2 * unaligned.c: Unaligned load/store trap handling with special
3 * cases for the kernel to do them more quickly.
5 * Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net)
6 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
10 #include <linux/jiffies.h>
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
14 #include <linux/module.h>
16 #include <asm/ptrace.h>
17 #include <asm/pstate.h>
18 #include <asm/processor.h>
19 #include <asm/uaccess.h>
20 #include <linux/smp.h>
21 #include <linux/bitops.h>
22 #include <linux/perf_event.h>
23 #include <linux/ratelimit.h>
24 #include <linux/context_tracking.h>
25 #include <asm/fpumacro.h>
26 #include <asm/cacheflush.h>
31 load, /* ld, ldd, ldh, ldsh */
32 store, /* st, std, sth, stsh */
33 both, /* Swap, ldstub, cas, ... */
39 static inline enum direction decode_direction(unsigned int insn)
41 unsigned long tmp = (insn >> 21) & 1;
46 switch ((insn>>19)&0xf) {
55 /* 16 = double-word, 8 = extra-word, 4 = word, 2 = half-word */
56 static inline int decode_access_size(struct pt_regs *regs, unsigned int insn)
60 tmp = ((insn >> 19) & 0xf);
61 if (tmp == 11 || tmp == 14) /* ldx/stx */
67 return 16; /* ldd/std - Although it is actually 8 */
71 printk("Impossible unaligned trap. insn=%08x\n", insn);
72 die_if_kernel("Byte sized unaligned access?!?!", regs);
74 /* GCC should never warn that control reaches the end
75 * of this function without returning a value because
76 * die_if_kernel() is marked with attribute 'noreturn'.
77 * Alas, some versions do...
84 static inline int decode_asi(unsigned int insn, struct pt_regs *regs)
86 if (insn & 0x800000) {
88 return (unsigned char)(regs->tstate >> 24); /* %asi */
90 return (unsigned char)(insn >> 5); /* imm_asi */
95 /* 0x400000 = signed, 0 = unsigned */
96 static inline int decode_signedness(unsigned int insn)
98 return (insn & 0x400000);
101 static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
102 unsigned int rd, int from_kernel)
104 if (rs2 >= 16 || rs1 >= 16 || rd >= 16) {
105 if (from_kernel != 0)
106 __asm__ __volatile__("flushw");
112 static inline long sign_extend_imm13(long imm)
114 return imm << 51 >> 51;
117 static unsigned long fetch_reg(unsigned int reg, struct pt_regs *regs)
119 unsigned long value, fp;
122 return (!reg ? 0 : regs->u_regs[reg]);
124 fp = regs->u_regs[UREG_FP];
126 if (regs->tstate & TSTATE_PRIV) {
127 struct reg_window *win;
128 win = (struct reg_window *)(fp + STACK_BIAS);
129 value = win->locals[reg - 16];
130 } else if (!test_thread_64bit_stack(fp)) {
131 struct reg_window32 __user *win32;
132 win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
133 get_user(value, &win32->locals[reg - 16]);
135 struct reg_window __user *win;
136 win = (struct reg_window __user *)(fp + STACK_BIAS);
137 get_user(value, &win->locals[reg - 16]);
142 static unsigned long *fetch_reg_addr(unsigned int reg, struct pt_regs *regs)
147 return ®s->u_regs[reg];
149 fp = regs->u_regs[UREG_FP];
151 if (regs->tstate & TSTATE_PRIV) {
152 struct reg_window *win;
153 win = (struct reg_window *)(fp + STACK_BIAS);
154 return &win->locals[reg - 16];
155 } else if (!test_thread_64bit_stack(fp)) {
156 struct reg_window32 *win32;
157 win32 = (struct reg_window32 *)((unsigned long)((u32)fp));
158 return (unsigned long *)&win32->locals[reg - 16];
160 struct reg_window *win;
161 win = (struct reg_window *)(fp + STACK_BIAS);
162 return &win->locals[reg - 16];
166 unsigned long compute_effective_address(struct pt_regs *regs,
167 unsigned int insn, unsigned int rd)
169 int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
170 unsigned int rs1 = (insn >> 14) & 0x1f;
171 unsigned int rs2 = insn & 0x1f;
175 maybe_flush_windows(rs1, 0, rd, from_kernel);
176 addr = (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
178 maybe_flush_windows(rs1, rs2, rd, from_kernel);
179 addr = (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
182 if (!from_kernel && test_thread_flag(TIF_32BIT))
188 /* This is just to make gcc think die_if_kernel does return... */
189 static void __used unaligned_panic(char *str, struct pt_regs *regs)
191 die_if_kernel(str, regs);
194 extern int do_int_load(unsigned long *dest_reg, int size,
195 unsigned long *saddr, int is_signed, int asi);
197 extern int __do_int_store(unsigned long *dst_addr, int size,
198 unsigned long src_val, int asi);
200 static inline int do_int_store(int reg_num, int size, unsigned long *dst_addr,
201 struct pt_regs *regs, int asi, int orig_asi)
203 unsigned long zero = 0;
204 unsigned long *src_val_p = &zero;
205 unsigned long src_val;
209 zero = (((long)(reg_num ?
