[PATCH 09/15] arc: Add memory management unit (MMU) support

cupertinomiranda
2020-11-11T16:18:30Z

From: Cupertino Miranda <cmiranda@synopsys.com>

Add Synopsys ARC MMU version 4 support. The implementation is
restricted to 8K page size support.

Signed-off-by: Cupertino Miranda <cmiranda@synopsys.com>
---
target/arc/mmu.c | 777 +++++++++++++++++++++++++++++++++++++++++++++++
target/arc/mmu.h | 166 ++++++++++
2 files changed, 943 insertions(+)
create mode 100644 target/arc/mmu.c
create mode 100644 target/arc/mmu.h

diff --git a/target/arc/mmu.c b/target/arc/mmu.c
new file mode 100644
index 0000000000..3d50489b15
--- /dev/null
+++ b/target/arc/mmu.c
@@ -0,0 +1,777 @@
+/*
+ * QEMU ARC CPU
+ *
+ * Copyright (c) 2020 Synppsys Inc.
+ * Contributed by Cupertino Miranda <cmiranda@synopsys.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * http://www.gnu.org/licenses/lgpl-2.1.html
+ */
+
+#include "qemu/osdep.h"
+#include "mmu.h"
+#include "target/arc/regs.h"
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/exec-all.h"
+
+
+uint32_t
+arc_mmu_aux_get(const struct arc_aux_reg_detail *aux_reg_detail, void *data)
+{
+ CPUARCState *env = (CPUARCState *) data;
+ struct arc_mmu *mmu = &env->mmu;
+ uint32_t reg = 0;
+
+ switch (aux_reg_detail->id) {
+ case AUX_ID_mmu_build:
+ /*
+ * For now hardcode the TLB geometry and canonical page sizes
+ * MMUv4: 2M Super Page, 8k Page, 4 way set associative,
+ * 1K entries (256x4), 4 uITLB, 8 uDTLB
+ */
+ reg = 0x04e21a4a;
+ break;
+ case AUX_ID_tlbindex:
+ reg = mmu->tlbindex;
+ break;
+ case AUX_ID_tlbpd0:
+ reg = mmu->tlbpd0;
+ break;
+ case AUX_ID_tlbpd1:
+ reg = mmu->tlbpd1;
+ break;
+ case AUX_ID_tlbpd1_hi:
+ reg = mmu->tlbpd1_hi;
+ break;
+ case AUX_ID_scratch_data0:
+ reg = mmu->scratch_data0;
+ break;
+ case AUX_ID_tlbcommand:
+ reg = mmu->tlbcmd;
+ break;
+ case AUX_ID_pid:
+ reg = (mmu->enabled << 31) | mmu->pid_asid;
+ break;
+ case AUX_ID_sasid0:
+ reg = mmu->sasid0;
+ break;
+ case AUX_ID_sasid1:
+ reg = mmu->sasid1;
+ break;
+ default:
+ break;
+ }
+
+ return reg;
+}
+
+void
+arc_mmu_aux_set(const struct arc_aux_reg_detail *aux_reg_detail,
+ uint32_t val, void *data)
+{
+ CPUARCState *env = (CPUARCState *) data;
+ CPUState *cs = env_cpu(env);
+ struct arc_mmu *mmu = &env->mmu;
+
+ switch (aux_reg_detail->id) {
+ /* AUX_ID_tlbcommand is more involved and handled seperately */
+ case AUX_ID_tlbindex:
+ mmu->tlbindex = val;
+ break;
+ case AUX_ID_tlbpd0:
+ mmu->tlbpd0 = val;
+ break;
+ case AUX_ID_tlbpd1:
+ mmu->tlbpd1 = val;
+ break;
+ case AUX_ID_tlbpd1_hi:
+ mmu->tlbpd1_hi = val;
+ break;
+ case AUX_ID_scratch_data0:
+ mmu->scratch_data0 = val;
+ break;
+ case AUX_ID_pid:
+ qemu_log_mask(CPU_LOG_MMU,
+ "[MMU] Writing PID_ASID with value 0x%08x at 0x%08x\n",
+ val, env->pc);
+ mmu->enabled = (val >> 31);
+ mmu->pid_asid = val & 0xff;
+ tlb_flush(cs);
+ break;
+ case AUX_ID_sasid0:
+ mmu->sasid0 = val;
