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/system.h>
20 #include <asm/uaccess.h>
21 #include <linux/smp.h>
22 #include <linux/bitops.h>
23 #include <linux/perf_event.h>
24 #include <linux/ratelimit.h>
25 #include <asm/fpumacro.h>
28 load, /* ld, ldd, ldh, ldsh */
29 store, /* st, std, sth, stsh */
30 both, /* Swap, ldstub, cas, ... */
36 static inline enum direction decode_direction(unsigned int insn)
38 unsigned long tmp = (insn >> 21) & 1;
43 switch ((insn>>19)&0xf) {
52 /* 16 = double-word, 8 = extra-word, 4 = word, 2 = half-word */
53 static inline int decode_access_size(struct pt_regs *regs, unsigned int insn)
57 tmp = ((insn >> 19) & 0xf);
58 if (tmp == 11 || tmp == 14) /* ldx/stx */
64 return 16; /* ldd/std - Although it is actually 8 */
68 printk("Impossible unaligned trap. insn=%08x\n", insn);
69 die_if_kernel("Byte sized unaligned access?!?!", regs);
71 /* GCC should never warn that control reaches the end
72 * of this function without returning a value because
73 * die_if_kernel() is marked with attribute 'noreturn'.
74 * Alas, some versions do...
81 static inline int decode_asi(unsigned int insn, struct pt_regs *regs)
83 if (insn & 0x800000) {
85 return (unsigned char)(regs->tstate >> 24); /* %asi */
87 return (unsigned char)(insn >> 5); /* imm_asi */
92 /* 0x400000 = signed, 0 = unsigned */
93 static inline int decode_signedness(unsigned int insn)
95 return (insn & 0x400000);
98 static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
99 unsigned int rd, int from_kernel)
101 if (rs2 >= 16 || rs1 >= 16 || rd >= 16) {
102 if (from_kernel != 0)
103 __asm__ __volatile__("flushw");
109 static inline long sign_extend_imm13(long imm)
111 return imm << 51 >> 51;
114 static unsigned long fetch_reg(unsigned int reg, struct pt_regs *regs)
119 return (!reg ? 0 : regs->u_regs[reg]);
120 if (regs->tstate & TSTATE_PRIV) {
121 struct reg_window *win;
122 win = (struct reg_window *)(regs->u_regs[UREG_FP] + STACK_BIAS);
123 value = win->locals[reg - 16];
124 } else if (test_thread_flag(TIF_32BIT)) {
125 struct reg_window32 __user *win32;
126 win32 = (struct reg_window32 __user *)((unsigned long)((u32)regs->u_regs[UREG_FP]));
127 get_user(value, &win32->locals[reg - 16]);
129 struct reg_window __user *win;
130 win = (struct reg_window __user *)(regs->u_regs[UREG_FP] + STACK_BIAS);
131 get_user(value, &win->locals[reg - 16]);
136 static unsigned long *fetch_reg_addr(unsigned int reg, struct pt_regs *regs)
139 return ®s->u_regs[reg];
140 if (regs->tstate & TSTATE_PRIV) {
141 struct reg_window *win;
142 win = (struct reg_window *)(regs->u_regs[UREG_FP] + STACK_BIAS);
143 return &win->locals[reg - 16];
144 } else if (test_thread_flag(TIF_32BIT)) {
145 struct reg_window32 *win32;
146 win32 = (struct reg_window32 *)((unsigned long)((u32)regs->u_regs[UREG_FP]));
147 return (unsigned long *)&win32->locals[reg - 16];
149 struct reg_window *win;
150 win = (struct reg_window *)(regs->u_regs[UREG_FP] + STACK_BIAS);
151 return &win->locals[reg - 16];
155 unsigned long compute_effective_address(struct pt_regs *regs,
156 unsigned int insn, unsigned int rd)
158 unsigned int rs1 = (insn >> 14) & 0x1f;
159 unsigned int rs2 = insn & 0x1f;
160 int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
163 maybe_flush_windows(rs1, 0, rd, from_kernel);
164 return (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
166 maybe_flush_windows(rs1, rs2, rd, from_kernel);
167 return (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
171 /* This is just to make gcc think die_if_kernel does return... */
172 static void __used unaligned_panic(char *str, struct pt_regs *regs)
174 die_if_kernel(str, regs);
177 extern int do_int_load(unsigned long *dest_reg, int size,
178 unsigned long *saddr, int is_signed, int asi);
180 extern int __do_int_store(unsigned long *dst_addr, int size,
181 unsigned long src_val, int asi);
183 static inline int do_int_store(int reg_num, int size, unsigned long *dst_addr,
184 struct pt_regs *regs, int asi, int orig_asi)
186 unsigned long zero = 0;
187 unsigned long *src_val_p = &zero;
188 unsigned long src_val;
192 zero = (((long)(reg_num ?