210 (unsigned)fetch_reg(reg_num, regs) : 0)) << 32) |
211 (unsigned)fetch_reg(reg_num + 1, regs);
212 } else if (reg_num) {
213 src_val_p = fetch_reg_addr(reg_num, regs);
215 src_val = *src_val_p;
216 if (unlikely(asi != orig_asi)) {
219 src_val = swab16(src_val);
222 src_val = swab32(src_val);
225 src_val = swab64(src_val);
233 return __do_int_store(dst_addr, size, src_val, asi);
236 static inline void advance(struct pt_regs *regs)
238 regs->tpc = regs->tnpc;
240 if (test_thread_flag(TIF_32BIT)) {
241 regs->tpc &= 0xffffffff;
242 regs->tnpc &= 0xffffffff;
246 static inline int floating_point_load_or_store_p(unsigned int insn)
248 return (insn >> 24) & 1;
251 static inline int ok_for_kernel(unsigned int insn)
253 return !floating_point_load_or_store_p(insn);
256 static void kernel_mna_trap_fault(int fixup_tstate_asi)
258 struct pt_regs *regs = current_thread_info()->kern_una_regs;
259 unsigned int insn = current_thread_info()->kern_una_insn;
260 const struct exception_table_entry *entry;
262 entry = search_exception_tables(regs->tpc);
264 unsigned long address;
266 address = compute_effective_address(regs, insn,
267 ((insn >> 25) & 0x1f));
268 if (address < PAGE_SIZE) {
269 printk(KERN_ALERT "Unable to handle kernel NULL "
270 "pointer dereference in mna handler");
272 printk(KERN_ALERT "Unable to handle kernel paging "
273 "request in mna handler");
274 printk(KERN_ALERT " at virtual address %016lx\n",address);
275 printk(KERN_ALERT "current->{active_,}mm->context = %016lx\n",
276 (current->mm ? CTX_HWBITS(current->mm->context) :
277 CTX_HWBITS(current->active_mm->context)));
278 printk(KERN_ALERT "current->{active_,}mm->pgd = %016lx\n",
279 (current->mm ? (unsigned long) current->mm->pgd :
280 (unsigned long) current->active_mm->pgd));
281 die_if_kernel("Oops", regs);
284 regs->tpc = entry->fixup;
285 regs->tnpc = regs->tpc + 4;
287 if (fixup_tstate_asi) {
288 regs->tstate &= ~TSTATE_ASI;
289 regs->tstate |= (ASI_AIUS << 24UL);
293 static void log_unaligned(struct pt_regs *regs)
295 static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
297 if (__ratelimit(&ratelimit)) {
298 printk("Kernel unaligned access at TPC[%lx] %pS\n",
299 regs->tpc, (void *) regs->tpc);
303 asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
305 enum direction dir = decode_direction(insn);
306 int size = decode_access_size(regs, insn);
309 current_thread_info()->kern_una_regs = regs;
310 current_thread_info()->kern_una_insn = insn;
312 orig_asi = asi = decode_asi(insn, regs);
314 /* If this is a {get,put}_user() on an unaligned userspace pointer,
315 * just signal a fault and do not log the event.
