Commit 4abb1e5b authored by David Hildenbrand's avatar David Hildenbrand Committed by Michael Ellerman
Browse files

powerpc/mm: factor out creating/removing linear mapping 



We want to stop abusing memory hotplug infrastructure in memtrace code
to perform allocations and remove the linear mapping. Instead we will use
alloc_contig_pages() and remove the linear mapping manually.

Let's factor out creating/removing the linear mapping into
arch_create_linear_mapping() / arch_remove_linear_mapping() - so in the
future, we might be able to have whole arch_add_memory() /
arch_remove_memory() be implemented in common code.

Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201111145322.15793-4-david@redhat.com
parent d6718941

arch/powerpc/mm/mem.c

+28 −13
Original line number Diff line number Diff line
@@ -120,34 +120,26 @@ static void flush_dcache_range_chunked(unsigned long start, unsigned long stop, 
	}

}



int __ref arch_add_memory(int nid, u64 start, u64 size,

int __ref arch_create_linear_mapping(int nid, u64 start, u64 size,

				     struct mhp_params *params)

{

	unsigned long start_pfn = start >> PAGE_SHIFT;

	unsigned long nr_pages = size >> PAGE_SHIFT;

	int rc;



	start = (unsigned long)__va(start);

	rc = create_section_mapping(start, start + size, nid,

				    params->pgprot);

	if (rc) {

		pr_warn("Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n",

		pr_warn("Unable to create linear mapping for 0x%llx..0x%llx: %d\n",

			start, start + size, rc);

		return -EFAULT;

	}



	return __add_pages(nid, start_pfn, nr_pages, params);

	return 0;

}



void __ref arch_remove_memory(int nid, u64 start, u64 size,

			     struct vmem_altmap *altmap)

void __ref arch_remove_linear_mapping(u64 start, u64 size)

{

	unsigned long start_pfn = start >> PAGE_SHIFT;

	unsigned long nr_pages = size >> PAGE_SHIFT;

	int ret;



	__remove_pages(start_pfn, nr_pages, altmap);



	/* Remove htab bolted mappings for this section of memory */

	start = (unsigned long)__va(start);

	flush_dcache_range_chunked(start, start + size, FLUSH_CHUNK_SIZE);
@@ -160,6 +152,29 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size, 
	 */

	vm_unmap_aliases();

}



int __ref arch_add_memory(int nid, u64 start, u64 size,

			  struct mhp_params *params)

{

	unsigned long start_pfn = start >> PAGE_SHIFT;

	unsigned long nr_pages = size >> PAGE_SHIFT;

	int rc;



	rc = arch_create_linear_mapping(nid, start, size, params);

	if (rc)

		return rc;

	return __add_pages(nid, start_pfn, nr_pages, params);

}



void __ref arch_remove_memory(int nid, u64 start, u64 size,

			      struct vmem_altmap *altmap)

{

	unsigned long start_pfn = start >> PAGE_SHIFT;

	unsigned long nr_pages = size >> PAGE_SHIFT;



	__remove_pages(start_pfn, nr_pages, altmap);

	arch_remove_linear_mapping(start, size);

}

#endif



#ifndef CONFIG_NEED_MULTIPLE_NODES

include/linux/memory_hotplug.h

+3 −0
Original line number Diff line number Diff line
@@ -375,6 +375,9 @@ extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map, 
					  unsigned long pnum);

extern struct zone *zone_for_pfn_range(int online_type, int nid, unsigned start_pfn,

		unsigned long nr_pages);

extern int arch_create_linear_mapping(int nid, u64 start, u64 size,

				      struct mhp_params *params);

void arch_remove_linear_mapping(u64 start, u64 size);

#endif /* CONFIG_MEMORY_HOTPLUG */



#endif /* __LINUX_MEMORY_HOTPLUG_H */

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