diff options
Diffstat (limited to 'arch/tile/kernel/traps.c')
| -rw-r--r-- | arch/tile/kernel/traps.c | 421 |
1 files changed, 0 insertions, 421 deletions
diff --git a/arch/tile/kernel/traps.c b/arch/tile/kernel/traps.c deleted file mode 100644 index 83a7186198d7..000000000000 --- a/arch/tile/kernel/traps.c +++ /dev/null @@ -1,421 +0,0 @@ -/* - * Copyright 2010 Tilera Corporation. All Rights Reserved. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation, version 2. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or - * NON INFRINGEMENT. See the GNU General Public License for - * more details. - */ - -#include <linux/sched.h> -#include <linux/sched/debug.h> -#include <linux/kernel.h> -#include <linux/kprobes.h> -#include <linux/kdebug.h> -#include <linux/module.h> -#include <linux/reboot.h> -#include <linux/uaccess.h> -#include <linux/ptrace.h> -#include <linux/hardirq.h> -#include <linux/nmi.h> -#include <asm/stack.h> -#include <asm/traps.h> -#include <asm/setup.h> - -#include <arch/interrupts.h> -#include <arch/spr_def.h> -#include <arch/opcode.h> - -void __init trap_init(void) -{ - /* Nothing needed here since we link code at .intrpt */ -} - -int unaligned_fixup = 1; - -static int __init setup_unaligned_fixup(char *str) -{ - /* - * Say "=-1" to completely disable it. If you just do "=0", we - * will still parse the instruction, then fire a SIGBUS with - * the correct address from inside the single_step code. - */ - if (kstrtoint(str, 0, &unaligned_fixup) != 0) - return 0; - - pr_info("Fixups for unaligned data accesses are %s\n", - unaligned_fixup >= 0 ? - (unaligned_fixup ? "enabled" : "disabled") : - "completely disabled"); - return 1; -} -__setup("unaligned_fixup=", setup_unaligned_fixup); - -#if CHIP_HAS_TILE_DMA() - -static int dma_disabled; - -static int __init nodma(char *str) -{ - pr_info("User-space DMA is disabled\n"); - dma_disabled = 1; - return 1; -} -__setup("nodma", nodma); - -/* How to decode SPR_GPV_REASON */ -#define IRET_ERROR (1U << 31) -#define MT_ERROR (1U << 30) -#define MF_ERROR (1U << 29) -#define SPR_INDEX ((1U << 15) - 1) -#define SPR_MPL_SHIFT 9 /* starting bit position for MPL encoded in SPR */ - -/* - * See if this GPV is just to notify the kernel of SPR use and we can - * retry the user instruction after adjusting some MPLs suitably. - */ -static int retry_gpv(unsigned int gpv_reason) -{ - int mpl; - - if (gpv_reason & IRET_ERROR) - return 0; - - BUG_ON((gpv_reason & (MT_ERROR|MF_ERROR)) == 0); - mpl = (gpv_reason & SPR_INDEX) >> SPR_MPL_SHIFT; - if (mpl == INT_DMA_NOTIFY && !dma_disabled) { - /* User is turning on DMA. Allow it and retry. */ - printk(KERN_DEBUG "Process %d/%s is now enabled for DMA\n", - current->pid, current->comm); - BUG_ON(current->thread.tile_dma_state.enabled); - current->thread.tile_dma_state.enabled = 1; - grant_dma_mpls(); - return 1; - } - - return 0; -} - -#endif /* CHIP_HAS_TILE_DMA() */ - -extern tile_bundle_bits bpt_code; - -asm(".pushsection .rodata.bpt_code,\"a\";" - ".align 8;" - "bpt_code: bpt;" - ".size bpt_code,.