percpu, module: implement and use is_kernel/module_percpu_address()

[safe/jmp/linux-2.6] / mm / percpu.c

diff --git a/mm/percpu.c b/mm/percpu.c
index 768419d..6e09741 100644 (file)
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1304,6 +1304,32 @@ void free_percpu(void __percpu *ptr)
 EXPORT_SYMBOL_GPL(free_percpu);
 
 /**
+ * is_kernel_percpu_address - test whether address is from static percpu area
+ * @addr: address to test
+ *
+ * Test whether @addr belongs to in-kernel static percpu area.  Module
+ * static percpu areas are not considered.  For those, use
+ * is_module_percpu_address().
+ *
+ * RETURNS:
+ * %true if @addr is from in-kernel static percpu area, %false otherwise.
+ */
+bool is_kernel_percpu_address(unsigned long addr)
+{
+       const size_t static_size = __per_cpu_end - __per_cpu_start;
+       void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr);
+       unsigned int cpu;
+
+       for_each_possible_cpu(cpu) {
+               void *start = per_cpu_ptr(base, cpu);
+
+               if ((void *)addr >= start && (void *)addr < start + static_size)
+                       return true;
+        }
+       return false;
+}
+
+/**
  * per_cpu_ptr_to_phys - convert translated percpu address to physical address
  * @addr: the address to be converted to physical address
  *