diff options
Diffstat (limited to 'drivers/gator/gator_annotate.c')
| -rw-r--r-- | drivers/gator/gator_annotate.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/gator/gator_annotate.c b/drivers/gator/gator_annotate.c new file mode 100644 index 00000000000..b2288b3ad81 --- /dev/null +++ b/drivers/gator/gator_annotate.c @@ -0,0 +1,149 @@ +/** + * Copyright (C) ARM Limited 2010-2012. 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 version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/sched.h> +#include <asm/uaccess.h> +#include <asm/current.h> +#include <linux/spinlock.h> + +static DEFINE_SPINLOCK(annotate_lock); +static bool collect_annotations = false; + +static int annotate_copy(struct file *file, char const __user *buf, size_t count) +{ + int cpu = 0; + int write = per_cpu(gator_buffer_write, cpu)[ANNOTATE_BUF]; + + if (file == NULL) { + // copy from kernel + memcpy(&per_cpu(gator_buffer, cpu)[ANNOTATE_BUF][write], buf, count); + } else { + // copy from user space + if (copy_from_user(&per_cpu(gator_buffer, cpu)[ANNOTATE_BUF][write], buf, count) != 0) + return -1; + } + per_cpu(gator_buffer_write, cpu)[ANNOTATE_BUF] = (write + count) & gator_buffer_mask[ANNOTATE_BUF]; + + return 0; +} + +static ssize_t annotate_write(struct file *file, char const __user *buf, size_t count_orig, loff_t *offset) +{ + int tid, cpu, header_size, available, contiguous, length1, length2, size, count = count_orig & 0x7fffffff; + + if (*offset) + return -EINVAL; + + if (!collect_annotations) { + return count_orig; + } + + cpu = 0; // Annotation only uses a single per-cpu buffer as the data must be in order to the engine + + if (file == NULL) { + tid = -1; // set the thread id to the kernel thread + } else { + tid = current->pid; + } + + // synchronize between cores + spin_lock(&annotate_lock); + + // determine total size of the payload + header_size = MAXSIZE_PACK32 * 3 + MAXSIZE_PACK64; + available = buffer_bytes_available(cpu, ANNOTATE_BUF) - header_size; + size = count < available ? count : available; + + if (size <= 0) { + size = 0; + goto annotate_write_out; + } + + // synchronize shared variables annotateBuf and annotatePos + if (collect_annotations && per_cpu(gator_buffer, cpu)[ANNOTATE_BUF]) { + gator_buffer_write_packed_int(cpu, ANNOTATE_BUF, smp_processor_id()); + gator_buffer_write_packed_int(cpu, ANNOTATE_BUF, tid); + gator_buffer_write_packed_int64(cpu, ANNOTATE_BUF, gator_get_time()); + gator_buffer_write_packed_int(cpu, ANNOTATE_BUF, size); + + // determine the sizes to capture, length1 + length2 will equal size + contiguous = contiguous_space_available(cpu, ANNOTATE_BUF); + if (size < contiguous) { + length1 = size; + length2 = 0; + } else { + length1 = contiguous; + length2 = size - contiguous; + } + + if (annotate_copy(file, buf, length1) != 0) { + size = -EINVAL; + goto annotate_write_out; + } + + if (length2 > 0 && annotate_copy(file, &buf[length1], length2) != 0) { + size = -EINVAL; + goto annotate_write_out; + } + + // Check and commit; commit is set to occur once buffer is 3/4 full + buffer_check(cpu, ANNOTATE_BUF); + } + +annotate_write_out: + spin_unlock(&annotate_lock); + + // return the number of bytes written + return size; +} + +#include "gator_annotate_kernel.c" + +static int annotate_release(struct inode *inode, struct file *file) +{ + int cpu = 0; + + // synchronize between cores + spin_lock(&annotate_lock); + + if (per_cpu(gator_buffer, cpu)[ANNOTATE_BUF] && buffer_check_space(cpu, ANNOTATE_BUF, MAXSIZE_PACK64 + 2 * MAXSIZE_PACK32)) { + uint32_t tid = current->pid; + gator_buffer_write_packed_int(cpu, ANNOTATE_BUF, tid); + gator_buffer_write_packed_int64(cpu, ANNOTATE_BUF, 0); // time + gator_buffer_write_packed_int(cpu, ANNOTATE_BUF, 0); // size + } + + spin_unlock(&annotate_lock); + + return 0; +} + +static const struct file_operations annotate_fops = { + .write = annotate_write, + .release = annotate_release +}; + +static int gator_annotate_create_files(struct super_block *sb, struct dentry *root) +{ + return gatorfs_create_file_perm(sb, root, "annotate", &annotate_fops, 0666); +} + +static int gator_annotate_start(void) +{ + collect_annotations = true; + return 0; +} + +static void gator_annotate_stop(void) +{ + collect_annotations = false; +} |