317 if (asi == ASI_AIUS) {
318 kernel_mna_trap_fault(0);
324 if (!ok_for_kernel(insn) || dir == both) {
325 printk("Unsupported unaligned load/store trap for kernel "
326 "at <%016lx>.\n", regs->tpc);
327 unaligned_panic("Kernel does fpu/atomic "
328 "unaligned load/store.", regs);
330 kernel_mna_trap_fault(0);
332 unsigned long addr, *reg_addr;
335 addr = compute_effective_address(regs, insn,
336 ((insn >> 25) & 0x1f));
337 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
351 reg_addr = fetch_reg_addr(((insn>>25)&0x1f), regs);
352 err = do_int_load(reg_addr, size,
353 (unsigned long *) addr,
354 decode_signedness(insn), asi);
355 if (likely(!err) && unlikely(asi != orig_asi)) {
356 unsigned long val_in = *reg_addr;
359 val_in = swab16(val_in);
362 val_in = swab32(val_in);
365 val_in = swab64(val_in);
377 err = do_int_store(((insn>>25)&0x1f), size,
378 (unsigned long *) addr, regs,
383 panic("Impossible kernel unaligned trap.");
387 kernel_mna_trap_fault(1);
393 int handle_popc(u32 insn, struct pt_regs *regs)
395 int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
396 int ret, rd = ((insn >> 25) & 0x1f);
399 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
401 maybe_flush_windows(0, 0, rd, from_kernel);
402 value = sign_extend_imm13(insn);
404 maybe_flush_windows(0, insn & 0x1f, rd, from_kernel);
405 value = fetch_reg(insn & 0x1f, regs);
407 ret = hweight64(value);
410 regs->u_regs[rd] = ret;
412 unsigned long fp = regs->u_regs[UREG_FP];
414 if (!test_thread_64bit_stack(fp)) {
415 struct reg_window32 __user *win32;
416 win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
417 put_user(ret, &win32->locals[rd - 16]);
419 struct reg_window __user *win;
420 win = (struct reg_window __user *)(fp + STACK_BIAS);
421 put_user(ret, &win->locals[rd - 16]);
428 extern void do_fpother(struct pt_regs *regs);
429 extern void do_privact(struct pt_regs *regs);
430 extern void sun4v_data_access_exception(struct pt_regs *regs,
432 unsigned long type_ctx);
434 int handle_ldf_stq(u32 insn, struct pt_regs *regs)
436 unsigned long addr = compute_effective_address(regs, insn, 0);
437 int freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
438 struct fpustate *f = FPUSTATE;
439 int asi = decode_asi(insn, regs);
440 int flag = (freg < 32) ? FPRS_DL : FPRS_DU;
442 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
444 save_and_clear_fpu();
445 current_thread_info()->xfsr[0] &= ~0x1c000;
447 current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
451 if (insn & 0x200000) {
453 u64 first = 0, second = 0;
455 if (current_thread_info()->fpsaved[0] & flag) {
456 first = *(u64 *)&f->regs[freg];
457 second = *(u64 *)&f->regs[freg+2];
469 /* Need to convert endians */
470 u64 tmp = __swab64p(&first);
472 first = __swab64p(&second);
477 if (tlb_type == hypervisor)
478 sun4v_data_access_exception(regs, addr, 0);
480 spitfire_data_access_exception(regs, 0, addr);
483 if (put_user (first >> 32, (u32 __user *)addr) ||
484 __put_user ((u32)first, (u32 __user *)(addr + 4)) ||
485 __put_user (second >> 32, (u32 __user *)(addr + 8)) ||
486 __put_user ((u32)second, (u32 __user *)(addr + 12))) {
487 if (tlb_type == hypervisor)
488 sun4v_data_access_exception(regs, addr, 0);
490 spitfire_data_access_exception(regs, 0, addr);
494 /* LDF, LDDF, LDQF */
495 u32 data[4] __attribute__ ((aligned(8)));
502 } else if (asi > ASI_SNFL) {
503 if (tlb_type == hypervisor)
504 sun4v_data_access_exception(regs, addr, 0);
506 spitfire_data_access_exception(regs, 0, addr);
509 switch (insn & 0x180000) {
510 case 0x000000: size = 1; break;
511 case 0x100000: size = 4; break;
512 default: size = 2; break;
514 for (i = 0; i < size; i++)
517 err = get_user (data[0], (u32 __user *) addr);
519 for (i = 1; i < size; i++)
520 err |= __get_user (data[i], (u32 __user *)(addr + 4*i));
522 if (err && !(asi & 0x2 /* NF */)) {
523 if (tlb_type == hypervisor)
524 sun4v_data_access_exception(regs, addr, 0);
