diff --git a/arch/metag/include/asm/switch.h b/arch/metag/include/asm/switch.h
new file mode 100644
index 0000000000000000000000000000000000000000..1fd6a587c8440815dcc778e387c165114dd1ce7e
--- /dev/null
+++ b/arch/metag/include/asm/switch.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2012 Imagination Technologies Ltd.
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef _ASM_METAG_SWITCH_H
+#define _ASM_METAG_SWITCH_H
+
+/* metag SWITCH codes */
+#define __METAG_SW_PERM_BREAK 0x400002 /* compiled in breakpoint */
+#define __METAG_SW_SYS_LEGACY 0x440000 /* legacy system calls */
+#define __METAG_SW_SYS 0x440001 /* system calls */
+
+/* metag SWITCH instruction encoding */
+#define __METAG_SW_ENCODING(TYPE) (0xaf000000 | (__METAG_SW_##TYPE))
+
+#endif /* _ASM_METAG_SWITCH_H */
diff --git a/arch/metag/include/asm/traps.h b/arch/metag/include/asm/traps.h
new file mode 100644
index 0000000000000000000000000000000000000000..ac808740bd848e1cc420e62b0f4c88dabe89ad01
--- /dev/null
+++ b/arch/metag/include/asm/traps.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2005,2008 Imagination Technologies
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+#ifndef _METAG_TBIVECTORS_H
+#define _METAG_TBIVECTORS_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/tbx.h>
+
+typedef TBIRES (*kick_irq_func_t)(TBIRES, int, int, int, PTBI, int *);
+
+extern TBIRES kick_handler(TBIRES, int, int, int, PTBI);
+struct kick_irq_handler {
+ struct list_head list;
+ kick_irq_func_t func;
+};
+
+extern void kick_register_func(struct kick_irq_handler *);
+extern void kick_unregister_func(struct kick_irq_handler *);
+
+extern void head_end(TBIRES, unsigned long);
+extern void restart_critical_section(TBIRES State);
+extern TBIRES tail_end_sys(TBIRES, int, int *);
+static inline TBIRES tail_end(TBIRES state)
+{
+ return tail_end_sys(state, -1, NULL);
+}
+
+DECLARE_PER_CPU(PTBI, pTBI);
+extern PTBI pTBI_get(unsigned int);
+
+extern int ret_from_fork(TBIRES arg);
+
+extern int do_page_fault(struct pt_regs *regs, unsigned long address,
+ unsigned int write_access, unsigned int trapno);
+
+extern TBIRES __TBIUnExpXXX(TBIRES State, int SigNum, int Triggers, int Inst,
+ PTBI pTBI);
+
+#endif
+
+#endif /* _METAG_TBIVECTORS_H */
diff --git a/arch/metag/kernel/kick.c b/arch/metag/kernel/kick.c
new file mode 100644
index 0000000000000000000000000000000000000000..c3090962c45be1193765ba9afd7c2c1b16131698
--- /dev/null
+++ b/arch/metag/kernel/kick.c
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2009 Imagination Technologies
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive
+ * for more details.
+ *
+ * The Meta KICK interrupt mechanism is generally a useful feature, so
+ * we provide an interface for registering multiple interrupt
+ * handlers. All the registered interrupt handlers are "chained". When
+ * a KICK interrupt is received the first function in the list is
+ * called. If that interrupt handler cannot handle the KICK the next
+ * one is called, then the next until someone handles it (or we run
+ * out of functions). As soon as one function handles the interrupt no
+ * other handlers are called.
+ *
+ * The only downside of chaining interrupt handlers is that each
+ * handler must be able to detect whether the KICK was intended for it
+ * or not. For example, when the IPI handler runs and it sees that
+ * there are no IPI messages it must not signal that the KICK was
+ * handled, thereby giving the other handlers a chance to run.
+ *
+ * The reason that we provide our own interface for calling KICK
+ * handlers instead of using the generic kernel infrastructure is that
+ * the KICK handlers require access to a CPU's pTBI structure. So we
+ * pass it as an argument.
+ */
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/types.h>
+
+#include <asm/traps.h>
+
+/*
+ * All accesses/manipulations of kick_handlers_list should be
+ * performed while holding kick_handlers_lock.
+ */
+static DEFINE_SPINLOCK(kick_handlers_lock);
+static LIST_HEAD(kick_handlers_list);
+
+void kick_register_func(struct kick_irq_handler *kh)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&kick_handlers_lock, flags);
+
+ list_add_tail(&kh->list, &kick_handlers_list);
+
+ spin_unlock_irqrestore(&kick_handlers_lock, flags);
+}
+
+void kick_unregister_func(struct kick_irq_handler *kh)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&kick_handlers_lock, flags);
+
+ list_del(&kh->list);
+
+ spin_unlock_irqrestore(&kick_handlers_lock, flags);
+}
+
+TBIRES
+kick_handler(TBIRES State, int SigNum, int Triggers, int Inst, PTBI pTBI)
+{
+ struct kick_irq_handler *kh;
+ struct list_head *lh;
+ int handled = 0;
+ TBIRES ret;
+
+ head_end(State, ~INTS_OFF_MASK);
+
+ /* If we interrupted user code handle any critical sections. */
+ if (State.Sig.SaveMask & TBICTX_PRIV_BIT)
+ restart_critical_section(State);
+
+ trace_hardirqs_off();
+
+ /*
+ * There is no need to disable interrupts here because we
+ * can't nest KICK interrupts in a KICK interrupt handler.
