|  | /* | 
|  | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) | 
|  | * | 
|  | * 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 | 
|  | */ | 
|  |  | 
|  | #include <linux/ptrace.h> | 
|  | #include <linux/module.h> | 
|  | #include <linux/mm.h> | 
|  | #include <linux/fs.h> | 
|  | #include <linux/kdev_t.h> | 
|  | #include <linux/fs_struct.h> | 
|  | #include <linux/proc_fs.h> | 
|  | #include <linux/file.h> | 
|  | #include <asm/arcregs.h> | 
|  |  | 
|  | /* | 
|  | * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25) | 
|  | *   -Prints 3 regs per line and a CR. | 
|  | *   -To continue, callee regs right after scratch, special handling of CR | 
|  | */ | 
|  | static noinline void print_reg_file(long *reg_rev, int start_num) | 
|  | { | 
|  | unsigned int i; | 
|  | char buf[512]; | 
|  | int n = 0, len = sizeof(buf); | 
|  |  | 
|  | /* weird loop because pt_regs regs rev r12..r0, r25..r13 */ | 
|  | for (i = start_num; i < start_num + 13; i++) { | 
|  | n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t", | 
|  | i, (unsigned long)*reg_rev); | 
|  |  | 
|  | if (((i + 1) % 3) == 0) | 
|  | n += scnprintf(buf + n, len - n, "\n"); | 
|  |  | 
|  | reg_rev--; | 
|  | } | 
|  |  | 
|  | if (start_num != 0) | 
|  | n += scnprintf(buf + n, len - n, "\n\n"); | 
|  |  | 
|  | pr_info("%s", buf); | 
|  | } | 
|  |  | 
|  | static void show_callee_regs(struct callee_regs *cregs) | 
|  | { | 
|  | print_reg_file(&(cregs->r13), 13); | 
|  | } | 
|  |  | 
|  | void print_task_path_n_nm(struct task_struct *tsk, char *buf) | 
|  | { | 
|  | struct path path; | 
|  | char *path_nm = NULL; | 
|  | struct mm_struct *mm; | 
|  | struct file *exe_file; | 
|  |  | 
|  | mm = get_task_mm(tsk); | 
|  | if (!mm) | 
|  | goto done; | 
|  |  | 
|  | exe_file = get_mm_exe_file(mm); | 
|  | mmput(mm); | 
|  |  | 
|  | if (exe_file) { | 
|  | path = exe_file->f_path; | 
|  | path_get(&exe_file->f_path); | 
|  | fput(exe_file); | 
|  | path_nm = d_path(&path, buf, 255); | 
|  | path_put(&path); | 
|  | } | 
|  |  | 
|  | done: | 
|  | pr_info("%s, TGID %u\n", path_nm, tsk->tgid); | 
|  | } | 
|  | EXPORT_SYMBOL(print_task_path_n_nm); | 
|  |  | 
|  | static void show_faulting_vma(unsigned long address, char *buf) | 
|  | { | 
|  | struct vm_area_struct *vma; | 
|  | struct inode *inode; | 
|  | unsigned long ino = 0; | 
|  | dev_t dev = 0; | 
|  | char *nm = buf; | 
|  |  | 
|  | vma = find_vma(current->active_mm, address); | 
|  |  | 
|  | /* check against the find_vma( ) behaviour which returns the next VMA | 
|  | * if the container VMA is not found | 
|  | */ | 
|  | if (vma && (vma->vm_start <= address)) { | 
|  | struct file *file = vma->vm_file; | 
|  | if (file) { | 
|  | struct path *path = &file->f_path; | 
|  | nm = d_path(path, buf, PAGE_SIZE - 1); | 
|  | inode = vma->vm_file->f_path.dentry->d_inode; | 
|  | dev = inode->i_sb->s_dev; | 
|  | ino = inode->i_ino; | 
|  | } | 
|  | pr_info("    @off 0x%lx in [%s]\n" | 
|  | "    VMA: 0x%08lx to 0x%08lx\n\n", | 
|  | address - vma->vm_start, nm, vma->vm_start, vma->vm_end); | 
|  | } else | 
|  | pr_info("    @No matching VMA found\n"); | 
|  | } | 
|  |  | 
|  | static void show_ecr_verbose(struct pt_regs *regs) | 
|  | { | 
|  | unsigned int vec, cause_code, cause_reg; | 
|  | unsigned long address; | 
|  |  | 
|  | cause_reg = current->thread.cause_code; | 
|  | pr_info("\n[ECR]: 0x%08x => ", cause_reg); | 
|  |  | 
|  | /* For Data fault, this is data address not instruction addr */ | 
|  | address = current->thread.fault_address; | 
