powerpc/ftrace: Minimise number of #ifdefs

A lot of #ifdefs can be replaced by IS_ENABLED()

Do so.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fold in changes suggested by Naveen and Christophe on list]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/18ce6708d6f8c71d87436f9c6019f04df4125128.1652074503.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/code-patching.h

@@ -219,7 +219,6 @@ static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
 	return addr;
 }
 
-#ifdef CONFIG_PPC64
 /*
  * Some instruction encodings commonly used in dynamic ftracing
  * and function live patching.
@@ -236,6 +235,5 @@ static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
 
 /* usually preceded by a mflr r0 */
 #define PPC_INST_STD_LR		PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF)
-#endif /* CONFIG_PPC64 */
 
 #endif /* _ASM_POWERPC_CODE_PATCHING_H */

arch/powerpc/include/asm/module.h

@@ -41,9 +41,7 @@ struct mod_arch_specific {
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 	unsigned long tramp;
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	unsigned long tramp_regs;
-#endif
 #endif
 
 	/* List of BUG addresses, source line numbers and filenames */

arch/powerpc/kernel/trace/ftrace.c

@@ -150,11 +150,7 @@ __ftrace_make_nop(struct module *mod,
 		return -EINVAL;
 	}
 
-	/* When using -mprofile-kernel or PPC32 there is no load to jump over */
-	pop = ppc_inst(PPC_RAW_NOP());
-
-#ifdef CONFIG_PPC64
-#ifdef CONFIG_MPROFILE_KERNEL
+	if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) {
 		if (copy_inst_from_kernel_nofault(&op, (void *)(ip - 4))) {
 			pr_err("Fetching instruction at %lx failed.\n", ip - 4);
 			return -EFAULT;
@@ -167,23 +163,7 @@ __ftrace_make_nop(struct module *mod,
 			       ppc_inst_as_str(op));
 			return -EINVAL;
 		}
-#else
-	/*
-	 * Our original call site looks like:
-	 *
-	 * bl <tramp>
-	 * ld r2,XX(r1)
-	 *
-	 * Milton Miller pointed out that we can not simply nop the branch.
-	 * If a task was preempted when calling a trace function, the nops
-	 * will remove the way to restore the TOC in r2 and the r2 TOC will
-	 * get corrupted.
-	 *
-	 * Use a b +8 to jump over the load.
-	 */
-
-	pop = ppc_inst(PPC_RAW_BRANCH(8));	/* b +8 */
-
+	} else if (IS_ENABLED(CONFIG_PPC64)) {
 		/*
 		 * Check what is in the next instruction. We can see ld r2,40(r1), but
 		 * on first pass after boot we will see mflr r0.
@@ -197,8 +177,27 @@ __ftrace_make_nop(struct module *mod,
 			pr_err("Expected %08lx found %s\n", PPC_INST_LD_TOC, ppc_inst_as_str(op));
 			return -EINVAL;
 		}
-#endif /* CONFIG_MPROFILE_KERNEL */
-#endif /* PPC64 */
+	}
+
+	/*
+	 * When using -mprofile-kernel or PPC32 there is no load to jump over.
+	 *
+	 * Otherwise our original call site looks like:
+	 *
+	 * bl <tramp>
+	 * ld r2,XX(r1)
+	 *
+	 * Milton Miller pointed out that we can not simply nop the branch.
+	 * If a task was preempted when calling a trace function, the nops
+	 * will remove the way to restore the TOC in r2 and the r2 TOC will
+	 * get corrupted.
+	 *
+	 * Use a b +8 to jump over the load.
+	 */
+	if (IS_ENABLED(CONFIG_MPROFILE_KERNEL) || IS_ENABLED(CONFIG_PPC32))
+		pop = ppc_inst(PPC_RAW_NOP());
+	else
+		pop = ppc_inst(PPC_RAW_BRANCH(8));	/* b +8 */
 
 	if (patch_instruction((u32 *)ip, pop)) {
 		pr_err("Patching NOP failed.\n");
@@ -207,6 +206,11 @@ __ftrace_make_nop(struct module *mod,
 
 	return 0;
 }
+#else
+static int __ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
+{
+	return 0;
+}
 #endif /* CONFIG_MODULES */
 
 static unsigned long find_ftrace_tramp(unsigned long ip)
@@ -279,11 +283,11 @@ static int setup_mcount_compiler_tramp(unsigned long tramp)
 	}
 
 	/* Let's re-write the tramp to go to ftrace_[regs_]caller */
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
 		ptr = ppc_global_function_entry((void *)ftrace_regs_caller);
-#else
+	else
 		ptr = ppc_global_function_entry((void *)ftrace_caller);
-#endif
+
 	if (patch_branch((u32 *)tramp, ptr, 0)) {
 		pr_debug("REL24 out of range!\n");
 		return -1;
@@ -352,10 +356,12 @@ int ftrace_make_nop(struct module *mod,
 		old = ftrace_call_replace(ip, addr, 1);
 		new = ppc_inst(PPC_RAW_NOP());
 		return ftrace_modify_code(ip, old, new);
-	} else if (core_kernel_text(ip))
+	} else if (core_kernel_text(ip)) {
 		return __ftrace_make_nop_kernel(rec, addr);
+	} else if (!IS_ENABLED(CONFIG_MODULES)) {
+		return -EINVAL;
+	}
 
-#ifdef CONFIG_MODULES
 	/*
 	 * Out of range jumps are called from modules.
 	 * We should either already have a pointer to the module
@@ -378,10 +384,6 @@ int ftrace_make_nop(struct module *mod,
 		mod = rec->arch.mod;
 
 	return __ftrace_make_nop(mod, rec, addr);
-#else
-	/* We should not get here without modules */
-	return -EINVAL;
-#endif /* CONFIG_MODULES */
 }
 
