/* $Id: unaligned.c,v 1.24 2002/02/09 19:49:31 davem Exp $ * unaligned.c: Unaligned load/store trap handling with special * cases for the kernel to do them more quickly. * * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) */ #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/smp_lock.h> #include <linux/bitops.h> #include <linux/kallsyms.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 ®s->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 __attribute_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 (jiffies - last_time > 5 * HZ) count = 0; if (count < 5) { last_time = jiffies; count++; printk("Kernel unaligned access at TPC[%lx] ", regs->tpc); print_symbol("%s\n", 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; }