blackfin architecture

This adds support for the Analog Devices Blackfin processor architecture, and
currently supports the BF533, BF532, BF531, BF537, BF536, BF534, and BF561
(Dual Core) devices, with a variety of development platforms including those
avaliable from Analog Devices (BF533-EZKit, BF533-STAMP, BF537-STAMP,
BF561-EZKIT), and Bluetechnix!  Tinyboards.

The Blackfin architecture was jointly developed by Intel and Analog Devices
Inc.  (ADI) as the Micro Signal Architecture (MSA) core and introduced it in
December of 2000.  Since then ADI has put this core into its Blackfin
processor family of devices.  The Blackfin core has the advantages of a clean,
orthogonal,RISC-like microprocessor instruction set.  It combines a dual-MAC
(Multiply/Accumulate), state-of-the-art signal processing engine and
single-instruction, multiple-data (SIMD) multimedia capabilities into a single
instruction-set architecture.

The Blackfin architecture, including the instruction set, is described by the
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
http://blackfin.uclinux.org/gf/download/frsrelease/29/2549/Blackfin_PRM.pdf

The Blackfin processor is already supported by major releases of gcc, and
there are binary and source rpms/tarballs for many architectures at:
http://blackfin.uclinux.org/gf/project/toolchain/frs There is complete
documentation, including "getting started" guides available at:
http://docs.blackfin.uclinux.org/ which provides links to the sources and
patches you will need in order to set up a cross-compiling environment for
bfin-linux-uclibc

This patch, as well as the other patches (toolchain, distribution,
uClibc) are actively supported by Analog Devices Inc, at:
http://blackfin.uclinux.org/

We have tested this on LTP, and our test plan (including pass/fails) can
be found at:
http://docs.blackfin.uclinux.org/doku.php?id=testing_the_linux_kernel

[m.kozlowski@tuxland.pl: balance parenthesis in blackfin header files]
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Aubrey Li <aubrey.li@analog.com>
Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 430 insertions, 0 deletions

