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linux/arch/sparc/kernel/unaligned_64.c
Sam Ravnborg a88b5ba8bd sparc,sparc64: unify kernel/ 
o Move all files from sparc64/kernel/ to sparc/kernel
  - rename as appropriate
o Update sparc/Makefile to the changes
o Update sparc/kernel/Makefile to include the sparc64 files

NOTE: This commit changes link order on sparc64!

Link order had to change for either of sparc32 and sparc64.
And assuming sparc64 see more testing than sparc32 change link
order on sparc64 where issues will be caught faster.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-04 09:17:21 -08:00

691 lines
17 KiB
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/*
* unaligned.c: Unaligned load/store trap handling with special
* cases for the kernel to do them more quickly.
*
* Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net)
* Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
*/
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <asm/asi.h>
#include <asm/ptrace.h>
#include <asm/pstate.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <linux/smp.h>
#include <linux/bitops.h>
#include <asm/fpumacro.h>
/* #define DEBUG_MNA */
enum direction {
load, /* ld, ldd, ldh, ldsh */
store, /* st, std, sth, stsh */
both, /* Swap, ldstub, cas, ... */
fpld,
fpst,
invalid,
};
#ifdef DEBUG_MNA
static char *dirstrings[] = {
"load", "store", "both", "fpload", "fpstore", "invalid"
};
#endif
static inline enum direction decode_direction(unsigned int insn)
{
unsigned long tmp = (insn >> 21) & 1;
if (!tmp)
return load;
else {
switch ((insn>>19)&0xf) {
case 15: /* swap* */
return both;
default:
return store;
}
}
}
/* 16 = double-word, 8 = extra-word, 4 = word, 2 = half-word */
static inline int decode_access_size(unsigned int insn)
{
unsigned int tmp;
tmp = ((insn >> 19) & 0xf);
if (tmp == 11 || tmp == 14) /* ldx/stx */
return 8;
tmp &= 3;
if (!tmp)
return 4;
else if (tmp == 3)
return 16; /* ldd/std - Although it is actually 8 */
else if (tmp == 2)
return 2;
else {
printk("Impossible unaligned trap. insn=%08x\n", insn);
die_if_kernel("Byte sized unaligned access?!?!", current_thread_info()->kregs);
/* GCC should never warn that control reaches the end
* of this function without returning a value because
* die_if_kernel() is marked with attribute 'noreturn'.
* Alas, some versions do...
*/
return 0;
}
}
static inline int decode_asi(unsigned int insn, struct pt_regs *regs)
{
if (insn & 0x800000) {
if (insn & 0x2000)
return (unsigned char)(regs->tstate >> 24); /* %asi */
else
return (unsigned char)(insn >> 5); /* imm_asi */
} else
return ASI_P;
}
/* 0x400000 = signed, 0 = unsigned */
static inline int decode_signedness(unsigned int insn)
{
return (insn & 0x400000);
}
static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
unsigned int rd, int from_kernel)
{
if (rs2 >= 16 || rs1 >= 16 || rd >= 16) {
if (from_kernel != 0)
__asm__ __volatile__("flushw");
else
flushw_user();
}
}
static inline long sign_extend_imm13(long imm)
{
return imm << 51 >> 51;
}
static unsigned long fetch_reg(unsigned int reg, struct pt_regs *regs)
{
unsigned long value;
if (reg < 16)
return (!reg ? 0 : regs->u_regs[reg]);
if (regs->tstate & TSTATE_PRIV) {
struct reg_window *win;
win = (struct reg_window *)(regs->u_regs[UREG_FP] + STACK_BIAS);
value = win->locals[reg - 16];
} else if (test_thread_flag(TIF_32BIT)) {
struct reg_window32 __user *win32;
win32 = (struct reg_window32 __user *)((unsigned long)((u32)regs->u_regs[UREG_FP]));
get_user(value, &win32->locals[reg - 16]);
} else {
struct reg_window __user *win;
win = (struct reg_window __user *)(regs->u_regs[UREG_FP] + STACK_BIAS);
get_user(value, &win->locals[reg - 16]);
}
return value;
}
static unsigned long *fetch_reg_addr(unsigned int reg, struct pt_regs *regs)
{
if (reg < 16)
return &regs->u_regs[reg];
if (regs->tstate & TSTATE_PRIV) {
struct reg_window *win;
win = (struct reg_window *)(regs->u_regs[UREG_FP] + STACK_BIAS);
return &win->locals[reg - 16];
} else if (test_thread_flag(TIF_32BIT)) {
struct reg_window32 *win32;
