Commit 8375b765 authored by Mike Rapoport (Microsoft)'s avatar Mike Rapoport (Microsoft) Committed by Andrew Morton
Browse files

kho: replace kho_preserve_phys() with kho_preserve_pages() 

to make it clear that KHO operates on pages rather than on a random
physical address.

The kho_preserve_pages() will be also used in upcoming support for vmalloc
preservation.

Link: https://lkml.kernel.org/r/20250921054458.4043761-3-rppt@kernel.org


Signed-off-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: default avatarPratyush Yadav <pratyush@kernel.org>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Changyuan Lyu <changyuanl@google.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 469661d0

include/linux/kexec_handover.h

+3 −2
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ enum kho_event { 


struct folio;

struct notifier_block;

struct page;



#define DECLARE_KHOSER_PTR(name, type) \

	union {                        \
@@ -43,7 +44,7 @@ bool kho_is_enabled(void); 
bool is_kho_boot(void);



int kho_preserve_folio(struct folio *folio);

int kho_preserve_phys(phys_addr_t phys, size_t size);

int kho_preserve_pages(struct page *page, unsigned int nr_pages);

struct folio *kho_restore_folio(phys_addr_t phys);

int kho_add_subtree(struct kho_serialization *ser, const char *name, void *fdt);

int kho_retrieve_subtree(const char *name, phys_addr_t *phys);
@@ -71,7 +72,7 @@ static inline int kho_preserve_folio(struct folio *folio) 
	return -EOPNOTSUPP;

}



static inline int kho_preserve_phys(phys_addr_t phys, size_t size)

static inline int kho_preserve_pages(struct page *page, unsigned int nr_pages)

{

	return -EOPNOTSUPP;

}

kernel/kexec_handover.c

+11 −14
Original line number Diff line number Diff line
@@ -725,26 +725,23 @@ int kho_preserve_folio(struct folio *folio) 
EXPORT_SYMBOL_GPL(kho_preserve_folio);



/**

 * kho_preserve_phys - preserve a physically contiguous range across kexec.

 * @phys: physical address of the range.

 * @size: size of the range.

 * kho_preserve_pages - preserve contiguous pages across kexec

 * @page: first page in the list.

 * @nr_pages: number of pages.

 *

 * Instructs KHO to preserve the memory range from @phys to @phys + @size

 * across kexec.

 * Preserve a contiguous list of order 0 pages. Must be restored using

 * kho_restore_pages() to ensure the pages are restored properly as order 0.

 *

 * Return: 0 on success, error code on failure

 */

int kho_preserve_phys(phys_addr_t phys, size_t size)

int kho_preserve_pages(struct page *page, unsigned int nr_pages)

{

	unsigned long pfn = PHYS_PFN(phys);

	struct kho_mem_track *track = &kho_out.ser.track;

	const unsigned long start_pfn = page_to_pfn(page);

	const unsigned long end_pfn = start_pfn + nr_pages;

	unsigned long pfn = start_pfn;

	unsigned long failed_pfn = 0;

	const unsigned long start_pfn = pfn;

	const unsigned long end_pfn = PHYS_PFN(phys + size);

	int err = 0;

	struct kho_mem_track *track = &kho_out.ser.track;



	if (!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size))

		return -EINVAL;



	while (pfn < end_pfn) {

		const unsigned int order =
@@ -764,7 +761,7 @@ int kho_preserve_phys(phys_addr_t phys, size_t size) 


	return err;

}

EXPORT_SYMBOL_GPL(kho_preserve_phys);

EXPORT_SYMBOL_GPL(kho_preserve_pages);



/* Handling for debug/kho/out */

mm/memblock.c

+3 −1
Original line number Diff line number Diff line
@@ -2452,8 +2452,10 @@ static int reserve_mem_kho_finalize(struct kho_serialization *ser) 


	for (i = 0; i < reserved_mem_count; i++) {

		struct reserve_mem_table *map = &reserved_mem_table[i];

		struct page *page = phys_to_page(map->start);

		unsigned int nr_pages = map->size >> PAGE_SHIFT;



		err |= kho_preserve_phys(map->start, map->size);

		err |= kho_preserve_pages(page, nr_pages);

	}



	err |= kho_preserve_folio(page_folio(kho_fdt));