forked from mirrors/linux
		
	 a927bd6ba9
			
		
	
	
		a927bd6ba9
		
	
	
	
	
		
			
			The core-mm has a default __weak implementation of phys_to_target_node()
to mirror the weak definition of memory_add_physaddr_to_nid().  That
symbol is exported for modules.  However, while the export in
mm/memory_hotplug.c exported the symbol in the configuration cases of:
	CONFIG_NUMA_KEEP_MEMINFO=y
	CONFIG_MEMORY_HOTPLUG=y
...and:
	CONFIG_NUMA_KEEP_MEMINFO=n
	CONFIG_MEMORY_HOTPLUG=y
...it failed to export the symbol in the case of:
	CONFIG_NUMA_KEEP_MEMINFO=y
	CONFIG_MEMORY_HOTPLUG=n
Not only is that broken, but Christoph points out that the kernel should
not be exporting any __weak symbol, which means that
memory_add_physaddr_to_nid() example that phys_to_target_node() copied
is broken too.
Rework the definition of phys_to_target_node() and
memory_add_physaddr_to_nid() to not require weak symbols.  Move to the
common arch override design-pattern of an asm header defining a symbol
to replace the default implementation.
The only common header that all memory_add_physaddr_to_nid() producing
architectures implement is asm/sparsemem.h.  In fact, powerpc already
defines its memory_add_physaddr_to_nid() helper in sparsemem.h.
Double-down on that observation and define phys_to_target_node() where
necessary in asm/sparsemem.h.  An alternate consideration that was
discarded was to put this override in asm/numa.h, but that entangles
with the definition of MAX_NUMNODES relative to the inclusion of
linux/nodemask.h, and requires powerpc to grow a new header.
The dependency on NUMA_KEEP_MEMINFO for DEV_DAX_HMEM_DEVICES is invalid
now that the symbol is properly exported / stubbed in all combinations
of CONFIG_NUMA_KEEP_MEMINFO and CONFIG_MEMORY_HOTPLUG.
[dan.j.williams@intel.com: v4]
  Link: https://lkml.kernel.org/r/160461461867.1505359.5301571728749534585.stgit@dwillia2-desk3.amr.corp.intel.com
[dan.j.williams@intel.com: powerpc: fix create_section_mapping compile warning]
  Link: https://lkml.kernel.org/r/160558386174.2948926.2740149041249041764.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: a035b6bf86 ("mm/memory_hotplug: introduce default phys_to_target_node() implementation")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lkml.kernel.org/r/160447639846.1133764.7044090803980177548.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
	
			
		
			
				
	
	
		
			61 lines
		
	
	
	
		
			1.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			61 lines
		
	
	
	
		
			1.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
 | |
| #ifndef _LINUX_NUMA_H
 | |
| #define _LINUX_NUMA_H
 | |
| #include <linux/types.h>
 | |
| 
 | |
| #ifdef CONFIG_NODES_SHIFT
 | |
| #define NODES_SHIFT     CONFIG_NODES_SHIFT
 | |
| #else
 | |
| #define NODES_SHIFT     0
 | |
| #endif
 | |
| 
 | |
| #define MAX_NUMNODES    (1 << NODES_SHIFT)
 | |
| 
 | |
| #define	NUMA_NO_NODE	(-1)
 | |
| 
 | |
| /* optionally keep NUMA memory info available post init */
 | |
| #ifdef CONFIG_NUMA_KEEP_MEMINFO
 | |
| #define __initdata_or_meminfo
 | |
| #else
 | |
| #define __initdata_or_meminfo __initdata
 | |
| #endif
 | |
| 
 | |
| #ifdef CONFIG_NUMA
 | |
| #include <linux/printk.h>
 | |
| #include <asm/sparsemem.h>
 | |
| 
 | |
| /* Generic implementation available */
 | |
| int numa_map_to_online_node(int node);
 | |
| 
 | |
| #ifndef memory_add_physaddr_to_nid
 | |
| static inline int memory_add_physaddr_to_nid(u64 start)
 | |
| {
 | |
| 	pr_info_once("Unknown online node for memory at 0x%llx, assuming node 0\n",
 | |
| 			start);
 | |
| 	return 0;
 | |
| }
 | |
| #endif
 | |
| #ifndef phys_to_target_node
 | |
| static inline int phys_to_target_node(u64 start)
 | |
| {
 | |
| 	pr_info_once("Unknown target node for memory at 0x%llx, assuming node 0\n",
 | |
| 			start);
 | |
| 	return 0;
 | |
| }
 | |
| #endif
 | |
| #else /* !CONFIG_NUMA */
 | |
| static inline int numa_map_to_online_node(int node)
 | |
| {
 | |
| 	return NUMA_NO_NODE;
 | |
| }
 | |
| static inline int memory_add_physaddr_to_nid(u64 start)
 | |
| {
 | |
| 	return 0;
 | |
| }
 | |
| static inline int phys_to_target_node(u64 start)
 | |
| {
 | |
| 	return 0;
 | |
| }
 | |
| #endif
 | |
| 
 | |
| #endif /* _LINUX_NUMA_H */
 |