+ */
+ spin_lock(&kick_handlers_lock);
+
+ list_for_each(lh, &kick_handlers_list) {
+ kh = list_entry(lh, struct kick_irq_handler, list);
+
+ ret = kh->func(State, SigNum, Triggers, Inst, pTBI, &handled);
+ if (handled)
+ break;
+ }
+
+ spin_unlock(&kick_handlers_lock);
+
+ WARN_ON(!handled);
+
+ return tail_end(ret);
+}
diff --git a/arch/metag/kernel/tbiunexp.S b/arch/metag/kernel/tbiunexp.S
new file mode 100644
index 0000000000000000000000000000000000000000..907bbe0b2e68a0ce5d3150a252b038bd7665686f
--- /dev/null
+++ b/arch/metag/kernel/tbiunexp.S
@@ -0,0 +1,22 @@
+/* Pass a breakpoint through to Codescape */
+
+#include <asm/tbx.h>
+
+ .text
+ .global ___TBIUnExpXXX
+ .type ___TBIUnExpXXX,function
+___TBIUnExpXXX:
+ TSTT D0Ar2,#TBICTX_CRIT_BIT ! Result of nestable int call?
+ BZ $LTBINormCase ! UnExpXXX at background level
+ MOV D0Re0,TXMASKI ! Read TXMASKI
+ XOR TXMASKI,D1Re0,D1Re0 ! Turn off BGNDHALT handling!
+ OR D0Ar2,D0Ar2,D0Re0 ! Preserve bits cleared
+$LTBINormCase:
+ MSETL [A0StP],D0Ar6,D0Ar4,D0Ar2 ! Save args on stack
+ SETL [A0StP++],D0Ar2,D1Ar1 ! Init area for returned values
+ SWITCH #0xC20208 ! Total stack frame size 8 Dwords
+ ! write back size 2 Dwords
+ GETL D0Re0,D1Re0,[--A0StP] ! Get result
+ SUB A0StP,A0StP,#(8*3) ! Recover stack frame
+ MOV PC,D1RtP
+ .size ___TBIUnExpXXX,.-___TBIUnExpXXX
diff --git a/arch/metag/kernel/traps.c b/arch/metag/kernel/traps.c
new file mode 100644
index 0000000000000000000000000000000000000000..1ad363ce1ee9d16c9727cd6e7541ed688a875dd0
--- /dev/null
+++ b/arch/metag/kernel/traps.c
@@ -0,0 +1,978 @@
+/*
+ * Meta exception handling.
+ *
+ * Copyright (C) 2005,2006,2007,2008,2009,2012 Imagination Technologies Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/kdebug.h>
+#include <linux/kexec.h>
+#include <linux/unistd.h>
+#include <linux/smp.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+
+#include <asm/bug.h>
+#include <asm/core_reg.h>
+#include <asm/irqflags.h>
+#include <asm/siginfo.h>
+#include <asm/traps.h>
+#include <asm/hwthread.h>
+#include <asm/switch.h>
+#include <asm/user_gateway.h>
+#include <asm/syscall.h>
+#include <asm/syscalls.h>
+
+/* Passing syscall arguments as long long is quicker. */
+typedef unsigned int (*LPSYSCALL) (unsigned long long,
+ unsigned long long,
+ unsigned long long);
+
+/*
+ * Users of LNKSET should compare the bus error bits obtained from DEFR
+ * against TXDEFR_LNKSET_SUCCESS only as the failure code will vary between
+ * different cores revisions.
+ */
+#define TXDEFR_LNKSET_SUCCESS 0x02000000
+#define TXDEFR_LNKSET_FAILURE 0x04000000
+
+/*
+ * Our global TBI handle. Initialised from setup.c/setup_arch.
+ */
+DECLARE_PER_CPU(PTBI, pTBI);
+
+#ifdef CONFIG_SMP
+static DEFINE_PER_CPU(unsigned int, trigger_mask);
+#else
+unsigned int global_trigger_mask;
+#endif
+
+unsigned long per_cpu__stack_save[NR_CPUS];
+
+static const char * const trap_names[] = {
+ [TBIXXF_SIGNUM_IIF] = "Illegal instruction fault",
+ [TBIXXF_SIGNUM_PGF] = "Privilege violation",
+ [TBIXXF_SIGNUM_DHF] = "Unaligned data access fault",
+ [TBIXXF_SIGNUM_IGF] = "Code fetch general read failure",
+ [TBIXXF_SIGNUM_DGF] = "Data access general read/write fault",
+ [TBIXXF_SIGNUM_IPF] = "Code fetch page fault",
+ [TBIXXF_SIGNUM_DPF] = "Data access page fault",
+ [TBIXXF_SIGNUM_IHF] = "Instruction breakpoint",
+ [TBIXXF_SIGNUM_DWF] = "Read-only data access fault",
+};
+
+const char *trap_name(int trapno)
+{
+ if (trapno >= 0 && trapno < ARRAY_SIZE(trap_names)
+ && trap_names[trapno])
+ return trap_names[trapno];
+ return "Unknown fault";
+}
+
+static DEFINE_SPINLOCK(die_lock);
+
+void die(const char *str, struct pt_regs *regs, long err,
+ unsigned long addr)
+{
+ static int die_counter;
+
+ oops_enter();
+
+ spin_lock_irq(&die_lock);
+ console_verbose();
+ bust_spinlocks(1);
+ pr_err("%s: err %04lx (%s) addr %08lx [#%d]\n", str, err & 0xffff,
+ trap_name(err & 0xffff), addr, ++die_counter);
+
+ print_modules();
+ show_regs(regs);
+
+ pr_err("Process: %s (pid: %d, stack limit = %p)\n", current->comm,
+ task_pid_nr(current), task_stack_page(current) + THREAD_SIZE);
+
+ bust_spinlocks(0);
+ add_taint(TAINT_DIE);
+ if (kexec_should_crash(current))
+ crash_kexec(regs);
+
+ if (in_interrupt())
+ panic("Fatal exception in interrupt");
+
+ if (panic_on_oops)
+ panic("Fatal exception");
+
+ spin_unlock_irq(&die_lock);
+ oops_exit();
+ do_exit(SIGSEGV);
+}
+
+#ifdef CONFIG_METAG_DSP
+/*
+ * The ECH encoding specifies the size of a DSPRAM as,
+ *
+ * "slots" / 4
+ *
+ * A "slot" is the size of two DSPRAM bank entries; an entry from
+ * DSPRAM bank A and an entry from DSPRAM bank B. One DSPRAM bank
+ * entry is 4 bytes.
