1 files changed, 270 insertions, 0 deletions
diff --git a/arch/sparc/kernel/ktlb.S b/arch/sparc/kernel/ktlb.S
new file mode 100644
index 000000000..6bfaf73ce
--- /dev/null
+++ b/arch/sparc/kernel/ktlb.S
@@ -0,0 +1,270 @@
+/* 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