ARC: MMU Exception Handling
* MMU I-TLB / D-TLB Miss Exceptions
- Fast Path TLB Refill Handler
- slowpath TLB creation via do_page_fault() -> update_mmu_cache()
* Duplicate PD Exception Handler
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/include/asm/arcregs.h b/arch/arc/include/asm/arcregs.h
index c12eb9b..1c24485 100644
--- a/arch/arc/include/asm/arcregs.h
+++ b/arch/arc/include/asm/arcregs.h
@@ -13,6 +13,7 @@
/* Build Configuration Registers */
#define ARC_REG_VECBASE_BCR 0x68
+#define ARC_REG_MMU_BCR 0x6f
/* status32 Bits Positions */
#define STATUS_H_BIT 0 /* CPU Halted */
@@ -36,6 +37,35 @@
#define STATUS_U_MASK (1<<STATUS_U_BIT)
#define STATUS_L_MASK (1<<STATUS_L_BIT)
+/*
+ * ECR: Exception Cause Reg bits-n-pieces
+ * [23:16] = Exception Vector
+ * [15: 8] = Exception Cause Code
+ * [ 7: 0] = Exception Parameters (for certain types only)
+ */
+#define ECR_VEC_MASK 0xff0000
+#define ECR_CODE_MASK 0x00ff00
+#define ECR_PARAM_MASK 0x0000ff
+
+/* Exception Cause Vector Values */
+#define ECR_V_INSN_ERR 0x02
+#define ECR_V_MACH_CHK 0x20
+#define ECR_V_ITLB_MISS 0x21
+#define ECR_V_DTLB_MISS 0x22
+#define ECR_V_PROTV 0x23
+
+/* Protection Violation Exception Cause Code Values */
+#define ECR_C_PROTV_INST_FETCH 0x00
+#define ECR_C_PROTV_LOAD 0x01
+#define ECR_C_PROTV_STORE 0x02
+#define ECR_C_PROTV_XCHG 0x03
+#define ECR_C_PROTV_MISALIG_DATA 0x04
+
+/* DTLB Miss Exception Cause Code Values */
+#define ECR_C_BIT_DTLB_LD_MISS 8
+#define ECR_C_BIT_DTLB_ST_MISS 9
+
+
/* Auxiliary registers */
#define AUX_IDENTITY 4
#define AUX_INTR_VEC_BASE 0x25
@@ -58,6 +88,44 @@
#define TIMER_CTRL_IE (1 << 0) /* Interupt when Count reachs limit */
#define TIMER_CTRL_NH (1 << 1) /* Count only when CPU NOT halted */
+#if defined(CONFIG_ARC_MMU_V1)
+#define CONFIG_ARC_MMU_VER 1
+#elif defined(CONFIG_ARC_MMU_V2)
+#define CONFIG_ARC_MMU_VER 2
+#elif defined(CONFIG_ARC_MMU_V3)
+#define CONFIG_ARC_MMU_VER 3
+#else
+#error "Error: MMU ver"
+#endif
+
+/* MMU Management regs */
+#define ARC_REG_TLBPD0 0x405
+#define ARC_REG_TLBPD1 0x406
+#define ARC_REG_TLBINDEX 0x407
+#define ARC_REG_TLBCOMMAND 0x408
+#define ARC_REG_PID 0x409
+#define ARC_REG_SCRATCH_DATA0 0x418
+
+/* Bits in MMU PID register */
+#define MMU_ENABLE (1 << 31) /* Enable MMU for process */
+
+/* Error code if probe fails */
+#define TLB_LKUP_ERR 0x80000000
+
+/* TLB Commands */
+#define TLBWrite 0x1
+#define TLBRead 0x2
+#define TLBGetIndex 0x3
+#define TLBProbe 0x4
+
+#if (CONFIG_ARC_MMU_VER >= 2)
+#define TLBWriteNI 0x5 /* write JTLB without inv uTLBs */
+#define TLBIVUTLB 0x6 /* explicitly inv uTLBs */
+#else
+#undef TLBWriteNI /* These cmds don't exist on older MMU */