+ */
+#define SLOT_SZ 8
+static inline unsigned int decode_dspram_size(unsigned int size)
+{
+ unsigned int _sz = size & 0x7f;
+
+ return _sz * SLOT_SZ * 4;
+}
+
+static void dspram_save(struct meta_ext_context *dsp_ctx,
+ unsigned int ramA_sz, unsigned int ramB_sz)
+{
+ unsigned int ram_sz[2];
+ int i;
+
+ ram_sz[0] = ramA_sz;
+ ram_sz[1] = ramB_sz;
+
+ for (i = 0; i < 2; i++) {
+ if (ram_sz[i] != 0) {
+ unsigned int sz;
+
+ if (i == 0)
+ sz = decode_dspram_size(ram_sz[i] >> 8);
+ else
+ sz = decode_dspram_size(ram_sz[i]);
+
+ if (dsp_ctx->ram[i] == NULL) {
+ dsp_ctx->ram[i] = kmalloc(sz, GFP_KERNEL);
+
+ if (dsp_ctx->ram[i] == NULL)
+ panic("couldn't save DSP context");
+ } else {
+ if (ram_sz[i] > dsp_ctx->ram_sz[i]) {
+ kfree(dsp_ctx->ram[i]);
+
+ dsp_ctx->ram[i] = kmalloc(sz,
+ GFP_KERNEL);
+
+ if (dsp_ctx->ram[i] == NULL)
+ panic("couldn't save DSP context");
+ }
+ }
+
+ if (i == 0)
+ __TBIDspramSaveA(ram_sz[i], dsp_ctx->ram[i]);
+ else
+ __TBIDspramSaveB(ram_sz[i], dsp_ctx->ram[i]);
+
+ dsp_ctx->ram_sz[i] = ram_sz[i];
+ }
+ }
+}
+#endif /* CONFIG_METAG_DSP */
+
+/*
+ * Allow interrupts to be nested and save any "extended" register
+ * context state, e.g. DSP regs and RAMs.
+ */
+static void nest_interrupts(TBIRES State, unsigned long mask)
+{
+#ifdef CONFIG_METAG_DSP
+ struct meta_ext_context *dsp_ctx;
+ unsigned int D0_8;
+
+ /*
+ * D0.8 may contain an ECH encoding. The upper 16 bits
+ * tell us what DSP resources the current process is
+ * using. OR the bits into the SaveMask so that
+ * __TBINestInts() knows what resources to save as
+ * part of this context.
+ *
+ * Don't save the context if we're nesting interrupts in the
+ * kernel because the kernel doesn't use DSP hardware.
+ */
+ D0_8 = __core_reg_get(D0.8);
+
+ if (D0_8 && (State.Sig.SaveMask & TBICTX_PRIV_BIT)) {
+ State.Sig.SaveMask |= (D0_8 >> 16);
+
+ dsp_ctx = current->thread.dsp_context;
+ if (dsp_ctx == NULL) {
+ dsp_ctx = kzalloc(sizeof(*dsp_ctx), GFP_KERNEL);
+ if (dsp_ctx == NULL)
+ panic("couldn't save DSP context: ENOMEM");
+
+ current->thread.dsp_context = dsp_ctx;
+ }
+
+ current->thread.user_flags |= (D0_8 & 0xffff0000);
+ __TBINestInts(State, &dsp_ctx->regs, mask);
+ dspram_save(dsp_ctx, D0_8 & 0x7f00, D0_8 & 0x007f);
+ } else
+ __TBINestInts(State, NULL, mask);
+#else
+ __TBINestInts(State, NULL, mask);
+#endif
+}
+
+void head_end(TBIRES State, unsigned long mask)
+{
+ unsigned int savemask = (unsigned short)State.Sig.SaveMask;
+ unsigned int ctx_savemask = (unsigned short)State.Sig.pCtx->SaveMask;
+
+ if (savemask & TBICTX_PRIV_BIT) {
+ ctx_savemask |= TBICTX_PRIV_BIT;
+ current->thread.user_flags = savemask;
+ }
+
+ /* Always undo the sleep bit */
+ ctx_savemask &= ~TBICTX_WAIT_BIT;
+
+ /* Always save the catch buffer and RD pipe if they are dirty */
+ savemask |= TBICTX_XCBF_BIT;
+
+ /* Only save the catch and RD if we have not already done so.