+ break;
+ case AUX_ID_sasid1:
+ mmu->sasid1 = val;
+ break;
+ default:
+ break;
+ }
+}
+
+/* vaddr can't have top bit */
+#define VPN(addr) ((addr) & (PAGE_MASK & (~0x80000000)))
+#define PFN(addr) ((addr) & PAGE_MASK)
+
+static void
+arc_mmu_debug_tlb_for_set(CPUARCState *env, int set)
+{
+ int j;
+ bool set_printed = false;
+
+ for (j = 0; j < N_WAYS; j++) {
+ struct arc_tlb_e *tlb = &env->mmu.nTLB[set][j];
+
+ if ((tlb->pd0 & PD0_V) != 0) {
+ if (set_printed == false) {
+ printf("set %d\n", set);
+ set_printed = true;
+ }
+ if (set_printed == true) {
+ printf(" way %d\n", j);
+ }
+ printf(" tlppd0: %08x: vaddr=\t%08x %s %s%s asid=%02x\n",
+ (unsigned int) tlb->pd0, (unsigned int) VPN(tlb->pd0),
+ (char *) ((tlb->pd0 & PD0_SZ) != 0 ? "sz1" : "sz0"),
+ (char *) ((tlb->pd0 & PD0_V) != 0 ? "V" : ""),
+ (char *) ((tlb->pd0 & PD0_G) != 0 ? "g" : ""),
+ tlb->pd0 & PD0_ASID);
+
+ printf(" tlppd1: %08x: paddr=\t%08x k:%s%s%s u:%s%s%s f:%s\n",
+ (unsigned int) tlb->pd1, (unsigned int) PFN(tlb->pd1),
+ (char *) ((tlb->pd1 & PD1_RK) != 0 ? "R" : "r"),
+ (char *) ((tlb->pd1 & PD1_WK) != 0 ? "W" : "w"),
+ (char *) ((tlb->pd1 & PD1_XK) != 0 ? "X" : "x"),
+ (char *) ((tlb->pd1 & PD1_RU) != 0 ? "R" : "r"),
+ (char *) ((tlb->pd1 & PD1_WU) != 0 ? "W" : "w"),
+ (char *) ((tlb->pd1 & PD1_XU) != 0 ? "X" : "x"),
+ (char *) ((tlb->pd1 & PD1_FC) != 0 ? "C" : "c"));
+ }
+ }
+}
+
+void
+arc_mmu_debug_tlb(CPUARCState *env)
+{
+ int i;
+
+ for (i = 0; i < N_SETS; i++) {
+ arc_mmu_debug_tlb_for_set(env, i);
+ }
+}
+
+void
+arc_mmu_debug_tlb_for_vaddr(CPUARCState *env, uint32_t vaddr)
+{
+ uint32_t set = (vaddr >> PAGE_SHIFT) & (N_SETS - 1);
+ arc_mmu_debug_tlb_for_set(env, set);
+}
+
+
+static struct arc_tlb_e *
+arc_mmu_get_tlb_at_index(uint32_t index, struct arc_mmu *mmu)
+{
+ uint32_t set = index / N_WAYS;
+ uint32_t bank = index % N_WAYS;
+ return &mmu->nTLB[set][bank];
+}
+
+static inline bool
+match_sasid(struct arc_tlb_e *tlb, struct arc_mmu *mmu)
+{
+ /* Match to a shared library. */
+ uint8_t position = tlb->pd0 & PD0_ASID_MATCH;
+ uint64_t pos = 1ULL << position;
+ uint64_t sasid = ((uint64_t) mmu->sasid1 << 32) | mmu->sasid0;
+ if ((pos & sasid) == 0) {
+ return false;
+ }
+ return true;
+}
+
+static struct arc_tlb_e *
+arc_mmu_lookup_tlb(uint32_t vaddr, uint32_t compare_mask, struct arc_mmu *mmu,
+ int *num_finds, uint32_t *index)
+{
+ struct arc_tlb_e *ret = NULL;
+ uint32_t set = (vaddr >> PAGE_SHIFT) & (N_SETS - 1);
+ struct arc_tlb_e *tlb = &mmu->nTLB[set][0];
+ int w;
+
+ if (num_finds != NULL) {
+ *num_finds = 0;
+ }
+
+ bool general_match = true;
+ for (w = 0; w < N_WAYS; w++, tlb++) {
+ uint32_t match = vaddr & compare_mask;
+ uint32_t final_compare_mask = compare_mask;
+
+ if ((tlb->pd0 & PD0_G) == 0) {
+ if ((tlb->pd0 & PD0_S) != 0) {
+ /* Match to a shared library. */
+ if (match_sasid(tlb, mmu) == false) {
+ general_match = false;
+ }
+ } else {
