v4.19.13 snapshot.
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
new file mode 100644
index 0000000..681d866
--- /dev/null
+++ b/include/linux/compiler.h
@@ -0,0 +1,364 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_COMPILER_H
+#define __LINUX_COMPILER_H
+
+#include <linux/compiler_types.h>
+
+#ifndef __ASSEMBLY__
+
+#ifdef __KERNEL__
+
+/*
+ * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
+ * to disable branch tracing on a per file basis.
+ */
+#if defined(CONFIG_TRACE_BRANCH_PROFILING) \
+ && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
+void ftrace_likely_update(struct ftrace_likely_data *f, int val,
+ int expect, int is_constant);
+
+#define likely_notrace(x) __builtin_expect(!!(x), 1)
+#define unlikely_notrace(x) __builtin_expect(!!(x), 0)
+
+#define __branch_check__(x, expect, is_constant) ({ \
+ long ______r; \
+ static struct ftrace_likely_data \
+ __attribute__((__aligned__(4))) \
+ __attribute__((section("_ftrace_annotated_branch"))) \
+ ______f = { \
+ .data.func = __func__, \
+ .data.file = __FILE__, \
+ .data.line = __LINE__, \
+ }; \
+ ______r = __builtin_expect(!!(x), expect); \
+ ftrace_likely_update(&______f, ______r, \
+ expect, is_constant); \
+ ______r; \
+ })
+
+/*
+ * Using __builtin_constant_p(x) to ignore cases where the return
+ * value is always the same. This idea is taken from a similar patch
+ * written by Daniel Walker.
+ */
+# ifndef likely
+# define likely(x) (__branch_check__(x, 1, __builtin_constant_p(x)))
+# endif
+# ifndef unlikely
+# define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x)))
+# endif
+
+#ifdef CONFIG_PROFILE_ALL_BRANCHES
+/*
+ * "Define 'is'", Bill Clinton
+ * "Define 'if'", Steven Rostedt
+ */
+#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
+#define __trace_if(cond) \
+ if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
+ ({ \
+ int ______r; \
+ static struct ftrace_branch_data \
+ __attribute__((__aligned__(4))) \
+ __attribute__((section("_ftrace_branch"))) \
+ ______f = { \
+ .func = __func__, \
+ .file = __FILE__, \
+ .line = __LINE__, \
+ }; \
+ ______r = !!(cond); \
+ ______f.miss_hit[______r]++; \
+ ______r; \
+ }))
+#endif /* CONFIG_PROFILE_ALL_BRANCHES */
+
+#else
+# define likely(x) __builtin_expect(!!(x), 1)
+# define unlikely(x) __builtin_expect(!!(x), 0)
+#endif
+
+/* Optimization barrier */
+#ifndef barrier
+# define barrier() __memory_barrier()
+#endif
+
+#ifndef barrier_data
+# define barrier_data(ptr) barrier()
+#endif
+
+/* workaround for GCC PR82365 if needed */
+#ifndef barrier_before_unreachable
+# define barrier_before_unreachable() do { } while (0)
+#endif
+
+/* Unreachable code */
+#ifdef CONFIG_STACK_VALIDATION
+/*
+ * These macros help objtool understand GCC code flow for unreachable code.
+ * The __COUNTER__ based labels are a hack to make each instance of the macros
+ * unique, to convince GCC not to merge duplicate inline asm statements.
+ */
+#define annotate_reachable() ({ \
+ asm volatile("%c0:\n\t" \
+ ".pushsection .discard.reachable\n\t" \
+ ".long %c0b - .\n\t" \
+ ".popsection\n\t" : : "i" (__COUNTER__)); \
+})
+#define annotate_unreachable() ({ \
+ asm volatile("%c0:\n\t" \
+ ".pushsection .discard.unreachable\n\t" \
+ ".long %c0b - .\n\t" \
+ ".popsection\n\t" : : "i" (__COUNTER__)); \
+})
+#define ASM_UNREACHABLE \
+ "999:\n\t" \
+ ".pushsection .discard.unreachable\n\t" \
+ ".long 999b - .\n\t" \
+ ".popsection\n\t"
+#else
+#define annotate_reachable()
+#define annotate_unreachable()
+#endif
+
+#ifndef ASM_UNREACHABLE
+# define ASM_UNREACHABLE
+#endif
+#ifndef unreachable
+# define unreachable() do { annotate_reachable(); do { } while (1); } while (0)
+#endif
+
+/*
+ * KENTRY - kernel entry point
+ * This can be used to annotate symbols (functions or data) that are used
+ * without their linker symbol being referenced explicitly. For example,
+ * interrupt vector handlers, or functions in the kernel image that are found
+ * programatically.
