arch/sparc/kernel/unaligned_64.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * 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/extable.h>
 #include <asm/asi.h>
 #include <asm/ptrace.h>
 #include <asm/pstate.h>
 #include <asm/processor.h>
 #include <linux/uaccess.h>
 #include <linux/smp.h>
 #include <linux/bitops.h>
 #include <linux/perf_event.h>
 #include <linux/ratelimit.h>
 #include <linux/context_tracking.h>
 #include <asm/fpumacro.h>
 #include <asm/cacheflush.h>
 #include <asm/setup.h>

 #include "entry.h"
 #include "kernel.h"

 enum direction {
 	load,    /* ld, ldd, ldh, ldsh */
 	store,   /* st, std, sth, stsh */
 	both,    /* Swap, ldstub, cas, ... */
 	fpld,
 	fpst,
 	invalid,
 };

 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(struct pt_regs *regs, 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?!?!", regs);

 		/* 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, fp;

 	if (reg < 16)
 		return (!reg ? 0 : regs->u_regs[reg]);

 	fp = regs->u_regs[UREG_FP];

 	if (regs->tstate & TSTATE_PRIV) {
 		struct reg_window *win;
 		win = (struct reg_window *)(fp + STACK_BIAS);
 		value = win->locals[reg - 16];
 	} else if (!test_thread_64bit_stack(fp)) {
 		struct reg_window32 __user *win32;
 		win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
 		get_user(value, &win32->locals[reg - 16]);
 	} else {
 		struct reg_window __user *win;
 		win = (struct reg_window __user *)(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)
 {
 	unsigned long fp;

 	if (reg < 16)
 		return &regs->u_regs[reg];

 	fp = regs->u_regs[UREG_FP];

 	if (regs->tstate & TSTATE_PRIV) {
 		struct reg_window *win;
 		win = (struct reg_window *)(fp + STACK_BIAS);
 		return &win->locals[reg - 16];
 	} else if (!test_thread_64bit_stack(fp)) {
 		struct reg_window32 *win32;
 		win32 = (struct reg_window32 *)((unsigned long)((u32)fp));
 		return (unsigned long *)&win32->locals[reg - 16];
 	} else {
 		struct reg_window *win;
 		win = (struct reg_window *)(fp + STACK_BIAS);
 		return &win->locals[reg - 16];
 	}
 }

 unsigned long compute_effective_address(struct pt_regs *regs,
 					unsigned int insn, unsigned int rd)
 {
 	int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
 	unsigned int rs1 = (insn >> 14) & 0x1f;
 	unsigned int rs2 = insn & 0x1f;
 	unsigned long addr;

 	if (insn & 0x2000) {
 		maybe_flush_windows(rs1, 0, rd, from_kernel);
 		addr = (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
 	} else {
 		maybe_flush_windows(rs1, rs2, rd, from_kernel);
 		addr = (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
 	}

 	if (!from_kernel && test_thread_flag(TIF_32BIT))
 		addr &= 0xffffffff;

 	return addr;
 }

 /* 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 int)fetch_reg(reg_num, regs) : 0)) << 32) |
 			(unsigned int)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 DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);

 	if (__ratelimit(&ratelimit)) {
 		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(regs, 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));
 		perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
 		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);
 	}
 }

 int handle_popc(u32 insn, struct pt_regs *regs)
 {
 	int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
 	int ret, rd = ((insn >> 25) & 0x1f);
 	u64 value;

 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 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);
 	}
 	ret = hweight64(value);
 	if (rd < 16) {
 		if (rd)
 			regs->u_regs[rd] = ret;
 	} else {
 		unsigned long fp = regs->u_regs[UREG_FP];

 		if (!test_thread_64bit_stack(fp)) {
 			struct reg_window32 __user *win32;
 			win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
 			put_user(ret, &win32->locals[rd - 16]);
 		} else {
 			struct reg_window __user *win;
 			win = (struct reg_window __user *)(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 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;
 	struct fpustate *f = FPUSTATE;
 	int asi = decode_asi(insn, regs);
 	int flag;

 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);

 	save_and_clear_fpu();
 	current_thread_info()->xfsr[0] &= ~0x1c000;
 	if (insn & 0x200000) {
 		/* STQ */
 		u64 first = 0, second = 0;

 		freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 		flag = (freg < 32) ? FPRS_DL : FPRS_DU;
 		if (freg & 3) {
 			current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
 			do_fpother(regs);
 			return 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;
 		}
 		if (size == 1)
 			freg = (insn >> 25) & 0x1f;
 		else
 			freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
 		flag = (freg < 32) ? FPRS_DL : FPRS_DU;

 		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;

 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);

 	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_64bit_stack(regs->u_regs[UREG_FP])) {
 		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)
 {
 	enum ctx_state prev_state = exception_enter();
 	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("lddfmna from kernel", regs);
 	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
 	if (test_thread_flag(TIF_32BIT))
 		pc = (u32)pc;
 	if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
 		int asi = decode_asi(insn, regs);
 		u32 first, second;
 		int err;

 		if ((asi > ASI_SNFL) ||
 		    (asi < ASI_P))
 			goto daex;
 		first = second = 0;
 		err = get_user(first, (u32 __user *)sfar);
 		if (!err)
 			err = get_user(second, (u32 __user *)(sfar + 4));
 		if (err) {
 			if (!(asi & 0x2))
 				goto daex;
 			first = second = 0;
 		}
 		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);
 		goto out;
 	}
 	advance(regs);
 out:
 	exception_exit(prev_state);
 }

 void handle_stdfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
 {
 	enum ctx_state prev_state = exception_enter();
 	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);
 	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
 	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);
 		goto out;
 	}
 	advance(regs);
 out:
 	exception_exit(prev_state);
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* 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/extable.h>
	#include <asm/asi.h>
	#include <asm/ptrace.h>
	#include <asm/pstate.h>
	#include <asm/processor.h>
	#include <linux/uaccess.h>
	#include <linux/smp.h>
	#include <linux/bitops.h>
	#include <linux/perf_event.h>
	#include <linux/ratelimit.h>
	#include <linux/context_tracking.h>
	#include <asm/fpumacro.h>
	#include <asm/cacheflush.h>
	#include <asm/setup.h>

