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-rw-r--r--include/linux/mmzone.h41
-rw-r--r--mm/memory_hotplug.c6
-rw-r--r--mm/sparse.c2
3 files changed, 39 insertions, 10 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index aab70355d64f..2b5757752333 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -1418,16 +1418,32 @@ extern size_t mem_section_usage_size(void);
* (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the
* worst combination is powerpc with 256k pages,
* which results in PFN_SECTION_SHIFT equal 6.
- * To sum it up, at least 6 bits are available.
+ * To sum it up, at least 6 bits are available on all architectures.
+ * However, we can exceed 6 bits on some other architectures except
+ * powerpc (e.g. 15 bits are available on x86_64, 13 bits are available
+ * with the worst case of 64K pages on arm64) if we make sure the
+ * exceeded bit is not applicable to powerpc.
*/
-#define SECTION_MARKED_PRESENT (1UL<<0)
-#define SECTION_HAS_MEM_MAP (1UL<<1)
-#define SECTION_IS_ONLINE (1UL<<2)
-#define SECTION_IS_EARLY (1UL<<3)
-#define SECTION_TAINT_ZONE_DEVICE (1UL<<4)
-#define SECTION_MAP_LAST_BIT (1UL<<5)
-#define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
-#define SECTION_NID_SHIFT 6
+enum {
+ SECTION_MARKED_PRESENT_BIT,
+ SECTION_HAS_MEM_MAP_BIT,
+ SECTION_IS_ONLINE_BIT,
+ SECTION_IS_EARLY_BIT,
+#ifdef CONFIG_ZONE_DEVICE
+ SECTION_TAINT_ZONE_DEVICE_BIT,
+#endif
+ SECTION_MAP_LAST_BIT,
+};
+
+#define SECTION_MARKED_PRESENT BIT(SECTION_MARKED_PRESENT_BIT)
+#define SECTION_HAS_MEM_MAP BIT(SECTION_HAS_MEM_MAP_BIT)
+#define SECTION_IS_ONLINE BIT(SECTION_IS_ONLINE_BIT)
+#define SECTION_IS_EARLY BIT(SECTION_IS_EARLY_BIT)
+#ifdef CONFIG_ZONE_DEVICE
+#define SECTION_TAINT_ZONE_DEVICE BIT(SECTION_TAINT_ZONE_DEVICE_BIT)
+#endif
+#define SECTION_MAP_MASK (~(BIT(SECTION_MAP_LAST_BIT) - 1))
+#define SECTION_NID_SHIFT SECTION_MAP_LAST_BIT
static inline struct page *__section_mem_map_addr(struct mem_section *section)
{
@@ -1466,12 +1482,19 @@ static inline int online_section(struct mem_section *section)
return (section && (section->section_mem_map & SECTION_IS_ONLINE));
}
+#ifdef CONFIG_ZONE_DEVICE
static inline int online_device_section(struct mem_section *section)
{
unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE;
return section && ((section->section_mem_map & flags) == flags);
}
+#else
+static inline int online_device_section(struct mem_section *section)
+{
+ return 0;
+}
+#endif
static inline int online_section_nr(unsigned long nr)
{
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 84990a14d51a..a2a6d280054f 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -670,12 +670,18 @@ static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned lon
}
+#ifdef CONFIG_ZONE_DEVICE
static void section_taint_zone_device(unsigned long pfn)
{
struct mem_section *ms = __pfn_to_section(pfn);
ms->section_mem_map |= SECTION_TAINT_ZONE_DEVICE;
}
+#else
+static inline void section_taint_zone_device(unsigned long pfn)
+{
+}
+#endif
/*
* Associate the pfn range with the given zone, initializing the memmaps
diff --git a/mm/sparse.c b/mm/sparse.c
index cb3bfae64036..e5a8a3a0edd7 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -281,7 +281,7 @@ static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long p
{
unsigned long coded_mem_map =
(unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
- BUILD_BUG_ON(SECTION_MAP_LAST_BIT > (1UL<<PFN_SECTION_SHIFT));
+ BUILD_BUG_ON(SECTION_MAP_LAST_BIT > PFN_SECTION_SHIFT);
BUG_ON(coded_mem_map & ~SECTION_MAP_MASK);
return coded_mem_map;
}