+ /* Match to a process. */
+ match |= mmu->pid_asid & PD0_PID_MATCH;
+ final_compare_mask |= PD0_PID_MATCH;
+ }
+ }
+
+ if (match == (tlb->pd0 & final_compare_mask) && general_match) {
+ ret = tlb;
+ if (num_finds != NULL) {
+ *num_finds += 1;
+ }
+ if (index != NULL) {
+ *index = (set * N_WAYS) + w;
+ }
+ }
+ }
+
+ if (ret == NULL) {
+ uint32_t way = mmu->way_sel[set];
+ ret = &mmu->nTLB[set][way];
+
+ /* TODO: Replace by something more significant. */
+ if (index != NULL) {
+ *index = (set * N_WAYS) + way;
+ }
+
+ mmu->way_sel[set] = (mmu->way_sel[set] + 1) & (N_WAYS - 1);
+ }
+
+ return ret;
+}
+
+/*
+ * TLB Insert/Delete triggered by writing the cmd to TLBCommand Aux
+ * - Requires PD0 and PD1 be setup apriori
+ */
+void
+arc_mmu_aux_set_tlbcmd(const struct arc_aux_reg_detail *aux_reg_detail,
+ uint32_t val, void *data)
+{
+ CPUARCState *env = (CPUARCState *) data;
+ CPUState *cs = env_cpu(env);
+ struct arc_mmu *mmu = &env->mmu;
+ uint32_t pd0 = mmu->tlbpd0;
+ uint32_t pd1 = mmu->tlbpd1;
+ int num_finds = 4;
+ uint32_t index;
+ struct arc_tlb_e *tlb;
+
+ mmu->tlbcmd = val;
+ uint32_t matching_mask = (PD0_VPN | PD0_SZ | PD0_G | PD0_S | PD0_ASID);
+
+ if ((pd0 & PD0_G) != 0) {
+ /*
+ * When Global do not check for asid match.
+ */
+ matching_mask &= ~(PD0_S | PD0_ASID);
+ }
+
+ /*
+ * NOTE: Write and WriteNI commands are the same because we do not model
+ * uTLBs in QEMU.
+ */
+ if (val == TLB_CMD_WRITE || val == TLB_CMD_WRITENI) {
+ /*
+ * TODO: Include index verification. We are always clearing the index as
+ * we assume it is always valid.
+ */
+ tlb = arc_mmu_get_tlb_at_index(mmu->tlbindex & TLBINDEX_INDEX, mmu);
+ tlb->pd0 = mmu->tlbpd0;
+ tlb->pd1 = mmu->tlbpd1;
+ }
+ if (val == TLB_CMD_READ) {
+ /*
+ * TODO: Include index verification. We are always clearing the index as
+ * we assume it is always valid.
+ */
+
+ tlb = arc_mmu_get_tlb_at_index(mmu->tlbindex & TLBINDEX_INDEX, mmu);
+ mmu->tlbpd0 = tlb->pd0;
+ mmu->tlbpd1 = tlb->pd1;
+
+ mmu->tlbindex &= ~(TLBINDEX_E | TLBINDEX_RC);
+ }
+ if (val == TLB_CMD_DELETE || val == TLB_CMD_INSERT) {
+ tlb_flush_page_by_mmuidx(cs, VPN(pd0), 3);
+
+ if ((pd0 & PD0_G) != 0) {
+ /*
+ * When Global do not check for asid match.
+ */
+ matching_mask &= ~(PD0_S | PD0_ASID);
+ }
+
+ matching_mask &= (VPN(PD0_VPN) | (~PD0_VPN)) ;
+ tlb = arc_mmu_lookup_tlb(pd0,
+ matching_mask | PD0_V,
+ &env->mmu, &num_finds, &index);
+
+ if (num_finds == 0) {
+ mmu->tlbindex = 0x80000000; /* No entry to delete */
+ } else if (num_finds == 1) {
+ mmu->tlbindex = index; /* Entry is deleted set index */
+ tlb->pd0 &= ~PD0_V;
+ num_finds--;
+ qemu_log_mask(CPU_LOG_MMU,
+ "[MMU] Delete at 0x%08x, pd0 = 0x%08x, pd1 = 0x%08x\n",
+ env->pc, tlb->pd0, tlb->pd1);
+ } else {
+ while (num_finds > 0) {
+ tlb->pd0 &= ~PD0_V;
+ qemu_log_mask(CPU_LOG_MMU,
+ "[MMU] Delete at 0x%08x, pd0 = 0x%08x, pd1 = 0x%08x\n",
+ env->pc, tlb->pd0, tlb->pd1);
