kernel/arch/nds32/mm/alignment.c
2024-07-22 17:22:30 +08:00

579 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#include <linux/proc_fs.h>
#include <linux/uaccess.h>
#include <linux/sysctl.h>
#include <asm/unaligned.h>
#define DEBUG(enable, tagged, ...) \
do{ \
if (enable) { \
if (tagged) \
pr_warn("[ %30s() ] ", __func__); \
pr_warn(__VA_ARGS__); \
} \
} while (0)
#define RT(inst) (((inst) >> 20) & 0x1FUL)
#define RA(inst) (((inst) >> 15) & 0x1FUL)
#define RB(inst) (((inst) >> 10) & 0x1FUL)
#define SV(inst) (((inst) >> 8) & 0x3UL)
#define IMM(inst) (((inst) >> 0) & 0x7FFFUL)
#define RA3(inst) (((inst) >> 3) & 0x7UL)
#define RT3(inst) (((inst) >> 6) & 0x7UL)
#define IMM3U(inst) (((inst) >> 0) & 0x7UL)
#define RA5(inst) (((inst) >> 0) & 0x1FUL)
#define RT4(inst) (((inst) >> 5) & 0xFUL)
#define GET_IMMSVAL(imm_value) \
(((imm_value >> 14) & 0x1) ? (imm_value - 0x8000) : imm_value)
#define __get8_data(val,addr,err) \
__asm__( \
"1: lbi.bi %1, [%2], #1\n" \
"2:\n" \
" .pushsection .text.fixup,\"ax\"\n" \
" .align 2\n" \
"3: movi %0, #1\n" \
" j 2b\n" \
" .popsection\n" \
" .pushsection __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 3b\n" \
" .popsection\n" \
: "=r" (err), "=&r" (val), "=r" (addr) \
: "0" (err), "2" (addr))
#define get16_data(addr, val_ptr) \
do { \
unsigned int err = 0, v, a = addr; \
__get8_data(v,a,err); \
*val_ptr = v << 0; \
__get8_data(v,a,err); \
*val_ptr |= v << 8; \
if (err) \
goto fault; \
*val_ptr = le16_to_cpu(*val_ptr); \
} while(0)
#define get32_data(addr, val_ptr) \
do { \
unsigned int err = 0, v, a = addr; \
__get8_data(v,a,err); \
*val_ptr = v << 0; \
__get8_data(v,a,err); \
*val_ptr |= v << 8; \
__get8_data(v,a,err); \
*val_ptr |= v << 16; \
__get8_data(v,a,err); \
*val_ptr |= v << 24; \
if (err) \
goto fault; \
*val_ptr = le32_to_cpu(*val_ptr); \
} while(0)
#define get_data(addr, val_ptr, len) \
if (len == 2) \
get16_data(addr, val_ptr); \
else \
get32_data(addr, val_ptr);
#define set16_data(addr, val) \
do { \
unsigned int err = 0, *ptr = addr ; \
val = le32_to_cpu(val); \
__asm__( \
"1: sbi.bi %2, [%1], #1\n" \
" srli %2, %2, #8\n" \
"2: sbi %2, [%1]\n" \
"3:\n" \
" .pushsection .text.fixup,\"ax\"\n" \
" .align 2\n" \
"4: movi %0, #1\n" \
" j 3b\n" \
" .popsection\n" \
" .pushsection __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 4b\n" \
" .long 2b, 4b\n" \
" .popsection\n" \
: "=r" (err), "+r" (ptr), "+r" (val) \
: "0" (err) \
); \
if (err) \
goto fault; \
} while(0)
#define set32_data(addr, val) \
do { \
unsigned int err = 0, *ptr = addr ; \
val = le32_to_cpu(val); \
__asm__( \
"1: sbi.bi %2, [%1], #1\n" \
" srli %2, %2, #8\n" \
"2: sbi.bi %2, [%1], #1\n" \
" srli %2, %2, #8\n" \
"3: sbi.bi %2, [%1], #1\n" \
" srli %2, %2, #8\n" \
"4: sbi %2, [%1]\n" \
"5:\n" \
" .pushsection .text.fixup,\"ax\"\n" \
" .align 2\n" \
"6: movi %0, #1\n" \
" j 5b\n" \
" .popsection\n" \
" .pushsection __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 6b\n" \
" .long 2b, 6b\n" \
" .long 3b, 6b\n" \
" .long 4b, 6b\n" \
" .popsection\n" \
: "=r" (err), "+r" (ptr), "+r" (val) \
: "0" (err) \
); \
if (err) \
goto fault; \
} while(0)
#define set_data(addr, val, len) \
if (len == 2) \
set16_data(addr, val); \
else \
set32_data(addr, val);
#define NDS32_16BIT_INSTRUCTION 0x80000000
extern pte_t va_present(struct mm_struct *mm, unsigned long addr);
