--- /dev/null
+/*
+ * M68K helper routines
+ *
+ * Copyright (c) 2007 CodeSourcery
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+#include "cpu.h"
+#include "exec/helper-proto.h"
+#include "exec/cpu_ldst.h"
+#include "exec/semihost.h"
+
+#if defined(CONFIG_USER_ONLY)
+
+void m68k_cpu_do_interrupt(CPUState *cs)
+{
+ cs->exception_index = -1;
+}
+
+static inline void do_interrupt_m68k_hardirq(CPUM68KState *env)
+{
+}
+
+#else
+
+/* Try to fill the TLB and return an exception if error. If retaddr is
+ NULL, it means that the function was called in C code (i.e. not
+ from generated code or from helper.c) */
+void tlb_fill(CPUState *cs, target_ulong addr, int is_write, int mmu_idx,
+ uintptr_t retaddr)
+{
+ int ret;
+
+ ret = m68k_cpu_handle_mmu_fault(cs, addr, is_write, mmu_idx);
+ if (unlikely(ret)) {
+ if (retaddr) {
+ /* now we have a real cpu fault */
+ cpu_restore_state(cs, retaddr);
+ }
+ cpu_loop_exit(cs);
+ }
+}
+
+static void do_rte(CPUM68KState *env)
+{
+ uint32_t sp;
+ uint32_t fmt;
+
+ sp = env->aregs[7];
+ fmt = cpu_ldl_kernel(env, sp);
+ env->pc = cpu_ldl_kernel(env, sp + 4);
+ sp |= (fmt >> 28) & 3;
+ env->sr = fmt & 0xffff;
+ env->aregs[7] = sp + 8;
+ m68k_switch_sp(env);
+}
+
+static void do_interrupt_all(CPUM68KState *env, int is_hw)
+{
+ CPUState *cs = CPU(m68k_env_get_cpu(env));
+ uint32_t sp;
+ uint32_t fmt;
+ uint32_t retaddr;
+ uint32_t vector;
+
+ fmt = 0;
+ retaddr = env->pc;
+
+ if (!is_hw) {
+ switch (cs->exception_index) {
+ case EXCP_RTE:
+ /* Return from an exception. */
+ do_rte(env);
+ return;
+ case EXCP_HALT_INSN:
+ if (semihosting_enabled()
+ && (env->sr & SR_S) != 0
+ && (env->pc & 3) == 0
+ && cpu_lduw_code(env, env->pc - 4) == 0x4e71
+ && cpu_ldl_code(env, env->pc) == 0x4e7bf000) {
+ env->pc += 4;
+ do_m68k_semihosting(env, env->dregs[0]);
+ return;
+ }
+ cs->halted = 1;
+ cs->exception_index = EXCP_HLT;
+ cpu_loop_exit(cs);
+ return;
+ }
+ if (cs->exception_index >= EXCP_TRAP0
+ && cs->exception_index <= EXCP_TRAP15) {
+ /* Move the PC after the trap instruction. */
+ retaddr += 2;
+ }
+ }
+
+ vector = cs->exception_index << 2;
+
+ fmt |= 0x40000000;
+ fmt |= vector << 16;
+ fmt |= env->sr;
+
+ env->sr |= SR_S;
+ if (is_hw) {
+ env->sr = (env->sr & ~SR_I) | (env->pending_level << SR_I_SHIFT);
+ env->sr &= ~SR_M;
+ }
+ m68k_switch_sp(env);
+ sp = env->aregs[7];
+ fmt |= (sp & 3) << 28;
+
+ /* ??? This could cause MMU faults. */
+ sp &= ~3;
+ sp -= 4;
+ cpu_stl_kernel(env, sp, retaddr);
+ sp -= 4;
+ cpu_stl_kernel(env, sp, fmt);
+ env->aregs[7] = sp;
+ /* Jump to vector. */
+ env->pc = cpu_ldl_kernel(env, env->vbr + vector);
+}
+
+void m68k_cpu_do_interrupt(CPUState *cs)
+{
+ M68kCPU *cpu = M68K_CPU(cs);
+ CPUM68KState *env = &cpu->env;
+
+ do_interrupt_all(env, 0);
+}
+
+static inline void do_interrupt_m68k_hardirq(CPUM68KState *env)
+{
+ do_interrupt_all(env, 1);
+}
+#endif
+
+bool m68k_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
+{
+ M68kCPU *cpu = M68K_CPU(cs);
+ CPUM68KState *env = &cpu->env;
+
+ if (interrupt_request & CPU_INTERRUPT_HARD
+ && ((env->sr & SR_I) >> SR_I_SHIFT) < env->pending_level) {
+ /* Real hardware gets the interrupt vector via an IACK cycle
+ at this point. Current emulated hardware doesn't rely on
+ this, so we provide/save the vector when the interrupt is
+ first signalled. */
+ cs->exception_index = env->pending_vector;
+ do_interrupt_m68k_hardirq(env);
+ return true;
+ }
+ return false;
+}
+
+static void raise_exception(CPUM68KState *env, int tt)
+{
+ CPUState *cs = CPU(m68k_env_get_cpu(env));
+
+ cs->exception_index = tt;
+ cpu_loop_exit(cs);
+}
+
+void HELPER(raise_exception)(CPUM68KState *env, uint32_t tt)
+{
+ raise_exception(env, tt);
+}
+
+void HELPER(divu)(CPUM68KState *env, uint32_t word)
+{
+ uint32_t num;
+ uint32_t den;
+ uint32_t quot;
+ uint32_t rem;
+ uint32_t flags;
+
+ num = env->div1;
+ den = env->div2;
+ /* ??? This needs to make sure the throwing location is accurate. */
+ if (den == 0) {
+ raise_exception(env, EXCP_DIV0);
+ }
+ quot = num / den;
+ rem = num % den;
+ flags = 0;
+ if (word && quot > 0xffff)
+ flags |= CCF_V;
+ if (quot == 0)
+ flags |= CCF_Z;
+ else if ((int32_t)quot < 0)
+ flags |= CCF_N;
+ env->div1 = quot;
+ env->div2 = rem;
+ env->cc_dest = flags;
+}
+
+void HELPER(divs)(CPUM68KState *env, uint32_t word)
+{
+ int32_t num;
+ int32_t den;
+ int32_t quot;
+ int32_t rem;
+ int32_t flags;
+
+ num = env->div1;
+ den = env->div2;
+ if (den == 0) {
+ raise_exception(env, EXCP_DIV0);
+ }
+ quot = num / den;
+ rem = num % den;
+ flags = 0;
+ if (word && quot != (int16_t)quot)
+ flags |= CCF_V;
+ if (quot == 0)
+ flags |= CCF_Z;
+ else if (quot < 0)
+ flags |= CCF_N;
+ env->div1 = quot;
+ env->div2 = rem;
+ env->cc_dest = flags;
+}
Code Review / kvmfornfv.git / blobdiff