193 (unsigned)fetch_reg(reg_num, regs) : 0)) << 32) |
194 (unsigned)fetch_reg(reg_num + 1, regs);
195 } else if (reg_num) {
196 src_val_p = fetch_reg_addr(reg_num, regs);
198 src_val = *src_val_p;
199 if (unlikely(asi != orig_asi)) {
202 src_val = swab16(src_val);
205 src_val = swab32(src_val);
208 src_val = swab64(src_val);
216 return __do_int_store(dst_addr, size, src_val, asi);
219 static inline void advance(struct pt_regs *regs)
221 regs->tpc = regs->tnpc;
223 if (test_thread_flag(TIF_32BIT)) {
224 regs->tpc &= 0xffffffff;
225 regs->tnpc &= 0xffffffff;
229 static inline int floating_point_load_or_store_p(unsigned int insn)
231 return (insn >> 24) & 1;
234 static inline int ok_for_kernel(unsigned int insn)
236 return !floating_point_load_or_store_p(insn);
239 static void kernel_mna_trap_fault(int fixup_tstate_asi)
241 struct pt_regs *regs = current_thread_info()->kern_una_regs;
242 unsigned int insn = current_thread_info()->kern_una_insn;
243 const struct exception_table_entry *entry;
245 entry = search_exception_tables(regs->tpc);
247 unsigned long address;
249 address = compute_effective_address(regs, insn,
250 ((insn >> 25) & 0x1f));
251 if (address < PAGE_SIZE) {
252 printk(KERN_ALERT "Unable to handle kernel NULL "
253 "pointer dereference in mna handler");
255 printk(KERN_ALERT "Unable to handle kernel paging "
256 "request in mna handler");
257 printk(KERN_ALERT " at virtual address %016lx\n",address);
258 printk(KERN_ALERT "current->{active_,}mm->context = %016lx\n",
259 (current->mm ? CTX_HWBITS(current->mm->context) :
260 CTX_HWBITS(current->active_mm->context)));
261 printk(KERN_ALERT "current->{active_,}mm->pgd = %016lx\n",
262 (current->mm ? (unsigned long) current->mm->pgd :
263 (unsigned long) current->active_mm->pgd));
264 die_if_kernel("Oops", regs);
267 regs->tpc = entry->fixup;
268 regs->tnpc = regs->tpc + 4;
270 if (fixup_tstate_asi) {
271 regs->tstate &= ~TSTATE_ASI;
272 regs->tstate |= (ASI_AIUS << 24UL);
276 static void log_unaligned(struct pt_regs *regs)
278 static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
280 if (__ratelimit(&ratelimit)) {
281 printk("Kernel unaligned access at TPC[%lx] %pS\n",
282 regs->tpc, (void *) regs->tpc);
286 asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
288 enum direction dir = decode_direction(insn);
289 int size = decode_access_size(regs, insn);
292 current_thread_info()->kern_una_regs = regs;
293 current_thread_info()->kern_una_insn = insn;
295 orig_asi = asi = decode_asi(insn, regs);
297 /* If this is a {get,put}_user() on an unaligned userspace pointer,
298 * just signal a fault and do not log the event.