 #ifdef CONFIG_MODULES
@@ -411,10 +413,9 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 	if (copy_inst_from_kernel_nofault(op, ip))
 		return -EFAULT;
 
-#ifdef CONFIG_PPC64_ELF_ABI_V1
-	if (copy_inst_from_kernel_nofault(op + 1, ip + 4))
+	if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1) &&
+	    copy_inst_from_kernel_nofault(op + 1, ip + 4))
 		return -EFAULT;
-#endif
 
 	if (!expected_nop_sequence(ip, op[0], op[1])) {
 		pr_err("Unexpected call sequence at %p: %s %s\n",
@@ -423,20 +424,15 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 	}
 
 	/* If we never set up ftrace trampoline(s), then bail */
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	if (!mod->arch.tramp || !mod->arch.tramp_regs) {
-#else
-	if (!mod->arch.tramp) {
-#endif
+	if (!mod->arch.tramp ||
+	    (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && !mod->arch.tramp_regs)) {
 		pr_err("No ftrace trampoline\n");
 		return -EINVAL;
 	}
 
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	if (rec->flags & FTRACE_FL_REGS)
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && rec->flags & FTRACE_FL_REGS)
 		tramp = mod->arch.tramp_regs;
 	else
-#endif
 		tramp = mod->arch.tramp;
 
 	if (module_trampoline_target(mod, tramp, &ptr)) {
@@ -460,6 +456,11 @@ __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 
 	return 0;
 }
+#else
+static int __ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+	return 0;
+}
 #endif /* CONFIG_MODULES */
 
 static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr)
@@ -472,16 +473,12 @@ static int __ftrace_make_call_kernel(struct dyn_ftrace *rec, unsigned long addr)
 	entry = ppc_global_function_entry((void *)ftrace_caller);
 	ptr = ppc_global_function_entry((void *)addr);
 
-	if (ptr != entry) {
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+	if (ptr != entry && IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
 		entry = ppc_global_function_entry((void *)ftrace_regs_caller);
+
 	if (ptr != entry) {
-#endif
 		pr_err("Unknown ftrace addr to patch: %ps\n", (void *)ptr);
 		return -EINVAL;
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-		}
-#endif
 	}
 
 	/* Make sure we have a nop */
@@ -524,10 +521,13 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 		old = ppc_inst(PPC_RAW_NOP());
 		new = ftrace_call_replace(ip, addr, 1);
 		return ftrace_modify_code(ip, old, new);
-	} else if (core_kernel_text(ip))
+	} else if (core_kernel_text(ip)) {
 		return __ftrace_make_call_kernel(rec, addr);
+	} else if (!IS_ENABLED(CONFIG_MODULES)) {
+		/* We should not get here without modules */
+		return -EINVAL;
+	}
 
-#ifdef CONFIG_MODULES
 	/*
 	 * Out of range jumps are called from modules.
 	 * Being that we are converting from nop, it had better
@@ -539,10 +539,6 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 	}
 
 	return __ftrace_make_call(rec, addr);
-#else
-	/* We should not get here without modules */
-	return -EINVAL;
-#endif /* CONFIG_MODULES */
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
@@ -633,6 +629,11 @@ __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 
 	return 0;
 }
+#else
+static int __ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long addr)
+{
+	return 0;
+}
 #endif
 
 int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
@@ -657,9 +658,11 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 		 * variant, so there is nothing to do here
 		 */
 		return 0;
+	} else if (!IS_ENABLED(CONFIG_MODULES)) {
+		/* We should not get here without modules */
+		return -EINVAL;
 	}
 
-#ifdef CONFIG_MODULES
 	/*
 	 * Out of range jumps are called from modules.
 	 */
@@ -669,10 +672,6 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 	}
 
 	return __ftrace_modify_call(rec, old_addr, addr);
-#else
-	/* We should not get here without modules */
-	return -EINVAL;
-#endif /* CONFIG_MODULES */
 }
 #endif
 
@@ -686,15 +685,13 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
 	new = ftrace_call_replace(ip, (unsigned long)func, 1);
 	ret = ftrace_modify_code(ip, old, new);
 
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	/* Also update the regs callback function */
-	if (!ret) {
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS) && !ret) {
 		ip = (unsigned long)(&ftrace_regs_call);
 		old = ppc_inst_read((u32 *)&ftrace_regs_call);
 		new = ftrace_call_replace(ip, (unsigned long)func, 1);
 		ret = ftrace_modify_code(ip, old, new);
 	}
-#endif
 
 	return ret;
 }
@@ -724,12 +721,15 @@ int __init ftrace_dyn_arch_init(void)
 		PPC_RAW_MTCTR(_R12),
 		PPC_RAW_BCTR()
 	};
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	unsigned long addr = ppc_global_function_entry((void *)ftrace_regs_caller);
-#else
-	unsigned long addr = ppc_global_function_entry((void *)ftrace_caller);
-#endif
-	long reladdr = addr - kernel_toc_addr();
+	unsigned long addr;
+	long reladdr;
+
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_REGS))
+		addr = ppc_global_function_entry((void *)ftrace_regs_caller);
+	else
+		addr = ppc_global_function_entry((void *)ftrace_caller);
+
+	reladdr = addr - kernel_toc_addr();
 
 	if (reladdr >= SZ_2G || reladdr < -(long)SZ_2G) {
 		pr_err("Address of %ps out of range of kernel_toc.\n",
@@ -746,11 +746,6 @@ int __init ftrace_dyn_arch_init(void)
 
 	return 0;
 }
-#else
-int __init ftrace_dyn_arch_init(void)
-{
-	return 0;
-}
 #endif
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER