tools headers UAPI: Sync openat2.h with the kernel sources

[linux-2.6-microblaze.git] / arch / Kconfig

diff --git a/arch/Kconfig b/arch/Kconfig
index 9fc4eb8..2bb3067 100644 (file)
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -603,6 +603,96 @@ config SHADOW_CALL_STACK
          reading and writing arbitrary memory may be able to locate them
          and hijack control flow by modifying the stacks.
 
          reading and writing arbitrary memory may be able to locate them
          and hijack control flow by modifying the stacks.
 

+config LTO
+       bool
+       help
+         Selected if the kernel will be built using the compiler's LTO feature.
+
+config LTO_CLANG
+       bool
+       select LTO
+       help
+         Selected if the kernel will be built using Clang's LTO feature.
+
+config ARCH_SUPPORTS_LTO_CLANG
+       bool
+       help
+         An architecture should select this option if it supports:
+         - compiling with Clang,
+         - compiling inline assembly with Clang's integrated assembler,
+         - and linking with LLD.
+
+config ARCH_SUPPORTS_LTO_CLANG_THIN
+       bool
+       help
+         An architecture should select this option if it can support Clang's
+         ThinLTO mode.
+
+config HAS_LTO_CLANG
+       def_bool y
+       # Clang >= 11: https://github.com/ClangBuiltLinux/linux/issues/510
+       depends on CC_IS_CLANG && CLANG_VERSION >= 110000 && LD_IS_LLD
+       depends on $(success,test $(LLVM) -eq 1)
+       depends on $(success,test $(LLVM_IAS) -eq 1)
+       depends on $(success,$(NM) --help | head -n 1 | grep -qi llvm)
+       depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm)
+       depends on ARCH_SUPPORTS_LTO_CLANG
+       depends on !FTRACE_MCOUNT_USE_RECORDMCOUNT
+       depends on !KASAN
+       depends on !GCOV_KERNEL
+       help
+         The compiler and Kconfig options support building with Clang's
+         LTO.
+
+choice
+       prompt "Link Time Optimization (LTO)"
+       default LTO_NONE
+       help
+         This option enables Link Time Optimization (LTO), which allows the
+         compiler to optimize binaries globally.
+
+         If unsure, select LTO_NONE. Note that LTO is very resource-intensive
+         so it's disabled by default.
+
+config LTO_NONE
+       bool "None"
+       help
+         Build the kernel normally, without Link Time Optimization (LTO).
+
+config LTO_CLANG_FULL
+       bool "Clang Full LTO (EXPERIMENTAL)"
+       depends on HAS_LTO_CLANG
+       depends on !COMPILE_TEST
+       select LTO_CLANG
+       help
+          This option enables Clang's full Link Time Optimization (LTO), which
+          allows the compiler to optimize the kernel globally. If you enable
+          this option, the compiler generates LLVM bitcode instead of ELF
+          object files, and the actual compilation from bitcode happens at
+          the LTO link step, which may take several minutes depending on the
+          kernel configuration. More information can be found from LLVM's
+          documentation:
+
+           https://llvm.org/docs/LinkTimeOptimization.html
+
+         During link time, this option can use a large amount of RAM, and
+         may take much longer than the ThinLTO option.
+
+config LTO_CLANG_THIN
+       bool "Clang ThinLTO (EXPERIMENTAL)"
+       depends on HAS_LTO_CLANG && ARCH_SUPPORTS_LTO_CLANG_THIN
+       select LTO_CLANG
+       help
+         This option enables Clang's ThinLTO, which allows for parallel
+         optimization and faster incremental compiles compared to the
+         CONFIG_LTO_CLANG_FULL option. More information can be found
+         from Clang's documentation:
+
+           https://clang.llvm.org/docs/ThinLTO.html
+
+         If unsure, say Y.
+endchoice
+

 config HAVE_ARCH_WITHIN_STACK_FRAMES
        bool
        help
 config HAVE_ARCH_WITHIN_STACK_FRAMES
        bool
        help


@@ -731,6 +821,12 @@ config HAVE_IRQ_EXIT_ON_IRQ_STACK
          This spares a stack switch and improves cache usage on softirq
          processing.
 
          This spares a stack switch and improves cache usage on softirq
          processing.
 

+config HAVE_SOFTIRQ_ON_OWN_STACK
+       bool
+       help
+         Architecture provides a function to run __do_softirq() on a
+         seperate stack.
+

 config PGTABLE_LEVELS
        int
        default 2
 config PGTABLE_LEVELS
        int
        default 2