-bpt_code;" - ".popsection"); - -static int special_ill(tile_bundle_bits bundle, int *sigp, int *codep) -{ - int sig, code, maxcode; - - if (bundle == bpt_code) { - *sigp = SIGTRAP; - *codep = TRAP_BRKPT; - return 1; - } - - /* If it's a "raise" bundle, then "ill" must be in pipe X1. */ -#ifdef __tilegx__ - if ((bundle & TILEGX_BUNDLE_MODE_MASK) != 0) - return 0; - if (get_Opcode_X1(bundle) != RRR_0_OPCODE_X1) - return 0; - if (get_RRROpcodeExtension_X1(bundle) != UNARY_RRR_0_OPCODE_X1) - return 0; - if (get_UnaryOpcodeExtension_X1(bundle) != ILL_UNARY_OPCODE_X1) - return 0; -#else - if (bundle & TILEPRO_BUNDLE_Y_ENCODING_MASK) - return 0; - if (get_Opcode_X1(bundle) != SHUN_0_OPCODE_X1) - return 0; - if (get_UnShOpcodeExtension_X1(bundle) != UN_0_SHUN_0_OPCODE_X1) - return 0; - if (get_UnOpcodeExtension_X1(bundle) != ILL_UN_0_SHUN_0_OPCODE_X1) - return 0; -#endif - - /* Check that the magic distinguishers are set to mean "raise". */ - if (get_Dest_X1(bundle) != 29 || get_SrcA_X1(bundle) != 37) - return 0; - - /* There must be an "addli zero, zero, VAL" in X0. */ - if (get_Opcode_X0(bundle) != ADDLI_OPCODE_X0) - return 0; - if (get_Dest_X0(bundle) != TREG_ZERO) - return 0; - if (get_SrcA_X0(bundle) != TREG_ZERO) - return 0; - - /* - * Validate the proposed signal number and si_code value. - * Note that we embed these in the static instruction itself - * so that we perturb the register state as little as possible - * at the time of the actual fault; it's unlikely you'd ever - * need to dynamically choose which kind of fault to raise - * from user space. - */ - sig = get_Imm16_X0(bundle) & 0x3f; - switch (sig) { - case SIGILL: - maxcode = NSIGILL; - break; - case SIGFPE: - maxcode = NSIGFPE; - break; - case SIGSEGV: - maxcode = NSIGSEGV; - break; - case SIGBUS: - maxcode = NSIGBUS; - break; - case SIGTRAP: - maxcode = NSIGTRAP; - break; - default: - return 0; - } - code = (get_Imm16_X0(bundle) >> 6) & 0xf; - if (code <= 0 || code > maxcode) - return 0; - - /* Make it the requested signal. */ - *sigp = sig; - *codep = code; - return 1; -} - -static const char *const int_name[] = { - [INT_MEM_ERROR] = "Memory error", - [INT_ILL] = "Illegal instruction", - [INT_GPV] = "General protection violation", - [INT_UDN_ACCESS] = "UDN access", - [INT_IDN_ACCESS] = "IDN access", -#if CHIP_HAS_SN() - [INT_SN_ACCESS] = "SN access", -#endif - [INT_SWINT_3] = "Software interrupt 3", - [INT_SWINT_2] = "Software interrupt 2", - [INT_SWINT_0] = "Software interrupt 0", - [INT_UNALIGN_DATA] = "Unaligned data", - [INT_DOUBLE_FAULT] = "Double fault", -#ifdef __tilegx__ - [INT_ILL_TRANS] = "Illegal virtual address", -#endif -}; - -static int do_bpt(struct pt_regs *regs) -{ - unsigned long bundle, bcode, bpt; - - bundle = *(unsigned long *)instruction_pointer(regs); - - /* - * bpt shoule be { bpt; nop }, which is 0x286a44ae51485000ULL. - * we encode the unused least significant bits for other purpose. - */ - bpt = bundle & ~((1ULL << 12) - 1); - if (bpt != TILE_BPT_BUNDLE) - return 0; - - bcode = bundle & ((1ULL << 12) - 1); - /* - * notify the kprobe handlers, if instruction is likely to - * pertain to them. - */ - switch (bcode) { - /* breakpoint_insn */ - case 0: - notify_die(DIE_BREAK, "debug", regs, bundle, - INT_ILL, SIGTRAP); - break; - /* compiled_bpt */ - case DIE_COMPILED_BPT: - notify_die(DIE_COMPILED_BPT, "debug", regs, bundle, - INT_ILL, SIGTRAP); - break; - /* breakpoint2_insn */ - case DIE_SSTEPBP: - notify_die(DIE_SSTEPBP, "single_step", regs, bundle, - INT_ILL, SIGTRAP); - break; - default: - return 0; - } - - return 1; -} - -void __kprobes do_trap(struct pt_regs *regs, int fault_num, - unsigned long reason) -{ - siginfo_t info; - int signo, code; - unsigned long address = 0; - tile_bundle_bits instr; - int is_kernel = !user_mode(regs); - - clear_siginfo(&info); - - /* Handle breakpoints, etc. */ - if (is_kernel && fault_num == INT_ILL && do_bpt(regs)) - return; - - /* Re-enable interrupts, if they were previously enabled. */ - if (!