Add oprofile support for metag.

Signed-off-by: James Hogan <james.ho...@imgtec.com>
---
 arch/metag/Kconfig                    |    1 +
 arch/metag/Makefile                   |    2 +
 arch/metag/oprofile/Makefile          |   16 ++
 arch/metag/oprofile/backtrace.c       |  134 ++++++++++++++++++
 arch/metag/oprofile/backtrace.h       |    6 +
 arch/metag/oprofile/op_model_meta12.c |  242 +++++++++++++++++++++++++++++++++
 6 files changed, 401 insertions(+), 0 deletions(-)
 create mode 100644 arch/metag/oprofile/Makefile
 create mode 100644 arch/metag/oprofile/backtrace.c
 create mode 100644 arch/metag/oprofile/backtrace.h
 create mode 100644 arch/metag/oprofile/op_model_meta12.c

diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index 4c731d80..d198c9b 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig
@@ -26,6 +26,7 @@ config METAG
        select HAVE_MEMBLOCK
        select HAVE_MEMBLOCK_NODE_MAP
        select HAVE_MOD_ARCH_SPECIFIC
+       select HAVE_OPROFILE
        select HAVE_PERF_EVENTS
        select HAVE_SYSCALL_TRACEPOINTS
        select IRQ_DOMAIN
diff --git a/arch/metag/Makefile b/arch/metag/Makefile
index d455140..53fc094 100644
--- a/arch/metag/Makefile
+++ b/arch/metag/Makefile
@@ -49,6 +49,8 @@ core-y                                        += 
arch/metag/mm/
 libs-y                                 += arch/metag/lib/
 libs-y                                 += arch/metag/tbx/
 
+drivers-$(CONFIG_OPROFILE)             += arch/metag/oprofile/
+
 boot                                   := arch/metag/boot
 