+ tlb = arc_mmu_lookup_tlb(pd0,
+ (VPN(PD0_VPN) | PD0_V
+ | PD0_SZ | PD0_G | PD0_S),
+ mmu, &num_finds, NULL);
+ }
+ }
+ }
+
+ if (val == TLB_CMD_INSERT) {
+ if ((pd0 & PD0_V) == 0) {
+ mmu->tlbindex = 0x80000000;
+ } else {
+ tlb->pd0 = pd0;
+ tlb->pd1 = pd1;
+
+ /* Set index for latest inserted element. */
+ mmu->tlbindex |= index;
+
+ /* TODO: More verifications needed. */
+
+ qemu_log_mask(CPU_LOG_MMU,
+ "[MMU] Insert at 0x%08x, PID = %d, VPN = 0x%08x, "
+ "PFN = 0x%08x, pd0 = 0x%08x, pd1 = 0x%08x\n",
+ env->pc,
+ pd0 & 0xff,
+ VPN(pd0), PFN(pd1),
+ pd0, pd1);
+ }
+ }
+
+ /* NOTE: We do not implement IVUTLB as we do not model uTLBs. */
+ assert(val == TLB_CMD_INSERT
+ || val == TLB_CMD_DELETE
+ || val == TLB_CMD_WRITE
+ || val == TLB_CMD_READ
+ || val == TLB_CMD_WRITENI
+ || val == TLB_CMD_IVUTLB
+ );
+}
+
+/* Function to verify if we have permission to use MMU TLB entry. */
+static bool
+arc_mmu_have_permission(CPUARCState *env,
+ struct arc_tlb_e *tlb,
+ enum mmu_access_type type)
+{
+ bool ret = false;
+ bool in_kernel_mode = !env->stat.Uf; /* Read status for user mode. */
+ switch (type) {
+ case MMU_MEM_READ:
+ ret = in_kernel_mode ? tlb->pd1 & PD1_RK : tlb->pd1 & PD1_RU;
+ break;
+ case MMU_MEM_WRITE:
+ ret = in_kernel_mode ? tlb->pd1 & PD1_WK : tlb->pd1 & PD1_WU;
+ break;
+ case MMU_MEM_FETCH:
+ ret = in_kernel_mode ? tlb->pd1 & PD1_XK : tlb->pd1 & PD1_XU;
+ break;
+ case MMU_MEM_ATTOMIC:
+ ret = in_kernel_mode ? tlb->pd1 & PD1_RK : tlb->pd1 & PD1_RU;
+ ret = ret & (in_kernel_mode ? tlb->pd1 & PD1_WK : tlb->pd1 & PD1_WU);
+ break;
+ case MMU_MEM_IRRELEVANT_TYPE:
+ ret = true;
+ break;
+ }
+
+ return ret;
+}
+
+#define SET_MMU_EXCEPTION(ENV, N, C, P) { \
+ ENV->mmu.exception.number = N; \
+ ENV->mmu.exception.causecode = C; \
+ ENV->mmu.exception.parameter = P; \
+}
+
+/* Translation function to get physical address from virtual address. */
+uint32_t
+arc_mmu_translate(struct CPUARCState *env,
+ uint32_t vaddr, enum mmu_access_type rwe,
+ uint32_t *index)
+{
+ struct arc_mmu *mmu = &(env->mmu);
+ struct arc_tlb_e *tlb = NULL;
+ int num_matching_tlb = 0;
+
+ SET_MMU_EXCEPTION(env, EXCP_NO_EXCEPTION, 0, 0);
+
+ if (rwe != MMU_MEM_IRRELEVANT_TYPE
+ && env->stat.Uf != 0 && vaddr >= 0x80000000) {
+ goto protv_exception;
+ }
+
+ /*
+ * Check that we are not addressing an address above 0x80000000.
+ * Return the same address in that case.
+ */
+ if ((vaddr >= 0x80000000) || mmu->enabled == false) {
+ return vaddr;
+ }
+
+ if (rwe != MMU_MEM_IRRELEVANT_TYPE) {
+ qemu_log_mask(CPU_LOG_MMU,
+ "[MMU] Translate at 0x%08x, vaddr 0x%08x, pid %d, rwe = %s\n",
+ env->pc, vaddr, mmu->pid_asid, RWE_STRING(rwe));
+ }
+
+ uint32_t match_pd0 = (VPN(vaddr) | PD0_V);
+ tlb = arc_mmu_lookup_tlb(match_pd0, (VPN(PD0_VPN) | PD0_V), mmu,
+ &num_matching_tlb, index);
+
+ /*
+ * Check for multiple matches in nTLB, and return machine check
+ * exception.