300 if (asi == ASI_AIUS) {
301 kernel_mna_trap_fault(0);
307 if (!ok_for_kernel(insn) || dir == both) {
308 printk("Unsupported unaligned load/store trap for kernel "
309 "at <%016lx>.\n", regs->tpc);
310 unaligned_panic("Kernel does fpu/atomic "
311 "unaligned load/store.", regs);
313 kernel_mna_trap_fault(0);
315 unsigned long addr, *reg_addr;
318 addr = compute_effective_address(regs, insn,
319 ((insn >> 25) & 0x1f));
320 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, 0, regs, addr);
334 reg_addr = fetch_reg_addr(((insn>>25)&0x1f), regs);
335 err = do_int_load(reg_addr, size,
336 (unsigned long *) addr,
337 decode_signedness(insn), asi);
338 if (likely(!err) && unlikely(asi != orig_asi)) {
339 unsigned long val_in = *reg_addr;
342 val_in = swab16(val_in);
345 val_in = swab32(val_in);
348 val_in = swab64(val_in);
360 err = do_int_store(((insn>>25)&0x1f), size,
361 (unsigned long *) addr, regs,
366 panic("Impossible kernel unaligned trap.");
370 kernel_mna_trap_fault(1);
376 static char popc_helper[] = {
377 0, 1, 1, 2, 1, 2, 2, 3,
378 1, 2, 2, 3, 2, 3, 3, 4,
381 int handle_popc(u32 insn, struct pt_regs *regs)
384 int ret, i, rd = ((insn >> 25) & 0x1f);
385 int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
387 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, 0, regs, 0);
389 maybe_flush_windows(0, 0, rd, from_kernel);
390 value = sign_extend_imm13(insn);
392 maybe_flush_windows(0, insn & 0x1f, rd, from_kernel);
393 value = fetch_reg(insn & 0x1f, regs);
395 for (ret = 0, i = 0; i < 16; i++) {
396 ret += popc_helper[value & 0xf];
401 regs->u_regs[rd] = ret;
403 if (test_thread_flag(TIF_32BIT)) {
404 struct reg_window32 __user *win32;
405 win32 = (struct reg_window32 __user *)((unsigned long)((u32)regs->u_regs[UREG_FP]));
406 put_user(ret, &win32->locals[rd - 16]);
408 struct reg_window __user *win;
409 win = (struct reg_window __user *)(regs->u_regs[UREG_FP] + STACK_BIAS);
410 put_user(ret, &win->locals[rd - 16]);
417 extern void do_fpother(struct pt_regs *regs);
418 extern void do_privact(struct pt_regs *regs);
419 extern void spitfire_data_access_exception(struct pt_regs *regs,
422 extern void sun4v_data_access_exception(struct pt_regs *regs,
424 unsigned long type_ctx);
426 int handle_ldf_stq(u32 insn, struct pt_regs *regs)
428 unsigned long addr = compute_effective_address(regs, insn, 0);
429 int freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
430 struct fpustate *f = FPUSTATE;
431 int asi = decode_asi(insn, regs);
432 int flag = (freg < 32) ? FPRS_DL : FPRS_DU;
434 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, 0, regs, 0);
436 save_and_clear_fpu();
437 current_thread_info()->xfsr[0] &= ~0x1c000;
439 current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
443 if (insn & 0x200000) {
445 u64 first = 0, second = 0;
447 if (current_thread_info()->fpsaved[0] & flag) {
448 first = *(u64 *)&f->regs[freg];
449 second = *(u64 *)&f->regs[freg+2];
461 /* Need to convert endians */
462 u64 tmp = __swab64p(&first);
464 first = __swab64p(&second);
469 if (tlb_type == hypervisor)
470 sun4v_data_access_exception(regs, addr, 0);
472 spitfire_data_access_exception(regs, 0, addr);
475 if (put_user (first >> 32, (u32 __user *)addr) ||
476 __put_user ((u32)first, (u32 __user *)(addr + 4)) ||
477 __put_user (second >> 32, (u32 __user *)(addr + 8)) ||
478 __put_user ((u32)second, (u32 __user *)(addr + 12))) {
479 if (tlb_type == hypervisor)
480 sun4v_data_access_exception(regs, addr, 0);
482 spitfire_data_access_exception(regs, 0, addr);
486 /* LDF, LDDF, LDQF */
487 u32 data[4] __attribute__ ((aligned(8)));
494 } else if (asi > ASI_SNFL) {
495 if (tlb_type == hypervisor)
496 sun4v_data_access_exception(regs, addr, 0);
498 spitfire_data_access_exception(regs, 0, addr);
501 switch (insn & 0x180000) {
502 case 0x000000: size = 1; break;
503 case 0x100000: size = 4; break;
504 default: size = 2; break;
506 for (i = 0; i < size; i++)
509 err = get_user (data[0], (u32 __user *) addr);
