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authorIngo Molnar <mingo@elte.hu>2009-03-08 16:48:51 +0100
committerIngo Molnar <mingo@elte.hu>2009-03-08 16:48:51 +0100
commitdba58e39ced7af63f2748d12bbb2b4ac83c72391 (patch)
treeee15a5e7667b51d0d0f7e8cb39064652f7c84c28 /include/asm-generic
parent9de36825b321fe9fe9cf73260554251af579f4ca (diff)
parent78ff7fae04554b49d29226ed12536268c2500d1f (diff)
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Merge branches 'tracing/doc', 'tracing/ftrace', 'tracing/printk' and 'tracing/textedit' into tracing/core
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/percpu.h52
-rw-r--r--include/asm-generic/sections.h2
-rw-r--r--include/asm-generic/vmlinux.lds.h55
3 files changed, 104 insertions, 5 deletions
diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
index b0e63c672eb..00f45ff081a 100644
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -80,4 +80,56 @@ extern void setup_per_cpu_areas(void);
#define DECLARE_PER_CPU(type, name) extern PER_CPU_ATTRIBUTES \
__typeof__(type) per_cpu_var(name)
+/*
+ * Optional methods for optimized non-lvalue per-cpu variable access.
+ *
+ * @var can be a percpu variable or a field of it and its size should
+ * equal char, int or long. percpu_read() evaluates to a lvalue and
+ * all others to void.
+ *
+ * These operations are guaranteed to be atomic w.r.t. preemption.
+ * The generic versions use plain get/put_cpu_var(). Archs are
+ * encouraged to implement single-instruction alternatives which don't
+ * require preemption protection.
+ */
+#ifndef percpu_read
+# define percpu_read(var) \
+ ({ \
+ typeof(per_cpu_var(var)) __tmp_var__; \
+ __tmp_var__ = get_cpu_var(var); \
+ put_cpu_var(var); \
+ __tmp_var__; \
+ })
+#endif
+
+#define __percpu_generic_to_op(var, val, op) \
+do { \
+ get_cpu_var(var) op val; \
+ put_cpu_var(var); \
+} while (0)
+
+#ifndef percpu_write
+# define percpu_write(var, val) __percpu_generic_to_op(var, (val), =)
+#endif
+
+#ifndef percpu_add
+# define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=)
+#endif
+
+#ifndef percpu_sub
+# define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=)
+#endif
+
+#ifndef percpu_and
+# define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=)
+#endif
+
+#ifndef percpu_or
+# define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=)
+#endif
+
+#ifndef percpu_xor
+# define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=)
+#endif
+
#endif /* _ASM_GENERIC_PERCPU_H_ */
diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h
index 79a7ff925bf..4ce48e87853 100644
--- a/include/asm-generic/sections.h
+++ b/include/asm-generic/sections.h
@@ -9,7 +9,7 @@ extern char __bss_start[], __bss_stop[];
extern char __init_begin[], __init_end[];
extern char _sinittext[], _einittext[];
extern char _end[];
-extern char __per_cpu_start[], __per_cpu_end[];
+extern char __per_cpu_load[], __per_cpu_start[], __per_cpu_end[];
extern char __kprobes_text_start[], __kprobes_text_end[];
extern char __initdata_begin[], __initdata_end[];
extern char __start_rodata[], __end_rodata[];
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 48ade3168b1..89997dfdf3d 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -448,12 +448,59 @@
*(.initcall7.init) \
*(.initcall7s.init)
+/**
+ * PERCPU_VADDR - define output section for percpu area
+ * @vaddr: explicit base address (optional)
+ * @phdr: destination PHDR (optional)
+ *
+ * Macro which expands to output section for percpu area. If @vaddr
+ * is not blank, it specifies explicit base address and all percpu
+ * symbols will be offset from the given address. If blank, @vaddr
+ * always equals @laddr + LOAD_OFFSET.
+ *
+ * @phdr defines the output PHDR to use if not blank. Be warned that
+ * output PHDR is sticky. If @phdr is specified, the next output
+ * section in the linker script will go there too. @phdr should have
+ * a leading colon.
+ *
+ * Note that this macros defines __per_cpu_load as an absolute symbol.
+ * If there is no need to put the percpu section at a predetermined
+ * address, use PERCPU().
+ */
+#define PERCPU_VADDR(vaddr, phdr) \
+ VMLINUX_SYMBOL(__per_cpu_load) = .; \
+ .data.percpu vaddr : AT(VMLINUX_SYMBOL(__per_cpu_load) \
+ - LOAD_OFFSET) { \
+ VMLINUX_SYMBOL(__per_cpu_start) = .; \
+ *(.data.percpu.first) \
+ *(.data.percpu.page_aligned) \
+ *(.data.percpu) \
+ *(.data.percpu.shared_aligned) \
+ VMLINUX_SYMBOL(__per_cpu_end) = .; \
+ } phdr \
+ . = VMLINUX_SYMBOL(__per_cpu_load) + SIZEOF(.data.percpu);
+
+/**
+ * PERCPU - define output section for percpu area, simple version
+ * @align: required alignment
+ *
+ * Align to @align and outputs output section for percpu area. This
+ * macro doesn't maniuplate @vaddr or @phdr and __per_cpu_load and
+ * __per_cpu_start will be identical.
+ *
+ * This macro is equivalent to ALIGN(align); PERCPU_VADDR( , ) except
+ * that __per_cpu_load is defined as a relative symbol against
+ * .data.percpu which is required for relocatable x86_32
+ * configuration.
+ */
#define PERCPU(align) \
. = ALIGN(align); \
- VMLINUX_SYMBOL(__per_cpu_start) = .; \
- .data.percpu : AT(ADDR(.data.percpu) - LOAD_OFFSET) { \
+ .data.percpu : AT(ADDR(.data.percpu) - LOAD_OFFSET) { \
+ VMLINUX_SYMBOL(__per_cpu_load) = .; \
+ VMLINUX_SYMBOL(__per_cpu_start) = .; \
+ *(.data.percpu.first) \
*(.data.percpu.page_aligned) \
*(.data.percpu) \
*(.data.percpu.shared_aligned) \
- } \
- VMLINUX_SYMBOL(__per_cpu_end) = .;
+ VMLINUX_SYMBOL(__per_cpu_end) = .; \
+ }