+ */
+ if (num_matching_tlb > 1) {
+ qemu_log_mask(CPU_LOG_MMU,
+ "[MMU] Machine Check exception. num_matching_tlb = %d\n",
+ num_matching_tlb);
+ SET_MMU_EXCEPTION(env, EXCP_MACHINE_CHECK, 0x01, 0x00);
+ return 0;
+ }
+
+
+ bool match = true;
+
+ if (num_matching_tlb == 0) {
+ match = false;
+ }
+
+ /* Check if entry if related to this address */
+ if (VPN(vaddr) != VPN(tlb->pd0) || (tlb->pd0 & PD0_V) == 0) {
+ /* Call the interrupt. */
+ match = false;
+ }
+
+ if (match == true) {
+ if ((tlb->pd0 & PD0_G) == 0) {
+ if ((tlb->pd0 & PD0_S) != 0) {
+ /* Match to a shared library. */
+ if (match_sasid(tlb, mmu) == false) {
+ match = false;
+ }
+ } else if ((tlb->pd0 & PD0_PID_MATCH) !=
+ (mmu->pid_asid & PD0_PID_MATCH)) {
+ /* Match to a process. */
+ match = false;
+ }
+ }
+ }
+
+ if (match == true && !arc_mmu_have_permission(env, tlb, rwe)) {
+ protv_exception:
+ qemu_log_mask(CPU_LOG_MMU,
+ "[MMU] ProtV exception at 0x%08x for 0x%08x. rwe = %s, "
+ "tlb->pd0 = %08x, tlb->pd1 = %08x\n",
+ env->pc,
+ vaddr,
+ RWE_STRING(rwe),
+ tlb->pd0, tlb->pd1);
+
+ SET_MMU_EXCEPTION(env, EXCP_PROTV, CAUSE_CODE(rwe), 0x08);
+ return 0;
+ }
+
+ if (match == true) {
+ if (rwe != MMU_MEM_IRRELEVANT_TYPE) {
+ qemu_log_mask(CPU_LOG_MMU,
+ "[MMU] Translated to 0x%08x, pd0=0x%08x, pd1=0x%08x\n",
+ (tlb->pd1 & PAGE_MASK) | (vaddr & (~PAGE_MASK)),
+ tlb->pd0, tlb->pd1);
+ }
+ return (tlb->pd1 & PAGE_MASK) | (vaddr & (~PAGE_MASK));
+ } else {
+ if (rwe != MMU_MEM_IRRELEVANT_TYPE) {
+ /* To remove eventually, just fail safe to check kernel. */
+ if (mmu->sasid0 != 0 || mmu->sasid1 != 0) {
+ assert(0);
+ } else {
+ mmu->tlbpd0 = (vaddr & (VPN(PD0_VPN)))
+ | PD0_V | (mmu->pid_asid & PD0_ASID);
+ }
+ if (rwe == MMU_MEM_FETCH) {
+ qemu_log_mask(CPU_LOG_MMU,
+ "[MMU] TLB_MissI exception at 0x%08x. rwe = %s, "
+ "vaddr = %08x, tlb->pd0 = %08x, tlb->pd1 = %08x\n",
+ env->pc,
+ RWE_STRING(rwe),
+ vaddr, tlb->pd0, tlb->pd1);
+ SET_MMU_EXCEPTION(env, EXCP_TLB_MISS_I, 0x00, 0x00);
+ } else {
+ qemu_log_mask(CPU_LOG_MMU,
+ "[MMU] TLB_MissD exception at 0x%08x. rwe = %s, "
+ "vaddr = %08x, tlb->pd0 = %08x, tlb->pd1 = %08x\n",
+ env->pc,
+ RWE_STRING(rwe),
+ vaddr, tlb->pd0, tlb->pd1);
+ SET_MMU_EXCEPTION(env, EXCP_TLB_MISS_D, CAUSE_CODE(rwe),
+ 0x00);
+ }
+ } else if (rwe != MMU_MEM_IRRELEVANT_TYPE) {
+ qemu_log_mask(CPU_LOG_MMU,
+ "[MMU] Failed to translate to 0x%08x\n",
+ vaddr);
+ }
+ return 0;
+ }
+}
+
+uint32_t arc_mmu_page_address_for(uint32_t vaddr)
+{
+ uint32_t ret = VPN(vaddr);
+ if (vaddr >= 0x80000000) {
+ ret |= 0x80000000;
+ }
+ return ret;
+}
+
+void arc_mmu_init(struct arc_mmu *mmu)
+{
+ mmu->enabled = 0;
+ mmu->pid_asid = 0;
+ mmu->sasid0 = 0;
+ mmu->sasid1 = 0;
+
+ mmu->tlbpd0 = 0;
+ mmu->tlbpd1 = 0;
+ mmu->tlbpd1_hi = 0;
+ mmu->tlbindex = 0;
+ mmu->tlbcmd = 0;
+ mmu->scratch_data0 = 0;
+
+ memset(mmu->nTLB, 0, sizeof(mmu->nTLB));
+}
+
+static int
+arc_mmu_get_prot_for_index(uint32_t index, CPUARCState *env)
+{
+ struct arc_tlb_e *tlb;
+ int ret = 0;
+ bool in_kernel_mode = !env->stat.Uf; /* Read status for user mode. */
+
+ tlb = arc_mmu_get_tlb_at_index(
+ index,
+ &env->mmu);
+
+ if ((in_kernel_mode && (tlb->pd1 & PD1_RK) != 0)
+ || (!in_kernel_mode && (tlb->pd1 & PD1_RU) != 0)) {
