| /* $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/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 __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; |
| } |