+ * Note - the RD bits are in the pCtx only, and not in the
+ * State.SaveMask.
+ */
+ if ((savemask & TBICTX_CBUF_BIT) ||
+ (ctx_savemask & TBICTX_CBRP_BIT)) {
+ /* Have we already saved the buffers though?
+ * - See TestTrack 5071 */
+ if (ctx_savemask & TBICTX_XCBF_BIT) {
+ /* Strip off the bits so the call to __TBINestInts
+ * won't save the buffers again. */
+ savemask &= ~TBICTX_CBUF_BIT;
+ ctx_savemask &= ~TBICTX_CBRP_BIT;
+ }
+ }
+
+#ifdef CONFIG_METAG_META21
+ {
+ unsigned int depth, txdefr;
+
+ /*
+ * Save TXDEFR state.
+ *
+ * The process may have been interrupted after a LNKSET, but
+ * before it could read the DEFR state, so we mustn't lose that
+ * state or it could end up retrying an atomic operation that
+ * succeeded.
+ *
+ * All interrupts are disabled at this point so we
+ * don't need to perform any locking. We must do this
+ * dance before we use LNKGET or LNKSET.
+ */
+ BUG_ON(current->thread.int_depth > HARDIRQ_BITS);
+
+ depth = current->thread.int_depth++;
+
+ txdefr = __core_reg_get(TXDEFR);
+
+ txdefr &= TXDEFR_BUS_STATE_BITS;
+ if (txdefr & TXDEFR_LNKSET_SUCCESS)
+ current->thread.txdefr_failure &= ~(1 << depth);
+ else
+ current->thread.txdefr_failure |= (1 << depth);
+ }
+#endif
+
+ State.Sig.SaveMask = savemask;
+ State.Sig.pCtx->SaveMask = ctx_savemask;
+
+ nest_interrupts(State, mask);
+
+#ifdef CONFIG_METAG_POISON_CATCH_BUFFERS
+ /* Poison the catch registers. This shows up any mistakes we have
+ * made in their handling MUCH quicker.
+ */
+ __core_reg_set(TXCATCH0, 0x87650021);
+ __core_reg_set(TXCATCH1, 0x87654322);
+ __core_reg_set(TXCATCH2, 0x87654323);
+ __core_reg_set(TXCATCH3, 0x87654324);
+#endif /* CONFIG_METAG_POISON_CATCH_BUFFERS */
+}
+
+TBIRES tail_end_sys(TBIRES State, int syscall, int *restart)
+{
+ struct pt_regs *regs = (struct pt_regs *)State.Sig.pCtx;
+ unsigned long flags;
+
+ local_irq_disable();
+
+ if (user_mode(regs)) {
+ flags = current_thread_info()->flags;
+ if (flags & _TIF_WORK_MASK &&
+ do_work_pending(regs, flags, syscall)) {
+ *restart = 1;
+ return State;
+ }
+
+#ifdef CONFIG_METAG_FPU
+ if (current->thread.fpu_context &&
+ current->thread.fpu_context->needs_restore) {
+ __TBICtxFPURestore(State, current->thread.fpu_context);
+ /*
+ * Clearing this bit ensures the FP unit is not made
+ * active again unless it is used.
+ */
+ State.Sig.SaveMask &= ~TBICTX_FPAC_BIT;
+ current->thread.fpu_context->needs_restore = false;
+ }
+ State.Sig.TrigMask |= TBI_TRIG_BIT(TBID_SIGNUM_DFR);
+#endif
+ }
+
+ /* TBI will turn interrupts back on at some point. */
+ if (!irqs_disabled_flags((unsigned long)State.Sig.TrigMask))
+ trace_hardirqs_on();
+
+#ifdef CONFIG_METAG_DSP
+ /*
+ * If we previously saved an extended context then restore it
+ * now. Otherwise, clear D0.8 because this process is not
+ * using DSP hardware.
+ */
+ if (State.Sig.pCtx->SaveMask & TBICTX_XEXT_BIT) {
+ unsigned int D0_8;
+ struct meta_ext_context *dsp_ctx = current->thread.dsp_context;
+
+ /* Make sure we're going to return to userland. */
+ BUG_ON(current->thread.int_depth != 1);
+
+ if (dsp_ctx->ram_sz[0] > 0)
+ __TBIDspramRestoreA(dsp_ctx->ram_sz[0],
+ dsp_ctx->ram[0]);
+ if (dsp_ctx->ram_sz[1] > 0)
+ __TBIDspramRestoreB(dsp_ctx->ram_sz[1],
+ dsp_ctx->ram[1]);
+
+ State.Sig.SaveMask |= State.Sig.pCtx->SaveMask;
+ __TBICtxRestore(State, current->thread.dsp_context);
+ D0_8 = __core_reg_get(D0.8);
+ D0_8 |= current->thread.user_flags & 0xffff0000;
+ D0_8 |= (dsp_ctx->ram_sz[1] | dsp_ctx->ram_sz[0]) & 0xffff;
+ __core_reg_set(D0.8, D0_8);
+ } else
+ __core_reg_set(D0.8, 0);
+#endif /* CONFIG_METAG_DSP */
+
+#ifdef CONFIG_METAG_META21
+ {
+ unsigned int depth, txdefr;
+
+ /*
+ * If there hasn't been a LNKSET since the last LNKGET then the
+ * link flag will be set, causing the next LNKSET to succeed if
+ * the addresses match. The two LNK operations may not be a pair
+ * (e.g. see atomic_read()), so the LNKSET should fail.
