diff options
Diffstat (limited to 'arch/metag/kernel/ftrace.c')
-rw-r--r-- | arch/metag/kernel/ftrace.c | 121 |
1 files changed, 0 insertions, 121 deletions
diff --git a/arch/metag/kernel/ftrace.c b/arch/metag/kernel/ftrace.c deleted file mode 100644 index f7b23d300881..000000000000 --- a/arch/metag/kernel/ftrace.c +++ /dev/null @@ -1,121 +0,0 @@ -/* - * Copyright (C) 2008 Imagination Technologies Ltd. - * Licensed under the GPL - * - * Dynamic ftrace support. - */ - -#include <linux/ftrace.h> -#include <linux/io.h> -#include <linux/uaccess.h> - -#include <asm/cacheflush.h> - -#define D04_MOVT_TEMPLATE 0x02200005 -#define D04_CALL_TEMPLATE 0xAC200005 -#define D1RTP_MOVT_TEMPLATE 0x03200005 -#define D1RTP_CALL_TEMPLATE 0xAC200006 - -static const unsigned long NOP[2] = {0xa0fffffe, 0xa0fffffe}; -static unsigned long movt_and_call_insn[2]; - -static unsigned char *ftrace_nop_replace(void) -{ - return (char *)&NOP[0]; -} - -static unsigned char *ftrace_call_replace(unsigned long pc, unsigned long addr) -{ - unsigned long hi16, low16; - - hi16 = (addr & 0xffff0000) >> 13; - low16 = (addr & 0x0000ffff) << 3; - - /* - * The compiler makes the call to mcount_wrapper() - * (Meta's wrapper around mcount()) through the register - * D0.4. So whenever we're patching one of those compiler-generated - * calls we also need to go through D0.4. Otherwise use D1RtP. - */ - if (pc == (unsigned long)&ftrace_call) { - writel(D1RTP_MOVT_TEMPLATE | hi16, &movt_and_call_insn[0]); - writel(D1RTP_CALL_TEMPLATE | low16, &movt_and_call_insn[1]); - } else { - writel(D04_MOVT_TEMPLATE | hi16, &movt_and_call_insn[0]); - writel(D04_CALL_TEMPLATE | low16, &movt_and_call_insn[1]); - } - - return (unsigned char *)&movt_and_call_insn[0]; -} - -static int ftrace_modify_code(unsigned long pc, unsigned char *old_code, - unsigned char *new_code) -{ - unsigned char replaced[MCOUNT_INSN_SIZE]; - - /* - * Note: - * We are paranoid about modifying text, as if a bug was to happen, it - * could cause us to read or write to someplace that could cause harm. - * Carefully read and modify the code with probe_kernel_*(), and make - * sure what we read is what we expected it to be before modifying it. - */ - - /* read the text we want to modify */ - if (probe_kernel_read(replaced, (void *)pc, MCOUNT_INSN_SIZE)) - return -EFAULT; - - /* Make sure it is what we expect it to be */ - if (memcmp(replaced, old_code, MCOUNT_INSN_SIZE) != 0) - return -EINVAL; - - /* replace the text with the new text */ - if (probe_kernel_write((void *)pc, new_code, MCOUNT_INSN_SIZE)) - return -EPERM; - - flush_icache_range(pc, pc + MCOUNT_INSN_SIZE); - - return 0; -} - -int ftrace_update_ftrace_func(ftrace_func_t func) -{ - int ret; - unsigned long pc; - unsigned char old[MCOUNT_INSN_SIZE], *new; - - pc = (unsigned long)&ftrace_call; - memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE); - new = ftrace_call_replace(pc, (unsigned long)func); - ret = ftrace_modify_code(pc, old, new); - - return ret; -} - -int ftrace_make_nop(struct module *mod, - struct dyn_ftrace *rec, unsigned long addr) -{ - unsigned char *new, *old; - unsigned long ip = rec->ip; - - old = ftrace_call_replace(ip, addr); - new = ftrace_nop_replace(); - - return ftrace_modify_code(ip, old, new); -} - -int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) -{ - unsigned char *new, *old; - unsigned long ip = rec->ip; - - old = ftrace_nop_replace(); - new = ftrace_call_replace(ip, addr); - - return ftrace_modify_code(ip, old, new); -} - -int __init ftrace_dyn_arch_init(void) -{ - return 0; -} |