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authorDan Williams <dan.j.williams@intel.com>2020-11-21 22:17:05 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-11-22 10:48:22 -0800
commita927bd6ba952d13c52b8b385030943032f659a3e (patch)
tree0076b0f51660546602ede3adf29071dc0e0cd7d8 /arch/powerpc/include/asm/mmzone.h
parentbc2dc4406c463174613047d8b7946e12c8808cda (diff)
mm: fix phys_to_target_node() and memory_add_physaddr_to_nid() exports
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: a035b6bf863e ("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>
Diffstat (limited to 'arch/powerpc/include/asm/mmzone.h')
-rw-r--r--arch/powerpc/include/asm/mmzone.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/mmzone.h b/arch/powerpc/include/asm/mmzone.h
index 91c69ff53a8a..6cda76b57c5d 100644
--- a/arch/powerpc/include/asm/mmzone.h
+++ b/arch/powerpc/include/asm/mmzone.h
@@ -46,5 +46,10 @@ u64 memory_hotplug_max(void);
#define __HAVE_ARCH_RESERVED_KERNEL_PAGES
#endif
+#ifdef CONFIG_MEMORY_HOTPLUG
+extern int create_section_mapping(unsigned long start, unsigned long end,
+ int nid, pgprot_t prot);
+#endif
+
#endif /* __KERNEL__ */
#endif /* _ASM_MMZONE_H_ */