|  |  | 
|  | vec = cause_reg >> 16; | 
|  | cause_code = (cause_reg >> 8) & 0xFF; | 
|  |  | 
|  | /* For DTLB Miss or ProtV, display the memory involved too */ | 
|  | if (vec == ECR_V_DTLB_MISS) { | 
|  | pr_cont("Invalid (%s) @ 0x%08lx by insn @ 0x%08lx\n", | 
|  | (cause_code == 0x01) ? "Read From" : | 
|  | ((cause_code == 0x02) ? "Write to" : "EX"), | 
|  | address, regs->ret); | 
|  | } else if (vec == ECR_V_ITLB_MISS) { | 
|  | pr_cont("Insn could not be fetched\n"); | 
|  | } else if (vec == ECR_V_MACH_CHK) { | 
|  | pr_cont("%s\n", (cause_code == 0x0) ? | 
|  | "Double Fault" : "Other Fatal Err"); | 
|  |  | 
|  | } else if (vec == ECR_V_PROTV) { | 
|  | if (cause_code == ECR_C_PROTV_INST_FETCH) | 
|  | pr_cont("Execute from Non-exec Page\n"); | 
|  | else if (cause_code == ECR_C_PROTV_LOAD) | 
|  | pr_cont("Read from Non-readable Page\n"); | 
|  | else if (cause_code == ECR_C_PROTV_STORE) | 
|  | pr_cont("Write to Non-writable Page\n"); | 
|  | else if (cause_code == ECR_C_PROTV_XCHG) | 
|  | pr_cont("Data exchange protection violation\n"); | 
|  | else if (cause_code == ECR_C_PROTV_MISALIG_DATA) | 
|  | pr_cont("Misaligned r/w from 0x%08lx\n", address); | 
|  | } else if (vec == ECR_V_INSN_ERR) { | 
|  | pr_cont("Illegal Insn\n"); | 
|  | } else { | 
|  | pr_cont("Check Programmer's Manual\n"); | 
|  | } | 
|  | } | 
|  |  | 
|  | /************************************************************************ | 
|  | *  API called by rest of kernel | 
|  | ***********************************************************************/ | 
|  |  | 
|  | void show_regs(struct pt_regs *regs) | 
|  | { | 
|  | struct task_struct *tsk = current; | 
|  | struct callee_regs *cregs; | 
|  | char *buf; | 
|  |  | 
|  | buf = (char *)__get_free_page(GFP_TEMPORARY); | 
|  | if (!buf) | 
|  | return; | 
|  |  | 
|  | print_task_path_n_nm(tsk, buf); | 
|  |  | 
|  | if (current->thread.cause_code) | 
|  | show_ecr_verbose(regs); | 
|  |  | 
|  | pr_info("[EFA]: 0x%08lx\n", current->thread.fault_address); | 
|  | pr_info("[ERET]: 0x%08lx (PC of Faulting Instr)\n", regs->ret); | 
|  |  | 
|  | show_faulting_vma(regs->ret, buf);	/* faulting code, not data */ | 
|  |  | 
|  | /* can't use print_vma_addr() yet as it doesn't check for | 
|  | * non-inclusive vma | 
|  | */ | 
|  |  | 
|  | /* print special regs */ | 
|  | pr_info("status32: 0x%08lx\n", regs->status32); | 
|  | pr_info(" SP: 0x%08lx\tFP: 0x%08lx\n", regs->sp, regs->fp); | 
|  | pr_info("BTA: 0x%08lx\tBLINK: 0x%08lx\n", | 
|  | regs->bta, regs->blink); | 
|  | pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n", | 
|  | regs->lp_start, regs->lp_end, regs->lp_count); | 
|  |  | 
|  | /* print regs->r0 thru regs->r12 | 
|  | * Sequential printing was generating horrible code | 
|  | */ | 
|  | print_reg_file(&(regs->r0), 0); | 
|  |  | 
|  | /* If Callee regs were saved, display them too */ | 
|  | cregs = (struct callee_regs *)current->thread.callee_reg; | 
|  | if (cregs) | 
|  | show_callee_regs(cregs); | 
|  |  | 
|  | free_page((unsigned long)buf); | 
|  | } | 
|  |  | 
|  | void show_kernel_fault_diag(const char *str, struct pt_regs *regs, | 
|  | unsigned long address, unsigned long cause_reg) | 
|  | { | 
|  | current->thread.fault_address = address; | 
|  | current->thread.cause_code = cause_reg; | 
|  |  | 
|  | /* Caller and Callee regs */ | 
|  | show_regs(regs); | 
|  |  | 
|  | /* Show stack trace if this Fatality happened in kernel mode */ | 
|  | if (!user_mode(regs)) | 
|  | show_stacktrace(current, regs); | 
|  | } | 
|  |  | 