diff --git a/arch/blackfin/kernel/ptrace.c b/arch/blackfin/kernel/ptrace.c
new file mode 100644
index 000000000000..d7c8e514cb92
--- /dev/null
+++ b/arch/blackfin/kernel/ptrace.c
@@ -0,0 +1,430 @@
+/*
+ * File:         arch/blackfin/kernel/ptrace.c
+ * Based on:     Taken from linux/kernel/ptrace.c
+ * Author:       linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
+ *
+ * Created:      1/23/92
+ * Description:
+ *
+ * Modified:
+ *               Copyright 2004-2006 Analog Devices Inc.
+ *
+ * Bugs:         Enter bugs at http://blackfin.uclinux.org/
+ *
+ * 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.
+ *
+ * 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.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/signal.h>
+
+#include <asm/uaccess.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/processor.h>
+#include <asm/asm-offsets.h>
+#include <asm/dma.h>
+
+#define MAX_SHARED_LIBS 3
+#define TEXT_OFFSET 0
+/*
+ * does not yet catch signals sent when the child dies.
+ * in exit.c or in signal.c.
+ */
+
+/* determines which bits in the SYSCFG reg the user has access to. */
+/* 1 = access 0 = no access */
+#define SYSCFG_MASK 0x0007	/* SYSCFG reg */
+/* sets the trace bits. */
+#define TRACE_BITS 0x0001
+
+/* Find the stack offset for a register, relative to thread.esp0. */
+#define PT_REG(reg)	((long)&((struct pt_regs *)0)->reg)
+
+/*
+ * Get the address of the live pt_regs for the specified task.
+ * These are saved onto the top kernel stack when the process
+ * is not running.
+ *
+ * Note: if a user thread is execve'd from kernel space, the
+ * kernel stack will not be empty on entry to the kernel, so
+ * ptracing these tasks will fail.
+ */
+static inline struct pt_regs *get_user_regs(struct task_struct *task)
+{
+	return (struct pt_regs *)
+	    ((unsigned long)task->thread_info +
+	     (THREAD_SIZE - sizeof(struct pt_regs)));
+}
+
+/*
+ * Get all user integer registers.
+ */
+static inline int ptrace_getregs(struct task_struct *tsk, void __user * uregs)
+{
+	struct pt_regs *regs = get_user_regs(tsk);
+	return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
+}
+
+/* Mapping from PT_xxx to the stack offset at which the register is
+ * saved.  Notice that usp has no stack-slot and needs to be treated
+ * specially (see get_reg/put_reg below).
+ */
+
+/*
+ * Get contents of register REGNO in task TASK.
+ */
+static inline long get_reg(struct task_struct *task, int regno)
+{
+	unsigned char *reg_ptr;
+
+	struct pt_regs *regs =
+	    (struct pt_regs *)((unsigned long)task->thread_info +
+			       (THREAD_SIZE - sizeof(struct pt_regs)));
+	reg_ptr = (char *)regs;
+
+	switch (regno) {
+	case PT_USP:
+		return task->thread.usp;
+	default:
+		if (regno <= 216)
+			return *(long *)(reg_ptr + regno);
+	}
+	/* slight mystery ... never seems to come here but kernel misbehaves without this code! */
+
+	printk(KERN_WARNING "Request to get for unknown register %d\n", regno);
+	return 0;
+}
+
+/*
+ * Write contents of register REGNO in task TASK.
+ */
+static inline int
+put_reg(struct task_struct *task, int regno, unsigned long data)
+{
+	char * reg_ptr;
+
+	struct pt_regs *regs =
+	    (struct pt_regs *)((unsigned long)task->thread_info +
+			       (THREAD_SIZE - sizeof(struct pt_regs)));
+	reg_ptr = (char *)regs;
+
+	switch (regno) {
+	case PT_PC:
+		/*********************************************************************/
+		/* At this point the kernel is most likely in exception.             */
+		/* The RETX register will be used to populate the pc of the process. */
+		/*********************************************************************/
+		regs->retx = data;
+		regs->pc = data;
+		break;
+	case PT_RETX:
+		break;		/* regs->retx = data; break; */
+	case PT_USP:
+		regs->usp = data;
+		task->thread.usp = data;
+		break;
+	default:
+		if (regno <= 216)
+		        *(long *)(reg_ptr + regno) = data;
+	}
+	return 0;
+}
+
+/*
+ * check that an address falls within the bounds of the target process's memory mappings
+ */
+static inline int is_user_addr_valid(struct task_struct *child,
+				     unsigned long start, unsigned long len)
+{
+	struct vm_list_struct *vml;
+	struct sram_list_struct *sraml;
+
+	for (vml = child->mm->context.vmlist; vml; vml = vml->next)
+		if (start >= vml->vma->vm_start && start + len <= vml->vma->vm_end)
+			return 0;
+
+	for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
+		if (start >= (unsigned long)sraml->addr
+		    && start + len <= (unsigned long)sraml->addr + sraml->length)
+			return 0;
+
+	return -EIO;
+}
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure the single step bit is not set.
+ */
+void ptrace_disable(struct task_struct *child)
+{
+	unsigned long tmp;
+	/* make sure the single step bit is not set. */
+	tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16);
+	put_reg(child, PT_SR, tmp);
+}
+
+long arch_ptrace(struct task_struct *child, long request, long addr, long data)
+{
+	int ret;
+	int add = 0;
+
+	switch (request) {
+		/* when I and D space are separate, these will need to be fixed. */
+	case PTRACE_PEEKDATA:
+		pr_debug("ptrace: PEEKDATA\n");
+		add = MAX_SHARED_LIBS * 4;	/* space between text and data */
+		/* fall through */
+	case PTRACE_PEEKTEXT:	/* read word at location addr. */
+		{
+			unsigned long tmp = 0;
+			int copied;
+
+			ret = -EIO;
+			pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + add %d %ld\n", addr, add,
+			         sizeof(data));
+			if (is_user_addr_valid(child, addr + add, sizeof(tmp)) < 0)
+				break;
+			pr_debug("ptrace: user address is valid\n");
+
+#if L1_CODE_LENGTH != 0
+			if (addr + add >= L1_CODE_START
+			    && addr + add + sizeof(tmp) <= L1_CODE_START + L1_CODE_LENGTH) {
