+/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_COMPILER_H
#define __LINUX_COMPILER_H
-#ifndef __ASSEMBLY__
+#include <linux/compiler_types.h>
-#ifdef __CHECKER__
-# define __user __attribute__((noderef, address_space(1)))
-# define __kernel /* default address space */
-# define __safe __attribute__((safe))
-# define __force __attribute__((force))
-# define __nocast __attribute__((nocast))
-# define __iomem __attribute__((noderef, address_space(2)))
-# define __acquires(x) __attribute__((context(x,0,1)))
-# define __releases(x) __attribute__((context(x,1,0)))
-# define __acquire(x) __context__(x,1)
-# define __release(x) __context__(x,-1)
-# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
-extern void __chk_user_ptr(const volatile void __user *);
-extern void __chk_io_ptr(const volatile void __iomem *);
-#else
-# define __user
-# define __kernel
-# define __safe
-# define __force
-# define __nocast
-# define __iomem
-# define __chk_user_ptr(x) (void)0
-# define __chk_io_ptr(x) (void)0
-# define __builtin_warning(x, y...) (1)
-# define __acquires(x)
-# define __releases(x)
-# define __acquire(x) (void)0
-# define __release(x) (void)0
-# define __cond_lock(x,c) (c)
-#endif
+#ifndef __ASSEMBLY__
#ifdef __KERNEL__
-#ifdef __GNUC__
-#include <linux/compiler-gcc.h>
-#endif
-
-#define notrace __attribute__((no_instrument_function))
-
-/* Intel compiler defines __GNUC__. So we will overwrite implementations
- * coming from above header files here
- */
-#ifdef __INTEL_COMPILER
-# include <linux/compiler-intel.h>
-#endif
-
-/*
- * Generic compiler-dependent macros required for kernel
- * build go below this comment. Actual compiler/compiler version
- * specific implementations come from the above header files
- */
-
-struct ftrace_branch_data {
- const char *func;
- const char *file;
- unsigned line;
- union {
- struct {
- unsigned long correct;
- unsigned long incorrect;
- };
- struct {
- unsigned long miss;
- unsigned long hit;
- };
- unsigned long miss_hit[2];
- };
-};
-
/*
* 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_branch_data *f, int val, int expect);
+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) ({ \
- int ______r; \
- static struct ftrace_branch_data \
- __attribute__((__aligned__(4))) \
- __attribute__((section("_ftrace_annotated_branch"))) \
+#define __branch_check__(x, expect, is_constant) ({ \
+ long ______r; \
+ static struct ftrace_likely_data \
+ __aligned(4) \
+ __section("_ftrace_annotated_branch") \
______f = { \
- .func = __func__, \
- .file = __FILE__, \
- .line = __LINE__, \
+ .data.func = __func__, \
+ .data.file = __FILE__, \
+ .data.line = __LINE__, \
}; \
- ______r = likely_notrace(x); \
- ftrace_likely_update(&______f, ______r, expect); \
+ ______r = __builtin_expect(!!(x), expect); \
+ ftrace_likely_update(&______f, ______r, \
+ expect, is_constant); \
______r; \
})
* written by Daniel Walker.
*/
# ifndef likely
-# define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
+# define likely(x) (__branch_check__(x, 1, __builtin_constant_p(x)))
# endif
# ifndef unlikely
-# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
+# 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; \
- }))
+#define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
+
+#define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
+
+#define __trace_if_value(cond) ({ \
+ static struct ftrace_branch_data \
+ __aligned(4) \
+ __section("_ftrace_branch") \
+ __if_trace = { \
+ .func = __func__, \
+ .file = __FILE__, \
+ .line = __LINE__, \
+ }; \
+ (cond) ? \
+ (__if_trace.miss_hit[1]++,1) : \
+ (__if_trace.miss_hit[0]++,0); \
+})
+
#endif /* CONFIG_PROFILE_ALL_BRANCHES */
#else
# define barrier() __memory_barrier()
#endif
-/* Unreachable code */
-#ifndef unreachable
-# define unreachable() do { } while (1)
+#ifndef barrier_data
+# define barrier_data(ptr) barrier()
#endif
-#ifndef RELOC_HIDE
-# define RELOC_HIDE(ptr, off) \
- ({ unsigned long __ptr; \
- __ptr = (unsigned long) (ptr); \
- (typeof(ptr)) (__ptr + (off)); })
+/* workaround for GCC PR82365 if needed */
+#ifndef barrier_before_unreachable
+# define barrier_before_unreachable() do { } while (0)
#endif
-#endif /* __KERNEL__ */
-
-#endif /* __ASSEMBLY__ */
-
-#ifdef __KERNEL__
+/* Unreachable code */
+#ifdef CONFIG_STACK_VALIDATION
/*
- * Allow us to mark functions as 'deprecated' and have gcc emit a nice
- * warning for each use, in hopes of speeding the functions removal.
- * Usage is:
- * int __deprecated foo(void)
+ * 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.
*/
-#ifndef __deprecated
-# define __deprecated /* unimplemented */
-#endif
+#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"
+
+/* Annotate a C jump table to allow objtool to follow the code flow */
+#define __annotate_jump_table __section(".rodata..c_jump_table")
-#ifdef MODULE
-#define __deprecated_for_modules __deprecated
#else
-#define __deprecated_for_modules
+#define annotate_reachable()
+#define annotate_unreachable()
+#define __annotate_jump_table
#endif
-#ifndef __must_check
-#define __must_check
+#ifndef ASM_UNREACHABLE
+# define ASM_UNREACHABLE
#endif
-
-#ifndef CONFIG_ENABLE_MUST_CHECK
-#undef __must_check
-#define __must_check
-#endif
-#ifndef CONFIG_ENABLE_WARN_DEPRECATED
-#undef __deprecated
-#undef __deprecated_for_modules
-#define __deprecated
-#define __deprecated_for_modules
+#ifndef unreachable
+# define unreachable() do { \
+ annotate_unreachable(); \
+ __builtin_unreachable(); \
+} while (0)
#endif
/*
- * Allow us to avoid 'defined but not used' warnings on functions and data,
- * as well as force them to be emitted to the assembly file.