+ ret |= PAGE_READ;
+ }
+
+ if ((in_kernel_mode && (tlb->pd1 & PD1_WK) != 0)
+ || (!in_kernel_mode && (tlb->pd1 & PD1_WU) != 0)) {
+ ret |= PAGE_WRITE;
+ }
+
+ if ((in_kernel_mode && (tlb->pd1 & PD1_XK) != 0)
+ || (!in_kernel_mode && (tlb->pd1 & PD1_XU) != 0)) {
+ ret |= PAGE_EXEC;
+ }
+
+ return ret;
+}
+
+static void QEMU_NORETURN raise_mem_exception(
+ CPUState *cs, target_ulong addr, uintptr_t host_pc,
+ int32_t excp_idx, uint8_t excp_cause_code, uint8_t excp_param)
+{
+ CPUARCState *env = &(ARC_CPU(cs)->env);
+ if (excp_idx != EXCP_TLB_MISS_I) {
+ cpu_restore_state(cs, host_pc, true);
+ }
+
+ env->efa = addr;
+ env->eret = env->pc;
+ env->erbta = env->bta;
+
+ cs->exception_index = excp_idx;
+ env->causecode = excp_cause_code;
+ env->param = excp_param;
+ cpu_loop_exit(cs);
+}
+
+/* MMU range */
+static const uint32_t MMU_VA_START = 0x00000000; /* inclusive */
+static const uint32_t MMU_VA_END = 0x80000000; /* exclusive */
+
+typedef enum {
+ DIRECT_ACTION,
+ MPU_ACTION,
+ MMU_ACTION,
+ EXCEPTION_ACTION
+} ACTION;
+
+/*
+ * Applying the following logic
+ * ,-----.-----.-----------.---------.---------------.
+ * | MMU | MPU | MMU range | mmu_idx | action |
+ * |-----+-----+-----------+---------+---------------|
+ * | dis | dis | x | x | phys = virt |
+ * |-----+-----+-----------+---------+---------------|
+ * | dis | ena | x | x | mpu_translate |
+ * |-----+-----+-----------+---------+---------------|
+ * | ena | dis | true | x | mmu_translate |
+ * |-----+-----+-----------+---------+---------------|
+ * | ena | dis | false | 0 | phys = virt |
+ * |-----+-----+-----------+---------+---------------|
+ * | ena | dis | false | 1 | exception |
+ * |-----+-----+-----------+---------+---------------|
+ * | ena | ena | false | x | mpu_translate |
+ * |-----+-----+-----------+---------+---------------|
+ * | ena | ena | true | x | mmu_translate |
+ * `-----^-----^-----------^---------^---------------'
+ */
+static int decide_action(const CPUARCState *env,
+ target_ulong addr,
+ int mmu_idx)
+{
+ static ACTION table[2][2][2][2] = { };
+ static bool is_initialized = false;
+ const bool is_user = (mmu_idx == 1);
+ const bool is_mmu_range = ((addr >= MMU_VA_START) && (addr < MMU_VA_END));
+
+ if (!is_initialized) {
+ /* Both MMU and MPU disabled */
+#define T true
+#define F false
+
+ table[F][F][F][F] = DIRECT_ACTION;
+ table[F][F][F][T] = DIRECT_ACTION;
+ table[F][F][T][F] = DIRECT_ACTION;
+ table[F][F][T][T] = DIRECT_ACTION;
+
+ /* Only MPU */
+ table[F][T][F][F] = MPU_ACTION;
+ table[F][T][F][T] = MPU_ACTION;
+ table[F][T][T][F] = MPU_ACTION;
+ table[F][T][T][T] = MPU_ACTION;
+
+ /* Only MMU; non-mmu range; kernel access */
+ table[T][F][F][F] = DIRECT_ACTION;
+ /* Only MMU; non-mmu range; user access */
+ table[T][F][F][T] = EXCEPTION_ACTION;
+
+ /* Only MMU; mmu range; both modes access */
+ table[T][F][T][F] = MMU_ACTION;
+ table[T][F][T][T] = MMU_ACTION;
+
+ /* Both MMU and MPU enabled; non-mmu range */
+ table[T][T][F][F] = MPU_ACTION;
+ table[T][T][F][T] = MPU_ACTION;
+
+ /* Both MMU and MPU enabled; mmu range */
+ table[T][T][T][F] = MMU_ACTION;
+ table[T][T][T][T] = MMU_ACTION;
+
+#undef T
+#undef F
+
+ is_initialized = true;