win32 = (struct reg_window32 *)((unsigned long)((u32)regs->u_regs[UREG_FP]));
return (unsigned long *)&win32->locals[reg - 16];
} else {
struct reg_window *win;
win = (struct reg_window *)(regs->u_regs[UREG_FP] + STACK_BIAS);
return &win->locals[reg - 16];
}
}
unsigned long compute_effective_address(struct pt_regs *regs,
unsigned int insn, unsigned int rd)
{
unsigned int rs1 = (insn >> 14) & 0x1f;
unsigned int rs2 = insn & 0x1f;
int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
if (insn & 0x2000) {
maybe_flush_windows(rs1, 0, rd, from_kernel);
return (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
} else {
maybe_flush_windows(rs1, rs2, rd, from_kernel);
return (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
}
}
/* This is just to make gcc think die_if_kernel does return... */
static void __used unaligned_panic(char *str, struct pt_regs *regs)
{
die_if_kernel(str, regs);
}
extern int do_int_load(unsigned long *dest_reg, int size,
unsigned long *saddr, int is_signed, int asi);
extern int __do_int_store(unsigned long *dst_addr, int size,
unsigned long src_val, int asi);
static inline int do_int_store(int reg_num, int size, unsigned long *dst_addr,
struct pt_regs *regs, int asi, int orig_asi)
{
unsigned long zero = 0;
unsigned long *src_val_p = &zero;
unsigned long src_val;
if (size == 16) {
size = 8;
zero = (((long)(reg_num ?
(unsigned)fetch_reg(reg_num, regs) : 0)) << 32) |
(unsigned)fetch_reg(reg_num + 1, regs);
} else if (reg_num) {
src_val_p = fetch_reg_addr(reg_num, regs);
}
src_val = *src_val_p;
if (unlikely(asi != orig_asi)) {
switch (size) {
case 2:
src_val = swab16(src_val);
break;
case 4:
src_val = swab32(src_val);
break;
case 8:
src_val = swab64(src_val);
break;
case 16:
default:
BUG();
break;
};
}
return __do_int_store(dst_addr, size, src_val, asi);
}
static inline void advance(struct pt_regs *regs)
{
regs->tpc = regs->tnpc;
regs->tnpc += 4;
if (test_thread_flag(TIF_32BIT)) {
regs->tpc &= 0xffffffff;
regs->tnpc &= 0xffffffff;
}
}
static inline int floating_point_load_or_store_p(unsigned int insn)
{
return (insn >> 24) & 1;
}
static inline int ok_for_kernel(unsigned int insn)
{
return !floating_point_load_or_store_p(insn);
}
static void kernel_mna_trap_fault(int fixup_tstate_asi)
{
struct pt_regs *regs = current_thread_info()->kern_una_regs;
unsigned int insn = current_thread_info()->kern_una_insn;
const struct exception_table_entry *entry;
entry = search_exception_tables(regs->tpc);
if (!entry) {
unsigned long address;
address = compute_effective_address(regs, insn,
((insn >> 25) & 0x1f));
if (address < PAGE_SIZE) {
printk(KERN_ALERT "Unable to handle kernel NULL "
"pointer dereference in mna handler");
} else
printk(KERN_ALERT "Unable to handle kernel paging "
"request in mna handler");
printk(KERN_ALERT " at virtual address %016lx\n",address);
printk(KERN_ALERT "current->{active_,}mm->context = %016lx\n",
(current->mm ? CTX_HWBITS(current->mm->context) :
CTX_HWBITS(current->active_mm->context)));
printk(KERN_ALERT "current->{active_,}mm->pgd = %016lx\n",
(current->mm ? (unsigned long) current->mm->pgd :
(unsigned long) current->active_mm->pgd));
die_if_kernel("Oops", regs);
/* Not reached */
}
regs->tpc = entry->fixup;
regs->tnpc = regs->tpc + 4;
if (fixup_tstate_asi) {
regs->tstate &= ~TSTATE_ASI;
regs->tstate |= (ASI_AIUS << 24UL);
}
}
static void log_unaligned(struct pt_regs *regs)
{
static unsigned long count, last_time;
if (time_after(jiffies, last_time + 5 * HZ))
count = 0;
if (count < 5) {
last_time = jiffies;
count++;
printk("Kernel unaligned access at TPC[%lx] %pS\n",
regs->tpc, (void *) regs->tpc);
}
}
asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
{
enum direction dir = decode_direction(insn);
int size = decode_access_size(insn);
int orig_asi, asi;
current_thread_info()->kern_una_regs = regs;
current_thread_info()->kern_una_insn = insn;
orig_asi = asi = decode_asi(insn, regs);
/* If this is a {get,put}_user() on an unaligned userspace pointer,
* just signal a fault and do not log the event.
