/*
* Altera Nios II helper routines.
*
* Copyright (c) 2012 Chris Wulff <crwulff@gmail.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 "cpu.h"
#include "qemu/host-utils.h"
#include "exec/exec-all.h"
#include "exec/cpu_ldst.h"
#include "exec/log.h"
#include "exec/helper-proto.h"
#include "semihosting/semihost.h"
#if defined(CONFIG_USER_ONLY)
void nios2_cpu_do_interrupt(CPUState *cs)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
CPUNios2State *env = &cpu->env;
cs->exception_index = -1;
env->regs[R_EA] = env->regs[R_PC] + 4;
}
bool nios2_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
MMUAccessType access_type, int mmu_idx,
bool probe, uintptr_t retaddr)
{
cs->exception_index = 0xaa;
cpu_loop_exit_restore(cs, retaddr);
}
#else /* !CONFIG_USER_ONLY */
void nios2_cpu_do_interrupt(CPUState *cs)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
CPUNios2State *env = &cpu->env;
switch (cs->exception_index) {
case EXCP_IRQ:
assert(env->regs[CR_STATUS] & CR_STATUS_PIE);
qemu_log_mask(CPU_LOG_INT, "interrupt at pc=%x\n", env->regs[R_PC]);
env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
env->regs[CR_STATUS] |= CR_STATUS_IH;
env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
env->regs[R_EA] = env->regs[R_PC] + 4;
env->regs[R_PC] = cpu->exception_addr;
break;
case EXCP_TLBD:
if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
qemu_log_mask(CPU_LOG_INT, "TLB MISS (fast) at pc=%x\n",
env->regs[R_PC]);
/* Fast TLB miss */
/* Variation from the spec. Table 3-35 of the cpu reference shows
* estatus not being changed for TLB miss but this appears to
* be incorrect. */
env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
env->regs[CR_STATUS] |= CR_STATUS_EH;
env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
env->regs[CR_TLBMISC] &= ~CR_TLBMISC_DBL;
env->regs[CR_TLBMISC] |= CR_TLBMISC_WR;
env->regs[R_EA] = env->regs[R_PC] + 4;
env->regs[R_PC] = cpu->fast_tlb_miss_addr;
} else {
qemu_log_mask(CPU_LOG_INT, "TLB MISS (double) at pc=%x\n",
env->regs[R_PC]);
/* Double TLB miss */
env->regs[CR_STATUS] |= CR_STATUS_EH;
env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
env->regs[CR_TLBMISC] |= CR_TLBMISC_DBL;
env->regs[R_PC] = cpu->exception_addr;
}
break;
case EXCP_TLBR:
case EXCP_TLBW:
case EXCP_TLBX:
qemu_log_mask(CPU_LOG_INT, "TLB PERM at pc=%x\n", env->regs[R_PC]);
env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
env->regs[CR_STATUS] |= CR_STATUS_EH;
env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
env->regs[CR_TLBMISC] |= CR_TLBMISC_WR;
}
env->regs[R_EA] = env->regs[R_PC] + 4;
env->regs[R_PC] = cpu->exception_addr;
break;
case EXCP_SUPERA:
case EXCP_SUPERI:
case EXCP_SUPERD:
qemu_log_mask(CPU_LOG_INT, "SUPERVISOR exception at pc=%x\n",
env->regs[R_PC]);
if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
env->regs[R_EA] = env->regs[R_PC] + 4;
}
env->regs[CR_STATUS] |= CR_STATUS_EH;
env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
env->regs[R_PC] = cpu->exception_addr;
break;
case EXCP_ILLEGAL:
case EXCP_TRAP:
qemu_log_mask(CPU_LOG_INT, "TRAP exception at pc=%x\n",
env->regs[R_PC]);
if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
env->regs[CR_ESTATUS] = env->regs[CR_STATUS];
env->regs[R_EA] = env->regs[R_PC] + 4;
}
env->regs[CR_STATUS] |= CR_STATUS_EH;
env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
env->regs[R_PC] = cpu->exception_addr;
break;
case EXCP_BREAK:
qemu_log_mask(CPU_LOG_INT, "BREAK exception at pc=%x\n",
