Software MMU support (used for memory mapped devices such as VGA)

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@347 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 241 insertions, 0 deletions

diff --git a/softmmu_template.h b/softmmu_template.h
new file mode 100644
index 0000000000..871cf5491c
--- /dev/null
+++ b/softmmu_template.h
@@ -0,0 +1,241 @@
+/*
+ *  Software MMU support
+ * 
+ *  Copyright (c) 2003 Fabrice Bellard
+ *
+ * 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 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#define DATA_SIZE (1 << SHIFT)
+
+#if DATA_SIZE == 8
+#define SUFFIX q
+#define DATA_TYPE uint64_t
+#elif DATA_SIZE == 4
+#define SUFFIX l
+#define DATA_TYPE uint32_t
+#elif DATA_SIZE == 2
+#define SUFFIX w
+#define DATA_TYPE uint16_t
+#elif DATA_SIZE == 1
+#define SUFFIX b
+#define DATA_TYPE uint8_t
+#else
+#error unsupported data size
+#endif
+
+static DATA_TYPE glue(slow_ld, SUFFIX)(unsigned long addr, void *retaddr);
+static void glue(slow_st, SUFFIX)(unsigned long addr, DATA_TYPE val,
+                                  void *retaddr);
+
+static inline DATA_TYPE glue(io_read, SUFFIX)(unsigned long physaddr, 
+                                              unsigned long tlb_addr)
+{
+    DATA_TYPE res;
+    int index;
+
+    index = (tlb_addr >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);
+#if SHIFT <= 2
+    res = io_mem_read[index][SHIFT](physaddr);
+#else
+#ifdef TARGET_WORDS_BIGENDIAN
+    res = (uint64_t)io_mem_read[index][2](physaddr) << 32;
+    res |= io_mem_read[index][2](physaddr + 4);
+#else
+    res = io_mem_read[index][2](physaddr);
+    res |= (uint64_t)io_mem_read[index][2](physaddr + 4) << 32;
+#endif
+#endif /* SHIFT > 2 */
+    return res;
+}
+
+static inline void glue(io_write, SUFFIX)(unsigned long physaddr, 
+                                          DATA_TYPE val,
+                                          unsigned long tlb_addr)
+{
+    int index;
+
+    index = (tlb_addr >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);
+#if SHIFT <= 2
+    io_mem_write[index][SHIFT](physaddr, val);
+#else
+#ifdef TARGET_WORDS_BIGENDIAN
+    io_mem_write[index][2](physaddr, val >> 32);
+    io_mem_write[index][2](physaddr + 4, val);
+#else
+    io_mem_write[index][2](physaddr, val);
+    io_mem_write[index][2](physaddr + 4, val >> 32);
+#endif
+#endif /* SHIFT > 2 */
+}
+
+/* handle all cases except unaligned access which span two pages */
+DATA_TYPE __attribute((regparm(1))) glue(glue(__ld, SUFFIX), _mmu)(unsigned long addr)
+{
+    DATA_TYPE res;
+    int is_user, index;
+    unsigned long physaddr, tlb_addr;
+    void *retaddr;
+    
+    /* test if there is match for unaligned or IO access */
+    /* XXX: could done more in memory macro in a non portable way */
+    is_user = (env->cpl == 3);
+    index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
+ redo:
+    tlb_addr = env->tlb_read[is_user][index].address;
+    if ((addr & TARGET_PAGE_MASK) == (tlb_addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {
+        physaddr = addr + env->tlb_read[is_user][index].addend;
+        if (tlb_addr & ~TARGET_PAGE_MASK) {
+            /* IO access */
+            if ((addr & (DATA_SIZE - 1)) != 0)
+                goto do_unaligned_access;
+            res = glue(io_read, SUFFIX)(physaddr, tlb_addr);
+        } else if (((addr & 0xfff) + DATA_SIZE - 1) >= TARGET_PAGE_SIZE) {
+            /* slow unaligned access (it spans two pages or IO) */
+        do_unaligned_access:
+            retaddr = __builtin_return_address(0);
+            res = glue(slow_ld, SUFFIX)(addr, retaddr);
+        } else {
+            /* unaligned access in the same page */
+            res = glue(glue(ldu, SUFFIX), _raw)((uint8_t *)physaddr);
+        }
+    } else {
+        /* the page is not in the TLB : fill it */
+        retaddr = __builtin_return_address(0);
+        tlb_fill(addr, 0, retaddr);
+        goto redo;
+    }
+    return res;
+}
+
+/* handle all unaligned cases */
+static DATA_TYPE glue(slow_ld, SUFFIX)(unsigned long addr, void *retaddr)
+{
+    DATA_TYPE res, res1, res2;
+    int is_user, index, shift;
+    unsigned long physaddr, tlb_addr, addr1, addr2;
+
+    is_user = (env->cpl == 3);