+ * We use a conditional-never LNKSET to clear the link flag
+ * without side effects.
+ */
+ asm volatile("LNKSETDNV [D0Re0],D0Re0");
+
+ depth = --current->thread.int_depth;
+
+ BUG_ON(user_mode(regs) && depth);
+
+ txdefr = __core_reg_get(TXDEFR);
+
+ txdefr &= ~TXDEFR_BUS_STATE_BITS;
+
+ /* Do we need to restore a failure code into TXDEFR? */
+ if (current->thread.txdefr_failure & (1 << depth))
+ txdefr |= (TXDEFR_LNKSET_FAILURE | TXDEFR_BUS_TRIG_BIT);
+ else
+ txdefr |= (TXDEFR_LNKSET_SUCCESS | TXDEFR_BUS_TRIG_BIT);
+
+ __core_reg_set(TXDEFR, txdefr);
+ }
+#endif
+ return State;
+}
+
+#ifdef CONFIG_SMP
+/*
+ * If we took an interrupt in the middle of __kuser_get_tls then we need
+ * to rewind the PC to the start of the function in case the process
+ * gets migrated to another thread (SMP only) and it reads the wrong tls
+ * data.
+ */
+static inline void _restart_critical_section(TBIRES State)
+{
+ unsigned long get_tls_start;
+ unsigned long get_tls_end;
+
+ get_tls_start = (unsigned long)__kuser_get_tls -
+ (unsigned long)&__user_gateway_start;
+
+ get_tls_start += USER_GATEWAY_PAGE;
+
+ get_tls_end = (unsigned long)__kuser_get_tls_end -
+ (unsigned long)&__user_gateway_start;
+
+ get_tls_end += USER_GATEWAY_PAGE;
+
+ if ((State.Sig.pCtx->CurrPC >= get_tls_start) &&
+ (State.Sig.pCtx->CurrPC < get_tls_end))
+ State.Sig.pCtx->CurrPC = get_tls_start;
+}
+#else
+/*
+ * If we took an interrupt in the middle of
+ * __kuser_cmpxchg then we need to rewind the PC to the
+ * start of the function.
+ */
+static inline void _restart_critical_section(TBIRES State)
+{
+ unsigned long cmpxchg_start;
+ unsigned long cmpxchg_end;
+
+ cmpxchg_start = (unsigned long)__kuser_cmpxchg -
+ (unsigned long)&__user_gateway_start;
+
+ cmpxchg_start += USER_GATEWAY_PAGE;
+
+ cmpxchg_end = (unsigned long)__kuser_cmpxchg_end -
+ (unsigned long)&__user_gateway_start;
+
+ cmpxchg_end += USER_GATEWAY_PAGE;
+
+ if ((State.Sig.pCtx->CurrPC >= cmpxchg_start) &&
+ (State.Sig.pCtx->CurrPC < cmpxchg_end))
+ State.Sig.pCtx->CurrPC = cmpxchg_start;
+}
+#endif
+
+/* Used by kick_handler() */
+void restart_critical_section(TBIRES State)
+{
+ _restart_critical_section(State);
+}
+
+TBIRES trigger_handler(TBIRES State, int SigNum, int Triggers, int Inst,
+ PTBI pTBI)
+{
+ head_end(State, ~INTS_OFF_MASK);
+
+ /* If we interrupted user code handle any critical sections. */
+ if (State.Sig.SaveMask & TBICTX_PRIV_BIT)
+ _restart_critical_section(State);
+
+ trace_hardirqs_off();
+
+ do_IRQ(SigNum, (struct pt_regs *)State.Sig.pCtx);
+
+ return tail_end(State);
+}
+
+static unsigned int load_fault(PTBICTXEXTCB0 pbuf)
+{
+ return pbuf->CBFlags & TXCATCH0_READ_BIT;
+}
+
+static unsigned long fault_address(PTBICTXEXTCB0 pbuf)
+{
+ return pbuf->CBAddr;
+}
+
+static void unhandled_fault(struct pt_regs *regs, unsigned long addr,
+ int signo, int code, int trapno)
+{
+ if (user_mode(regs)) {
+ siginfo_t info;
+
+ if (show_unhandled_signals && unhandled_signal(current, signo)
+ && printk_ratelimit()) {
+
+ pr_info("pid %d unhandled fault: pc 0x%08x, addr 0x%08lx, trap %d (%s)\n",
+ current->pid, regs->ctx.CurrPC, addr,
+ trapno, trap_name(trapno));
+ print_vma_addr(" in ", regs->ctx.CurrPC);
+ print_vma_addr(" rtp in ", regs->ctx.DX[4].U1);
+ printk("\n");
+ show_regs(regs);
+ }
+
+ info.si_signo = signo;
+ info.si_errno = 0;
+ info.si_code = code;
+ info.si_addr = (__force void __user *)addr;
+ info.si_trapno = trapno;
+ force_sig_info(signo, &info, current);
+ } else {
+ die("Oops", regs, trapno, addr);
+ }
+}
+
+static int handle_data_fault(PTBICTXEXTCB0 pcbuf, struct pt_regs *regs,
+ unsigned int data_address, int trapno)
+{
+ int ret;
+
+ ret = do_page_fault(regs, data_address, !load_fault(pcbuf), trapno);
+
+ return ret;
+}
+
+static unsigned long get_inst_fault_address(struct pt_regs *regs)
+{
+ return regs->ctx.CurrPC;
+}
+
+TBIRES fault_handler(TBIRES State, int SigNum, int Triggers,
+ int Inst, PTBI pTBI)
+{
+ struct pt_regs *regs = (struct pt_regs *)State.Sig.pCtx;
+ PTBICTXEXTCB0 pcbuf = (PTBICTXEXTCB0)®s->extcb0;
+ unsigned long data_address;
+
+ head_end(State, ~INTS_OFF_MASK);