 boot_targets                           += uImage
diff --git a/arch/metag/oprofile/Makefile b/arch/metag/oprofile/Makefile
new file mode 100644
index 0000000..4b4ceee
--- /dev/null
+++ b/arch/metag/oprofile/Makefile
@@ -0,0 +1,16 @@
+obj-y          += oprofile.o
+
+oprofile-core-y        += buffer_sync.o
+oprofile-core-y        += cpu_buffer.o
+oprofile-core-y        += event_buffer.o
+oprofile-core-y        += oprof.o
+oprofile-core-y        += oprofile_files.o
+oprofile-core-y        += oprofile_stats.o
+oprofile-core-y        += oprofilefs.o
+oprofile-core-y        += timer_int.o
+
+oprofile-y     += backtrace.o
+oprofile-y     += op_model_meta12.o
+oprofile-y     += $(addprefix ../../../drivers/oprofile/,$(oprofile-core-y))
+
+ccflags-y      += -Werror
diff --git a/arch/metag/oprofile/backtrace.c b/arch/metag/oprofile/backtrace.c
new file mode 100644
index 0000000..0ae7489
--- /dev/null
+++ b/arch/metag/oprofile/backtrace.c
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2010 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/oprofile.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include "backtrace.h"
+
+#ifdef CONFIG_FRAME_POINTER
+
+#ifdef CONFIG_KALLSYMS
+#include <linux/kallsyms.h>
+#include <linux/module.h>
+
+static unsigned long tbi_boing_addr;
+static unsigned long tbi_boing_size;
+#endif
+
+static void user_backtrace_fp(unsigned long __user *fp, unsigned int depth)
+{
+       while (depth-- && access_ok(VERIFY_READ, fp, 8)) {
+               unsigned long addr;
+               unsigned long __user *fpnew;
+               if (__copy_from_user_inatomic(&addr, fp + 1, sizeof(addr)))
+                       break;
+               addr -= 4;
+
+               oprofile_add_trace(addr);
+
+               /* stack grows up, so frame pointers must decrease */
+               if (__copy_from_user_inatomic(&fpnew, fp + 0, sizeof(fpnew)))
+                       break;
+               if (fpnew > fp)
+                       break;
+               fp = fpnew;
+       }
+}
+
+static void kernel_backtrace_fp(unsigned long *fp, unsigned long *stack,
+                               unsigned int depth)
+{
+#ifdef CONFIG_KALLSYMS
+       /* We need to know where TBIBoingVec is and it's size */
+       if (!tbi_boing_addr) {
+               unsigned long size;
+               unsigned long offset;
+               char modname[MODULE_NAME_LEN];
+               char name[KSYM_NAME_LEN];
+               tbi_boing_addr = kallsyms_lookup_name("___TBIBoingVec");
+               if (!tbi_boing_addr)
+                       tbi_boing_addr = 1;
+               else if (!lookup_symbol_attrs(tbi_boing_addr, &size,
+                                               &offset, modname, name))
+                       tbi_boing_size = size;
+       }
+#endif
+       /* 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).
+        */
+       while (depth-- && fp >= stack && fp + 8 <= stack + THREAD_SIZE) {
+               unsigned long addr;
+               unsigned long *fpnew;
+
+               addr = fp[1] - 4;
+               if (!__kernel_text_address(addr))
+                       break;
+
+               oprofile_add_trace(addr);
+
+               /* stack grows up, so frame pointers must decrease */
+               fpnew = (unsigned long *)fp[0];
+               if (fpnew > fp)
+                       break;
+               fp = fpnew;
+
+#ifdef CONFIG_KALLSYMS
+               /* If we've reached TBIBoingVec then we're at an interrupt
+                * entry point or a syscall entry point. The frame pointer
+                * points to a pt_regs which can be used to continue tracing on
+                * the other side of the boing.
+                */
+               if (tbi_boing_size && addr >= tbi_boing_addr &&
+                               addr < tbi_boing_addr + tbi_boing_size) {
+                       struct pt_regs *regs = (struct pt_regs *)fp;
+                       /* OProfile doesn't understand backtracing into
+                        * userland.
+                        */
+                       if (!user_mode(regs) && --depth) {
+                               oprofile_add_trace(regs->ctx.CurrPC);
+                               metag_backtrace(regs, depth);
+                       }
+                       break;
+               }
+#endif
+       }
+}
+#else
+static void kernel_backtrace_sp(unsigned long *sp, unsigned int depth)
+{
+       while (!kstack_end(sp)) {
+               unsigned long addr = *sp--;
+
+               if (!__kernel_text_address(addr - 4))
+                       continue;
+               if (!depth--)
+                       break;
+               oprofile_add_trace(addr);
+       }
+}
+#endif
+
+void metag_backtrace(struct pt_regs * const regs, unsigned int depth)
+{
+#ifdef CONFIG_FRAME_POINTER
+       unsigned long *fp = (unsigned long *)regs->ctx.AX[1].U0;
+       if (user_mode(regs))
+               user_backtrace_fp((unsigned long __user __force *)fp, depth);
+       else
+               kernel_backtrace_fp(fp, task_stack_page(current), depth);
+#else
+       if (!user_mode(regs)) {
+               unsigned long *sp = (unsigned long *)regs->ctx.AX[0].U0;
+               kernel_backtrace_sp(sp, depth);
+       }
+#endif
+}
diff --git a/arch/metag/oprofile/backtrace.h b/arch/metag/oprofile/backtrace.h
new file mode 100644
index 0000000..c0fcc42
--- /dev/null
+++ b/arch/metag/oprofile/backtrace.h
@@ -0,0 +1,6 @@
+#ifndef _METAG_OPROFILE_BACKTRACE_H
+#define _METAG_OPROFILE_BACKTRACE_H
+
+void metag_backtrace(struct pt_regs * const regs, unsigned int depth);
+
+#endif
diff --git a/arch/metag/oprofile/op_model_meta12.c 
b/arch/metag/oprofile/op_model_meta12.c
new file mode 100644
index 0000000..0cb103c
--- /dev/null
+++ b/arch/metag/oprofile/op_model_meta12.c
@@ -0,0 +1,242 @@
+/*
+ *  Meta version derived from arch/sh/oprofile/op_model_sh7750.c
+ *    Copyright (C) 2008 Imagination Technologies Ltd.
+ *
+ * arch/sh/oprofile/op_model_sh7750.c
+ *
+ * OProfile support for SH7750/SH7750S Performance Counters
+ *
+ * Copyright (C) 2003, 2004  Paul Mundt
+ *
+ * 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/kernel.h>
+#include <linux/oprofile.h>
+#include <linux/profile.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/metag_mem.h>
