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>

4 files changed, 96 insertions, 7 deletions

diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 0e67f72d9316..13ba7a83808d 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -140,7 +140,7 @@ static void __init setup_cpu_pda_map(void)
  */
 void __init setup_per_cpu_areas(void)
 {
-        ssize_t size = PERCPU_ENOUGH_ROOM;
+        ssize_t size, old_size;
         char *ptr;
         int cpu;
 
@@ -148,7 +148,8 @@ void __init setup_per_cpu_areas(void)
         setup_cpu_pda_map();
 
         /* Copy section for each CPU (we discard the original) */
-        size = PERCPU_ENOUGH_ROOM;
+        old_size = PERCPU_ENOUGH_ROOM;
+        size = old_size + per_cpu_dyn_array_size();
         printk(KERN_INFO "PERCPU: Allocating %zd bytes of per cpu data\n",
                           size);
 
@@ -176,6 +177,8 @@ void __init setup_per_cpu_areas(void)
                 per_cpu_offset(cpu) = ptr - __per_cpu_start;
                 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
 
+                per_cpu_alloc_dyn_array(cpu, ptr + old_size);
+
         }
 
         printk(KERN_DEBUG "NR_CPUS: %d, nr_cpu_ids: %d, nr_node_ids %d\n",
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__ */
 
 /**
diff --git a/init/main.c b/init/main.c
index 638d3a786412..416bca4f734f 100644
--- a/init/main.c
+++ b/init/main.c
@@ -391,17 +391,19 @@ EXPORT_SYMBOL(__per_cpu_offset);
 
 static void __init setup_per_cpu_areas(void)
 {
-        unsigned long size, i;
+        unsigned long size, i, old_size;
         char *ptr;
         unsigned long nr_possible_cpus = num_possible_cpus();
 
         /* Copy section for each CPU (we discard the original) */
-        size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
+        old_size = PERCPU_ENOUGH_ROOM;
+        size = ALIGN(old_size + per_cpu_dyn_array_size(), PAGE_SIZE);
         ptr = alloc_bootmem_pages(size * nr_possible_cpus);
 
         for_each_possible_cpu(i) {
                 __per_cpu_offset[i] = ptr - __per_cpu_start;
                 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
+                per_cpu_alloc_dyn_array(i, ptr + old_size);
                 ptr += size;
         }
 }
@@ -559,6 +561,63 @@ void pre_alloc_dyn_array(void)
 #endif
 }
 
+unsigned long per_cpu_dyn_array_size(void)
+{
+        unsigned long total_size = 0;
+#ifdef CONFIG_HAVE_DYN_ARRAY
+        unsigned long size;
+        struct dyn_array **daa;
+
+        for (daa = __per_cpu_dyn_array_start ; daa < __per_cpu_dyn_array_end; daa++) {
+                struct dyn_array *da = *daa;
+
+                size = da->size * (*da->nr);
+                print_fn_descriptor_symbol("per_cpu_dyna_array %s ", da->name);
+                printk(KERN_CONT "size:%#lx nr:%d align:%#lx\n",
+                        da->size, *da->nr, da->align);
+                total_size += roundup(size, da->align);
+        }
+        if (total_size)
+                printk(KERN_DEBUG "per_cpu_dyna_array total_size: %#lx\n",
+                         total_size);
+#endif
+        return total_size;
+}
+
+void per_cpu_alloc_dyn_array(int cpu, char *ptr)
+{
+#ifdef CONFIG_HAVE_DYN_ARRAY
+        unsigned long size, phys;
+        struct dyn_array **daa;
+        unsigned long addr;
+        void **array;
+
+        phys = virt_to_phys(ptr);
+
+        for (daa = __per_cpu_dyn_array_start ; daa < __per_cpu_dyn_array_end; daa++) {
+                struct dyn_array *da = *daa;
+
+                size = da->size * (*da->nr);
+                print_fn_descriptor_symbol("per_cpu_dyna_array %s ", da->name);
+                printk(KERN_CONT "size:%#lx nr:%d align:%#lx",
+                        da->size, *da->nr, da->align);
+
+                phys = roundup(phys, da->align);
+                addr = (unsigned long)da->name;
+                addr += per_cpu_offset(cpu);
+                array = (void **)addr;
+                *array = phys_to_virt(phys);
+                *da->name = *array; /* so init_work could use it directly */
+                printk(KERN_CONT " %p ==> [%#lx - %#lx]\n", array, phys, phys + size);
+                phys += size;
+
+                if (da->init_work) {
+                        da->init_work(da);
+                }
+        }
+#endif
+}
+
 asmlinkage void __init start_kernel(void)
 {
         char * command_line;