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Commit 5768f08b authored by Arun KS's avatar Arun KS Committed by Sudarshan Rajagopalan
Browse files

arm64: Honor limits set by bootloader 



Introduce a variable to save bootloader enforced memory limits and
restricts adding beyond this boundary during a memory hotplug. Also,
export this symbol so that other kernel module have access to it.

Change-Id: I28c100644b7287ec4625c4c018b5fffc865e2e72
Signed-off-by: default avatarArun KS <arunks@codeaurora.org>
[sudaraja@codeaurora.org: check limit with physical address of page]
Signed-off-by: default avatarSudarshan Rajagopalan <sudaraja@codeaurora.org>
parent f486fb89

arch/arm64/include/asm/memory.h

+3 −0
Original line number Original line Diff line number Diff line
@@ -189,6 +189,9 @@ extern u64 kimage_vaddr; 
/* the offset between the kernel virtual and physical mappings */

/* the offset between the kernel virtual and physical mappings */

extern u64			kimage_voffset;

extern u64			kimage_voffset;





/* physical memory limit imposed by the booloader */

extern phys_addr_t bootloader_memory_limit;



static inline unsigned long kaslr_offset(void)

static inline unsigned long kaslr_offset(void)

{

{

	return kimage_vaddr - KIMAGE_VADDR;

	return kimage_vaddr - KIMAGE_VADDR;

arch/arm64/mm/init.c

+27 −0
Original line number Original line Diff line number Diff line
@@ -313,6 +313,7 @@ static void __init arm64_memory_present(void) 
#endif

#endif





static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX;

static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX;

phys_addr_t bootloader_memory_limit;





/*

/*

 * Limit the memory size that was specified via FDT.

 * Limit the memory size that was specified via FDT.
@@ -395,6 +396,12 @@ void __init arm64_memblock_init(void) 
		memblock_remove(0, memstart_addr);

		memblock_remove(0, memstart_addr);

	}

	}





	/*

	 * Save bootloader imposed memory limit before we overwirte

	 * memblock.

	 */

	bootloader_memory_limit = memblock_end_of_DRAM();



	/*

	/*

	 * Apply the memory limit if it was set. Since the kernel may be loaded

	 * Apply the memory limit if it was set. Since the kernel may be loaded

	 * high up in memory, add back the kernel region that must be accessible

	 * high up in memory, add back the kernel region that must be accessible
@@ -835,4 +842,24 @@ int arch_remove_memory(u64 start, u64 size) 
}

}





#endif /* CONFIG_MEMORY_HOTREMOVE */

#endif /* CONFIG_MEMORY_HOTREMOVE */

static int arm64_online_page(struct page *page)

{

	unsigned long phy_addr = page_to_phys(page);



	if (phy_addr + PAGE_SIZE >= bootloader_memory_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;

}

core_initcall(arm64_memory_hotplug_init);

#endif /* CONFIG_MEMORY_HOTPLUG */
 
#endif /* CONFIG_MEMORY_HOTPLUG */

include/linux/memory_hotplug.h

+1 −1
Original line number Original line Diff line number Diff line
@@ -104,7 +104,7 @@ extern int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn, 
	unsigned long *valid_start, unsigned long *valid_end);

	unsigned long *valid_start, unsigned long *valid_end);

extern void __offline_isolated_pages(unsigned long, unsigned long);

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 set_online_page_callback(online_page_callback_t callback);

extern int restore_online_page_callback(online_page_callback_t callback);

extern int restore_online_page_callback(online_page_callback_t callback);

mm/memory_hotplug.c

+7 −5
Original line number Original line Diff line number Diff line
@@ -47,7 +47,7 @@ 
 * and restore_online_page_callback() for generic callback restore.

 * 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 online_page_callback_t online_page_callback = generic_online_page;

static DEFINE_MUTEX(online_page_callback_lock);

static DEFINE_MUTEX(online_page_callback_lock);
@@ -679,11 +679,12 @@ void __online_page_free(struct page *page) 
}

}

EXPORT_SYMBOL_GPL(__online_page_free);

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_set_limits(page);

	__online_page_increment_counters(page);

	__online_page_increment_counters(page);

	__online_page_free(page);

	__online_page_free(page);

	return 0;

}

}





static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,

static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
@@ -692,11 +693,12 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, 
	unsigned long i;

	unsigned long i;

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

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

	struct page *page;

	struct page *page;



	int ret;

	if (PageReserved(pfn_to_page(start_pfn)))

	if (PageReserved(pfn_to_page(start_pfn)))

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

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

			page = pfn_to_page(start_pfn + i);

			page = pfn_to_page(start_pfn + i);

			(*online_page_callback)(page);

			ret = (*online_page_callback)(page);

			if (!ret)

				onlined_pages++;

				onlined_pages++;

		}

		}