+
+#include "backtrace.h"
+
+/*
+ * Meta has 2 perf counters
+ */
+#define NR_CNTRS       2
+
+struct op_counter_config {
+       unsigned long enabled;
+       unsigned long event;
+       unsigned long count;
+       unsigned long unit_mask;
+
+       /* Dummy values for userspace tool compliance */
+       unsigned long kernel;
+       unsigned long user;
+};
+
+static struct op_counter_config ctr[NR_CNTRS];
+
+static u32 meta_read_counter(int counter)
+{
+       u32 val = metag_in32(counter ? PERF_COUNT0 : PERF_COUNT1);
+       return val;
+}
+
+static void meta_write_counter(int counter, u32 val)
+{
+       metag_out32(val, counter ? PERF_COUNT0 : PERF_COUNT1);
+}
+
+/*
+ * Unfortunately we don't have a native exception or interrupt for counter
+ * overflow.
+ *
+ * OProfile on the other hand likes to have samples taken periodically, so
+ * for now we just piggyback the timer interrupt to get the expected
+ * behavior.
+ */
+
+static int meta_timer_notify(struct pt_regs *regs)
+{
+       int i;
+       u32 val, total_val, sub_val;
+       u32 enabled_threads;
+
+       for (i = 0; i < NR_CNTRS; i++) {
+               if (!ctr[i].enabled)
+                       continue;
+
+               /* Disable performance monitoring. */
+               enabled_threads = meta_read_counter(i);
+               meta_write_counter(i, 0);
+
+               sub_val = total_val = val = enabled_threads & PERF_COUNT_BITS;
+
+               if (val >= ctr[i].count) {
+                       while (val > ctr[i].count) {
+                               oprofile_add_sample(regs, i);
+                               val -= ctr[i].count;
+                       }
+                       /* val may be < ctr[i].count but > 0 */
+                       sub_val -= val;
+                       total_val -= sub_val;
+               }
+
+               /* Enable performance monitoring. */
+               enabled_threads &= (PERF_CTRL_BITS | PERF_THREAD_BITS);
+               enabled_threads = enabled_threads | total_val;
+               meta_write_counter(i, enabled_threads);
+       }
+
+       return 0;
+}
+
+/*
+ * Files will be in a path like:
+ *
+ *  /<oprofilefs mount point>/<counter number>/<file>
+ *
+ * So when dealing with <file>, we look to the parent dentry for the counter
+ * number.
+ */
+static inline int to_counter(struct file *file)
+{
+       long val;
+       const unsigned char *name = file->f_path.dentry->d_parent->d_name.name;
+
+       if (kstrtol(name, 10, &val))
+               return 0;
+
+       return val;
+}
+
+static ssize_t meta_write(struct file *file, const char __user *buf,
+                               size_t count, loff_t *ppos, int mask, int shift)
+{
+       int counter = to_counter(file);
+       unsigned long write_val;
+       u32 read_val;
+
+       if (oprofilefs_ulong_from_user(&write_val, buf, count))
+               return -EFAULT;
+
+       read_val = meta_read_counter(counter) & ~mask;
+       write_val <<= shift;
+
+       write_val = read_val | (write_val & mask);
+       meta_write_counter(counter, write_val);
+
+       return count;
+}
+
+/*
+ * These functions handle turning perfomance counters on for particular
+ * threads by writing to files.
+ */
+static ssize_t meta_read_thread(struct file *file, char __user *buf,
+                                size_t count, loff_t *ppos)
+{
+       int counter = to_counter(file);
+       u32 val = meta_read_counter(counter);
+
+       val &= PERF_THREAD_BITS;
+       val >>= PERF_THREAD_S;
+
+       return oprofilefs_ulong_to_user((unsigned long)val, buf, count, ppos);
+}
+
+static ssize_t meta_write_thread(struct file *file, const char __user *buf,
+                                 size_t count, loff_t *ppos)
+{
+       meta_write(file, buf, count, ppos, PERF_THREAD_BITS, PERF_THREAD_S);
+       return count;
+}
+
+static const struct file_operations thread_fops = {
+       .read           = meta_read_thread,
+       .write          = meta_write_thread,
+};
+
+static int meta_perf_counter_create_files(struct super_block *sb,
+                                         struct dentry *root)
+{
+       int i;
+
+       for (i = 0; i < NR_CNTRS; i++) {
+               struct dentry *dir;
+               char buf[4];
+
+               snprintf(buf, sizeof(buf), "%d", i);
+               dir = oprofilefs_mkdir(sb, root, buf);
+
+               oprofilefs_create_ulong(sb, dir, "enabled", &ctr[i].enabled);
+               oprofilefs_create_ulong(sb, dir, "event", &ctr[i].event);
+               oprofilefs_create_ulong(sb, dir, "count", &ctr[i].count);
+               oprofilefs_create_file(sb, dir, "unit_mask", &thread_fops);
+
+               /* Dummy entries */
+               oprofilefs_create_ulong(sb, dir, "kernel", &ctr[i].kernel);
+               oprofilefs_create_ulong(sb, dir, "user", &ctr[i].user);
+       }
+
+       return 0;
+}
+
+static int meta_perf_counter_start(void)
+{
+       int i;
+       u32 event, read_val;
+
+       for (i = 0; i < NR_CNTRS; i++) {
+               if (!ctr[i].enabled)
+                       continue;
+
+               event = ctr[i].event << PERF_CTRL_S;
+               read_val = meta_read_counter(i) & ~PERF_CTRL_BITS;
+               meta_write_counter(i, read_val | event);
+       }
+
+       return register_timer_hook(meta_timer_notify);
+}
+
+static void meta_perf_counter_stop(void)
+{
+       u32 val;
+
+       val = meta_read_counter(0) & ~PERF_THREAD_BITS;
+       meta_write_counter(0, val);
+
+       val = meta_read_counter(1) & ~PERF_THREAD_BITS;
+       meta_write_counter(1, val);
+
+       unregister_timer_hook(meta_timer_notify);
+}
+
+int __init oprofile_arch_init(struct oprofile_operations *ops)
+{
+       ops->cpu_type = "metag";
+       ops->create_files = meta_perf_counter_create_files;
+       ops->start = meta_perf_counter_start;
+       ops->stop = meta_perf_counter_stop;
+       ops->backtrace = metag_backtrace;
+
+       pr_info("oprofile: using %s performance monitoring.\n", ops->cpu_type);
+
+       /* Clear the counters. */
+       meta_write_counter(0, 0);
+       meta_write_counter(1, 0);
+
+       return 0;
+}
+
+void oprofile_arch_exit(void)
+{
+}
+
-- 
1.7.7.6


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