+    index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
+ redo:
+    tlb_addr = env->tlb_read[is_user][index].address;
+    if ((addr & TARGET_PAGE_MASK) == (tlb_addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {
+        physaddr = addr + env->tlb_read[is_user][index].addend;
+        if (tlb_addr & ~TARGET_PAGE_MASK) {
+            /* IO access */
+            if ((addr & (DATA_SIZE - 1)) != 0)
+                goto do_unaligned_access;
+            res = glue(io_read, SUFFIX)(physaddr, tlb_addr);
+        } else if (((addr & 0xfff) + DATA_SIZE - 1) >= TARGET_PAGE_SIZE) {
+        do_unaligned_access:
+            /* slow unaligned access (it spans two pages) */
+            addr1 = addr & ~(DATA_SIZE - 1);
+            addr2 = addr1 + DATA_SIZE;
+            res1 = glue(slow_ld, SUFFIX)(addr1, retaddr);
+            res2 = glue(slow_ld, SUFFIX)(addr2, retaddr);
+            shift = (addr & (DATA_SIZE - 1)) * 8;
+#ifdef TARGET_WORDS_BIGENDIAN
+            res = (res1 << shift) | (res2 >> ((DATA_SIZE * 8) - shift));
+#else
+            res = (res1 >> shift) | (res2 << ((DATA_SIZE * 8) - shift));
+#endif
+        } else {
+            /* unaligned/aligned access in the same page */
+            res = glue(glue(ldu, SUFFIX), _raw)((uint8_t *)physaddr);
+        }
+    } else {
+        /* the page is not in the TLB : fill it */
+        tlb_fill(addr, 0, retaddr);
+        goto redo;
+    }
+    return res;
+}
+
+
+void __attribute((regparm(2))) glue(glue(__st, SUFFIX), _mmu)(unsigned long addr, DATA_TYPE val)
+{
+    unsigned long physaddr, tlb_addr;
+    void *retaddr;
+    int is_user, index;
+    
+    is_user = (env->cpl == 3);
+    index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
+ redo:
+    tlb_addr = env->tlb_write[is_user][index].address;
+    if ((addr & TARGET_PAGE_MASK) == (tlb_addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {
+        physaddr = addr + env->tlb_read[is_user][index].addend;
+        if (tlb_addr & ~TARGET_PAGE_MASK) {
+            /* IO access */
+            if ((addr & (DATA_SIZE - 1)) != 0)
+                goto do_unaligned_access;
+            glue(io_write, SUFFIX)(physaddr, val, tlb_addr);
+        } else if (((addr & 0xfff) + DATA_SIZE - 1) >= TARGET_PAGE_SIZE) {
+        do_unaligned_access:
+            retaddr = __builtin_return_address(0);
+            glue(slow_st, SUFFIX)(addr, val, retaddr);
+        } else {
+            /* aligned/unaligned access in the same page */
+            glue(glue(st, SUFFIX), _raw)((uint8_t *)physaddr, val);
+        }
+    } else {
+        /* the page is not in the TLB : fill it */
+        retaddr = __builtin_return_address(0);
+        tlb_fill(addr, 1, retaddr);
+        goto redo;
+    }
+}
+
+/* handles all unaligned cases */
+static void glue(slow_st, SUFFIX)(unsigned long addr, DATA_TYPE val,
+                                  void *retaddr)
+{
+    unsigned long physaddr, tlb_addr;
+    int is_user, index, i;
+
+    is_user = (env->cpl == 3);
+    index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
+ redo:
+    tlb_addr = env->tlb_write[is_user][index].address;
+    if ((addr & TARGET_PAGE_MASK) == (tlb_addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {
+        physaddr = addr + env->tlb_read[is_user][index].addend;
+        if (tlb_addr & ~TARGET_PAGE_MASK) {
+            /* IO access */
+            if ((addr & (DATA_SIZE - 1)) != 0)
+                goto do_unaligned_access;
+            glue(io_write, SUFFIX)(physaddr, val, tlb_addr);
+        } else if (((addr & 0xfff) + DATA_SIZE - 1) >= TARGET_PAGE_SIZE) {
+        do_unaligned_access:
+            /* XXX: not efficient, but simple */
+            for(i = 0;i < DATA_SIZE; i++) {
+#ifdef TARGET_WORDS_BIGENDIAN
+                slow_stb(addr + i, val >> (((DATA_SIZE - 1) * 8) - (i * 8)), retaddr);
+#else
+                slow_stb(addr + i, val >> (i * 8), retaddr);
+#endif
+            }
+        } else {
+            /* aligned/unaligned access in the same page */
+            glue(glue(st, SUFFIX), _raw)((uint8_t *)physaddr, val);
+        }
+    } else {
+        /* the page is not in the TLB : fill it */
+        tlb_fill(addr, 1, retaddr);
+        goto redo;
+    }
+}
+
+#undef SHIFT
+#undef DATA_TYPE
+#undef SUFFIX
+#undef DATA_SIZE