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qemu/target/nios2/helper.c
Chris Wulff 032c76bc6f nios2: Add architecture emulation support 
Add support for emulating Altera NiosII R1 architecture into qemu.
This patch is based on previous work by Chris Wulff from 2012 and
updated to latest mainline QEMU.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chris Wulff <crwulff@gmail.com>
Cc: Jeff Da Silva <jdasilva@altera.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Sandra Loosemore <sandra@codesourcery.com>
Cc: Yves Vandervennet <yvanderv@altera.com>
Cc: Alexander Graf <agraf@suse.de>
Message-Id: <20170118220146.489-3-marex@denx.de>
[rth: Remove tlb_flush from nios2_cpu_reset.]
Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-01-24 13:10:35 -08:00

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/*
* 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 <stdio.h>
#include <string.h>
#include <assert.h>
#include "cpu.h"
#include "qemu/osdep.h"
#include "qemu/host-utils.h"
#include "qapi/error.h"
#include "exec/exec-all.h"
#include "exec/log.h"
#include "exec/helper-proto.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;
}
int nios2_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw, int mmu_idx)
{
cs->exception_index = 0xaa;
/* Page 0x1000 is kuser helper */
if (address < 0x1000 || address >= 0x2000) {
cpu_dump_state(cs, stderr, fprintf, 0);
}
return 1;
}
#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:
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;
}
}
static int cpu_nios2_handle_virtual_page(
CPUState *cs, target_ulong address, int rw, int mmu_idx)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
CPUNios2State *env = &cpu->env;
target_ulong vaddr, paddr;
Nios2MMULookup lu;
unsigned int hit;
hit = mmu_translate(env, &lu, address, rw, mmu_idx);
if (hit) {
vaddr = address & TARGET_PAGE_MASK;
paddr = lu.paddr + vaddr - lu.vaddr;
if (((rw == 0) && (lu.prot & PAGE_READ)) ||
((rw == 1) && (lu.prot & PAGE_WRITE)) ||
((rw == 2) && (lu.prot & PAGE_EXEC))) {
tlb_set_page(cs, vaddr, paddr, lu.prot,
mmu_idx, TARGET_PAGE_SIZE);
return 0;
} else {
/* Permission violation */
cs->exception_index = (rw == 0) ? EXCP_TLBR :
((rw == 1) ? EXCP_TLBW :
EXCP_TLBX);
}
} else {
cs->exception_index = EXCP_TLBD;
}
if (rw == 2) {
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];
env->regs[CR_BADADDR] = address;
return 1;
}
int nios2_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw, int mmu_idx)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
CPUNios2State *env = &cpu->env;
if (cpu->mmu_present) {
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);
} else if (address >= 0x80000000) {
/* Kernel virtual page */
return cpu_nios2_handle_virtual_page(cs, address, rw, mmu_idx);
} else {
/* User virtual page */
return cpu_nios2_handle_virtual_page(cs, address, rw, mmu_idx);
}
} else {
if (address >= 0x80000000) {
/* Illegal access from user mode */
cs->exception_index = EXCP_SUPERA;
env->regs[CR_BADADDR] = address;
return 1;
} else {
/* User virtual page */
return cpu_nios2_handle_virtual_page(cs, address, rw, mmu_idx);
}
}
} else {
/* No MMU */
address &= TARGET_PAGE_MASK;
tlb_set_page(cs, address, address, PAGE_BITS,
mmu_idx, TARGET_PAGE_SIZE);
}
return 0;
}
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);
}
#endif /* !CONFIG_USER_ONLY */
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