|  | #ifdef CONFIG_DEBUG_FS | 
|  |  | 
|  | #include <linux/module.h> | 
|  | #include <linux/fs.h> | 
|  | #include <linux/mount.h> | 
|  | #include <linux/pagemap.h> | 
|  | #include <linux/init.h> | 
|  | #include <linux/namei.h> | 
|  | #include <linux/debugfs.h> | 
|  |  | 
|  | static struct dentry *test_dentry; | 
|  | static struct dentry *test_dir; | 
|  | static struct dentry *test_u32_dentry; | 
|  |  | 
|  | static u32 clr_on_read = 1; | 
|  |  | 
|  | #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT | 
|  | u32 numitlb, numdtlb, num_pte_not_present; | 
|  |  | 
|  | static int fill_display_data(char *kbuf) | 
|  | { | 
|  | size_t num = 0; | 
|  | num += sprintf(kbuf + num, "I-TLB Miss %x\n", numitlb); | 
|  | num += sprintf(kbuf + num, "D-TLB Miss %x\n", numdtlb); | 
|  | num += sprintf(kbuf + num, "PTE not present %x\n", num_pte_not_present); | 
|  |  | 
|  | if (clr_on_read) | 
|  | numitlb = numdtlb = num_pte_not_present = 0; | 
|  |  | 
|  | return num; | 
|  | } | 
|  |  | 
|  | static int tlb_stats_open(struct inode *inode, struct file *file) | 
|  | { | 
|  | file->private_data = (void *)__get_free_page(GFP_KERNEL); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | /* called on user read(): display the couters */ | 
|  | static ssize_t tlb_stats_output(struct file *file,	/* file descriptor */ | 
|  | char __user *user_buf,	/* user buffer */ | 
|  | size_t len,		/* length of buffer */ | 
|  | loff_t *offset)		/* offset in the file */ | 
|  | { | 
|  | size_t num; | 
|  | char *kbuf = (char *)file->private_data; | 
|  |  | 
|  | /* All of the data can he shoved in one iteration */ | 
|  | if (*offset != 0) | 
|  | return 0; | 
|  |  | 
|  | num = fill_display_data(kbuf); | 
|  |  | 
|  | /* simple_read_from_buffer() is helper for copy to user space | 
|  | It copies up to @2 (num) bytes from kernel buffer @4 (kbuf) at offset | 
|  | @3 (offset) into the user space address starting at @1 (user_buf). | 
|  | @5 (len) is max size of user buffer | 
|  | */ | 
|  | return simple_read_from_buffer(user_buf, num, offset, kbuf, len); | 
|  | } | 
|  |  | 
|  | /* called on user write : clears the counters */ | 
|  | static ssize_t tlb_stats_clear(struct file *file, const char __user *user_buf, | 
|  | size_t length, loff_t *offset) | 
|  | { | 
|  | numitlb = numdtlb = num_pte_not_present = 0; | 
|  | return length; | 
|  | } | 
|  |  | 
|  | static int tlb_stats_close(struct inode *inode, struct file *file) | 
|  | { | 
|  | free_page((unsigned long)(file->private_data)); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static const struct file_operations tlb_stats_file_ops = { | 
|  | .read = tlb_stats_output, | 
|  | .write = tlb_stats_clear, | 
|  | .open = tlb_stats_open, | 
|  | .release = tlb_stats_close | 
|  | }; | 
|  | #endif | 
|  |  | 
|  | static int __init arc_debugfs_init(void) | 
|  | { | 
|  | test_dir = debugfs_create_dir("arc", NULL); | 
|  |  | 
|  | #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT | 
|  | test_dentry = debugfs_create_file("tlb_stats", 0444, test_dir, NULL, | 
|  | &tlb_stats_file_ops); | 
|  | #endif | 
|  |  | 
|  | test_u32_dentry = | 
|  | debugfs_create_u32("clr_on_read", 0444, test_dir, &clr_on_read); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | module_init(arc_debugfs_init); | 
|  |  | 
|  | static void __exit arc_debugfs_exit(void) | 
|  | { | 
|  | debugfs_remove(test_u32_dentry); | 
|  | debugfs_remove(test_dentry); | 
|  | debugfs_remove(test_dir); | 
|  | } | 
|  | module_exit(arc_debugfs_exit); | 
|  |  | 
|  | #endif |