+
+ /* Hardware breakpoint or data watch */
+ if ((SigNum == TBIXXF_SIGNUM_IHF) ||
+ ((SigNum == TBIXXF_SIGNUM_DHF) &&
+ (pcbuf[0].CBFlags & (TXCATCH0_WATCH1_BIT |
+ TXCATCH0_WATCH0_BIT)))) {
+ State = __TBIUnExpXXX(State, SigNum, Triggers, Inst,
+ pTBI);
+ return tail_end(State);
+ }
+
+ local_irq_enable();
+
+ data_address = fault_address(pcbuf);
+
+ switch (SigNum) {
+ case TBIXXF_SIGNUM_IGF:
+ /* 1st-level entry invalid (instruction fetch) */
+ case TBIXXF_SIGNUM_IPF: {
+ /* 2nd-level entry invalid (instruction fetch) */
+ unsigned long addr = get_inst_fault_address(regs);
+ do_page_fault(regs, addr, 0, SigNum);
+ break;
+ }
+
+ case TBIXXF_SIGNUM_DGF:
+ /* 1st-level entry invalid (data access) */
+ case TBIXXF_SIGNUM_DPF:
+ /* 2nd-level entry invalid (data access) */
+ case TBIXXF_SIGNUM_DWF:
+ /* Write to read only page */
+ handle_data_fault(pcbuf, regs, data_address, SigNum);
+ break;
+
+ case TBIXXF_SIGNUM_IIF:
+ /* Illegal instruction */
+ unhandled_fault(regs, regs->ctx.CurrPC, SIGILL, ILL_ILLOPC,
+ SigNum);
+ break;
+
+ case TBIXXF_SIGNUM_DHF:
+ /* Unaligned access */
+ unhandled_fault(regs, data_address, SIGBUS, BUS_ADRALN,
+ SigNum);
+ break;
+ case TBIXXF_SIGNUM_PGF:
+ /* Privilege violation */
+ unhandled_fault(regs, data_address, SIGSEGV, SEGV_ACCERR,
+ SigNum);
+ break;
+ default:
+ BUG();
+ break;
+ }
+
+ return tail_end(State);
+}
+
+static bool switch_is_syscall(unsigned int inst)
+{
+ return inst == __METAG_SW_ENCODING(SYS);
+}
+
+static bool switch_is_legacy_syscall(unsigned int inst)
+{
+ return inst == __METAG_SW_ENCODING(SYS_LEGACY);
+}
+
+static inline void step_over_switch(struct pt_regs *regs, unsigned int inst)
+{
+ regs->ctx.CurrPC += 4;
+}
+
+static inline int test_syscall_work(void)
+{
+ return current_thread_info()->flags & _TIF_WORK_SYSCALL_MASK;
+}
+
+TBIRES switch1_handler(TBIRES State, int SigNum, int Triggers,
+ int Inst, PTBI pTBI)
+{
+ struct pt_regs *regs = (struct pt_regs *)State.Sig.pCtx;
+ unsigned int sysnumber;
+ unsigned long long a1_a2, a3_a4, a5_a6;
+ LPSYSCALL syscall_entry;
+ int restart;
+
+ head_end(State, ~INTS_OFF_MASK);
+
+ /*
+ * If this is not a syscall SWITCH it could be a breakpoint.
+ */
+ if (!switch_is_syscall(Inst)) {
+ /*
+ * Alert the user if they're trying to use legacy system
+ * calls. This suggests they need to update their C
+ * library and build against up to date kernel headers.
+ */
+ if (switch_is_legacy_syscall(Inst))
+ pr_warn_once("WARNING: A legacy syscall was made. Your userland needs updating.\n");
+ /*
+ * We don't know how to handle the SWITCH and cannot
+ * safely ignore it, so treat all unknown switches
+ * (including breakpoints) as traps.
+ */
+ force_sig(SIGTRAP, current);
+ return tail_end(State);
+ }
+
+ local_irq_enable();
+
+restart_syscall:
+ restart = 0;
+ sysnumber = regs->ctx.DX[0].U1;
+
+ if (test_syscall_work())
+ sysnumber = syscall_trace_enter(regs);
+
+ /* Skip over the SWITCH instruction - or you just get 'stuck' on it! */
+ step_over_switch(regs, Inst);
+
+ if (sysnumber >= __NR_syscalls) {
+ pr_debug("unknown syscall number: %d\n", sysnumber);
+ syscall_entry = (LPSYSCALL) sys_ni_syscall;
+ } else {
+ syscall_entry = (LPSYSCALL) sys_call_table[sysnumber];
+ }
+
+ /* Use 64bit loads for speed. */
+ a5_a6 = *(unsigned long long *)®s->ctx.DX[1];
+ a3_a4 = *(unsigned long long *)®s->ctx.DX[2];
+ a1_a2 = *(unsigned long long *)®s->ctx.DX[3];
+
+ /* here is the actual call to the syscall handler functions */
+ regs->ctx.DX[0].U0 = syscall_entry(a1_a2, a3_a4, a5_a6);
+
+ if (test_syscall_work())
+ syscall_trace_leave(regs);
+
+ State = tail_end_sys(State, sysnumber, &restart);
+ /* Handlerless restarts shouldn't go via userland */
+ if (restart)
+ goto restart_syscall;
+ return State;
+}
+
+TBIRES switchx_handler(TBIRES State, int SigNum, int Triggers,
+ int Inst, PTBI pTBI)
+{
+ struct pt_regs *regs = (struct pt_regs *)State.Sig.pCtx;
+
+ /*
+ * This can be caused by any user process simply executing an unusual
+ * SWITCH instruction. If there's no DA, __TBIUnExpXXX will cause the
+ * thread to stop, so signal a SIGTRAP instead.