526 spitfire_data_access_exception(regs, 0, addr);
529 if (asi & 0x8) /* Little */ {
533 case 1: data[0] = le32_to_cpup(data + 0); break;
534 default:*(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 0));
536 case 4: tmp = le64_to_cpup((u64 *)(data + 0));
537 *(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 2));
538 *(u64 *)(data + 2) = tmp;
542 if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
543 current_thread_info()->fpsaved[0] = FPRS_FEF;
544 current_thread_info()->gsr[0] = 0;
546 if (!(current_thread_info()->fpsaved[0] & flag)) {
548 memset(f->regs, 0, 32*sizeof(u32));
550 memset(f->regs+32, 0, 32*sizeof(u32));
552 memcpy(f->regs + freg, data, size * 4);
553 current_thread_info()->fpsaved[0] |= flag;
559 void handle_ld_nf(u32 insn, struct pt_regs *regs)
561 int rd = ((insn >> 25) & 0x1f);
562 int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
565 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
567 maybe_flush_windows(0, 0, rd, from_kernel);
568 reg = fetch_reg_addr(rd, regs);
569 if (from_kernel || rd < 16) {
571 if ((insn & 0x780000) == 0x180000)
573 } else if (!test_thread_64bit_stack(regs->u_regs[UREG_FP])) {
574 put_user(0, (int __user *) reg);
575 if ((insn & 0x780000) == 0x180000)
576 put_user(0, ((int __user *) reg) + 1);
578 put_user(0, (unsigned long __user *) reg);
579 if ((insn & 0x780000) == 0x180000)
580 put_user(0, (unsigned long __user *) reg + 1);
585 void handle_lddfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
587 enum ctx_state prev_state = exception_enter();
588 unsigned long pc = regs->tpc;
589 unsigned long tstate = regs->tstate;
594 struct fpustate *f = FPUSTATE;
596 if (tstate & TSTATE_PRIV)
597 die_if_kernel("lddfmna from kernel", regs);
598 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
599 if (test_thread_flag(TIF_32BIT))
601 if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
602 int asi = decode_asi(insn, regs);
606 if ((asi > ASI_SNFL) ||
610 err = get_user(first, (u32 __user *)sfar);
612 err = get_user(second, (u32 __user *)(sfar + 4));
618 save_and_clear_fpu();
619 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
620 value = (((u64)first) << 32) | second;
621 if (asi & 0x8) /* Little */
622 value = __swab64p(&value);
623 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
624 if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
625 current_thread_info()->fpsaved[0] = FPRS_FEF;
626 current_thread_info()->gsr[0] = 0;
628 if (!(current_thread_info()->fpsaved[0] & flag)) {
630 memset(f->regs, 0, 32*sizeof(u32));
632 memset(f->regs+32, 0, 32*sizeof(u32));
634 *(u64 *)(f->regs + freg) = value;
635 current_thread_info()->fpsaved[0] |= flag;
638 if (tlb_type == hypervisor)
639 sun4v_data_access_exception(regs, sfar, sfsr);
641 spitfire_data_access_exception(regs, sfsr, sfar);
646 exception_exit(prev_state);
649 void handle_stdfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
651 enum ctx_state prev_state = exception_enter();
652 unsigned long pc = regs->tpc;
653 unsigned long tstate = regs->tstate;
658 struct fpustate *f = FPUSTATE;
660 if (tstate & TSTATE_PRIV)
661 die_if_kernel("stdfmna from kernel", regs);
662 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
663 if (test_thread_flag(TIF_32BIT))
665 if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
666 int asi = decode_asi(insn, regs);
667 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
669 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
670 if ((asi > ASI_SNFL) ||
673 save_and_clear_fpu();
674 if (current_thread_info()->fpsaved[0] & flag)
675 value = *(u64 *)&f->regs[freg];
681 value = __swab64p(&value); break;
684 if (put_user (value >> 32, (u32 __user *) sfar) ||
685 __put_user ((u32)value, (u32 __user *)(sfar + 4)))
689 if (tlb_type == hypervisor)
690 sun4v_data_access_exception(regs, sfar, sfsr);
692 spitfire_data_access_exception(regs, sfsr, sfar);
697 exception_exit(prev_state);