+ }
+
+ return table[env->mmu.enabled][env->mpu.enabled][is_mmu_range][is_user];
+}
+
+
+#ifndef CONFIG_USER_ONLY
+/* Softmmu support function for MMU. */
+bool arc_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
+ MMUAccessType access_type, int mmu_idx,
+ bool probe, uintptr_t retaddr)
+{
+ /* TODO: this rwe should go away when the TODO below is done */
+ enum mmu_access_type rwe = (char) access_type;
+ CPUARCState *env = &((ARC_CPU(cs))->env);
+ int action = decide_action(env, address, mmu_idx);
+
+ switch (action) {
+ case DIRECT_ACTION:
+ tlb_set_page(cs, address & PAGE_MASK, address & PAGE_MASK,
+ PAGE_READ | PAGE_WRITE | PAGE_EXEC,
+ mmu_idx, TARGET_PAGE_SIZE);
+ break;
+ case MPU_ACTION:
+ if (arc_mpu_translate(env, address, access_type, mmu_idx)) {
+ if (probe) {
+ return false;
+ }
+ MPUException *mpu_excp = &env->mpu.exception;
+ raise_mem_exception(cs, address, retaddr,
+ mpu_excp->number, mpu_excp->code, mpu_excp->param);
+ }
+ break;
+ case MMU_ACTION: {
+ /*
+ * TODO: these lines must go inside arc_mmu_translate and it
+ * should only signal a failure or success --> generate an
+ * exception or not
+ */
+ uint32_t index;
+ target_ulong paddr = arc_mmu_translate(env, address, rwe, &index);
+ if ((enum exception_code_list) env->mmu.exception.number !=
+ EXCP_NO_EXCEPTION) {
+ if (probe) {
+ return false;
+ }
+ const struct mmu_exception *mmu_excp = &env->mmu.exception;
+ raise_mem_exception(cs, address, retaddr,
+ mmu_excp->number, mmu_excp->causecode, mmu_excp->parameter);
+ } else {
+ int prot = arc_mmu_get_prot_for_index(index, env);
+ address = arc_mmu_page_address_for(address);
+ tlb_set_page(cs, address, paddr & PAGE_MASK, prot,
+ mmu_idx, TARGET_PAGE_SIZE);
+ }
+ break;
+ }
+ case EXCEPTION_ACTION:
+ if (probe) {
+ return false;
+ }
+ /* TODO: like TODO above, this must move inside mmu */
+ qemu_log_mask(CPU_LOG_MMU, "[MMU_TLB_FILL] ProtV "
+ "exception at 0x%08x. rwe = %s\n",
+ env->pc, RWE_STRING(rwe));
+ raise_mem_exception(cs, address, retaddr,
+ EXCP_PROTV, CAUSE_CODE(rwe), 0x08);
+ break;
+ default:
+ g_assert_not_reached();
+ }
+
+ return true;
+}
+#endif /* ifndef CONFIG_USER_ONLY */
diff --git a/target/arc/mmu.h b/target/arc/mmu.h
new file mode 100644
index 0000000000..0afc9af3eb
--- /dev/null
+++ b/target/arc/mmu.h
@@ -0,0 +1,166 @@
+/*
+ * QEMU ARC CPU
+ *
+ * Copyright (c) 2020 Synppsys Inc.
+ * Contributed by Cupertino Miranda <cmiranda@synopsys.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * http://www.gnu.org/licenses/lgpl-2.1.html
+ */
+
+#ifndef ARC_MMU_H
+#define ARC_MMU_H
+
+#include "target/arc/regs.h"
+
+/* PD0 flags */
+#define PD0_VPN 0x7ffff000
+#define PD0_ASID 0x000000ff
+#define PD0_G 0x00000100 /* Global */
+#define PD0_V 0x00000200 /* Valid */
+#define PD0_SZ 0x00000400 /* Size: Normal or Super Page */
+#define PD0_L 0x00000800 /* Lock */
+#define PD0_S 0x80000000 /* Shared Library ASID */
+#define PD0_FLG (PD0_G | PD0_V | PD0_SZ | PD0_L)
+
+#define PD0_ASID_MATCH 0x0000003f
+#define PD0_PID_MATCH 0x000000ff
+
+/* PD1 permission bits */
+#define PD1_PPN 0xfffff000 /* Cached */
+#define PD1_FC 0x00000001 /* Cached */
+#define PD1_XU 0x00000002 /* User Execute */
