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-rw-r--r--arch/arc/include/asm/tlb-mmu1.h101
1 files changed, 101 insertions, 0 deletions
diff --git a/arch/arc/include/asm/tlb-mmu1.h b/arch/arc/include/asm/tlb-mmu1.h
new file mode 100644
index 000000000..a3083b36f
--- /dev/null
+++ b/arch/arc/include/asm/tlb-mmu1.h
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ */
+
+#ifndef __ASM_TLB_MMU_V1_H__
+#define __ASM_TLB_MMU_V1_H__
+
+#include <asm/mmu.h>
+
+#if defined(__ASSEMBLY__) && (CONFIG_ARC_MMU_VER == 1)
+
+.macro TLB_WRITE_HEURISTICS
+
+#define JH_HACK1
+#undef JH_HACK2
+#undef JH_HACK3
+
+#ifdef JH_HACK3
+; Calculate set index for 2-way MMU
+; -avoiding use of GetIndex from MMU
+; and its unpleasant LFSR pseudo-random sequence
+;
+; r1 = TLBPD0 from TLB_RELOAD above
+;
+; -- jh_ex_way_set not cleared on startup
+; didn't want to change setup.c
+; hence extra instruction to clean
+;
+; -- should be in cache since in same line
+; as r0/r1 saves above
+;
+ld r0,[jh_ex_way_sel] ; victim pointer
+and r0,r0,1 ; clean
+xor.f r0,r0,1 ; flip
+st r0,[jh_ex_way_sel] ; store back
+asr r0,r1,12 ; get set # <<1, note bit 12=R=0
+or.nz r0,r0,1 ; set way bit
+and r0,r0,0xff ; clean
+sr r0,[ARC_REG_TLBINDEX]
+#endif
+
+#ifdef JH_HACK2
+; JH hack #2
+; Faster than hack #1 in non-thrash case, but hard-coded for 2-way MMU
+; Slower in thrash case (where it matters) because more code is executed
+; Inefficient due to two-register paradigm of this miss handler
+;
+/* r1 = data TLBPD0 at this point */
+lr r0,[eret] /* instruction address */
+xor r0,r0,r1 /* compare set # */
+and.f r0,r0,0x000fe000 /* 2-way MMU mask */
+bne 88f /* not in same set - no need to probe */
+
+lr r0,[eret] /* instruction address */
+and r0,r0,PAGE_MASK /* VPN of instruction address */
+; lr r1,[ARC_REG_TLBPD0] /* Data VPN+ASID - already in r1 from TLB_RELOAD*/
+and r1,r1,0xff /* Data ASID */
+or r0,r0,r1 /* Instruction address + Data ASID */
+
+lr r1,[ARC_REG_TLBPD0] /* save TLBPD0 containing data TLB*/
+sr r0,[ARC_REG_TLBPD0] /* write instruction address to TLBPD0 */
+sr TLBProbe, [ARC_REG_TLBCOMMAND] /* Look for instruction */
+lr r0,[ARC_REG_TLBINDEX] /* r0 = index where instruction is, if at all */
+sr r1,[ARC_REG_TLBPD0] /* restore TLBPD0 */
+
+xor r0,r0,1 /* flip bottom bit of data index */
+b.d 89f
+sr r0,[ARC_REG_TLBINDEX] /* and put it back */
+88:
+sr TLBGetIndex, [ARC_REG_TLBCOMMAND]
+89:
+#endif
+
+#ifdef JH_HACK1
+;
+; Always checks whether instruction will be kicked out by dtlb miss
+;
+mov_s r3, r1 ; save PD0 prepared by TLB_RELOAD in r3
+lr r0,[eret] /* instruction address */
+and r0,r0,PAGE_MASK /* VPN of instruction address */
+bmsk r1,r3,7 /* Data ASID, bits 7-0 */
+or_s r0,r0,r1 /* Instruction address + Data ASID */
+
+sr r0,[ARC_REG_TLBPD0] /* write instruction address to TLBPD0 */
+sr TLBProbe, [ARC_REG_TLBCOMMAND] /* Look for instruction */
+lr r0,[ARC_REG_TLBINDEX] /* r0 = index where instruction is, if at all */
+sr r3,[ARC_REG_TLBPD0] /* restore TLBPD0 */
+
+sr TLBGetIndex, [ARC_REG_TLBCOMMAND]
+lr r1,[ARC_REG_TLBINDEX] /* r1 = index where MMU wants to put data */
+cmp r0,r1 /* if no match on indices, go around */
+xor.eq r1,r1,1 /* flip bottom bit of data index */
+sr r1,[ARC_REG_TLBINDEX] /* and put it back */
+#endif
+
+.endm
+
+#endif
+
+#endif