extern pte_t va_kernel_present(unsigned long addr);
extern int va_readable(struct pt_regs *regs, unsigned long addr);
extern int va_writable(struct pt_regs *regs, unsigned long addr);
int unalign_access_mode = 0, unalign_access_debug = 0;
static inline unsigned long *idx_to_addr(struct pt_regs *regs, int idx)
{
/* this should be consistent with ptrace.h */
if (idx >= 0 && idx <= 25) /* R0-R25 */
return &regs->uregs[0] + idx;
else if (idx >= 28 && idx <= 30) /* FP, GP, LP */
return &regs->fp + (idx - 28);
else if (idx == 31) /* SP */
return &regs->sp;
else
return NULL; /* cause a segfault */
}
static inline unsigned long get_inst(unsigned long addr)
{
return be32_to_cpu(get_unaligned((u32 *) addr));
}
static inline unsigned long sign_extend(unsigned long val, int len)
{
unsigned long ret = 0;
unsigned char *s, *t;
int i = 0;
val = cpu_to_le32(val);
s = (void *)&val;
t = (void *)&ret;
while (i++ < len)
*t++ = *s++;
if (((*(t - 1)) & 0x80) && (i < 4)) {
while (i++ <= 4)
*t++ = 0xff;
}
return le32_to_cpu(ret);
}
static inline int do_16(unsigned long inst, struct pt_regs *regs)
{
int imm, regular, load, len, addr_mode, idx_mode;
unsigned long unaligned_addr, target_val, source_idx, target_idx,
shift = 0;
switch ((inst >> 9) & 0x3F) {
case 0x12: /* LHI333 */
imm = 1;
regular = 1;
load = 1;
len = 2;
addr_mode = 3;
idx_mode = 3;
break;
case 0x10: /* LWI333 */
imm = 1;
regular = 1;
load = 1;
len = 4;
addr_mode = 3;
idx_mode = 3;
break;
case 0x11: /* LWI333.bi */
imm = 1;
regular = 0;
load = 1;
len = 4;
addr_mode = 3;
idx_mode = 3;
break;
case 0x1A: /* LWI450 */
imm = 0;
regular = 1;
load = 1;
len = 4;
addr_mode = 5;
idx_mode = 4;
break;
case 0x16: /* SHI333 */
imm = 1;
regular = 1;
load = 0;
len = 2;
addr_mode = 3;
idx_mode = 3;
break;
case 0x14: /* SWI333 */
imm = 1;
regular = 1;
load = 0;
len = 4;
addr_mode = 3;
idx_mode = 3;
break;
case 0x15: /* SWI333.bi */
imm = 1;
regular = 0;
load = 0;
len = 4;
addr_mode = 3;
idx_mode = 3;
break;
case 0x1B: /* SWI450 */
imm = 0;
regular = 1;
load = 0;
len = 4;
addr_mode = 5;
idx_mode = 4;
break;
default:
return -EFAULT;
}
if (addr_mode == 3) {
unaligned_addr = *idx_to_addr(regs, RA3(inst));
source_idx = RA3(inst);
} else {
unaligned_addr = *idx_to_addr(regs, RA5(inst));
source_idx = RA5(inst);
}
if (idx_mode == 3)
target_idx = RT3(inst);
else
target_idx = RT4(inst);
if (imm)
shift = IMM3U(inst) * len;
if (regular)
unaligned_addr += shift;
if (load) {
if (!access_ok((void *)unaligned_addr, len))
return -EACCES;
get_data(unaligned_addr, &target_val, len);
*idx_to_addr(regs, target_idx) = target_val;
} else {
if (!access_ok((void *)unaligned_addr, len))
return -EACCES;
target_val = *idx_to_addr(regs, target_idx);
set_data((void *)unaligned_addr, target_val, len);
}
if (!regular)
*idx_to_addr(regs, source_idx) = unaligned_addr + shift;
regs->ipc += 2;
return 0;
fault:
return -EACCES;
}
static inline int do_32(unsigned long inst, struct pt_regs *regs)
{
int imm, regular, load, len, sign_ext;
unsigned long unaligned_addr, target_val, shift;
unaligned_addr = *idx_to_addr(regs, RA(inst));
switch ((inst >> 25) << 1) {
case 0x02: /* LHI */
imm = 1;
regular = 1;
load = 1;
len = 2;
sign_ext = 0;
break;
case 0x0A: /* LHI.bi */
imm = 1;
regular = 0;
load = 1;
len = 2;
sign_ext = 0;
break;
case 0x22: /* LHSI */
imm = 1;
regular = 1;
load = 1;
len = 2;
sign_ext = 1;
break;
case 0x2A: /* LHSI.bi */
imm = 1;
