_IN store and the retry
+ * instruction get nop'd out and we get here to branch
+ * to the sun4v tlb load code. The registers are setup
+ * as follows:
+ *
+ * %g4: vaddr
+ * %g5: PTE
+ * %g6: TAG
+ *
+ * The sun4v TLB load wants the PTE in %g3 so we fix that
+ * up here.
+ */
+ ba,pt %xcc, sun4v_itlb_load
+ mov %g5, %g3
+
+kvmap_itlb_longpath:
+
+661: rdpr %pstate, %g5
+ wrpr %g5, PSTATE_AG | PSTATE_MG, %pstate
+ .section .sun4v_2insn_patch, "ax"
+ .word 661b
+ SET_GL(1)
+ nop
+ .previous
+
+ rdpr %tpc, %g5
+ ba,pt %xcc, sparc64_realfault_common
+ mov FAULT_CODE_ITLB, %g4
+
+kvmap_itlb_obp:
+ OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_itlb_longpath)
+
+ TSB_LOCK_TAG(%g1, %g2, %g7)
+
+ TSB_WRITE(%g1, %g5, %g6)
+
+ ba,pt %xcc, kvmap_itlb_load
+ nop
+
+kvmap_dtlb_obp:
+ OBP_TRANS_LOOKUP(%g4, %g5, %g2, %g3, kvmap_dtlb_longpath)
+
+ TSB_LOCK_TAG(%g1, %g2, %g7)
+
+ TSB_WRITE(%g1, %g5, %g6)
+
+ ba,pt %xcc, kvmap_dtlb_load
+ nop
+
+kvmap_linear_early:
+ sethi %hi(kern_linear_pte_xor), %g7
+ ldx [%g7 + %lo(kern_linear_pte_xor)], %g2
+ ba,pt %xcc, kvmap_dtlb_tsb4m_load
+ xor %g2, %g4, %g5
+
+ .align 32
+kvmap_dtlb_tsb4m_load:
+ TSB_LOCK_TAG(%g1, %g2, %g7)
+ TSB_WRITE(%g1, %g5, %g6)
+ ba,pt %xcc, kvmap_dtlb_load
+ nop
+
+kvmap_dtlb:
+ /* %g6: TAG TARGET */
+ mov TLB_TAG_ACCESS, %g4
+ ldxa [%g4] ASI_DMMU, %g4
+
+ /* The kernel executes in context zero, therefore we do not
+ * need to clear the context ID bits out of %g4 here.
+ */
+
+ /* sun4v_dtlb_miss branches here with the missing virtual
+ * address already loaded into %g4
+ */
+kvmap_dtlb_4v:
+ brgez,pn %g4, kvmap_dtlb_nonlinear
+ nop
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ /* Index through the base page size TSB even for linear
+ * mappings when using page allocation debugging.
+ */
+ KERN_TSB_LOOKUP_TL1(%g4, %g6, %g5, %g1, %g2, %g3, kvmap_dtlb_load)
+#else
+ /* Correct TAG_TARGET is already in %g6, check 4mb TSB. */
+ KERN_TSB4M_LOOKUP_TL1(%g6, %g5, %g1, %g2, %g3, kvmap_dtlb_load)
+#endif
+ /* Linear mapping TSB lookup failed. Fallthrough to kernel
+ * page table based lookup.
+ */
+ .globl kvmap_linear_patch
+kvmap_linear_patch:
+ ba,a,pt %xcc, kvmap_linear_early
+
+kvmap_dtlb_vmalloc_addr:
+ KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_dtlb_longpath)
+
+ TSB_LOCK_TAG(%g1, %g2, %g7)
+ TSB_WRITE(%g1, %g5, %g6)
+
+ /* fallthrough to TLB load */
+
+kvmap_dtlb_load:
+
+661: stxa %g5, [%g0] ASI_DTLB_DATA_IN ! Reload TLB
+ retry
+ .section .sun4v_2insn_patch, "ax"
+ .word 661b
+ nop
+ nop
+ .previous
+
+ /* For sun4v the ASI_DTLB_DATA_IN store and the retry
+ * instruction get nop'd out and we get here to branch
+ * to the sun4v tlb load code. The registers are setup
+ * as follows:
+ *
+ * %g4: vaddr
+ * %g5: PTE
+ * %g6: TAG
+ *
+ * The sun4v TLB load wants the PTE in %g3 so we fix that
+ * up here.
+ */
+ ba,pt %xcc, sun4v_dtlb_load
+ mov %g5, %g3
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+kvmap_vmemmap:
+ KERN_PGTABLE_WALK(%g4, %g5, %g2, kvmap_dtlb_longpath)
+ ba,a,pt %xcc, kvmap_dtlb_load
+#endif
+
+kvmap_dtlb_nonlinear:
+ /* Catch kernel NULL pointer derefs. */
+ sethi %hi(PAGE_SIZE), %g5
+ cmp %g4, %g5
+ bleu,pn %xcc, kvmap_dtlb_longpath
+ nop
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+ /* Do not use the TSB for vmemmap. */
+ sethi %hi(VMEMMAP_BASE), %g5
+ ldx [%g5 + %lo(VMEMMAP_BASE)], %g5
+ cmp %g4,%g5
+ bgeu,pn %xcc, kvmap_vmemmap
+ nop
+#endif
+
+ KERN_TSB_LOOKUP_TL1(%g4, %g6, %g5, %g1, %g2, %g3, kvmap_dtlb_load)
+
+kvmap_dtlb_tsbmiss:
+ sethi %hi(MODULES_VADDR), %g5
+ cmp %g4, %g5
+ blu,pn %xcc, kvmap_dtlb_longpath
+ sethi %hi(VMALLOC_END), %g5
+ ldx [%g5 + %lo(VMALLOC_END)], %g5
+ cmp %g4, %g5
+ bgeu,pn %xcc, kvmap_dtlb_longpath
+ nop
+
+kvmap_check_obp:
+ sethi %hi(LOW_OBP_ADDRESS), %g5
+ cmp %g4, %g5
+ blu,pn %xcc, kvmap_dtlb_vmalloc_addr
+ mov 0x1, %g5
+ sllx %g5, 32, %g5
+ cmp %g4, %g5
+ blu,pn %xcc, kvmap_dtlb_obp
+ nop
+ ba,pt %xcc, kvmap_dtlb_vmalloc_addr
+ nop
+
+kvmap_dtlb_longpath:
+
+661: rdpr %pstate, %g5
+ wrpr %g5, PSTATE_AG | PSTATE_MG, %pstate
+ .section .sun4v_2insn_patch, "ax"
+ .word 661b
+ SET_GL(1)
+ ldxa [%g0] ASI_SCRATCHPAD, %g5
+ .previous
+
+ rdpr %tl, %g3
+ cmp %g3, 1
+
+661: mov TLB_TAG_ACCESS, %g4
+ ldxa [%g4] ASI_DMMU, %g5
+ .section .sun4v_2insn_patch, "ax"
+ .word 661b
+ ldx [%g5 + HV_FAULT_D_ADDR_OFFSET], %g5
+ nop
+ .previous
+
+ /* The kernel executes in context zero, therefore we do not
+ * need to clear the context ID bits out of %g5 here.
+ */
+
+ be,pt %xcc, sparc64_realfault_common
+ mov FAULT_CODE_DTLB, %g4
+ ba,pt %xcc, winfix_trampoline
+ nop