	#include "entry.h"
	#include "kernel.h"

	enum direction {
	load, /* ld, ldd, ldh, ldsh */
	store, /* st, std, sth, stsh */
	both, /* Swap, ldstub, cas, ... */
	fpld,
	fpst,
	invalid,
	};

	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(struct pt_regs *regs, 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?!?!", regs);

	/* 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, fp;

	if (reg < 16)
	return (!reg ? 0 : regs->u_regs[reg]);

	fp = regs->u_regs[UREG_FP];

	if (regs->tstate & TSTATE_PRIV) {
	struct reg_window *win;
	win = (struct reg_window *)(fp + STACK_BIAS);
	value = win->locals[reg - 16];
	} else if (!test_thread_64bit_stack(fp)) {
	struct reg_window32 __user *win32;
	win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
	get_user(value, &win32->locals[reg - 16]);
	} else {
	struct reg_window __user *win;
	win = (struct reg_window __user *)(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)
	{
	unsigned long fp;

	if (reg < 16)
	return &regs->u_regs[reg];

	fp = regs->u_regs[UREG_FP];

	if (regs->tstate & TSTATE_PRIV) {
	struct reg_window *win;
	win = (struct reg_window *)(fp + STACK_BIAS);
	return &win->locals[reg - 16];
	} else if (!test_thread_64bit_stack(fp)) {
	struct reg_window32 *win32;
	win32 = (struct reg_window32 *)((unsigned long)((u32)fp));
	return (unsigned long *)&win32->locals[reg - 16];
	} else {
	struct reg_window *win;
	win = (struct reg_window *)(fp + STACK_BIAS);
	return &win->locals[reg - 16];
	}
	}

	unsigned long compute_effective_address(struct pt_regs *regs,
	unsigned int insn, unsigned int rd)
	{
	int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
	unsigned int rs1 = (insn >> 14) & 0x1f;
	unsigned int rs2 = insn & 0x1f;
	unsigned long addr;

	if (insn & 0x2000) {
	maybe_flush_windows(rs1, 0, rd, from_kernel);
	addr = (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
	} else {
	maybe_flush_windows(rs1, rs2, rd, from_kernel);
	addr = (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
	}

	if (!from_kernel && test_thread_flag(TIF_32BIT))
	addr &= 0xffffffff;

	return addr;
	}

	/* 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 int)fetch_reg(reg_num, regs) : 0)) << 32) \|
	(unsigned int)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 DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);

	if (__ratelimit(&ratelimit)) {
	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(regs, 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));
	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
	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);
	}
	}

	int handle_popc(u32 insn, struct pt_regs *regs)
	{
	int from_kernel = (regs->tstate & TSTATE_PRIV) != 0;
	int ret, rd = ((insn >> 25) & 0x1f);
	u64 value;

	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 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);
	}
	ret = hweight64(value);
	if (rd < 16) {
	if (rd)
	regs->u_regs[rd] = ret;
	} else {
	unsigned long fp = regs->u_regs[UREG_FP];

	if (!test_thread_64bit_stack(fp)) {
	struct reg_window32 __user *win32;
	win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
	put_user(ret, &win32->locals[rd - 16]);
	} else {
	struct reg_window __user *win;
	win = (struct reg_window __user *)(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 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;
	struct fpustate *f = FPUSTATE;
	int asi = decode_asi(insn, regs);
	int flag;

	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);

	save_and_clear_fpu();
	current_thread_info()->xfsr[0] &= ~0x1c000;
	if (insn & 0x200000) {
	/* STQ */
	u64 first = 0, second = 0;

	freg = ((insn >> 25) & 0x1e) \| ((insn >> 20) & 0x20);
	flag = (freg < 32) ? FPRS_DL : FPRS_DU;
	if (freg & 3) {
	current_thread_info()->xfsr[0] \|= (6 << 14) /* invalid_fp_register */;
	do_fpother(regs);
	return 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;
	}
	if (size == 1)
	freg = (insn >> 25) & 0x1f;
	else
	freg = ((insn >> 25) & 0x1e) \| ((insn >> 20) & 0x20);
	flag = (freg < 32) ? FPRS_DL : FPRS_DU;

	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 + 4i));
	}
	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;

	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);

	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_64bit_stack(regs->u_regs[UREG_FP])) {
	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)
	{
	enum ctx_state prev_state = exception_enter();
	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("lddfmna from kernel", regs);
	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
	if (test_thread_flag(TIF_32BIT))
	pc = (u32)pc;
	if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
	int asi = decode_asi(insn, regs);
	u32 first, second;
	int err;

	if ((asi > ASI_SNFL) \|\|
	(asi < ASI_P))
	goto daex;
	first = second = 0;
	err = get_user(first, (u32 __user *)sfar);
	if (!err)
	err = get_user(second, (u32 __user *)(sfar + 4));
	if (err) {
	if (!(asi & 0x2))
	goto daex;
	first = second = 0;
	}
	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);
	goto out;
	}
	advance(regs);
	out:
	exception_exit(prev_state);
	}

	void handle_stdfmna(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
	{
	enum ctx_state prev_state = exception_enter();
	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);
	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, sfar);
	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);
	goto out;
	}
	advance(regs);
	out:
	exception_exit(prev_state);
	}