qemu/target/cris/mmu.c
Chetan Pant bf1b52d199 cris tcg cpus: Fix Lesser GPL version number
There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.

Signed-off-by: Chetan Pant <chetan4windows@gmail.com>
Message-Id: <20201023121649.19123-1-chetan4windows@gmail.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2020-11-15 16:39:05 +01:00

357 lines
9.7 KiB
C

/*
* CRIS mmu emulation.
*
* Copyright (c) 2007 AXIS Communications AB
* Written by Edgar E. Iglesias.
*
* 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/>.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "exec/exec-all.h"
#include "mmu.h"
#ifdef DEBUG
#define D(x) x
#define D_LOG(...) qemu_log(__VA_ARGS__)
#else
#define D(x) do { } while (0)
#define D_LOG(...) do { } while (0)
#endif
void cris_mmu_init(CPUCRISState *env)
{
env->mmu_rand_lfsr = 0xcccc;
}
#define SR_POLYNOM 0x8805
static inline unsigned int compute_polynom(unsigned int sr)
{
unsigned int i;
unsigned int f;
f = 0;
for (i = 0; i < 16; i++) {
f += ((SR_POLYNOM >> i) & 1) & ((sr >> i) & 1);
}
return f;
}
static void cris_mmu_update_rand_lfsr(CPUCRISState *env)
{
unsigned int f;
/* Update lfsr at every fault. */
f = compute_polynom(env->mmu_rand_lfsr);
env->mmu_rand_lfsr >>= 1;
env->mmu_rand_lfsr |= (f << 15);
env->mmu_rand_lfsr &= 0xffff;
}
static inline int cris_mmu_enabled(uint32_t rw_gc_cfg)
{
return (rw_gc_cfg & 12) != 0;
}
static inline int cris_mmu_segmented_addr(int seg, uint32_t rw_mm_cfg)
{
return (1 << seg) & rw_mm_cfg;
}
static uint32_t cris_mmu_translate_seg(CPUCRISState *env, int seg)
{
uint32_t base;
int i;
if (seg < 8) {
base = env->sregs[SFR_RW_MM_KBASE_LO];
} else {
base = env->sregs[SFR_RW_MM_KBASE_HI];
}
i = seg & 7;
base >>= i * 4;
base &= 15;
base <<= 28;
return base;
}
/* Used by the tlb decoder. */
#define EXTRACT_FIELD(src, start, end) \
(((src) >> start) & ((1 << (end - start + 1)) - 1))
static inline void set_field(uint32_t *dst, unsigned int val,
unsigned int offset, unsigned int width)
{
uint32_t mask;
mask = (1 << width) - 1;
mask <<= offset;
val <<= offset;
val &= mask;
*dst &= ~(mask);
*dst |= val;
}
#ifdef DEBUG
static void dump_tlb(CPUCRISState *env, int mmu)
{
int set;
int idx;
uint32_t hi, lo, tlb_vpn, tlb_pfn;
for (set = 0; set < 4; set++) {
for (idx = 0; idx < 16; idx++) {
lo = env->tlbsets[mmu][set][idx].lo;
hi = env->tlbsets[mmu][set][idx].hi;
tlb_vpn = EXTRACT_FIELD(hi, 13, 31);
tlb_pfn = EXTRACT_FIELD(lo, 13, 31);
printf("TLB: [%d][%d] hi=%x lo=%x v=%x p=%x\n",
set, idx, hi, lo, tlb_vpn, tlb_pfn);
}
}
}
#endif
/* rw 0 = read, 1 = write, 2 = exec. */
static int cris_mmu_translate_page(struct cris_mmu_result *res,
CPUCRISState *env, uint32_t vaddr,
int rw, int usermode, int debug)
{
unsigned int vpage;
unsigned int idx;
uint32_t pid, lo, hi;
uint32_t tlb_vpn, tlb_pfn = 0;
int tlb_pid, tlb_g, tlb_v, tlb_k, tlb_w, tlb_x;
int cfg_v, cfg_k, cfg_w, cfg_x;
int set, match = 0;
uint32_t r_cause;
uint32_t r_cfg;
int rwcause;
int mmu = 1; /* Data mmu is default. */
int vect_base;
r_cause = env->sregs[SFR_R_MM_CAUSE];
r_cfg = env->sregs[SFR_RW_MM_CFG];
pid = env->pregs[PR_PID] & 0xff;
switch (rw) {
case 2:
rwcause = CRIS_MMU_ERR_EXEC;
mmu = 0;
break;
case 1:
rwcause = CRIS_MMU_ERR_WRITE;
break;
default:
case 0:
rwcause = CRIS_MMU_ERR_READ;
break;
}
/* I exception vectors 4 - 7, D 8 - 11. */
vect_base = (mmu + 1) * 4;
vpage = vaddr >> 13;
/*
* We know the index which to check on each set.