(regs->flags & PT_FLAGS_DISABLE_IRQ)) - local_irq_enable(); - - /* - * If it hits in kernel mode and we can't fix it up, just exit the - * current process and hope for the best. - */ - if (is_kernel) { - const char *name; - char buf[100]; - if (fixup_exception(regs)) /* ILL_TRANS or UNALIGN_DATA */ - return; - if (fault_num >= 0 && - fault_num < ARRAY_SIZE(int_name) && - int_name[fault_num] != NULL) - name = int_name[fault_num]; - else - name = "Unknown interrupt"; - if (fault_num == INT_GPV) - snprintf(buf, sizeof(buf), "; GPV_REASON %#lx", reason); -#ifdef __tilegx__ - else if (fault_num == INT_ILL_TRANS) - snprintf(buf, sizeof(buf), "; address %#lx", reason); -#endif - else - buf[0] = '\0'; - pr_alert("Kernel took bad trap %d (%s) at PC %#lx%s\n", - fault_num, name, regs->pc, buf); - show_regs(regs); - do_exit(SIGKILL); /* FIXME: implement i386 die() */ - } - - switch (fault_num) { - case INT_MEM_ERROR: - signo = SIGBUS; - code = BUS_OBJERR; - break; - case INT_ILL: - if (copy_from_user(&instr, (void __user *)regs->pc, - sizeof(instr))) { - pr_err("Unreadable instruction for INT_ILL: %#lx\n", - regs->pc); - do_exit(SIGKILL); - } - if (!special_ill(instr, &signo, &code)) { - signo = SIGILL; - code = ILL_ILLOPC; - } - address = regs->pc; - break; - case INT_GPV: -#if CHIP_HAS_TILE_DMA() - if (retry_gpv(reason)) - return; -#endif - /*FALLTHROUGH*/ - case INT_UDN_ACCESS: - case INT_IDN_ACCESS: -#if CHIP_HAS_SN() - case INT_SN_ACCESS: -#endif - signo = SIGILL; - code = ILL_PRVREG; - address = regs->pc; - break; - case INT_SWINT_3: - case INT_SWINT_2: - case INT_SWINT_0: - signo = SIGILL; - code = ILL_ILLTRP; - address = regs->pc; - break; - case INT_UNALIGN_DATA: -#ifndef __tilegx__ /* Emulated support for single step debugging */ - if (unaligned_fixup >= 0) { - struct single_step_state *state = - current_thread_info()->step_state; - if (!state || - (void __user *)(regs->pc) != state->buffer) { - single_step_once(regs); - return; - } - } -#endif - signo = SIGBUS; - code = BUS_ADRALN; - address = 0; - break; - case INT_DOUBLE_FAULT: - /* - * For double fault, "reason" is actually passed as - * SYSTEM_SAVE_K_2, the hypervisor's double-fault info, so - * we can provide the original fault number rather than - * the uninteresting "INT_DOUBLE_FAULT" so the user can - * learn what actually struck while PL0 ICS was set. - */ - fault_num = reason; - signo = SIGILL; - code = ILL_DBLFLT; - address = regs->pc; - break; -#ifdef __tilegx__ - case INT_ILL_TRANS: { - /* Avoid a hardware erratum with the return address stack. */ - fill_ra_stack(); - - signo = SIGSEGV; - address = reason; - code = SEGV_MAPERR; - break; - } -#endif - default: - panic("Unexpected do_trap interrupt number %d", fault_num); - } - - info.si_signo = signo; - info.si_code = code; - info.si_addr = (void __user *)address; - if (signo == SIGILL) - info.si_trapno = fault_num; - if (signo != SIGTRAP) - trace_unhandled_signal("trap", regs, address, signo); - force_sig_info(signo, &info, current); -} - -void do_nmi(struct pt_regs *regs, int fault_num, unsigned long reason) -{ - nmi_enter(); - switch (reason) { -#ifdef arch_trigger_cpumask_backtrace - case TILE_NMI_DUMP_STACK: - nmi_cpu_backtrace(regs); - break; -#endif - default: - panic("Unexpected do_nmi type %ld", reason); - } - nmi_exit(); -} - -/* Deprecated function currently only used here. */ -extern void _dump_stack(int dummy, ulong pc, ulong lr, ulong sp, ulong r52); - -void kernel_double_fault(int dummy, ulong pc, ulong lr, ulong sp, ulong r52) -{ - _dump_stack(dummy, pc, lr, sp, r52); - pr_emerg("Double fault: exiting\n"); - machine_halt(); -} |