Commit b27652dd authored by Kevin Hao's avatar Kevin Hao Committed by Scott Wood
Browse files

powerpc: introduce early_get_first_memblock_info 



For a relocatable kernel since it can be loaded at any place, there
is no any relation between the kernel start addr and the memstart_addr.
So we can't calculate the memstart_addr from kernel start addr. And
also we can't wait to do the relocation after we get the real
memstart_addr from device tree because it is so late. So introduce
a new function we can use to get the first memblock address and size
in a very early stage (before machine_init).

Signed-off-by: default avatarKevin Hao <haokexin@gmail.com>
Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
parent 78a235ef

arch/powerpc/kernel/prom.c

+40 −1
Original line number Diff line number Diff line
@@ -523,6 +523,20 @@ static int __init early_init_dt_scan_memory_ppc(unsigned long node, 
	return early_init_dt_scan_memory(node, uname, depth, data);

}



/*

 * For a relocatable kernel, we need to get the memstart_addr first,

 * then use it to calculate the virtual kernel start address. This has

 * to happen at a very early stage (before machine_init). In this case,

 * we just want to get the memstart_address and would not like to mess the

 * memblock at this stage. So introduce a variable to skip the memblock_add()

 * for this reason.

 */

#ifdef CONFIG_RELOCATABLE

static int add_mem_to_memblock = 1;

#else

#define add_mem_to_memblock 1

#endif



void __init early_init_dt_add_memory_arch(u64 base, u64 size)

{

#ifdef CONFIG_PPC64
@@ -543,6 +557,7 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size) 
	}



	/* Add the chunk to the MEMBLOCK list */

	if (add_mem_to_memblock)

		memblock_add(base, size);

}
@@ -740,6 +755,30 @@ void __init early_init_devtree(void *params) 
	DBG(" <- early_init_devtree()\n");

}



#ifdef CONFIG_RELOCATABLE

/*

 * This function run before early_init_devtree, so we have to init

 * initial_boot_params.

 */

void __init early_get_first_memblock_info(void *params, phys_addr_t *size)

{

	/* Setup flat device-tree pointer */

	initial_boot_params = params;



	/*

	 * Scan the memory nodes and set add_mem_to_memblock to 0 to avoid

	 * mess the memblock.

	 */

	add_mem_to_memblock = 0;

	of_scan_flat_dt(early_init_dt_scan_root, NULL);

	of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);

	add_mem_to_memblock = 1;



	if (size)

		*size = first_memblock_size;

}

#endif



/*******

 *

 * New implementation of the OF "find" APIs, return a refcounted

include/linux/of_fdt.h

+1 −0
Original line number Diff line number Diff line
@@ -116,6 +116,7 @@ extern const void *of_flat_dt_match_machine(const void *default_match, 
extern void unflatten_device_tree(void);

extern void unflatten_and_copy_device_tree(void);

extern void early_init_devtree(void *);

extern void early_get_first_memblock_info(void *, phys_addr_t *);

#else /* CONFIG_OF_FLATTREE */

static inline const char *of_flat_dt_get_machine_name(void) { return NULL; }

static inline void unflatten_device_tree(void) {}

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