* Scan both I and D.
*/
idx = vpage & 15;
for (set = 0; set < 4; set++) {
lo = env->tlbsets[mmu][set][idx].lo;
hi = env->tlbsets[mmu][set][idx].hi;
tlb_vpn = hi >> 13;
tlb_pid = EXTRACT_FIELD(hi, 0, 7);
tlb_g = EXTRACT_FIELD(lo, 4, 4);
D_LOG("TLB[%d][%d][%d] v=%x vpage=%x lo=%x hi=%x\n",
mmu, set, idx, tlb_vpn, vpage, lo, hi);
if ((tlb_g || (tlb_pid == pid)) && tlb_vpn == vpage) {
match = 1;
break;
}
}
res->bf_vec = vect_base;
if (match) {
cfg_w = EXTRACT_FIELD(r_cfg, 19, 19);
cfg_k = EXTRACT_FIELD(r_cfg, 18, 18);
cfg_x = EXTRACT_FIELD(r_cfg, 17, 17);
cfg_v = EXTRACT_FIELD(r_cfg, 16, 16);
tlb_pfn = EXTRACT_FIELD(lo, 13, 31);
tlb_v = EXTRACT_FIELD(lo, 3, 3);
tlb_k = EXTRACT_FIELD(lo, 2, 2);
tlb_w = EXTRACT_FIELD(lo, 1, 1);
tlb_x = EXTRACT_FIELD(lo, 0, 0);
/*
* set_exception_vector(0x04, i_mmu_refill);
* set_exception_vector(0x05, i_mmu_invalid);
* set_exception_vector(0x06, i_mmu_access);
* set_exception_vector(0x07, i_mmu_execute);
* set_exception_vector(0x08, d_mmu_refill);
* set_exception_vector(0x09, d_mmu_invalid);
* set_exception_vector(0x0a, d_mmu_access);
* set_exception_vector(0x0b, d_mmu_write);
*/
if (cfg_k && tlb_k && usermode) {
D(printf("tlb: kernel protected %x lo=%x pc=%x\n",
vaddr, lo, env->pc));
match = 0;
res->bf_vec = vect_base + 2;
} else if (rw == 1 && cfg_w && !tlb_w) {
D(printf("tlb: write protected %x lo=%x pc=%x\n",
vaddr, lo, env->pc));
match = 0;
/* write accesses never go through the I mmu. */
res->bf_vec = vect_base + 3;
} else if (rw == 2 && cfg_x && !tlb_x) {
D(printf("tlb: exec protected %x lo=%x pc=%x\n",
vaddr, lo, env->pc));
match = 0;
res->bf_vec = vect_base + 3;
} else if (cfg_v && !tlb_v) {
D(printf("tlb: invalid %x\n", vaddr));
match = 0;
res->bf_vec = vect_base + 1;
}
res->prot = 0;
if (match) {
res->prot |= PAGE_READ;
if (tlb_w) {
res->prot |= PAGE_WRITE;
}
if (mmu == 0 && (cfg_x || tlb_x)) {
res->prot |= PAGE_EXEC;
}
} else {
D(dump_tlb(env, mmu));
}
} else {
/* If refill, provide a randomized set. */
set = env->mmu_rand_lfsr & 3;
}
if (!match && !debug) {
cris_mmu_update_rand_lfsr(env);
/* Compute index. */
idx = vpage & 15;
/* Update RW_MM_TLB_SEL. */
env->sregs[SFR_RW_MM_TLB_SEL] = 0;