+ */
+ head_end(State, ~INTS_OFF_MASK);
+ if (user_mode(regs))
+ force_sig(SIGTRAP, current);
+ else
+ State = __TBIUnExpXXX(State, SigNum, Triggers, Inst, pTBI);
+ return tail_end(State);
+}
+
+#ifdef CONFIG_METAG_META21
+TBIRES fpe_handler(TBIRES State, int SigNum, int Triggers, int Inst, PTBI pTBI)
+{
+ struct pt_regs *regs = (struct pt_regs *)State.Sig.pCtx;
+ unsigned int error_state = Triggers;
+ siginfo_t info;
+
+ head_end(State, ~INTS_OFF_MASK);
+
+ local_irq_enable();
+
+ info.si_signo = SIGFPE;
+
+ if (error_state & TXSTAT_FPE_INVALID_BIT)
+ info.si_code = FPE_FLTINV;
+ else if (error_state & TXSTAT_FPE_DIVBYZERO_BIT)
+ info.si_code = FPE_FLTDIV;
+ else if (error_state & TXSTAT_FPE_OVERFLOW_BIT)
+ info.si_code = FPE_FLTOVF;
+ else if (error_state & TXSTAT_FPE_UNDERFLOW_BIT)
+ info.si_code = FPE_FLTUND;
+ else if (error_state & TXSTAT_FPE_INEXACT_BIT)
+ info.si_code = FPE_FLTRES;
+ else
+ info.si_code = 0;
+ info.si_errno = 0;
+ info.si_addr = (__force void __user *)regs->ctx.CurrPC;
+ force_sig_info(SIGFPE, &info, current);
+
+ return tail_end(State);
+}
+#endif
+
+#ifdef CONFIG_METAG_SUSPEND_MEM
+struct traps_context {
+ PTBIAPIFN fnSigs[TBID_SIGNUM_MAX + 1];
+};
+
+static struct traps_context *metag_traps_context;
+
+int traps_save_context(void)
+{
+ unsigned long cpu = smp_processor_id();
+ PTBI _pTBI = per_cpu(pTBI, cpu);
+ struct traps_context *context;
+
+ context = kzalloc(sizeof(*context), GFP_ATOMIC);
+ if (!context)
+ return -ENOMEM;
+
+ memcpy(context->fnSigs, (void *)_pTBI->fnSigs, sizeof(context->fnSigs));
+
+ metag_traps_context = context;
+ return 0;
+}
+
+int traps_restore_context(void)
+{
+ unsigned long cpu = smp_processor_id();
+ PTBI _pTBI = per_cpu(pTBI, cpu);
+ struct traps_context *context = metag_traps_context;
+
+ metag_traps_context = NULL;
+
+ memcpy((void *)_pTBI->fnSigs, context->fnSigs, sizeof(context->fnSigs));
+
+ kfree(context);
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_SMP
+unsigned int get_trigger_mask(void)
+{
+ unsigned long cpu = smp_processor_id();
+ return per_cpu(trigger_mask, cpu);
+}
+
+static void set_trigger_mask(unsigned int mask)
+{
+ unsigned long cpu = smp_processor_id();
+ per_cpu(trigger_mask, cpu) = mask;
+}
+#else
+static void set_trigger_mask(unsigned int mask)
+{
+ global_trigger_mask = mask;
+}
+#endif
+
+void __cpuinit per_cpu_trap_init(unsigned long cpu)
+{
+ TBIRES int_context;
+ unsigned int thread = cpu_2_hwthread_id[cpu];
+
+ set_trigger_mask(TBI_INTS_INIT(thread) | /* interrupts */
+ TBI_TRIG_BIT(TBID_SIGNUM_LWK) | /* low level kick */
+ TBI_TRIG_BIT(TBID_SIGNUM_SW1) |
+ TBI_TRIG_BIT(TBID_SIGNUM_SWS));
+
+ /* non-priv - use current stack */
+ int_context.Sig.pCtx = NULL;
+ /* Start with interrupts off */
+ int_context.Sig.TrigMask = INTS_OFF_MASK;
+ int_context.Sig.SaveMask = 0;
+
+ /* And call __TBIASyncTrigger() */
+ __TBIASyncTrigger(int_context);
+}
+
+void __init trap_init(void)
+{
+ unsigned long cpu = smp_processor_id();
+ PTBI _pTBI = per_cpu(pTBI, cpu);
+
+ _pTBI->fnSigs[TBID_SIGNUM_XXF] = fault_handler;
+ _pTBI->fnSigs[TBID_SIGNUM_SW0] = switchx_handler;
+ _pTBI->fnSigs[TBID_SIGNUM_SW1] = switch1_handler;
+ _pTBI->fnSigs[TBID_SIGNUM_SW2] = switchx_handler;
+ _pTBI->fnSigs[TBID_SIGNUM_SW3] = switchx_handler;
+ _pTBI->fnSigs[TBID_SIGNUM_SWK] = kick_handler;
