@@ -70,6 +70,9 @@ typedef int __bitwise mhp_t;
*/
#define MEMHP_MERGE_RESOURCE ((__force mhp_t)BIT(0))
+bool mhp_range_allowed(u64 start, u64 size, bool need_mapping);
+struct range mhp_get_pluggable_range(bool need_mapping);
+
/*
* Extended parameters for memory hotplug:
* altmap: alternative allocator for memmap array (optional)
@@ -281,6 +284,13 @@ static inline bool movable_node_is_enabled(void)
}
#endif /* ! CONFIG_MEMORY_HOTPLUG */
+/*
+ * Keep this declaration outside CONFIG_MEMORY_HOTPLUG as some
+ * platforms might override and use arch_get_mappable_range()
+ * for internal non memory hotplug purposes.
+ */
+struct range arch_get_mappable_range(void);
+
#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
/*
* pgdat resizing functions
@@ -107,6 +107,9 @@ static struct resource *register_memory_resource(u64 start, u64 size,
if (strcmp(resource_name, "System RAM"))
flags |= IORESOURCE_SYSRAM_DRIVER_MANAGED;
+ if (!mhp_range_allowed(start, size, true))
+ return ERR_PTR(-E2BIG);
+
/*
* Make sure value parsed from 'mem=' only restricts memory adding
* while booting, so that memory hotplug won't be impacted. Please
@@ -284,22 +287,6 @@ static int check_pfn_span(unsigned long pfn, unsigned long nr_pages,
return 0;
}
-static int check_hotplug_memory_addressable(unsigned long pfn,
- unsigned long nr_pages)
-{
- const u64 max_addr = PFN_PHYS(pfn + nr_pages) - 1;
-
- if (max_addr >> MAX_PHYSMEM_BITS) {
- const u64 max_allowed = (1ull << (MAX_PHYSMEM_BITS + 1)) - 1;
- WARN(1,
- "Hotplugged memory exceeds maximum addressable address, range=%#llx-%#llx, maximum=%#llx\n",
- (u64)PFN_PHYS(pfn), max_addr, max_allowed);
- return -E2BIG;
- }
-
- return 0;
-}
-
/*
* Reasonably generic function for adding memory. It is
* expected that archs that support memory hotplug will
@@ -317,9 +304,7 @@ int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages,
if (WARN_ON_ONCE(!params->pgprot.pgprot))
return -EINVAL;
- err = check_hotplug_memory_addressable(pfn, nr_pages);
- if (err)
- return err;
+ VM_BUG_ON(!mhp_range_allowed(PFN_PHYS(pfn), nr_pages * PAGE_SIZE, false));
if (altmap) {
/*
@@ -1180,6 +1165,61 @@ int add_memory_driver_managed(int nid, u64 start, u64 size,
}
EXPORT_SYMBOL_GPL(add_memory_driver_managed);
+/*
+ * Platforms should define arch_get_mappable_range() that provides
+ * maximum possible addressable physical memory range for which the
+ * linear mapping could be created. The platform returned address
+ * range must adhere to these following semantics.
+ *
+ * - range.start <= range.end
+ * - Range includes both end points [range.start..range.end]
+ *
+ * There is also a fallback definition provided here, allowing the
+ * entire possible physical address range in case any platform does
+ * not define arch_get_mappable_range().
+ */
+struct range __weak arch_get_mappable_range(void)
+{
+ struct range mhp_range = {
+ .start = 0UL,
+ .end = -1ULL,
+ };
+ return mhp_range;
+}
+
+struct range mhp_get_pluggable_range(bool need_mapping)
+{
+ const u64 max_phys = (1ULL << MAX_PHYSMEM_BITS) - 1;
+ struct range mhp_range;
+
+ if (need_mapping) {
+ mhp_range = arch_get_mappable_range();
+ if (mhp_range.start > max_phys) {
+ mhp_range.start = 0;
+ mhp_range.end = 0;
+ }
+ mhp_range.end = min_t(u64, mhp_range.end, max_phys);
+ } else {
+ mhp_range.start = 0;
+ mhp_range.end = max_phys;
+ }
+ return mhp_range;
+}
+EXPORT_SYMBOL_GPL(mhp_get_pluggable_range);
+
+bool mhp_range_allowed(u64 start, u64 size, bool need_mapping)
+{
+ struct range mhp_range = mhp_get_pluggable_range(need_mapping);
+ u64 end = start + size;
+
+ if (start < end && start >= mhp_range.start && (end - 1) <= mhp_range.end)
+ return true;
+
+ pr_warn("Hotplug memory [%#llx-%#llx] exceeds maximum addressable range [%#llx-%#llx]\n",
+ start, end, mhp_range.start, mhp_range.end);
+ return false;
+}
+
#ifdef CONFIG_MEMORY_HOTREMOVE
/*
* Confirm all pages in a range [start, end) belong to the same zone (skipping
@@ -185,6 +185,7 @@ static void dev_pagemap_percpu_release(struct percpu_ref *ref)
static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params,
int range_id, int nid)
{
+ const bool is_private = pgmap->type == MEMORY_DEVICE_PRIVATE;
struct range *range = &pgmap->ranges[range_id];
struct dev_pagemap *conflict_pgmap;
int error, is_ram;
@@ -230,6 +231,9 @@ static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params,
if (error)
goto err_pfn_remap;
+ if (!mhp_range_allowed(range->start, range_len(range), !is_private))
+ goto err_pfn_remap;
+
mem_hotplug_begin();
/*
@@ -243,7 +247,7 @@ static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params,
* the CPU, we do want the linear mapping and thus use
* arch_add_memory().
*/
- if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
+ if (is_private) {
error = add_pages(nid, PHYS_PFN(range->start),
PHYS_PFN(range_len(range)), params);
} else {