env->regs[R_PC]);
/* The semihosting instruction is "break 1". */
if (semihosting_enabled() &&
cpu_ldl_code(env, env->regs[R_PC]) == 0x003da07a) {
qemu_log_mask(CPU_LOG_INT, "Entering semihosting\n");
env->regs[R_PC] += 4;
do_nios2_semihosting(env);
break;
}
if ((env->regs[CR_STATUS] & CR_STATUS_EH) == 0) {
env->regs[CR_BSTATUS] = env->regs[CR_STATUS];
env->regs[R_BA] = env->regs[R_PC] + 4;
}
env->regs[CR_STATUS] |= CR_STATUS_EH;
env->regs[CR_STATUS] &= ~(CR_STATUS_PIE | CR_STATUS_U);
env->regs[CR_EXCEPTION] &= ~(0x1F << 2);
env->regs[CR_EXCEPTION] |= (cs->exception_index & 0x1F) << 2;
env->regs[R_PC] = cpu->exception_addr;
break;
default:
cpu_abort(cs, "unhandled exception type=%d\n",
cs->exception_index);
break;
}
}
hwaddr nios2_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
CPUNios2State *env = &cpu->env;
target_ulong vaddr, paddr = 0;
Nios2MMULookup lu;
unsigned int hit;
if (cpu->mmu_present && (addr < 0xC0000000)) {
hit = mmu_translate(env, &lu, addr, 0, 0);
if (hit) {
vaddr = addr & TARGET_PAGE_MASK;
paddr = lu.paddr + vaddr - lu.vaddr;
} else {
paddr = -1;
qemu_log("cpu_get_phys_page debug MISS: %#" PRIx64 "\n", addr);
}
} else {
paddr = addr & TARGET_PAGE_MASK;
}
return paddr;
}
void nios2_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
MMUAccessType access_type,
int mmu_idx, uintptr_t retaddr)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
CPUNios2State *env = &cpu->env;
env->regs[CR_BADADDR] = addr;
env->regs[CR_EXCEPTION] = EXCP_UNALIGN << 2;
helper_raise_exception(env, EXCP_UNALIGN);
}
bool nios2_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
MMUAccessType access_type, int mmu_idx,
bool probe, uintptr_t retaddr)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
CPUNios2State *env = &cpu->env;
unsigned int excp = EXCP_TLBD;
target_ulong vaddr, paddr;
Nios2MMULookup lu;
unsigned int hit;
if (!cpu->mmu_present) {
/* No MMU */
address &= TARGET_PAGE_MASK;
tlb_set_page(cs, address, address, PAGE_BITS,
mmu_idx, TARGET_PAGE_SIZE);
return true;
}
if (MMU_SUPERVISOR_IDX == mmu_idx) {
if (address >= 0xC0000000) {
/* Kernel physical page - TLB bypassed */
address &= TARGET_PAGE_MASK;
tlb_set_page(cs, address, address, PAGE_BITS,
mmu_idx, TARGET_PAGE_SIZE);
return true;
}
} else {
if (address >= 0x80000000) {
/* Illegal access from user mode */
if (probe) {
return false;
}
cs->exception_index = EXCP_SUPERA;
env->regs[CR_BADADDR] = address;
cpu_loop_exit_restore(cs, retaddr);
}
}
/* Virtual page. */
hit = mmu_translate(env, &lu, address, access_type, mmu_idx);
if (hit) {
vaddr = address & TARGET_PAGE_MASK;
paddr = lu.paddr + vaddr - lu.vaddr;
if (((access_type == MMU_DATA_LOAD) && (lu.prot & PAGE_READ)) ||
((access_type == MMU_DATA_STORE) && (lu.prot & PAGE_WRITE)) ||
((access_type == MMU_INST_FETCH) && (lu.prot & PAGE_EXEC))) {
tlb_set_page(cs, vaddr, paddr, lu.prot,
mmu_idx, TARGET_PAGE_SIZE);
return true;
}
/* Permission violation */
excp = (access_type == MMU_DATA_LOAD ? EXCP_TLBR :
access_type == MMU_DATA_STORE ? EXCP_TLBW : EXCP_TLBX);
}
if (probe) {
return false;
}
if (access_type == MMU_INST_FETCH) {
env->regs[CR_TLBMISC] &= ~CR_TLBMISC_D;
} else {
env->regs[CR_TLBMISC] |= CR_TLBMISC_D;
}
env->regs[CR_PTEADDR] &= CR_PTEADDR_PTBASE_MASK;
env->regs[CR_PTEADDR] |= (address >> 10) & CR_PTEADDR_VPN_MASK;
env->mmu.pteaddr_wr = env->regs[CR_PTEADDR];
cs->exception_index = excp;
env->regs[CR_BADADDR] = address;
cpu_loop_exit_restore(cs, retaddr);
}
#endif /* !CONFIG_USER_ONLY */