+				safe_dma_memcpy (&tmp, (const void *)(addr + add), sizeof(tmp));
+				copied = sizeof(tmp);
+			} else
+#endif
+			copied =
+			    access_process_vm(child, addr + add, &tmp,
+					      sizeof(tmp), 0);
+			pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
+			if (copied != sizeof(tmp))
+				break;
+			ret = put_user(tmp, (unsigned long *)data);
+			break;
+		}
+
+		/* read the word at location addr in the USER area. */
+	case PTRACE_PEEKUSR:
+		{
+			unsigned long tmp;
+			ret = -EIO;
+			tmp = 0;
+			if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
+				printk(KERN_WARNING "ptrace error : PEEKUSR : temporarily returning "
+				                    "0 - %x sizeof(pt_regs) is %lx\n",
+				     (int)addr, sizeof(struct pt_regs));
+				break;
+			}
+			if (addr == sizeof(struct pt_regs)) {
+				/* PT_TEXT_ADDR */
+				tmp = child->mm->start_code + TEXT_OFFSET;
+			} else if (addr == (sizeof(struct pt_regs) + 4)) {
+				/* PT_TEXT_END_ADDR */
+				tmp = child->mm->end_code;
+			} else if (addr == (sizeof(struct pt_regs) + 8)) {
+				/* PT_DATA_ADDR */
+				tmp = child->mm->start_data;
+#ifdef CONFIG_BINFMT_ELF_FDPIC
+			} else if (addr == (sizeof(struct pt_regs) + 12)) {
+				tmp = child->mm->context.exec_fdpic_loadmap;
+			} else if (addr == (sizeof(struct pt_regs) + 16)) {
+				tmp = child->mm->context.interp_fdpic_loadmap;
+#endif
+			} else {
+				tmp = get_reg(child, addr);
+			}
+			ret = put_user(tmp, (unsigned long *)data);
+			break;
+		}
+
+		/* when I and D space are separate, this will have to be fixed. */
+	case PTRACE_POKEDATA:
+		printk(KERN_NOTICE "ptrace: PTRACE_PEEKDATA\n");
+		/* fall through */
+	case PTRACE_POKETEXT:	/* write the word at location addr. */
+		{
+			int copied;
+
+			ret = -EIO;
+			pr_debug("ptrace: POKETEXT at addr 0x%08lx + add %d %ld bytes %lx\n",
+			         addr, add, sizeof(data), data);
+			if (is_user_addr_valid(child, addr + add, sizeof(data)) < 0)
+				break;
+			pr_debug("ptrace: user address is valid\n");
+
+#if L1_CODE_LENGTH != 0
+			if (addr + add >= L1_CODE_START
+			    && addr + add + sizeof(data) <= L1_CODE_START + L1_CODE_LENGTH) {
+				safe_dma_memcpy ((void *)(addr + add), &data, sizeof(data));
+				copied = sizeof(data);
+			} else
+#endif
+			copied =
+			    access_process_vm(child, addr + add, &data,
+					      sizeof(data), 1);
+			pr_debug("ptrace: copied size %d\n", copied);
+			if (copied != sizeof(data))
+				break;
+			ret = 0;
+			break;
+		}
+
+	case PTRACE_POKEUSR:	/* write the word at location addr in the USER area */
+		ret = -EIO;
+		if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
+			printk(KERN_WARNING "ptrace error : POKEUSR: temporarily returning 0\n");
+			break;
+		}
+
+		if (addr >= (sizeof(struct pt_regs))) {
+			ret = 0;
+			break;
+		}
+		if (addr == PT_SYSCFG) {
+			data &= SYSCFG_MASK;
+			data |= get_reg(child, PT_SYSCFG);
+		}
+		ret = put_reg(child, addr, data);
+		break;
+
+	case PTRACE_SYSCALL:	/* continue and stop at next (return from) syscall */
+	case PTRACE_CONT:
+		{		/* restart after signal. */
+			long tmp;
+
+			pr_debug("ptrace_cont\n");
+
+			ret = -EIO;
+			if (!valid_signal(data))
+				break;
+			if (request == PTRACE_SYSCALL)
+				set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+			else
+				clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+
+			child->exit_code = data;
+			/* make sure the single step bit is not set. */
+			tmp = get_reg(child, PT_SYSCFG) & ~(TRACE_BITS);
+			put_reg(child, PT_SYSCFG, tmp);
+			pr_debug("before wake_up_process\n");
+			wake_up_process(child);
+			ret = 0;
+			break;
+		}
+
+	/*
+	 * make the child exit.  Best I can do is send it a sigkill.
+	 * perhaps it should be put in the status that it wants to
+	 * exit.
+	 */
+	case PTRACE_KILL:
+		{
+			long tmp;
+			ret = 0;
+			if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
+				break;
+			child->exit_code = SIGKILL;
+			/* make sure the single step bit is not set. */
+			tmp = get_reg(child, PT_SYSCFG) & ~(TRACE_BITS);
+			put_reg(child, PT_SYSCFG, tmp);
+			wake_up_process(child);
+			break;
+		}
+
+	case PTRACE_SINGLESTEP:
+		{		/* set the trap flag. */
+			long tmp;
+
+			pr_debug("single step\n");
+			ret = -EIO;
+			if (!valid_signal(data))
+				break;
+			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+
+			tmp = get_reg(child, PT_SYSCFG) | (TRACE_BITS);
+			put_reg(child, PT_SYSCFG, tmp);
+
+			child->exit_code = data;
+			/* give it a chance to run. */
+			wake_up_process(child);
+			ret = 0;
+			break;
+		}
+
+	case PTRACE_DETACH:
+		{		/* detach a process that was attached. */
+			ret = ptrace_detach(child, data);
+			break;
+		}
+
+	case PTRACE_GETREGS:
+		{
+
+			/* Get all gp regs from the child. */
+			ret = ptrace_getregs(child, (void __user *)data);
+			break;
+		}
+
+	case PTRACE_SETREGS:
+		{
+			printk(KERN_NOTICE
+			       "ptrace: SETREGS: **** NOT IMPLEMENTED ***\n");
+			/* Set all gp regs in the child. */
+			ret = 0;
+			break;
+		}
+	default:
+		ret = ptrace_request(child, request, addr, data);
+		break;
+	}
+
+	return ret;
+}
+
+asmlinkage void syscall_trace(void)
+{
+
+	if (!test_thread_flag(TIF_SYSCALL_TRACE))
+		return;
+
+	if (!(current->ptrace & PT_PTRACED))
+		return;
+
+	/* the 0x80 provides a way for the tracing parent to distinguish
+	 * between a syscall stop and SIGTRAP delivery
+	 */
+	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
+				 ? 0x80 : 0));
+
+	/*
+	 * this isn't the same as continuing with a signal, but it will do
+	 * for normal use.  strace only continues with a signal if the
+	 * stopping signal is not SIGTRAP.  -brl
+	 */
+	if (current->exit_code) {
+		send_sig(current->exit_code, current, 1);
+		current->exit_code = 0;
+	}
+}