+#undef TLBIVUTLB
+#endif
+
/* Instruction cache related Auxiliary registers */
#define ARC_REG_IC_BCR 0x77 /* Build Config reg */
#define ARC_REG_IC_IVIC 0x10
@@ -205,6 +273,24 @@
* Build Configuration Registers, with encoded hardware config
*/
+struct bcr_mmu_1_2 {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ unsigned int ver:8, ways:4, sets:4, u_itlb:8, u_dtlb:8;
+#else
+ unsigned int u_dtlb:8, u_itlb:8, sets:4, ways:4, ver:8;
+#endif
+};
+
+struct bcr_mmu_3 {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ unsigned int ver:8, ways:4, sets:4, osm:1, reserv:3, pg_sz:4,
+ u_itlb:4, u_dtlb:4;
+#else
+ unsigned int u_dtlb:4, u_itlb:4, pg_sz:4, reserv:3, osm:1, sets:4,
+ ways:4, ver:8;
+#endif
+};
+
struct bcr_cache {
#ifdef CONFIG_CPU_BIG_ENDIAN
unsigned int pad:12, line_len:4, sz:4, config:4, ver:8;
@@ -218,12 +304,17 @@
* Generic structures to hold build configuration used at runtime
*/
+struct cpuinfo_arc_mmu {
+ unsigned int ver, pg_sz, sets, ways, u_dtlb, u_itlb, num_tlb;
+};
+
struct cpuinfo_arc_cache {
unsigned int has_aliasing, sz, line_len, assoc, ver;
};
struct cpuinfo_arc {
struct cpuinfo_arc_cache icache, dcache;
+ struct cpuinfo_arc_mmu mmu;
};
extern struct cpuinfo_arc cpuinfo_arc700[];
diff --git a/arch/arc/include/asm/tlb-mmu1.h b/arch/arc/include/asm/tlb-mmu1.h
new file mode 100644
index 0000000..a5ff961
--- /dev/null
+++ b/arch/arc/include/asm/tlb-mmu1.h
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_TLB_MMU_V1_H__
+#define __ASM_TLB_MMU_V1_H__
+
+#if defined(__ASSEMBLY__) && defined(CONFIG_ARC_MMU_VER == 1)
+
+#include <asm/tlb.h>
+
+.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
diff --git a/arch/arc/include/asm/tlb.h b/arch/arc/include/asm/tlb.h
new file mode 100644
index 0000000..b571e12
--- /dev/null
+++ b/arch/arc/include/asm/tlb.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _ASM_ARC_TLB_H
+#define _ASM_ARC_TLB_H
+
+#ifdef __KERNEL__
+
+#include <asm/pgtable.h>
+
+/* Masks for actual TLB "PD"s */
+#define PTE_BITS_IN_PD0 (_PAGE_GLOBAL | _PAGE_PRESENT)
+#define PTE_BITS_IN_PD1 (PAGE_MASK | _PAGE_CACHEABLE | \
+ _PAGE_EXECUTE | _PAGE_WRITE | _PAGE_READ | \
+ _PAGE_K_EXECUTE | _PAGE_K_WRITE | _PAGE_K_READ)
+
+#ifndef __ASSEMBLY__
+
+#include <linux/pagemap.h>
+#include <asm-generic/tlb.h>
+
+#ifdef CONFIG_ARC_DBG_TLB_PARANOIA
+void tlb_paranoid_check(unsigned int pid_sw, unsigned long address);
+#else
+#define tlb_paranoid_check(a, b)
+#endif
+
+void arc_mmu_init(void);
+extern char *arc_mmu_mumbojumbo(int cpu_id, char *buf, int len);
+void __init read_decode_mmu_bcr(void);
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __KERNEL__ */
+
+#endif /* _ASM_ARC_TLB_H */