*/
if (asi == ASI_AIUS) {
kernel_mna_trap_fault(0);
return;
}
log_unaligned(regs);
if (!ok_for_kernel(insn) || dir == both) {
printk("Unsupported unaligned load/store trap for kernel "
"at <%016lx>.\n", regs->tpc);
unaligned_panic("Kernel does fpu/atomic "
"unaligned load/store.", regs);
kernel_mna_trap_fault(0);
} else {
unsigned long addr, *reg_addr;
int err;
addr = compute_effective_address(regs, insn,
((insn >> 25) & 0x1f));
#ifdef DEBUG_MNA
printk("KMNA: pc=%016lx [dir=%s addr=%016lx size=%d] "
"retpc[%016lx]\n",
regs->tpc, dirstrings[dir], addr, size,
regs->u_regs[UREG_RETPC]);
#endif
switch (asi) {
case ASI_NL:
case ASI_AIUPL:
case ASI_AIUSL:
case ASI_PL:
case ASI_SL:
case ASI_PNFL:
case ASI_SNFL:
asi &= ~0x08;
break;
};
switch (dir) {
case load:
reg_addr = fetch_reg_addr(((insn>>25)&0x1f), regs);
err = do_int_load(reg_addr, size,
(unsigned long *) addr,
decode_signedness(insn), asi);
if (likely(!err) && unlikely(asi != orig_asi)) {
unsigned long val_in = *reg_addr;
switch (size) {
case 2:
val_in = swab16(val_in);
break;
case 4:
val_in = swab32(val_in);
break;
case 8:
val_in = swab64(val_in);
break;
case 16:
default:
BUG();
break;
};
*reg_addr = val_in;
}
break;
case store:
err = do_int_store(((insn>>25)&0x1f), size,
(unsigned long *) addr, regs,
asi, orig_asi);
break;
default:
panic("Impossible kernel unaligned trap.");
/* Not reached... */
}
if (unlikely(err))
kernel_mna_trap_fault(1);
else
advance(regs);
}
}
static char popc_helper[] = {
0, 1, 1, 2, 1, 2, 2, 3,
1, 2, 2, 3, 2, 3, 3, 4,
};
int handle_popc(u32 insn, struct pt_regs *regs)
{
u64 value;
int ret, i, rd = ((insn >> 25) & 0x1f);
int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
if (insn & 0x2000) {
maybe_flush_windows(0, 0, rd, from_kernel);
value = sign_extend_imm13(insn);
} else {
maybe_flush_windows(0, insn & 0x1f, rd, from_kernel);
value = fetch_reg(insn & 0x1f, regs);
}
for (ret = 0, i = 0; i < 16; i++) {
ret += popc_helper[value & 0xf];
value >>= 4;
}
if (rd < 16) {
if (rd)
regs->u_regs[rd] = ret;
} else {
if (test_thread_flag(TIF_32BIT)) {
struct reg_window32 __user *win32;
win32 = (struct reg_window32 __user *)((unsigned long)((u32)regs->u_regs[UREG_FP]));
put_user(ret, &win32->locals[rd - 16]);
} else {
struct reg_window __user *win;
win = (struct reg_window __user *)(regs->u_regs[UREG_FP] + STACK_BIAS);
put_user(ret, &win->locals[rd - 16]);
}
}
advance(regs);
return 1;
}
extern void do_fpother(struct pt_regs *regs);
extern void do_privact(struct pt_regs *regs);
extern void spitfire_data_access_exception(struct pt_regs *regs,
unsigned long sfsr,
unsigned long sfar);
extern void sun4v_data_access_exception(struct pt_regs *regs,
unsigned long addr,
unsigned long type_ctx);
int handle_ldf_stq(u32 insn, struct pt_regs *regs)
{
unsigned long addr = compute_effective_address(regs, insn, 0);
int freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
struct fpustate *f = FPUSTATE;
