#define _LINUX_PERCPU_DEFS_H
/*
- * Determine the real variable name from the name visible in the
- * kernel sources.
- */
-#define per_cpu_var(var) per_cpu__##var
-
-/*
* Base implementations of per-CPU variable declarations and definitions, where
* the section in which the variable is to be placed is provided by the
- * 'section' argument. This may be used to affect the parameters governing the
+ * 'sec' argument. This may be used to affect the parameters governing the
* variable's storage.
*
* NOTE! The sections for the DECLARE and for the DEFINE must match, lest
* linkage errors occur due the compiler generating the wrong code to access
* that section.
*/
-#define DECLARE_PER_CPU_SECTION(type, name, section) \
- extern \
- __attribute__((__section__(PER_CPU_BASE_SECTION section))) \
- PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
+#define __PCPU_ATTRS(sec) \
+ __percpu __attribute__((section(PER_CPU_BASE_SECTION sec))) \
+ PER_CPU_ATTRIBUTES
-#define DEFINE_PER_CPU_SECTION(type, name, section) \
- __attribute__((__section__(PER_CPU_BASE_SECTION section))) \
- PER_CPU_ATTRIBUTES PER_CPU_DEF_ATTRIBUTES \
- __typeof__(type) per_cpu__##name
+#define __PCPU_DUMMY_ATTRS \
+ __attribute__((section(".discard"), unused))
+
+/*
+ * Macro which verifies @ptr is a percpu pointer without evaluating
+ * @ptr. This is to be used in percpu accessors to verify that the
+ * input parameter is a percpu pointer.
+ */
+#define __verify_pcpu_ptr(ptr) do { \
+ const void __percpu *__vpp_verify = (typeof(ptr))NULL; \
+ (void)__vpp_verify; \
+} while (0)
+
+/*
+ * s390 and alpha modules require percpu variables to be defined as
+ * weak to force the compiler to generate GOT based external
+ * references for them. This is necessary because percpu sections
+ * will be located outside of the usually addressable area.
+ *
+ * This definition puts the following two extra restrictions when
+ * defining percpu variables.
+ *
+ * 1. The symbol must be globally unique, even the static ones.
+ * 2. Static percpu variables cannot be defined inside a function.
+ *
+ * Archs which need weak percpu definitions should define
+ * ARCH_NEEDS_WEAK_PER_CPU in asm/percpu.h when necessary.
+ *
+ * To ensure that the generic code observes the above two
+ * restrictions, if CONFIG_DEBUG_FORCE_WEAK_PER_CPU is set weak
+ * definition is used for all cases.
+ */
+#if defined(ARCH_NEEDS_WEAK_PER_CPU) || defined(CONFIG_DEBUG_FORCE_WEAK_PER_CPU)
+/*
+ * __pcpu_scope_* dummy variable is used to enforce scope. It
+ * receives the static modifier when it's used in front of
+ * DEFINE_PER_CPU() and will trigger build failure if
+ * DECLARE_PER_CPU() is used for the same variable.
+ *
+ * __pcpu_unique_* dummy variable is used to enforce symbol uniqueness
+ * such that hidden weak symbol collision, which will cause unrelated
+ * variables to share the same address, can be detected during build.
+ */
+#define DECLARE_PER_CPU_SECTION(type, name, sec) \
+ extern __PCPU_DUMMY_ATTRS char __pcpu_scope_##name; \
+ extern __PCPU_ATTRS(sec) __typeof__(type) name
+
+#define DEFINE_PER_CPU_SECTION(type, name, sec) \
+ __PCPU_DUMMY_ATTRS char __pcpu_scope_##name; \
+ extern __PCPU_DUMMY_ATTRS char __pcpu_unique_##name; \
+ __PCPU_DUMMY_ATTRS char __pcpu_unique_##name; \
+ __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES __weak \
+ __typeof__(type) name
+#else
+/*
+ * Normal declaration and definition macros.
+ */
+#define DECLARE_PER_CPU_SECTION(type, name, sec) \
+ extern __PCPU_ATTRS(sec) __typeof__(type) name
+
+#define DEFINE_PER_CPU_SECTION(type, name, sec) \
+ __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES \
+ __typeof__(type) name
+#endif
/*
* Variant on the per-CPU variable declaration/definition theme used for
DEFINE_PER_CPU_SECTION(type, name, PER_CPU_SHARED_ALIGNED_SECTION) \
____cacheline_aligned_in_smp
+#define DECLARE_PER_CPU_ALIGNED(type, name) \
+ DECLARE_PER_CPU_SECTION(type, name, PER_CPU_ALIGNED_SECTION) \
+ ____cacheline_aligned
+
+#define DEFINE_PER_CPU_ALIGNED(type, name) \
+ DEFINE_PER_CPU_SECTION(type, name, PER_CPU_ALIGNED_SECTION) \
+ ____cacheline_aligned
+
/*
* Declaration/definition used for per-CPU variables that must be page aligned.
*/
-#define DECLARE_PER_CPU_PAGE_ALIGNED(type, name) \
- DECLARE_PER_CPU_SECTION(type, name, ".page_aligned")
+#define DECLARE_PER_CPU_PAGE_ALIGNED(type, name) \
+ DECLARE_PER_CPU_SECTION(type, name, ".page_aligned") \
+ __aligned(PAGE_SIZE)
#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name) \
- DEFINE_PER_CPU_SECTION(type, name, ".page_aligned")
+ DEFINE_PER_CPU_SECTION(type, name, ".page_aligned") \
+ __aligned(PAGE_SIZE)
/*
- * Intermodule exports for per-CPU variables.
+ * Intermodule exports for per-CPU variables. sparse forgets about
+ * address space across EXPORT_SYMBOL(), change EXPORT_SYMBOL() to
+ * noop if __CHECKER__.
*/
-#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
-#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
-
+#ifndef __CHECKER__
+#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(var)
+#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(var)
+#else
+#define EXPORT_PER_CPU_SYMBOL(var)
+#define EXPORT_PER_CPU_SYMBOL_GPL(var)
+#endif
#endif /* _LINUX_PERCPU_DEFS_H */