unicore32-softmmu: Implement softmmu specific functions

This patch implements softmmu specific functions, include tlb_fill,
switch_mode, do_interrupt and uc32_cpu_handle_mmu_fault.
So the full exception handlers and page table walking could work now.

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

1 files changed, 232 insertions, 4 deletions

diff --git a/target-unicore32/softmmu.c b/target-unicore32/softmmu.c
index 6fec77e0b0..373f94b274 100644
--- a/target-unicore32/softmmu.c
+++ b/target-unicore32/softmmu.c
@@ -14,21 +14,249 @@
 
 #include <cpu.h>
 
+#undef DEBUG_UC32
+
+#ifdef DEBUG_UC32
+#define DPRINTF(fmt, ...) printf("%s: " fmt , __func__, ## __VA_ARGS__)
+#else
+#define DPRINTF(fmt, ...) do {} while (0)
+#endif
+
+#define SUPERPAGE_SIZE             (1 << 22)
+#define UC32_PAGETABLE_READ        (1 << 8)
+#define UC32_PAGETABLE_WRITE       (1 << 7)
+#define UC32_PAGETABLE_EXEC        (1 << 6)
+#define UC32_PAGETABLE_EXIST       (1 << 2)
+#define PAGETABLE_TYPE(x)          ((x) & 3)
+
+
+/* Map CPU modes onto saved register banks.  */
+static inline int bank_number(int mode)
+{
+    switch (mode) {
+    case ASR_MODE_USER:
+    case ASR_MODE_SUSR:
+        return 0;
+    case ASR_MODE_PRIV:
+        return 1;
+    case ASR_MODE_TRAP:
+        return 2;
+    case ASR_MODE_EXTN:
+        return 3;
+    case ASR_MODE_INTR:
+        return 4;
+    }
+    cpu_abort(cpu_single_env, "Bad mode %x\n", mode);
+    return -1;
+}
+
 void switch_mode(CPUUniCore32State *env, int mode)
 {
-    cpu_abort(env, "%s not supported yet\n", __func__);
+    int old_mode;
+    int i;
+
+    old_mode = env->uncached_asr & ASR_M;
+    if (mode == old_mode) {
+        return;
+    }
+
+    i = bank_number(old_mode);
+    env->banked_r29[i] = env->regs[29];
+    env->banked_r30[i] = env->regs[30];
+    env->banked_bsr[i] = env->bsr;
+
+    i = bank_number(mode);
+    env->regs[29] = env->banked_r29[i];
+    env->regs[30] = env->banked_r30[i];
+    env->bsr = env->banked_bsr[i];
 }
 