int asi = decode_asi(insn, regs);
int flag = (freg < 32) ? FPRS_DL : FPRS_DU;
save_and_clear_fpu();
current_thread_info()->xfsr[0] &= ~0x1c000;
if (freg & 3) {
current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
do_fpother(regs);
return 0;
}
if (insn & 0x200000) {
/* STQ */
u64 first = 0, second = 0;
if (current_thread_info()->fpsaved[0] & flag) {
first = *(u64 *)&f->regs[freg];
second = *(u64 *)&f->regs[freg+2];
}
if (asi < 0x80) {
do_privact(regs);
return 1;
}
switch (asi) {
case ASI_P:
case ASI_S: break;
case ASI_PL:
case ASI_SL:
{
/* Need to convert endians */
u64 tmp = __swab64p(&first);
first = __swab64p(&second);
second = tmp;
break;
}
default:
if (tlb_type == hypervisor)
sun4v_data_access_exception(regs, addr, 0);
else
spitfire_data_access_exception(regs, 0, addr);
return 1;
}
if (put_user (first >> 32, (u32 __user *)addr) ||
__put_user ((u32)first, (u32 __user *)(addr + 4)) ||
__put_user (second >> 32, (u32 __user *)(addr + 8)) ||
__put_user ((u32)second, (u32 __user *)(addr + 12))) {
if (tlb_type == hypervisor)
sun4v_data_access_exception(regs, addr, 0);
else
spitfire_data_access_exception(regs, 0, addr);
return 1;
}
} else {
/* LDF, LDDF, LDQF */
u32 data[4] __attribute__ ((aligned(8)));
int size, i;
int err;
if (asi < 0x80) {
do_privact(regs);
return 1;
} else if (asi > ASI_SNFL) {
if (tlb_type == hypervisor)
sun4v_data_access_exception(regs, addr, 0);
else
spitfire_data_access_exception(regs, 0, addr);
return 1;
}
switch (insn & 0x180000) {
case 0x000000: size = 1; break;
case 0x100000: size = 4; break;
default: size = 2; break;
}
for (i = 0; i < size; i++)
data[i] = 0;
err = get_user (data[0], (u32 __user *) addr);
if (!err) {
for (i = 1; i < size; i++)
err |= __get_user (data[i], (u32 __user *)(addr + 4*i));
}
if (err && !(asi & 0x2 /* NF */)) {
if (tlb_type == hypervisor)
sun4v_data_access_exception(regs, addr, 0);
else
spitfire_data_access_exception(regs, 0, addr);
return 1;
}
if (asi & 0x8) /* Little */ {
u64 tmp;
switch (size) {
case 1: data[0] = le32_to_cpup(data + 0); break;
default:*(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 0));
break;
case 4: tmp = le64_to_cpup((u64 *)(data + 0));
*(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 2));
*(u64 *)(data + 2) = tmp;
break;
}
}
if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
current_thread_info()->fpsaved[0] = FPRS_FEF;
current_thread_info()->gsr[0] = 0;
}
if (!(current_thread_info()->fpsaved[0] & flag)) {
if (freg < 32)
memset(f->regs, 0, 32*sizeof(u32));
else
memset(f->regs+32, 0, 32*sizeof(u32));
}
memcpy(f->regs + freg, data, size * 4);
current_thread_info()->fpsaved[0] |= flag;
}
advance(regs);
return 1;
}
void handle_ld_nf(u32 insn, struct pt_regs *regs)
{
int rd = ((insn >> 25) & 0x1f);
int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
unsigned long *reg;
maybe_flush_windows(0, 0, rd, from_kernel);
reg = fetch_reg_addr(rd, regs);
if (from_kernel || rd < 16) {
