add per_cpu_dyn_array support

allow dyn-array in per_cpu area, allocated dynamically.

usage:

|  /* in .h */
| struct kernel_stat {
|        struct cpu_usage_stat   cpustat;
|        unsigned int *irqs;
| };
|
|  /* in .c */
| DEFINE_PER_CPU(struct kernel_stat, kstat);
|
| DEFINE_PER_CPU_DYN_ARRAY_ADDR(per_cpu__kstat_irqs, per_cpu__kstat.irqs, sizeof(unsigned int), nr_irqs, sizeof(unsigned long), NULL);

after setup_percpu()/per_cpu_alloc_dyn_array(), the dyn_array in
per_cpu area is ready to use.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 30 insertions, 3 deletions

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 7881406c03ec..c68eda9d9a90 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -216,6 +216,12 @@
                 VMLINUX_SYMBOL(__dyn_array_start) = .;                  \
                 *(.dyn_array.init)                                      \
                 VMLINUX_SYMBOL(__dyn_array_end) = .;                    \
+        }                                                               \
+        . = ALIGN((align));                                             \
+        .per_cpu_dyn_array.init : AT(ADDR(.per_cpu_dyn_array.init) - LOAD_OFFSET) {     \
+                VMLINUX_SYMBOL(__per_cpu_dyn_array_start) = .;          \
+                *(.per_cpu_dyn_array.init)                              \
+                VMLINUX_SYMBOL(__per_cpu_dyn_array_end) = .;            \
         }
 #define SECURITY_INIT                                                   \
         .security_initcall.init : AT(ADDR(.security_initcall.init) - LOAD_OFFSET) { \
diff --git a/include/linux/init.h b/include/linux/init.h
index cf9fa7f174af..332806826b8e 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -255,12 +255,13 @@ struct dyn_array {
         void (*init_work)(void *);
 };
 extern struct dyn_array *__dyn_array_start[], *__dyn_array_end[];
+extern struct dyn_array *__per_cpu_dyn_array_start[], *__per_cpu_dyn_array_end[];
 
-#define DEFINE_DYN_ARRAY(nameX, sizeX, nrX, alignX, init_workX) \
+#define DEFINE_DYN_ARRAY_ADDR(nameX, addrX, sizeX, nrX, alignX, init_workX) \
                 static struct dyn_array __dyn_array_##nameX __initdata = \
-                {       .name = (void **)&nameX,\
+                {       .name = (void **)&(nameX),\
                         .size = sizeX,\
-                        .nr   = &nrX,\
+                        .nr   = &(nrX),\
                         .align = alignX,\
                         .init_work = init_workX,\
                 }; \
@@ -268,7 +269,27 @@ extern struct dyn_array *__dyn_array_start[], *__dyn_array_end[];
                 __attribute__((__section__(".dyn_array.init"))) = \
                         &__dyn_array_##nameX
 
+#define DEFINE_DYN_ARRAY(nameX, sizeX, nrX, alignX, init_workX) \
+        DEFINE_DYN_ARRAY_ADDR(nameX, nameX, sizeX, nrX, alignX, init_workX)
+
+#define DEFINE_PER_CPU_DYN_ARRAY_ADDR(nameX, addrX, sizeX, nrX, alignX, init_workX) \
+                static struct dyn_array __per_cpu_dyn_array_##nameX __initdata = \
+                {       .name = (void **)&(addrX),\
+                        .size = sizeX,\
+                        .nr   = &(nrX),\
+                        .align = alignX,\
+                        .init_work = init_workX,\
+                }; \
+                static struct dyn_array *__per_cpu_dyn_array_ptr_##nameX __used \
+                __attribute__((__section__(".per_cpu_dyn_array.init"))) = \
+                        &__per_cpu_dyn_array_##nameX
+
+#define DEFINE_PER_CPU_DYN_ARRAY(nameX, sizeX, nrX, alignX, init_workX) \
+        DEFINE_PER_CPU_DYN_ARRAY_ADDR(nameX, nameX, nrX, alignX, init_workX)
+
 extern void pre_alloc_dyn_array(void);
+extern unsigned long per_cpu_dyn_array_size(void);
+extern void per_cpu_alloc_dyn_array(int cpu, char *ptr);
 #endif /* __ASSEMBLY__ */
 
 /**