+/* Handle a CPU exception.  */
 void do_interrupt(CPUUniCore32State *env)
 {
-    cpu_abort(env, "%s not supported yet\n", __func__);
+    uint32_t addr;
+    int new_mode;
+
+    switch (env->exception_index) {
+    case UC32_EXCP_PRIV:
+        new_mode = ASR_MODE_PRIV;
+        addr = 0x08;
+        break;
+    case UC32_EXCP_ITRAP:
+        DPRINTF("itrap happened at %x\n", env->regs[31]);
+        new_mode = ASR_MODE_TRAP;
+        addr = 0x0c;
+        break;
+    case UC32_EXCP_DTRAP:
+        DPRINTF("dtrap happened at %x\n", env->regs[31]);
+        new_mode = ASR_MODE_TRAP;
+        addr = 0x10;
+        break;
+    case UC32_EXCP_INTR:
+        new_mode = ASR_MODE_INTR;
+        addr = 0x18;
+        break;
+    default:
+        cpu_abort(env, "Unhandled exception 0x%x\n", env->exception_index);
+        return;
+    }
+    /* High vectors.  */
+    if (env->cp0.c1_sys & (1 << 13)) {
+        addr += 0xffff0000;
+    }
+
+    switch_mode(env, new_mode);
+    env->bsr = cpu_asr_read(env);
+    env->uncached_asr = (env->uncached_asr & ~ASR_M) | new_mode;
+    env->uncached_asr |= ASR_I;
+    /* The PC already points to the proper instruction.  */
+    env->regs[30] = env->regs[31];
+    env->regs[31] = addr;
+    env->interrupt_request |= CPU_INTERRUPT_EXITTB;
+}
+
+static int get_phys_addr_ucv2(CPUUniCore32State *env, uint32_t address,
+        int access_type, int is_user, uint32_t *phys_ptr, int *prot,
+        target_ulong *page_size)
+{
+    int code;
+    uint32_t table;
+    uint32_t desc;
+    uint32_t phys_addr;
+
+    /* Pagetable walk.  */
+    /* Lookup l1 descriptor.  */
+    table = env->cp0.c2_base & 0xfffff000;
+    table |= (address >> 20) & 0xffc;
+    desc = ldl_phys(table);
+    code = 0;
+    switch (PAGETABLE_TYPE(desc)) {
+    case 3:
+        /* Superpage  */
+        if (!(desc & UC32_PAGETABLE_EXIST)) {
+            code = 0x0b; /* superpage miss */
+            goto do_fault;
+        }
+        phys_addr = (desc & 0xffc00000) | (address & 0x003fffff);
+        *page_size = SUPERPAGE_SIZE;
+        break;
+    case 0:
+        /* Lookup l2 entry.  */
+        if (is_user) {
+            DPRINTF("PGD address %x, desc %x\n", table, desc);
+        }
+        if (!(desc & UC32_PAGETABLE_EXIST)) {
+            code = 0x05; /* second pagetable miss */
+            goto do_fault;
+        }
+        table = (desc & 0xfffff000) | ((address >> 10) & 0xffc);
+        desc = ldl_phys(table);
+        /* 4k page.  */
+        if (is_user) {
+            DPRINTF("PTE address %x, desc %x\n", table, desc);
+        }
+        if (!(desc & UC32_PAGETABLE_EXIST)) {
+            code = 0x08; /* page miss */
+            goto do_fault;
+        }
+        switch (PAGETABLE_TYPE(desc)) {
+        case 0:
+            phys_addr = (desc & 0xfffff000) | (address & 0xfff);
+            *page_size = TARGET_PAGE_SIZE;
+            break;
+        default:
+            cpu_abort(env, "wrong page type!");
+        }
+        break;
+    default:
+        cpu_abort(env, "wrong page type!");
+    }
+
+    *phys_ptr = phys_addr;
+    *prot = 0;
+    /* Check access permissions.  */
+    if (desc & UC32_PAGETABLE_READ) {
+        *prot |= PAGE_READ;
+    } else {
+        if (is_user && (access_type == 0)) {
+            code = 0x11; /* access unreadable area */
+            goto do_fault;
+        }
+    }
+
+    if (desc & UC32_PAGETABLE_WRITE) {
+        *prot |= PAGE_WRITE;
+    } else {
+        if (is_user && (access_type == 1)) {
+            code = 0x12; /* access unwritable area */
+            goto do_fault;
+        }
+    }
+
+    if (desc & UC32_PAGETABLE_EXEC) {
+        *prot |= PAGE_EXEC;
+    } else {
+        if (is_user && (access_type == 2)) {
+            code = 0x13; /* access unexecutable area */
+            goto do_fault;
+        }
+    }
+
+do_fault:
+    return code;
 }
 
 int uc32_cpu_handle_mmu_fault(CPUUniCore32State *env, target_ulong address,
                               int access_type, int mmu_idx)
 {
-    cpu_abort(env, "%s not supported yet\n", __func__);
-    return 1;
+    uint32_t phys_addr;
+    target_ulong page_size;
+    int prot;
+    int ret, is_user;
+
+    ret = 1;
+    is_user = mmu_idx == MMU_USER_IDX;
+
+    if ((env->cp0.c1_sys & 1) == 0) {
+        /* MMU disabled.  */
+        phys_addr = address;
+        prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
+        page_size = TARGET_PAGE_SIZE;
+        ret = 0;
+    } else {
+        if ((address & (1 << 31)) || (is_user)) {
+            ret = get_phys_addr_ucv2(env, address, access_type, is_user,
+                                    &phys_addr, &prot, &page_size);
+            if (is_user) {
+                DPRINTF("user space access: ret %x, address %x, "
+                        "access_type %x, phys_addr %x, prot %x\n",
+                        ret, address, access_type, phys_addr, prot);
+            }
+        } else {
+            /*IO memory */
+            phys_addr = address | (1 << 31);
+            prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
+            page_size = TARGET_PAGE_SIZE;
+            ret = 0;
+        }
+    }
+
+    if (ret == 0) {
+        /* Map a single page.  */
+        phys_addr &= TARGET_PAGE_MASK;
+        address &= TARGET_PAGE_MASK;
+        tlb_set_page(env, address, phys_addr, prot, mmu_idx, page_size);
+        return 0;
+    }
+
+    env->cp0.c3_faultstatus = ret;
+    env->cp0.c4_faultaddr = address;
+    if (access_type == 2) {
+        env->exception_index = UC32_EXCP_ITRAP;
+    } else {
+        env->exception_index = UC32_EXCP_DTRAP;
+    }
+    return ret;
 }
 
 target_phys_addr_t cpu_get_phys_page_debug(CPUUniCore32State *env,