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Commit ea4e70e7 authored by Arun KS's avatar Arun KS
Browse files

arm64: Honor limits set by bootloader 



Introduce a varible to save bootloader enforced memory limits and
restricts adding beyond this boundary during a memory hotplug.

Change-Id: I28c100644b7287ec4625c4c018b5fffc865e2e72
Signed-off-by: default avatarArun KS <arunks@codeaurora.org>
parent 2247011a

arch/arm64/mm/init.c

+27 −0
Original line number Diff line number Diff line
@@ -152,6 +152,7 @@ static void __init arm64_memory_present(void) 
#endif



static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX;

static phys_addr_t bootloader_memory_limit;



/*

 * Limit the memory size that was specified via FDT.
@@ -205,6 +206,11 @@ void __init arm64_memblock_init(void) 
	 * via the linear mapping.

	 */

	if (memory_limit != (phys_addr_t)ULLONG_MAX) {

		/*

		 * Save bootloader imposed memory limit before we overwirte

		 * memblock.

		 */

		bootloader_memory_limit = memblock_end_of_DRAM();

		memblock_enforce_memory_limit(memory_limit);

		memblock_add(__pa(_text), (u64)(_end - _text));

	}
@@ -607,4 +613,25 @@ int arch_remove_memory(u64 start, u64 size) 
}



#endif /* CONFIG_MEMORY_HOTREMOVE */

static int arm64_online_page(struct page *page)

{

	unsigned long target_pfn = page_to_pfn(page);

	unsigned long limit = __phys_to_pfn(bootloader_memory_limit);



	if (target_pfn >= limit)

		return -EINVAL;



	__online_page_set_limits(page);

	__online_page_increment_counters(page);

	__online_page_free(page);



	return 0;

}



static int __init arm64_memory_hotplug_init(void)

{

	set_online_page_callback(&arm64_online_page);

	return 0;

}

subsys_initcall(arm64_memory_hotplug_init);

#endif /* CONFIG_MEMORY_HOTPLUG */

include/linux/memory_hotplug.h

+1 −1
Original line number Diff line number Diff line
@@ -89,7 +89,7 @@ extern int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn, 
	unsigned long *valid_start, unsigned long *valid_end);

extern void __offline_isolated_pages(unsigned long, unsigned long);



typedef void (*online_page_callback_t)(struct page *page);

typedef int (*online_page_callback_t)(struct page *page);



extern int set_online_page_callback(online_page_callback_t callback);

extern int restore_online_page_callback(online_page_callback_t callback);

mm/memory_hotplug.c

+7 −4
Original line number Diff line number Diff line
@@ -45,7 +45,7 @@ 
 * and restore_online_page_callback() for generic callback restore.

 */



static void generic_online_page(struct page *page);

static int generic_online_page(struct page *page);



static online_page_callback_t online_page_callback = generic_online_page;

static DEFINE_MUTEX(online_page_callback_lock);
@@ -857,11 +857,12 @@ void __online_page_free(struct page *page) 
}

EXPORT_SYMBOL_GPL(__online_page_free);



static void generic_online_page(struct page *page)

static int generic_online_page(struct page *page)

{

	__online_page_set_limits(page);

	__online_page_increment_counters(page);

	__online_page_free(page);

	return 0;

}



static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
@@ -870,10 +871,12 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, 
	unsigned long i;

	unsigned long onlined_pages = *(unsigned long *)arg;

	struct page *page;

	int ret;

	if (PageReserved(pfn_to_page(start_pfn)))

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

			page = pfn_to_page(start_pfn + i);

			(*online_page_callback)(page);

			ret = (*online_page_callback)(page);

			if (!ret)

				onlined_pages++;

		}

	*(unsigned long *)arg = onlined_pages;