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git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git
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Dan Williams
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.
[[email protected]: v4]
Link: https://lkml.kernel.org/r/160461461867.1505359.5301571728749534585.stgit@dwillia2-desk3.amr.corp.intel.com
[[email protected]: 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 <[email protected]>
Reported-by: Thomas Gleixner <[email protected]>
Reported-by: kernel test robot <[email protected]>
Reported-by: Christoph Hellwig <[email protected]>
Signed-off-by: Dan Williams <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Tested-by: Randy Dunlap <[email protected]>
Tested-by: Thomas Gleixner <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Cc: Joao Martins <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Link: https://lkml.kernel.org/r/160447639846.1133764.7044090803980177548.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Linus Torvalds <[email protected]>
31 lines
843 B
C
31 lines
843 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_POWERPC_SPARSEMEM_H
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#define _ASM_POWERPC_SPARSEMEM_H 1
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#ifdef __KERNEL__
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#ifdef CONFIG_SPARSEMEM
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/*
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* SECTION_SIZE_BITS 2^N: how big each section will be
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* MAX_PHYSMEM_BITS 2^N: how much memory we can have in that space
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*/
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#define SECTION_SIZE_BITS 24
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#endif /* CONFIG_SPARSEMEM */
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#ifdef CONFIG_MEMORY_HOTPLUG
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extern int remove_section_mapping(unsigned long start, unsigned long end);
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extern int memory_add_physaddr_to_nid(u64 start);
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#define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
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#ifdef CONFIG_NUMA
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extern int hot_add_scn_to_nid(unsigned long scn_addr);
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#else
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static inline int hot_add_scn_to_nid(unsigned long scn_addr)
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{
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return 0;
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}
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#endif /* CONFIG_NUMA */
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#endif /* CONFIG_MEMORY_HOTPLUG */
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#endif /* __KERNEL__ */
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#endif /* _ASM_POWERPC_SPARSEMEM_H */
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