- *
- * As of gcc 3.4, static functions that are not marked with attribute((used))
- * may be elided from the assembly file. As of gcc 3.4, static data not so
- * marked will not be elided, but this may change in a future gcc version.
- *
- * NOTE: Because distributions shipped with a backported unit-at-a-time
- * compiler in gcc 3.3, we must define __used to be __attribute__((used))
- * for gcc >=3.3 instead of 3.4.
+ * 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.
*
- * In prior versions of gcc, such functions and data would be emitted, but
- * would be warned about except with attribute((unused)).
+ * Not required for symbols exported with EXPORT_SYMBOL, or initcalls. Those
+ * are handled in their own way (with KEEP() in linker scripts).
*
- * Mark functions that are referenced only in inline assembly as __used so
- * the code is emitted even though it appears to be unreferenced.
+ * 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 __used
-# define __used /* unimplemented */
+#ifndef KENTRY
+# define KENTRY(sym) \
+ extern typeof(sym) sym; \
+ static const unsigned long __kentry_##sym \
+ __used \
+ __section("___kentry" "+" #sym ) \
+ = (unsigned long)&sym;
#endif
-#ifndef __maybe_unused
-# define __maybe_unused /* unimplemented */
+#ifndef RELOC_HIDE
+# define RELOC_HIDE(ptr, off) \
+ ({ unsigned long __ptr; \
+ __ptr = (unsigned long) (ptr); \
+ (typeof(ptr)) (__ptr + (off)); })
#endif
-#ifndef __always_unused
-# define __always_unused /* unimplemented */
+#ifndef OPTIMIZER_HIDE_VAR
+/* Make the optimizer believe the variable can be manipulated arbitrarily. */
+#define OPTIMIZER_HIDE_VAR(var) \
+ __asm__ ("" : "=r" (var) : "0" (var))
#endif
-#ifndef noinline
-#define noinline
+/* Not-quite-unique ID. */
+#ifndef __UNIQUE_ID
+# define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
#endif
+#include <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
/*
- * Rather then using noinline to prevent stack consumption, use
- * noinline_for_stack instead. For documentaiton reasons.
+ * 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 noinline_for_stack noinline
-
-#ifndef __always_inline
-#define __always_inline inline
+# define __no_kasan_or_inline __no_sanitize_address notrace __maybe_unused
+#else
+# define __no_kasan_or_inline __always_inline
#endif
-#endif /* __KERNEL__ */
+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();
+ }
+}
/*
- * From the GCC manual:
+ * 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.
*
- * Many functions do not examine any values except their arguments,
- * and have no effects except the return value. Basically this is
- * just slightly more strict class than the `pure' attribute above,
- * since function is not allowed to read global memory.
+ * 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.
*
- * Note that a function that has pointer arguments and examines the
- * data pointed to must _not_ be declared `const'. Likewise, a
- * function that calls a non-`const' function usually must not be
- * `const'. It does not make sense for a `const' function to return
- * `void'.
+ * 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.
*/
-#ifndef __attribute_const__
-# define __attribute_const__ /* unimplemented */
-#endif
+
+#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)); \
+ __u.__val; \
+})
+#define READ_ONCE(x) __READ_ONCE(x, 1)
/*
- * Tell gcc if a function is cold. The compiler will assume any path
- * directly leading to the call is unlikely.
+ * 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)
+{
+ 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; \
+})
-#ifndef __cold
-#define __cold
-#endif
+#endif /* __KERNEL__ */
-/* Simple shorthand for a section definition */
-#ifndef __section
-# define __section(S) __attribute__ ((__section__(#S)))
-#endif
+/*
+ * 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 * __section(".discard.addressable") __used \
+ __PASTE(__addressable_##sym, __LINE__) = (void *)&sym;
-/* Are two types/vars the same type (ignoring qualifiers)? */
-#ifndef __same_type
-# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
-#endif
+/**
+ * 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__ */
/* Compile time object size, -1 for unknown */
#ifndef __compiletime_object_size
# define __compiletime_error(message)
#endif
-/*
- * Prevent the compiler from merging or refetching accesses. The compiler
- * is also forbidden from reordering successive instances of ACCESS_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
- * ACCESS_ONCE() in different C statements.
+#ifdef __OPTIMIZE__
+# define __compiletime_assert(condition, msg, prefix, suffix) \
+ do { \
+ extern void prefix ## suffix(void) __compiletime_error(msg); \
+ if (!(condition)) \
+ prefix ## suffix(); \
+ } 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
*
- * This macro does absolutely -nothing- to prevent the CPU from reordering,
- * merging, or refetching absolutely anything at any time. Its main intended
- * use is to mediate communication between process-level code and irq/NMI
- * handlers, all running on the same CPU.
+ * 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 ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
+#define compiletime_assert(condition, msg) \
+ _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
+
+#define compiletime_assert_atomic_type(t) \
+ compiletime_assert(__native_word(t), \
+ "Need native word sized stores/loads for atomicity.")
+
+/* &a[0] degrades to a pointer: a different type from an array */
+#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
#endif /* __LINUX_COMPILER_H */
projects / platform / kernel / u-boot.git / blobdiff