Commit a927bd6b authored by Dan Williams's avatar Dan Williams Committed by Linus Torvalds

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: a035b6bf ("mm/memory_hotplug: introduce default phys_to_target_node() implementation")
Reported-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Reported-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reported-by: default avatarkernel test robot <lkp@intel.com>
Reported-by: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Tested-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Tested-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarChristoph 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.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent bc2dc440
......@@ -18,4 +18,10 @@
#endif
#endif /* CONFIG_SPARSEMEM */
#ifdef CONFIG_MEMORY_HOTPLUG
int memory_add_physaddr_to_nid(u64 addr);
#define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
#endif
#endif /* _ASM_IA64_SPARSEMEM_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_ */
......@@ -13,9 +13,9 @@
#endif /* CONFIG_SPARSEMEM */
#ifdef CONFIG_MEMORY_HOTPLUG
extern int create_section_mapping(unsigned long start, unsigned long end,
int nid, pgprot_t prot);
extern int remove_section_mapping(unsigned long start, unsigned long end);
extern int memory_add_physaddr_to_nid(u64 start);
#define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
#ifdef CONFIG_NUMA
extern int hot_add_scn_to_nid(unsigned long scn_addr);
......@@ -26,6 +26,5 @@ static inline int hot_add_scn_to_nid(unsigned long scn_addr)
}
#endif /* CONFIG_NUMA */
#endif /* CONFIG_MEMORY_HOTPLUG */
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_SPARSEMEM_H */
......@@ -50,6 +50,7 @@
#include <asm/rtas.h>
#include <asm/kasan.h>
#include <asm/svm.h>
#include <asm/mmzone.h>
#include <mm/mmu_decl.h>
......
......@@ -28,4 +28,14 @@
#endif
#endif /* CONFIG_SPARSEMEM */
#ifndef __ASSEMBLY__
#ifdef CONFIG_NUMA_KEEP_MEMINFO
extern int phys_to_target_node(phys_addr_t start);
#define phys_to_target_node phys_to_target_node
extern int memory_add_physaddr_to_nid(u64 start);
#define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
#endif
#endif /* __ASSEMBLY__ */
#endif /* _ASM_X86_SPARSEMEM_H */
......@@ -938,6 +938,7 @@ int phys_to_target_node(phys_addr_t start)
return meminfo_to_nid(&numa_reserved_meminfo, start);
}
EXPORT_SYMBOL_GPL(phys_to_target_node);
int memory_add_physaddr_to_nid(u64 start)
{
......@@ -947,4 +948,5 @@ int memory_add_physaddr_to_nid(u64 start)
nid = numa_meminfo.blk[0].nid;
return nid;
}
EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
#endif
......@@ -50,7 +50,6 @@ config DEV_DAX_HMEM
Say M if unsure.
config DEV_DAX_HMEM_DEVICES
depends on NUMA_KEEP_MEMINFO # for phys_to_target_node()
depends on DEV_DAX_HMEM && DAX=y
def_bool y
......
......@@ -281,20 +281,6 @@ static inline bool movable_node_is_enabled(void)
}
#endif /* ! CONFIG_MEMORY_HOTPLUG */
#ifdef CONFIG_NUMA
extern int memory_add_physaddr_to_nid(u64 start);
extern int phys_to_target_node(u64 start);
#else
static inline int memory_add_physaddr_to_nid(u64 start)
{
return 0;
}
static inline int phys_to_target_node(u64 start)
{
return 0;
}
#endif
#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
/*
* pgdat resizing functions
......
......@@ -21,13 +21,41 @@
#endif
#ifdef CONFIG_NUMA
#include <linux/printk.h>
#include <asm/sparsemem.h>
/* Generic implementation available */
int numa_map_to_online_node(int node);
#else
#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 */
......@@ -350,24 +350,6 @@ int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages,
return err;
}
#ifdef CONFIG_NUMA
int __weak 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;
}
EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
int __weak phys_to_target_node(u64 start)
{
pr_info_once("Unknown target node for memory at 0x%llx, assuming node 0\n",
start);
return 0;
}
EXPORT_SYMBOL_GPL(phys_to_target_node);
#endif
/* find the smallest valid pfn in the range [start_pfn, end_pfn) */
static unsigned long find_smallest_section_pfn(int nid, struct zone *zone,
unsigned long start_pfn,
......
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