+ *
+ * Not required for symbols exported with EXPORT_SYMBOL, or initcalls. Those
+ * are handled in their own way (with KEEP() in linker scripts).
+ *
+ * KENTRY can be avoided if the symbols in question are marked as KEEP() in the
+ * linker script. For example an architecture could KEEP() its entire
+ * boot/exception vector code rather than annotate each function and data.
+ */
+#ifndef KENTRY
+# define KENTRY(sym) \
+ extern typeof(sym) sym; \
+ static const unsigned long __kentry_##sym \
+ __used \
+ __attribute__((section("___kentry" "+" #sym ), used)) \
+ = (unsigned long)&sym;
+#endif
+
+#ifndef RELOC_HIDE
+# define RELOC_HIDE(ptr, off) \
+ ({ unsigned long __ptr; \
+ __ptr = (unsigned long) (ptr); \
+ (typeof(ptr)) (__ptr + (off)); })
+#endif
+
+#ifndef OPTIMIZER_HIDE_VAR
+#define OPTIMIZER_HIDE_VAR(var) barrier()
+#endif
+
+/* Not-quite-unique ID. */
+#ifndef __UNIQUE_ID
+# define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
+#endif
+
+#include <uapi/linux/types.h>
+
+#define __READ_ONCE_SIZE \
+({ \
+ switch (size) { \
+ case 1: *(__u8 *)res = *(volatile __u8 *)p; break; \
+ case 2: *(__u16 *)res = *(volatile __u16 *)p; break; \
+ case 4: *(__u32 *)res = *(volatile __u32 *)p; break; \
+ case 8: *(__u64 *)res = *(volatile __u64 *)p; break; \
+ default: \
+ barrier(); \
+ __builtin_memcpy((void *)res, (const void *)p, size); \
+ barrier(); \
+ } \
+})
+
+static __always_inline
+void __read_once_size(const volatile void *p, void *res, int size)
+{
+ __READ_ONCE_SIZE;
+}
+
+#ifdef CONFIG_KASAN
+/*
+ * We can't declare function 'inline' because __no_sanitize_address confilcts
+ * with inlining. Attempt to inline it may cause a build failure.
+ * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
+ * '__maybe_unused' allows us to avoid defined-but-not-used warnings.
+ */
+# define __no_kasan_or_inline __no_sanitize_address __maybe_unused
+#else
+# define __no_kasan_or_inline __always_inline
+#endif
+
+static __no_kasan_or_inline
+void __read_once_size_nocheck(const volatile void *p, void *res, int size)
+{
+ __READ_ONCE_SIZE;
+}
+
+static __always_inline void __write_once_size(volatile void *p, void *res, int size)
+{
+ switch (size) {
+ case 1: *(volatile __u8 *)p = *(__u8 *)res; break;
+ case 2: *(volatile __u16 *)p = *(__u16 *)res; break;
+ case 4: *(volatile __u32 *)p = *(__u32 *)res; break;
+ case 8: *(volatile __u64 *)p = *(__u64 *)res; break;
+ default:
+ barrier();
+ __builtin_memcpy((void *)p, (const void *)res, size);
+ barrier();
+ }
+}
+
+/*
+ * Prevent the compiler from merging or refetching reads or writes. The
+ * compiler is also forbidden from reordering successive instances of
+ * READ_ONCE and WRITE_ONCE, but only when the compiler is aware of some
+ * particular ordering. One way to make the compiler aware of ordering is to
+ * put the two invocations of READ_ONCE or WRITE_ONCE in different C
+ * statements.
+ *
+ * These two macros will also work on aggregate data types like structs or
+ * unions. If the size of the accessed data type exceeds the word size of
+ * the machine (e.g., 32 bits or 64 bits) READ_ONCE() and WRITE_ONCE() will
+ * fall back to memcpy(). There's at least two memcpy()s: one for the
+ * __builtin_memcpy() and then one for the macro doing the copy of variable
+ * - '__u' allocated on the stack.
