Commit 3ddfda11 authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar
Browse files

generic: add dyn_array support 



Allow crazy big arrays via bootmem at init stage.
Architectures use CONFIG_HAVE_DYN_ARRAY to enable it.

usage:

| static struct irq_desc irq_desc_init __initdata = {
|        .status = IRQ_DISABLED,
|        .chip = &no_irq_chip,
|        .handle_irq = handle_bad_irq,
|        .depth = 1,
|        .lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock),
| #ifdef CONFIG_SMP
|        .affinity = CPU_MASK_ALL
| #endif
| };
|
| static void __init init_work(void *data)
| {
|        struct dyn_array *da = data;
|        struct  irq_desc *desc;
|        int i;
|
|        desc = *da->name;
|
|        for (i = 0; i < *da->nr; i++)
|                memcpy(&desc[i], &irq_desc_init, sizeof(struct irq_desc));
| }
|
| struct irq_desc *irq_desc;
| DEFINE_DYN_ARRAY(irq_desc, sizeof(struct irq_desc), nr_irqs, PAGE_SIZE, init_work);

after pre_alloc_dyn_array() after setup_arch(), the array is ready to be
used.

Via this facility we can replace irq_desc[NR_IRQS] array with dyn_array
irq_desc[nr_irqs].

v2: remove _nopanic in pre_alloc_dyn_array()

Signed-off-by: default avatarYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 38395738

include/asm-generic/vmlinux.lds.h

+7 −0
Original line number Diff line number Diff line
@@ -210,6 +210,13 @@ 
 * All archs are supposed to use RO_DATA() */

#define RODATA RO_DATA(4096)



#define DYN_ARRAY_INIT(align)							\

	. = ALIGN((align));						\

	.dyn_array.init : AT(ADDR(.dyn_array.init) - LOAD_OFFSET) {	\

		VMLINUX_SYMBOL(__dyn_array_start) = .;			\

		*(.dyn_array.init)					\

		VMLINUX_SYMBOL(__dyn_array_end) = .;			\

	}

#define SECURITY_INIT							\

	.security_initcall.init : AT(ADDR(.security_initcall.init) - LOAD_OFFSET) { \

		VMLINUX_SYMBOL(__security_initcall_start) = .;		\

include/linux/init.h

+23 −0
Original line number Diff line number Diff line
@@ -246,6 +246,29 @@ struct obs_kernel_param { 


/* Relies on boot_command_line being set */

void __init parse_early_param(void);



struct dyn_array {

	void **name;

	unsigned long size;

	unsigned int *nr;

	unsigned long align;

	void (*init_work)(void *);

};

extern struct dyn_array *__dyn_array_start[], *__dyn_array_end[];



#define DEFINE_DYN_ARRAY(nameX, sizeX, nrX, alignX, init_workX) \

		static struct dyn_array __dyn_array_##nameX __initdata = \

		{	.name = (void **)&nameX,\

			.size = sizeX,\

			.nr   = &nrX,\

			.align = alignX,\

			.init_work = init_workX,\

		}; \

		static struct dyn_array *__dyn_array_ptr_##nameX __used \

		__attribute__((__section__(".dyn_array.init"))) = \

			&__dyn_array_##nameX



extern void pre_alloc_dyn_array(void);

#endif /* __ASSEMBLY__ */



/**

init/main.c

+24 −0
Original line number Diff line number Diff line
@@ -536,6 +536,29 @@ void __init __weak thread_info_cache_init(void) 
{

}



void pre_alloc_dyn_array(void)

{

#ifdef CONFIG_HAVE_DYN_ARRAY

	unsigned long size, phys = 0;

	struct dyn_array **daa;



	for (daa = __dyn_array_start ; daa < __dyn_array_end; daa++) {

		struct dyn_array *da = *daa;



		size = da->size * (*da->nr);

		print_fn_descriptor_symbol("dyna_array %s ", da->name);

		printk(KERN_CONT "size:%#lx nr:%d align:%#lx",

			da->size, *da->nr, da->align);

		*da->name = __alloc_bootmem(size, da->align, phys);

		phys = virt_to_phys(*da->name);

		printk(KERN_CONT " ==> [%#lx - %#lx]\n", phys, phys + size);



		if (da->init_work)

			da->init_work(da);

	}

#endif

}



asmlinkage void __init start_kernel(void)

{

	char * command_line;
@@ -567,6 +590,7 @@ asmlinkage void __init start_kernel(void) 
	printk(KERN_NOTICE);

	printk(linux_banner);

	setup_arch(&command_line);

	pre_alloc_dyn_array();

	mm_init_owner(&init_mm, &init_task);

	setup_command_line(command_line);

	unwind_setup();

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