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Commit 60fe3910 authored by Thiago Jung Bauermann's avatar Thiago Jung Bauermann Committed by Michael Ellerman
Browse files

kexec_file: Allow arch-specific memory walking for kexec_add_buffer 



Allow architectures to specify a different memory walking function for
kexec_add_buffer. x86 uses iomem to track reserved memory ranges, but
PowerPC uses the memblock subsystem.

Signed-off-by: default avatarThiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: default avatarDave Young <dyoung@redhat.com>
Acked-by: default avatarBalbir Singh <bsingharora@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 0ab5171b

include/linux/kexec.h

+28 −1
Original line number Diff line number Diff line
@@ -148,7 +148,34 @@ struct kexec_file_ops { 
	kexec_verify_sig_t *verify_sig;

#endif

};

#endif



/**

 * struct kexec_buf - parameters for finding a place for a buffer in memory

 * @image:	kexec image in which memory to search.

 * @buffer:	Contents which will be copied to the allocated memory.

 * @bufsz:	Size of @buffer.

 * @mem:	On return will have address of the buffer in memory.

 * @memsz:	Size for the buffer in memory.

 * @buf_align:	Minimum alignment needed.

 * @buf_min:	The buffer can't be placed below this address.

 * @buf_max:	The buffer can't be placed above this address.

 * @top_down:	Allocate from top of memory.

 */

struct kexec_buf {

	struct kimage *image;

	char *buffer;

	unsigned long bufsz;

	unsigned long mem;

	unsigned long memsz;

	unsigned long buf_align;

	unsigned long buf_min;

	unsigned long buf_max;

	bool top_down;

};



int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,

			       int (*func)(u64, u64, void *));

#endif /* CONFIG_KEXEC_FILE */



struct kimage {

	kimage_entry_t head;

kernel/kexec_file.c

+22 −8
Original line number Diff line number Diff line
@@ -428,6 +428,27 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg) 
	return locate_mem_hole_bottom_up(start, end, kbuf);

}



/**

 * arch_kexec_walk_mem - call func(data) on free memory regions

 * @kbuf:	Context info for the search. Also passed to @func.

 * @func:	Function to call for each memory region.

 *

 * Return: The memory walk will stop when func returns a non-zero value

 * and that value will be returned. If all free regions are visited without

 * func returning non-zero, then zero will be returned.

 */

int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,

			       int (*func)(u64, u64, void *))

{

	if (kbuf->image->type == KEXEC_TYPE_CRASH)

		return walk_iomem_res_desc(crashk_res.desc,

					   IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,

					   crashk_res.start, crashk_res.end,

					   kbuf, func);

	else

		return walk_system_ram_res(0, ULONG_MAX, kbuf, func);

}



/*

 * Helper function for placing a buffer in a kexec segment. This assumes

 * that kexec_mutex is held.
@@ -474,14 +495,7 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz, 
	kbuf->top_down = top_down;



	/* Walk the RAM ranges and allocate a suitable range for the buffer */

	if (image->type == KEXEC_TYPE_CRASH)

		ret = walk_iomem_res_desc(crashk_res.desc,

				IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,

				crashk_res.start, crashk_res.end, kbuf,

				locate_mem_hole_callback);

	else

		ret = walk_system_ram_res(0, -1, kbuf,

					  locate_mem_hole_callback);

	ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);

	if (ret != 1) {

		/* A suitable memory range could not be found for buffer */

		return -EADDRNOTAVAIL;

kernel/kexec_internal.h

+0 −16
Original line number Diff line number Diff line
@@ -20,22 +20,6 @@ struct kexec_sha_region { 
	unsigned long len;

};



/*

 * Keeps track of buffer parameters as provided by caller for requesting

 * memory placement of buffer.

 */

struct kexec_buf {

	struct kimage *image;

	char *buffer;

	unsigned long bufsz;

	unsigned long mem;

	unsigned long memsz;

	unsigned long buf_align;

	unsigned long buf_min;

	unsigned long buf_max;

	bool top_down;		/* allocate from top of memory hole */

};



void kimage_file_post_load_cleanup(struct kimage *image);

#else /* CONFIG_KEXEC_FILE */

static inline void kimage_file_post_load_cleanup(struct kimage *image) { }