set_field(&env->sregs[SFR_RW_MM_TLB_SEL], idx, 0, 4);
set_field(&env->sregs[SFR_RW_MM_TLB_SEL], set, 4, 2);
/* Update RW_MM_CAUSE. */
set_field(&r_cause, rwcause, 8, 2);
set_field(&r_cause, vpage, 13, 19);
set_field(&r_cause, pid, 0, 8);
env->sregs[SFR_R_MM_CAUSE] = r_cause;
D(printf("refill vaddr=%x pc=%x\n", vaddr, env->pc));
}
D(printf("%s rw=%d mtch=%d pc=%x va=%x vpn=%x tlbvpn=%x pfn=%x pid=%x"
" %x cause=%x sel=%x sp=%x %x %x\n",
__func__, rw, match, env->pc,
vaddr, vpage,
tlb_vpn, tlb_pfn, tlb_pid,
pid,
r_cause,
env->sregs[SFR_RW_MM_TLB_SEL],
env->regs[R_SP], env->pregs[PR_USP], env->ksp));
res->phy = tlb_pfn << TARGET_PAGE_BITS;
return !match;
}
void cris_mmu_flush_pid(CPUCRISState *env, uint32_t pid)
{
target_ulong vaddr;
unsigned int idx;
uint32_t lo, hi;
uint32_t tlb_vpn;
int tlb_pid, tlb_g, tlb_v;
unsigned int set;
unsigned int mmu;
pid &= 0xff;
for (mmu = 0; mmu < 2; mmu++) {
for (set = 0; set < 4; set++) {
for (idx = 0; idx < 16; idx++) {
lo = env->tlbsets[mmu][set][idx].lo;
hi = env->tlbsets[mmu][set][idx].hi;
tlb_vpn = EXTRACT_FIELD(hi, 13, 31);
tlb_pid = EXTRACT_FIELD(hi, 0, 7);
tlb_g = EXTRACT_FIELD(lo, 4, 4);
tlb_v = EXTRACT_FIELD(lo, 3, 3);
if (tlb_v && !tlb_g && (tlb_pid == pid)) {
vaddr = tlb_vpn << TARGET_PAGE_BITS;
D_LOG("flush pid=%x vaddr=%x\n", pid, vaddr);
tlb_flush_page(env_cpu(env), vaddr);
}
}
}
}
}
int cris_mmu_translate(struct cris_mmu_result *res,
CPUCRISState *env, uint32_t vaddr,
int rw, int mmu_idx, int debug)
{
int seg;
int miss = 0;
int is_user = mmu_idx == MMU_USER_IDX;
uint32_t old_srs;
old_srs = env->pregs[PR_SRS];
/* rw == 2 means exec, map the access to the insn mmu. */
env->pregs[PR_SRS] = rw == 2 ? 1 : 2;
if (!cris_mmu_enabled(env->sregs[SFR_RW_GC_CFG])) {
res->phy = vaddr;
res->prot = PAGE_BITS;
goto done;
}
seg = vaddr >> 28;
if (!is_user && cris_mmu_segmented_addr(seg, env->sregs[SFR_RW_MM_CFG])) {
uint32_t base;
miss = 0;
base = cris_mmu_translate_seg(env, seg);
res->phy = base | (0x0fffffff & vaddr);
res->prot = PAGE_BITS;
} else {
miss = cris_mmu_translate_page(res, env, vaddr, rw,
is_user, debug);
}
done:
env->pregs[PR_SRS] = old_srs;
return miss;
}