+
+#ifdef CONFIG_METAG_META21
+ _pTBI->fnSigs[TBID_SIGNUM_DFR] = __TBIHandleDFR;
+ _pTBI->fnSigs[TBID_SIGNUM_FPE] = fpe_handler;
+#endif
+
+ per_cpu_trap_init(cpu);
+}
+
+void tbi_startup_interrupt(int irq)
+{
+ unsigned long cpu = smp_processor_id();
+ PTBI _pTBI = per_cpu(pTBI, cpu);
+
+ BUG_ON(irq > TBID_SIGNUM_MAX);
+
+ /* For TR1 and TR2, the thread id is encoded in the irq number */
+ if (irq >= TBID_SIGNUM_T10 && irq < TBID_SIGNUM_TR3)
+ cpu = hwthread_id_2_cpu[(irq - TBID_SIGNUM_T10) % 4];
+
+ set_trigger_mask(get_trigger_mask() | TBI_TRIG_BIT(irq));
+
+ _pTBI->fnSigs[irq] = trigger_handler;
+}
+
+void tbi_shutdown_interrupt(int irq)
+{
+ unsigned long cpu = smp_processor_id();
+ PTBI _pTBI = per_cpu(pTBI, cpu);
+
+ BUG_ON(irq > TBID_SIGNUM_MAX);
+
+ set_trigger_mask(get_trigger_mask() & ~TBI_TRIG_BIT(irq));
+
+ _pTBI->fnSigs[irq] = __TBIUnExpXXX;
+}
+
+int ret_from_fork(TBIRES arg)
+{
+ struct task_struct *prev = arg.Switch.pPara;
+ struct task_struct *tsk = current;
+ struct pt_regs *regs = task_pt_regs(tsk);
+ int (*fn)(void *);
+ TBIRES Next;
+
+ schedule_tail(prev);
+
+ if (tsk->flags & PF_KTHREAD) {
+ fn = (void *)regs->ctx.DX[4].U1;
+ BUG_ON(!fn);
+
+ fn((void *)regs->ctx.DX[3].U1);
+ }
+
+ if (test_syscall_work())
+ syscall_trace_leave(regs);
+
+ preempt_disable();
+
+ Next.Sig.TrigMask = get_trigger_mask();
+ Next.Sig.SaveMask = 0;
+ Next.Sig.pCtx = ®s->ctx;
+
+ set_gateway_tls(current->thread.tls_ptr);
+
+ preempt_enable_no_resched();
+
+ /* And interrupts should come back on when we resume the real usermode
+ * code. Call __TBIASyncResume()
+ */
+ __TBIASyncResume(tail_end(Next));
+ /* ASyncResume should NEVER return */
+ BUG();
+ return 0;
+}
+
+void show_trace(struct task_struct *tsk, unsigned long *sp,
+ struct pt_regs *regs)
+{
+ unsigned long addr;
+#ifdef CONFIG_FRAME_POINTER
+ unsigned long fp, fpnew;
+ unsigned long stack;
+#endif
+
+ if (regs && user_mode(regs))
+ return;
+
+ printk("\nCall trace: ");
+#ifdef CONFIG_KALLSYMS
+ printk("\n");
+#endif
+
+ if (!tsk)
+ tsk = current;
+
+#ifdef CONFIG_FRAME_POINTER
+ if (regs) {
+ print_ip_sym(regs->ctx.CurrPC);
+ fp = regs->ctx.AX[1].U0;
+ } else {
+ fp = __core_reg_get(A0FrP);
+ }
+
+ /* detect when the frame pointer has been used for other purposes and
+ * doesn't point to the stack (it may point completely elsewhere which
+ * kstack_end may not detect).
+ */
+ stack = (unsigned long)task_stack_page(tsk);
+ while (fp >= stack && fp + 8 <= stack + THREAD_SIZE) {
+ addr = __raw_readl((unsigned long *)(fp + 4)) - 4;
+ if (kernel_text_address(addr))
+ print_ip_sym(addr);
+ else
+ break;
+ /* stack grows up, so frame pointers must decrease */
+ fpnew = __raw_readl((unsigned long *)(fp + 0));
+ if (fpnew >= fp)
+ break;
+ fp = fpnew;
+ }
+#else
+ while (!kstack_end(sp)) {
+ addr = (*sp--) - 4;
+ if (kernel_text_address(addr))
+ print_ip_sym(addr);
+ }
+#endif
+
+ printk("\n");
+
+ debug_show_held_locks(tsk);
+}
+
+void show_stack(struct task_struct *tsk, unsigned long *sp)
+{
+ if (!tsk)
+ tsk = current;
+ if (tsk == current)
+ sp = (unsigned long *)current_stack_pointer;
+ else
+ sp = (unsigned long *)tsk->thread.kernel_context->AX[0].U0;
+
+ show_trace(tsk, sp, NULL);
+}
+
+void dump_stack(void)
+{
+ show_stack(NULL, NULL);
+}
+EXPORT_SYMBOL(dump_stack);