tracing: Remove redundant config HAVE_FTRACE_MCOUNT_RECORD

Ftrace is tightly coupled with architecture specific code because it
requires the use of trampolines written in assembly. This means that when
a new feature or optimization is made, it must be done for all
architectures. To simplify the approach, CONFIG_HAVE_FTRACE_* configs are
added to denote which architecture has the new enhancement so that other
architectures can still function until they too have been updated.

The CONFIG_HAVE_FTRACE_MCOUNT was added to help simplify the
DYNAMIC_FTRACE work, but now every architecture that implements
DYNAMIC_FTRACE also has HAVE_FTRACE_MCOUNT set too, making it redundant
with the HAVE_DYNAMIC_FTRACE.

Remove the HAVE_FTRACE_MCOUNT config and use DYNAMIC_FTRACE directly where
applicable.

Link: https://lore.kernel.org/all/[email protected]/

Cc: Masami Hiramatsu <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Steven Rostedt (Google) <[email protected]>

Author: rostedt

Documentation/trace/ftrace-design.rst

@@ -238,19 +238,15 @@ You need very few things to get the syscalls tracing in an arch.
   - Tag this arch as HAVE_SYSCALL_TRACEPOINTS.
 
 
-HAVE_FTRACE_MCOUNT_RECORD
--------------------------
+HAVE_DYNAMIC_FTRACE
+-------------------
 
 See scripts/recordmcount.pl for more info.  Just fill in the arch-specific
 details for how to locate the addresses of mcount call sites via objdump.
 This option doesn't make much sense without also implementing dynamic ftrace.
 
-
-HAVE_DYNAMIC_FTRACE
--------------------
-
-You will first need HAVE_FTRACE_MCOUNT_RECORD and HAVE_FUNCTION_TRACER, so
-scroll your reader back up if you got over eager.
+You will first need HAVE_FUNCTION_TRACER, so scroll your reader back up if you
+got over eager.
 
 Once those are out of the way, you will need to implement:
 	- asm/ftrace.h:

arch/arm/Kconfig

@@ -107,7 +107,6 @@ config ARM
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
 	select HAVE_EXIT_THREAD
 	select HAVE_GUP_FAST if ARM_LPAE
-	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
 	select HAVE_FUNCTION_ERROR_INJECTION
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_TRACER if !XIP_KERNEL

arch/arm64/Kconfig

@@ -223,7 +223,6 @@ config ARM64
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
 	select HAVE_GUP_FAST
 	select HAVE_FTRACE_GRAPH_FUNC
-	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_ERROR_INJECTION
 	select HAVE_FUNCTION_GRAPH_FREGS

arch/csky/Kconfig

@@ -80,7 +80,6 @@ config CSKY
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_ERROR_INJECTION
-	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZO
 	select HAVE_KERNEL_LZMA

arch/loongarch/Kconfig

@@ -144,7 +144,6 @@ config LOONGARCH
 	select HAVE_EXIT_THREAD
 	select HAVE_GUP_FAST
 	select HAVE_FTRACE_GRAPH_FUNC
-	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_ARG_ACCESS_API
 	select HAVE_FUNCTION_ERROR_INJECTION
 	select HAVE_FUNCTION_GRAPH_FREGS

arch/microblaze/Kconfig

@@ -28,7 +28,6 @@ config MICROBLAZE
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DMA_CONTIGUOUS
 	select HAVE_DYNAMIC_FTRACE
-	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_TRACER
 	select HAVE_PAGE_SIZE_4KB

arch/mips/Kconfig

@@ -73,7 +73,6 @@ config MIPS
 	select HAVE_EBPF_JIT if !CPU_MICROMIPS
 	select HAVE_EXIT_THREAD
 	select HAVE_GUP_FAST
-	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_TRACER
 	select HAVE_GCC_PLUGINS

arch/parisc/Kconfig

@@ -81,7 +81,6 @@ config PARISC
 	select HAVE_KPROBES
 	select HAVE_KRETPROBES
 	select HAVE_DYNAMIC_FTRACE if $(cc-option,-fpatchable-function-entry=1,1)
-	select HAVE_FTRACE_MCOUNT_RECORD if HAVE_DYNAMIC_FTRACE
 	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
 	select HAVE_KPROBES_ON_FTRACE
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS

arch/powerpc/Kconfig

@@ -246,7 +246,6 @@ config PPC
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
 	select HAVE_GUP_FAST
 	select HAVE_FTRACE_GRAPH_FUNC
-	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_ARG_ACCESS_API
 	select HAVE_FUNCTION_DESCRIPTORS	if PPC64_ELF_ABI_V1
 	select HAVE_FUNCTION_ERROR_INJECTION

arch/riscv/Kconfig

@@ -159,7 +159,6 @@ config RISCV
 	select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG)
 	select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE
 	select HAVE_FTRACE_GRAPH_FUNC
-	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
 	select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS
 	select HAVE_FUNCTION_GRAPH_FREGS
 	select HAVE_FUNCTION_TRACER if !XIP_KERNEL