[PATCH] avr32 architecture

This adds support for the Atmel AVR32 architecture as well as the AT32AP7000
CPU and the AT32STK1000 development board.

AVR32 is a new high-performance 32-bit RISC microprocessor core, designed for
cost-sensitive embedded applications, with particular emphasis on low power
consumption and high code density.  The AVR32 architecture is not binary
compatible with earlier 8-bit AVR architectures.

The AVR32 architecture, including the instruction set, is described by the
AVR32 Architecture Manual, available from

http://www.atmel.com/dyn/resources/prod_documents/doc32000.pdf

The Atmel AT32AP7000 is the first CPU implementing the AVR32 architecture.  It
features a 7-stage pipeline, 16KB instruction and data caches and a full
Memory Management Unit.  It also comes with a large set of integrated
peripherals, many of which are shared with the AT91 ARM-based controllers from
Atmel.

Full data sheet is available from

http://www.atmel.com/dyn/resources/prod_documents/doc32003.pdf

while the CPU core implementation including caches and MMU is documented by
the AVR32 AP Technical Reference, available from

http://www.atmel.com/dyn/resources/prod_documents/doc32001.pdf

Information about the AT32STK1000 development board can be found at

http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3918

including a BSP CD image with an earlier version of this patch, development
tools (binaries and source/patches) and a root filesystem image suitable for
booting from SD card.

Alternatively, there's a preliminary "getting started" guide available at
http://avr32linux.org/twiki/bin/view/Main/GettingStarted which provides links
to the sources and patches you will need in order to set up a cross-compiling
environment for avr32-linux.

This patch, as well as the other patches included with the BSP and the
toolchain patches, is actively supported by Atmel Corporation.

[dmccr@us.ibm.com: Fix more pxx_page macro locations]
[bunk@stusta.de: fix `make defconfig']
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Dave McCracken <dmccr@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 328 insertions, 0 deletions

diff --git a/arch/avr32/kernel/signal.c b/arch/avr32/kernel/signal.c
new file mode 100644
index 000000000000..33096651c24f
--- /dev/null
+++ b/arch/avr32/kernel/signal.c
@@ -0,0 +1,328 @@
+/*
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * Based on linux/arch/sh/kernel/signal.c
+ *  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/suspend.h>
+
+#include <asm/uaccess.h>
+#include <asm/ucontext.h>
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
+			       struct pt_regs *regs)
+{
+	return do_sigaltstack(uss, uoss, regs->sp);
+}
+
+struct rt_sigframe
+{
+	struct siginfo info;
+	struct ucontext uc;
+	unsigned long retcode;
+};
+
+static int
+restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+	int err = 0;
+
+#define COPY(x)		err |= __get_user(regs->x, &sc->x)
+	COPY(sr);
+	COPY(pc);
+	COPY(lr);
+	COPY(sp);
+	COPY(r12);
+	COPY(r11);
+	COPY(r10);
+	COPY(r9);
+	COPY(r8);
+	COPY(r7);
+	COPY(r6);
+	COPY(r5);
+	COPY(r4);
+	COPY(r3);
+	COPY(r2);
+	COPY(r1);
+	COPY(r0);
+#undef	COPY
+
+	/*
+	 * Don't allow anyone to pretend they're running in supervisor
+	 * mode or something...
+	 */
+	err |= !valid_user_regs(regs);
+
+	return err;
+}
+
+
+asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
+{
+	struct rt_sigframe __user *frame;
+	sigset_t set;
+
+	frame = (struct rt_sigframe __user *)regs->sp;
+	pr_debug("SIG return: frame = %p\n", frame);
+
+	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+
+	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+		goto badframe;
+
+	sigdelsetmask(&set, ~_BLOCKABLE);
+	spin_lock_irq(&current->sighand->siglock);
+	current->blocked = set;
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+
+	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
+		goto badframe;
+
+	pr_debug("Context restored: pc = %08lx, lr = %08lx, sp = %08lx\n",
+		 regs->pc, regs->lr, regs->sp);
+
+	return regs->r12;
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+static int
+setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
+{
+	int err = 0;
+
+#define COPY(x)		err |= __put_user(regs->x, &sc->x)
+	COPY(sr);
+	COPY(pc);
+	COPY(lr);
+	COPY(sp);
+	COPY(r12);
+	COPY(r11);
+	COPY(r10);
+	COPY(r9);
+	COPY(r8);
+	COPY(r7);
+	COPY(r6);
+	COPY(r5);
+	COPY(r4);
+	COPY(r3);
+	COPY(r2);
+	COPY(r1);
+	COPY(r0);
+#undef	COPY
+
+	return err;
+}
+
+static inline void __user *
+get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
+{
+	unsigned long sp = regs->sp;
+
+	if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
+		sp = current->sas_ss_sp + current->sas_ss_size;
+
+	return (void __user *)((sp - framesize) & ~3);
+}
+
+static int
+setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+	       sigset_t *set, struct pt_regs *regs)
+{
+	struct rt_sigframe __user *frame;
+	int err = 0;
+
+	frame = get_sigframe(ka, regs, sizeof(*frame));
+	err = -EFAULT;
+	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
+		goto out;
+
+	/*
+	 * Set up the return code:
+	 *
+	 *	mov	r8, __NR_rt_sigreturn
+	 *	scall
+	 *
+	 * Note: This will blow up since we're using a non-executable
+	 * stack. Better use SA_RESTORER.
+	 */
+#if __NR_rt_sigreturn > 127
+# error __NR_rt_sigreturn must be < 127 to fit in a short mov
+#endif
+	err = __put_user(0x3008d733 | (__NR_rt_sigreturn << 20),
+			 &frame->retcode);
+
+	err |= copy_siginfo_to_user(&frame->info, info);
+
+	/* Set up the ucontext */
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(NULL, &frame->uc.uc_link);
+	err |= __put_user((void __user *)current->sas_ss_sp,
+			  &frame->uc.uc_stack.ss_sp);
+	err |= __put_user(sas_ss_flags(regs->sp),
+			  &frame->uc.uc_stack.ss_flags);
+	err |= __put_user(current->sas_ss_size,
+			  &frame->uc.uc_stack.ss_size);
+	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs);
+	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+	if (err)
+		goto out;
+
+	regs->r12 = sig;
+	regs->r11 = (unsigned long) &frame->info;
+	regs->r10 = (unsigned long) &frame->uc;
+	regs->sp = (unsigned long) frame;
+	if (ka->sa.sa_flags & SA_RESTORER)
+		regs->lr = (unsigned long)ka->sa.sa_restorer;
+	else {
+		printk(KERN_NOTICE "[%s:%d] did not set SA_RESTORER\n",
+		       current->comm, current->pid);
+		regs->lr = (unsigned long) &frame->retcode;
+	}
+
+	pr_debug("SIG deliver [%s:%d]: sig=%d sp=0x%lx pc=0x%lx->0x%p lr=0x%lx\n",
+		 current->comm, current->pid, sig, regs->sp,
+		 regs->pc, ka->sa.sa_handler, regs->lr);
+
+	regs->pc = (unsigned long) ka->sa.sa_handler;
+
+out:
+	return err;
+}
+
+static inline void restart_syscall(struct pt_regs *regs)
+{
+	if (regs->r12 == -ERESTART_RESTARTBLOCK)
+		regs->r8 = __NR_restart_syscall;
+	else
+		regs->r12 = regs->r12_orig;
+	regs->pc -= 2;
+}
+
+static inline void
+handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
+	      sigset_t *oldset, struct pt_regs *regs, int syscall)
+{
+	int ret;
+
+	/*
+	 * Set up the stack frame
+	 */
+	ret = setup_rt_frame(sig, ka, info, oldset, regs);
+
+	/*
+	 * Check that the resulting registers are sane
+	 */
+	ret |= !valid_user_regs(regs);
+
+	/*
+	 * Block the signal if we were unsuccessful.
+	 */
+	if (ret != 0 || !(ka->sa.sa_flags & SA_NODEFER)) {
+		spin_lock_irq(&current->sighand->siglock);
+		sigorsets(&current->blocked, &current->blocked,
+			  &ka->sa.sa_mask);
+		sigaddset(&current->blocked, sig);
+		recalc_sigpending();
+		spin_unlock_irq(&current->sighand->siglock);
+	}
+
+	if (ret == 0)
+		return;
+
+	force_sigsegv(sig, current);
+}
+
+/*
+ * Note that 'init' is a special process: it doesn't get signals it
+ * doesn't want to handle. Thus you cannot kill init even with a
+ * SIGKILL even by mistake.
+ */
+int do_signal(struct pt_regs *regs, sigset_t *oldset, int syscall)
+{
+	siginfo_t info;
+	int signr;
+	struct k_sigaction ka;
+
+	/*
+	 * We want the common case to go fast, which is why we may in
+	 * certain cases get here from kernel mode. Just return
+	 * without doing anything if so.
+	 */
+	if (!user_mode(regs))
+		return 0;
+
+	if (try_to_freeze()) {
+		signr = 0;
+		if (!signal_pending(current))
+			goto no_signal;
+	}
+
+	if (test_thread_flag(TIF_RESTORE_SIGMASK))
+		oldset = &current->saved_sigmask;
+	else if (!oldset)
+		oldset = &current->blocked;
+
+	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+no_signal:
+	if (syscall) {
+		switch (regs->r12) {
+		case -ERESTART_RESTARTBLOCK:
+		case -ERESTARTNOHAND:
+			if (signr > 0) {
+				regs->r12 = -EINTR;
+				break;
+			}
+			/* fall through */
+		case -ERESTARTSYS:
+			if (signr > 0 && !(ka.sa.sa_flags & SA_RESTART)) {
+				regs->r12 = -EINTR;
+				break;
+			}
+			/* fall through */
+		case -ERESTARTNOINTR:
+			restart_syscall(regs);
+		}
+	}
+
+	if (signr == 0) {
+		/* No signal to deliver -- put the saved sigmask back */
+		if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+			clear_thread_flag(TIF_RESTORE_SIGMASK);
+			sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+		}
+		return 0;
+	}
+
+	handle_signal(signr, &ka, &info, oldset, regs, syscall);
+	return 1;
+}
+
+asmlinkage void do_notify_resume(struct pt_regs *regs, struct thread_info *ti)
+{
+	int syscall = 0;
+
+	if ((sysreg_read(SR) & MODE_MASK) == MODE_SUPERVISOR)
+		syscall = 1;
+
+	if (ti->flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
+		do_signal(regs, &current->blocked, syscall);
+}