+#define PD1_WU 0x00000004 /* User Write */
+#define PD1_RU 0x00000008 /* User Read */
+#define PD1_XK 0x00000010 /* Kernel Execute */
+#define PD1_WK 0x00000020 /* Kernel Write */
+#define PD1_RK 0x00000040 /* Kernel Read */
+#define PD1_FLG (PD1_FC | PD1_XU | PD1_WU | PD1_RU | PD1_XK | PD1_WK | PD1_RK)
+
+#define TLBINDEX_INDEX 0x00001fff
+#define TLBINDEX_E 0x80000000
+#define TLBINDEX_RC 0x70000000
+
+#define TLB_CMD_WRITE 0x1
+#define TLB_CMD_WRITENI 0x5
+#define TLB_CMD_READ 0x2
+#define TLB_CMD_INSERT 0x7
+#define TLB_CMD_DELETE 0x8
+#define TLB_CMD_IVUTLB 0x6
+
+#define N_SETS 256
+#define N_WAYS 4
+#define TLB_ENTRIES (N_SETS * N_WAYS)
+
+#define PAGE_SHIFT TARGET_PAGE_BITS
+#define PAGE_SIZE (1 << PAGE_SHIFT)
+#define PAGE_MASK (~(PAGE_SIZE - 1))
+
+/* NOTE: Do not reorder, this is casted in tbl_fill function. */
+enum mmu_access_type {
+ MMU_MEM_READ = 0,
+ MMU_MEM_WRITE,
+ MMU_MEM_FETCH, /* Read for execution. */
+ MMU_MEM_ATTOMIC,
+ MMU_MEM_IRRELEVANT_TYPE,
+};
+
+#define RWE_STRING(RWE) \
+ (RWE == MMU_MEM_READ ? "MEM_READ" : \
+ (RWE == MMU_MEM_WRITE ? "MEM_WRITE" : \
+ (RWE == MMU_MEM_ATTOMIC ? "MEM_ATTOMIC" : \
+ (RWE == MMU_MEM_FETCH ? "MEM_FETCH" : \
+ (RWE == MMU_MEM_IRRELEVANT_TYPE ? "MEM_IRRELEVANT" \
+ : "NOT_VALID_RWE")))))
+
+
+#define CAUSE_CODE(ENUM) \
+ ((ENUM == MMU_MEM_FETCH) ? 0 : \
+ ((ENUM == MMU_MEM_READ) ? 1 : \
+ ((ENUM == MMU_MEM_WRITE) ? 2 : 3)))
+
+
+struct arc_tlb_e {
+ /*
+ * TLB entry is {PD0,PD1} tuple, kept "unpacked" to avoid bit fiddling
+ * flags includes both PD0 flags and PD1 permissions.
+ */
+ uint32_t pd0, pd1;
+};
+
+#define RAISE_MMU_EXCEPTION(ENV) { \
+ do_exception_no_delayslot(ENV, \
+ ENV->mmu.exception.number, \
+ ENV->mmu.exception.causecode, \
+ ENV->mmu.exception.parameter); \
+}
+
+struct arc_mmu {
+ uint32_t enabled;
+ struct mmu_exception {
+ int32_t number;
+ uint8_t causecode;
+ uint8_t parameter;
+ } exception;
+
+ struct arc_tlb_e nTLB[N_SETS][N_WAYS];
+
+ /* insert uses vaddr to find set; way selection could be random/rr/lru */
+ uint32_t way_sel[N_SETS];
+
+ /*
+ * Current Address Space ID (in whose context mmu lookups done)
+ * Note that it is actually present in AUX PID reg, which we don't
+ * explicitly maintain, but {re,de}construct as needed by LR/SR insns
+ * respectively.
+ */
+ uint32_t pid_asid;
+ uint32_t sasid0;
+ uint32_t sasid1;
+
+ uint32_t tlbpd0;
+ uint32_t tlbpd1;
+ uint32_t tlbpd1_hi;
+ uint32_t tlbindex;
+ uint32_t tlbcmd;
+ uint32_t scratch_data0;
+};
+
+
+struct CPUARCState;
+
+
+extern void
+arc_mmu_aux_set_tlbcmd(const struct arc_aux_reg_detail *aux_reg_detail,
+ uint32_t val, void *data);
+extern void
+arc_mmu_aux_set(const struct arc_aux_reg_detail *aux_reg_detail,
+ uint32_t val, void *data) ;
+
+extern uint32_t
+arc_mmu_aux_get(const struct arc_aux_reg_detail *aux_reg_detail, void *data);
+
+uint32_t
+arc_mmu_translate(struct CPUARCState *env,
+ uint32_t vaddr, enum mmu_access_type rwe,
+ uint32_t *index);
+
+void arc_mmu_debug_tlb(struct CPUARCState *env);
+void arc_mmu_debug_tlb_for_vaddr(struct CPUARCState *env, uint32_t vaddr);
+
+uint32_t arc_mmu_page_address_for(uint32_t vaddr);
+
+void arc_mmu_init(struct arc_mmu *mmu);
+
+#endif /* ARC_MMU_H */
--
2.20.1