511 for (i = 1; i < size; i++)
512 err |= __get_user (data[i], (u32 __user *)(addr + 4*i));
514 if (err && !(asi & 0x2 /* NF */)) {
515 if (tlb_type == hypervisor)
516 sun4v_data_access_exception(regs, addr, 0);
518 spitfire_data_access_exception(regs, 0, addr);
521 if (asi & 0x8) /* Little */ {
525 case 1: data[0] = le32_to_cpup(data + 0); break;
526 default:*(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 0));
528 case 4: tmp = le64_to_cpup((u64 *)(data + 0));
529 *(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 2));
530 *(u64 *)(data + 2) = tmp;
534 if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
535 current_thread_info()->fpsaved[0] = FPRS_FEF;
536 current_thread_info()->gsr[0] = 0;
538 if (!(current_thread_info()->fpsaved[0] & flag)) {
540 memset(f->regs, 0, 32*sizeof(u32));
542 memset(f->regs+32, 0, 32*sizeof(u32));
544 memcpy(f->regs + freg, data, size * 4);
545 current_thread_info()->fpsaved[0] |= flag;
551 void handle_ld_nf(u32 insn, struct pt_regs *regs)
553 int rd = ((insn >> 25) & 0x1f);
554 int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
557 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, 0, regs, 0);
559 maybe_flush_windows(0, 0, rd, from_kernel);
560 reg = fetch_reg_addr(rd, regs);
561 if (from_kernel || rd < 16) {
563 if ((insn & 0x780000) == 0x180000)
565 } else if (test_thread_flag(TIF_32BIT)) {
566 put_user(0, (int __user *) reg);
567 if ((insn & 0x780000) == 0x180000)
568 put_user(0, ((int __user *) reg) + 1);
570 put_user(0, (unsigned long __user *) reg);
571 if ((insn & 0x780000) == 0x180000)
572 put_user(0, (unsigned long __user *) reg + 1);
577 void handle_lddfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
579 unsigned long pc = regs->tpc;
580 unsigned long tstate = regs->tstate;
585 struct fpustate *f = FPUSTATE;
587 if (tstate & TSTATE_PRIV)
588 die_if_kernel("lddfmna from kernel", regs);
589 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, 0, regs, sfar);
590 if (test_thread_flag(TIF_32BIT))
592 if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
593 int asi = decode_asi(insn, regs);
597 if ((asi > ASI_SNFL) ||
601 err = get_user(first, (u32 __user *)sfar);
603 err = get_user(second, (u32 __user *)(sfar + 4));
609 save_and_clear_fpu();
610 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
611 value = (((u64)first) << 32) | second;
612 if (asi & 0x8) /* Little */
613 value = __swab64p(&value);
614 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
615 if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
616 current_thread_info()->fpsaved[0] = FPRS_FEF;
617 current_thread_info()->gsr[0] = 0;
619 if (!(current_thread_info()->fpsaved[0] & flag)) {
621 memset(f->regs, 0, 32*sizeof(u32));
623 memset(f->regs+32, 0, 32*sizeof(u32));
625 *(u64 *)(f->regs + freg) = value;
626 current_thread_info()->fpsaved[0] |= flag;
629 if (tlb_type == hypervisor)
630 sun4v_data_access_exception(regs, sfar, sfsr);
632 spitfire_data_access_exception(regs, sfsr, sfar);
638 void handle_stdfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
640 unsigned long pc = regs->tpc;
641 unsigned long tstate = regs->tstate;
646 struct fpustate *f = FPUSTATE;
648 if (tstate & TSTATE_PRIV)
649 die_if_kernel("stdfmna from kernel", regs);
650 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, 0, regs, sfar);
651 if (test_thread_flag(TIF_32BIT))
653 if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
654 int asi = decode_asi(insn, regs);
655 freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
657 flag = (freg < 32) ? FPRS_DL : FPRS_DU;
658 if ((asi > ASI_SNFL) ||
661 save_and_clear_fpu();
662 if (current_thread_info()->fpsaved[0] & flag)
663 value = *(u64 *)&f->regs[freg];
669 value = __swab64p(&value); break;
672 if (put_user (value >> 32, (u32 __user *) sfar) ||
673 __put_user ((u32)value, (u32 __user *)(sfar + 4)))
677 if (tlb_type == hypervisor)
678 sun4v_data_access_exception(regs, sfar, sfsr);
680 spitfire_data_access_exception(regs, sfsr, sfar);