+ *
+ * Their two major use cases are: (1) Mediating communication between
+ * process-level code and irq/NMI handlers, all running on the same CPU,
+ * and (2) Ensuring that the compiler does not fold, spindle, or otherwise
+ * mutilate accesses that either do not require ordering or that interact
+ * with an explicit memory barrier or atomic instruction that provides the
+ * required ordering.
+ */
+#include <asm/barrier.h>
+#include <linux/kasan-checks.h>
+
+#define __READ_ONCE(x, check) \
+({ \
+ union { typeof(x) __val; char __c[1]; } __u; \
+ if (check) \
+ __read_once_size(&(x), __u.__c, sizeof(x)); \
+ else \
+ __read_once_size_nocheck(&(x), __u.__c, sizeof(x)); \
+ smp_read_barrier_depends(); /* Enforce dependency ordering from x */ \
+ __u.__val; \
+})
+#define READ_ONCE(x) __READ_ONCE(x, 1)
+
+/*
+ * Use READ_ONCE_NOCHECK() instead of READ_ONCE() if you need
+ * to hide memory access from KASAN.
+ */
+#define READ_ONCE_NOCHECK(x) __READ_ONCE(x, 0)
+
+static __no_kasan_or_inline
+unsigned long read_word_at_a_time(const void *addr)
+{
+ kasan_check_read(addr, 1);
+ return *(unsigned long *)addr;
+}
+
+#define WRITE_ONCE(x, val) \
+({ \
+ union { typeof(x) __val; char __c[1]; } __u = \
+ { .__val = (__force typeof(x)) (val) }; \
+ __write_once_size(&(x), __u.__c, sizeof(x)); \
+ __u.__val; \
+})
+
+#endif /* __KERNEL__ */
+
+/*
+ * Force the compiler to emit 'sym' as a symbol, so that we can reference
+ * it from inline assembler. Necessary in case 'sym' could be inlined
+ * otherwise, or eliminated entirely due to lack of references that are
+ * visible to the compiler.
+ */
+#define __ADDRESSABLE(sym) \
+ static void * __attribute__((section(".discard.addressable"), used)) \
+ __PASTE(__addressable_##sym, __LINE__) = (void *)&sym;
+
+/**
+ * offset_to_ptr - convert a relative memory offset to an absolute pointer
+ * @off: the address of the 32-bit offset value
+ */
+static inline void *offset_to_ptr(const int *off)
+{
+ return (void *)((unsigned long)off + *off);
+}
+
+#endif /* __ASSEMBLY__ */
+
+#ifndef __optimize
+# define __optimize(level)
+#endif
+
+/* Compile time object size, -1 for unknown */
+#ifndef __compiletime_object_size
+# define __compiletime_object_size(obj) -1
+#endif
+#ifndef __compiletime_warning
+# define __compiletime_warning(message)
+#endif
+#ifndef __compiletime_error
+# define __compiletime_error(message)
+/*
+ * Sparse complains of variable sized arrays due to the temporary variable in
+ * __compiletime_assert. Unfortunately we can't just expand it out to make
+ * sparse see a constant array size without breaking compiletime_assert on old
+ * versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
+ */
+# ifndef __CHECKER__
+# define __compiletime_error_fallback(condition) \
+ do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
+# endif
+#endif
+#ifndef __compiletime_error_fallback
+# define __compiletime_error_fallback(condition) do { } while (0)
+#endif
+
+#ifdef __OPTIMIZE__
+# define __compiletime_assert(condition, msg, prefix, suffix) \
+ do { \
+ int __cond = !(condition); \
+ extern void prefix ## suffix(void) __compiletime_error(msg); \
+ if (__cond) \
+ prefix ## suffix(); \
+ __compiletime_error_fallback(__cond); \
+ } while (0)
+#else
+# define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0)
+#endif
+
+#define _compiletime_assert(condition, msg, prefix, suffix) \
+ __compiletime_assert(condition, msg, prefix, suffix)
+
+/**
+ * compiletime_assert - break build and emit msg if condition is false
+ * @condition: a compile-time constant condition to check
+ * @msg: a message to emit if condition is false
+ *
+ * In tradition of POSIX assert, this macro will break the build if the
+ * supplied condition is *false*, emitting the supplied error message if the
+ * compiler has support to do so.
+ */
+#define compiletime_assert(condition, msg) \
+ _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
+
+#define compiletime_assert_atomic_type(t) \
+ compiletime_assert(__native_word(t), \
+ "Need native word sized stores/loads for atomicity.")
+
+#endif /* __LINUX_COMPILER_H */