reg[0] = 0;
if ((insn & 0x780000) == 0x180000)
reg[1] = 0;
} else if (test_thread_flag(TIF_32BIT)) {
put_user(0, (int __user *) reg);
if ((insn & 0x780000) == 0x180000)
put_user(0, ((int __user *) reg) + 1);
} else {
put_user(0, (unsigned long __user *) reg);
if ((insn & 0x780000) == 0x180000)
put_user(0, (unsigned long __user *) reg + 1);
}
advance(regs);
}
void handle_lddfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
{
unsigned long pc = regs->tpc;
unsigned long tstate = regs->tstate;
u32 insn;
u32 first, second;
u64 value;
u8 freg;
int flag;
struct fpustate *f = FPUSTATE;
if (tstate & TSTATE_PRIV)
die_if_kernel("lddfmna from kernel", regs);
if (test_thread_flag(TIF_32BIT))
pc = (u32)pc;
if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
int asi = decode_asi(insn, regs);
if ((asi > ASI_SNFL) ||
(asi < ASI_P))
goto daex;
if (get_user(first, (u32 __user *)sfar) ||
get_user(second, (u32 __user *)(sfar + 4))) {
if (asi & 0x2) /* NF */ {
first = 0; second = 0;
} else
goto daex;
}
save_and_clear_fpu();
freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
value = (((u64)first) << 32) | second;
if (asi & 0x8) /* Little */
value = __swab64p(&value);
flag = (freg < 32) ? FPRS_DL : FPRS_DU;
if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
current_thread_info()->fpsaved[0] = FPRS_FEF;
current_thread_info()->gsr[0] = 0;
}
if (!(current_thread_info()->fpsaved[0] & flag)) {
if (freg < 32)
memset(f->regs, 0, 32*sizeof(u32));
else
memset(f->regs+32, 0, 32*sizeof(u32));
}
*(u64 *)(f->regs + freg) = value;
current_thread_info()->fpsaved[0] |= flag;
} else {
daex:
if (tlb_type == hypervisor)
sun4v_data_access_exception(regs, sfar, sfsr);
else
spitfire_data_access_exception(regs, sfsr, sfar);
return;
}
advance(regs);
return;
}
void handle_stdfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
{
unsigned long pc = regs->tpc;
unsigned long tstate = regs->tstate;
u32 insn;
u64 value;
u8 freg;
int flag;
struct fpustate *f = FPUSTATE;
if (tstate & TSTATE_PRIV)
die_if_kernel("stdfmna from kernel", regs);
if (test_thread_flag(TIF_32BIT))
pc = (u32)pc;
if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
int asi = decode_asi(insn, regs);
freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
value = 0;
flag = (freg < 32) ? FPRS_DL : FPRS_DU;
if ((asi > ASI_SNFL) ||
(asi < ASI_P))
goto daex;
save_and_clear_fpu();
if (current_thread_info()->fpsaved[0] & flag)
value = *(u64 *)&f->regs[freg];
switch (asi) {
case ASI_P:
case ASI_S: break;
case ASI_PL:
case ASI_SL:
value = __swab64p(&value); break;
default: goto daex;
}
if (put_user (value >> 32, (u32 __user *) sfar) ||
__put_user ((u32)value, (u32 __user *)(sfar + 4)))
goto daex;
} else {
daex:
if (tlb_type == hypervisor)
sun4v_data_access_exception(regs, sfar, sfsr);
else
spitfire_data_access_exception(regs, sfsr, sfar);
return;
}
advance(regs);
return;
}
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