regular = 0;
load = 1;
len = 2;
sign_ext = 1;
break;
case 0x04: /* LWI */
imm = 1;
regular = 1;
load = 1;
len = 4;
sign_ext = 0;
break;
case 0x0C: /* LWI.bi */
imm = 1;
regular = 0;
load = 1;
len = 4;
sign_ext = 0;
break;
case 0x12: /* SHI */
imm = 1;
regular = 1;
load = 0;
len = 2;
sign_ext = 0;
break;
case 0x1A: /* SHI.bi */
imm = 1;
regular = 0;
load = 0;
len = 2;
sign_ext = 0;
break;
case 0x14: /* SWI */
imm = 1;
regular = 1;
load = 0;
len = 4;
sign_ext = 0;
break;
case 0x1C: /* SWI.bi */
imm = 1;
regular = 0;
load = 0;
len = 4;
sign_ext = 0;
break;
default:
switch (inst & 0xff) {
case 0x01: /* LH */
imm = 0;
regular = 1;
load = 1;
len = 2;
sign_ext = 0;
break;
case 0x05: /* LH.bi */
imm = 0;
regular = 0;
load = 1;
len = 2;
sign_ext = 0;
break;
case 0x11: /* LHS */
imm = 0;
regular = 1;
load = 1;
len = 2;
sign_ext = 1;
break;
case 0x15: /* LHS.bi */
imm = 0;
regular = 0;
load = 1;
len = 2;
sign_ext = 1;
break;
case 0x02: /* LW */
imm = 0;
regular = 1;
load = 1;
len = 4;
sign_ext = 0;
break;
case 0x06: /* LW.bi */
imm = 0;
regular = 0;
load = 1;
len = 4;
sign_ext = 0;
break;
case 0x09: /* SH */
imm = 0;
regular = 1;
load = 0;
len = 2;
sign_ext = 0;
break;
case 0x0D: /* SH.bi */
imm = 0;
regular = 0;
load = 0;
len = 2;
sign_ext = 0;
break;
case 0x0A: /* SW */
imm = 0;
regular = 1;
load = 0;
len = 4;
sign_ext = 0;
break;
case 0x0E: /* SW.bi */
imm = 0;
regular = 0;
load = 0;
len = 4;
sign_ext = 0;
break;
default:
return -EFAULT;
}
}
if (imm)
shift = GET_IMMSVAL(IMM(inst)) * len;
else
shift = *idx_to_addr(regs, RB(inst)) << SV(inst);
if (regular)
unaligned_addr += shift;
if (load) {
if (!access_ok((void *)unaligned_addr, len))
return -EACCES;
get_data(unaligned_addr, &target_val, len);
if (sign_ext)
*idx_to_addr(regs, RT(inst)) =
sign_extend(target_val, len);
else
*idx_to_addr(regs, RT(inst)) = target_val;
} else {
if (!access_ok((void *)unaligned_addr, len))
return -EACCES;
target_val = *idx_to_addr(regs, RT(inst));
set_data((void *)unaligned_addr, target_val, len);
}
if (!regular)
*idx_to_addr(regs, RA(inst)) = unaligned_addr + shift;
regs->ipc += 4;
return 0;
fault:
return -EACCES;
}
int do_unaligned_access(unsigned long addr, struct pt_regs *regs)
{
unsigned long inst;
int ret = -EFAULT;
mm_segment_t seg;
inst = get_inst(regs->ipc);
DEBUG((unalign_access_debug > 0), 1,
"Faulting addr: 0x%08lx, pc: 0x%08lx [inst: 0x%08lx ]\n", addr,
regs->ipc, inst);
seg = force_uaccess_begin();
if (inst & NDS32_16BIT_INSTRUCTION)
ret = do_16((inst >> 16) & 0xffff, regs);
else
ret = do_32(inst, regs);
force_uaccess_end(seg);
return ret;
}
#ifdef CONFIG_PROC_FS
static struct ctl_table alignment_tbl[3] = {
{
.procname = "enable",
.data = &unalign_access_mode,
.maxlen = sizeof(unalign_access_mode),
.mode = 0666,
.proc_handler = &proc_dointvec
}
,
{
.procname = "debug_info",
.data = &unalign_access_debug,
.maxlen = sizeof(unalign_access_debug),
.mode = 0644,
.proc_handler = &proc_dointvec
}
,
{}
};
static struct ctl_table nds32_sysctl_table[2] = {
{
.procname = "unaligned_access",
.mode = 0555,
.child = alignment_tbl},
{}
};
static struct ctl_path nds32_path[2] = {
{.procname = "nds32"},
{}
};
/*
* Initialize nds32 alignment-correction interface
*/
static int __init nds32_sysctl_init(void)
{
register_sysctl_paths(nds32_path, nds32_sysctl_table);
return 0;
}
__initcall(nds32_sysctl_init);
#endif /* CONFIG_PROC_FS */