1 files changed, 690 insertions, 0 deletions

diff --git a/arch/sparc/kernel/unaligned_64.c b/arch/sparc/kernel/unaligned_64.c
new file mode 100644
index 000000000000..203ddfad9f27
--- /dev/null
+++ b/arch/sparc/kernel/unaligned_64.c
@@ -0,0 +1,690 @@
+/*
+ * 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;
+}