commit db051a0dac13db24d58470d75cee0ce7c6b031a1 upstream.
Only memory to be added to the buddy and to be onlined/offlined by user space using /sys/devices/system/memory/... needs (and should have!) memory block devices.
Factor out creation of memory block devices. Create all devices after arch_add_memory() succeeded. We can later drop the want_memblock parameter, because it is now effectively stale.
Only after memory block devices have been added, memory can be onlined by user space. This implies, that memory is not visible to user space at all before arch_add_memory() succeeded.
While at it - use WARN_ON_ONCE instead of BUG_ON in moved unregister_memory() - introduce find_memory_block_by_id() to search via block id - Use find_memory_block_by_id() in init_memory_block() to catch duplicates
Link: http://lkml.kernel.org/r/20190527111152.16324-8-david@redhat.com Signed-off-by: David Hildenbrand david@redhat.com Reviewed-by: Pavel Tatashin pasha.tatashin@soleen.com Acked-by: Michal Hocko mhocko@suse.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: "Rafael J. Wysocki" rafael@kernel.org Cc: David Hildenbrand david@redhat.com Cc: "mike.travis@hpe.com" mike.travis@hpe.com Cc: Ingo Molnar mingo@kernel.org Cc: Andrew Banman andrew.banman@hpe.com Cc: Oscar Salvador osalvador@suse.de Cc: Qian Cai cai@lca.pw Cc: Wei Yang richard.weiyang@gmail.com Cc: Arun KS arunks@codeaurora.org Cc: Mathieu Malaterre malat@debian.org Cc: Alex Deucher alexander.deucher@amd.com Cc: Andy Lutomirski luto@kernel.org Cc: Anshuman Khandual anshuman.khandual@arm.com Cc: Ard Biesheuvel ard.biesheuvel@linaro.org Cc: Baoquan He bhe@redhat.com Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Borislav Petkov bp@alien8.de Cc: Catalin Marinas catalin.marinas@arm.com Cc: Chintan Pandya cpandya@codeaurora.org Cc: Christophe Leroy christophe.leroy@c-s.fr Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Dan Williams dan.j.williams@intel.com Cc: Dave Hansen dave.hansen@linux.intel.com Cc: "David S. Miller" davem@davemloft.net Cc: Fenghua Yu fenghua.yu@intel.com Cc: Heiko Carstens heiko.carstens@de.ibm.com Cc: "H. Peter Anvin" hpa@zytor.com Cc: Jonathan Cameron Jonathan.Cameron@huawei.com Cc: Joonsoo Kim iamjoonsoo.kim@lge.com Cc: Jun Yao yaojun8558363@gmail.com Cc: "Kirill A. Shutemov" kirill.shutemov@linux.intel.com Cc: Logan Gunthorpe logang@deltatee.com Cc: Mark Brown broonie@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: Masahiro Yamada yamada.masahiro@socionext.com Cc: Michael Ellerman mpe@ellerman.id.au Cc: Mike Rapoport rppt@linux.vnet.ibm.com Cc: Nicholas Piggin npiggin@gmail.com Cc: Oscar Salvador osalvador@suse.com Cc: Paul Mackerras paulus@samba.org Cc: Peter Zijlstra peterz@infradead.org Cc: Rich Felker dalias@libc.org Cc: Rob Herring robh@kernel.org Cc: Robin Murphy robin.murphy@arm.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Tony Luck tony.luck@intel.com Cc: Vasily Gorbik gor@linux.ibm.com Cc: Will Deacon will.deacon@arm.com Cc: Yoshinori Sato ysato@users.sourceforge.jp Cc: Yu Zhao yuzhao@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: David Hildenbrand david@redhat.com --- drivers/base/memory.c | 82 +++++++++++++++++++++++++++--------------- include/linux/memory.h | 2 +- mm/memory_hotplug.c | 15 ++++---- 3 files changed, 63 insertions(+), 36 deletions(-)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c index f9818d75ac43..b89b9c3efa59 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -39,6 +39,11 @@ static inline int base_memory_block_id(int section_nr) return section_nr / sections_per_block; }
+static inline int pfn_to_block_id(unsigned long pfn) +{ + return base_memory_block_id(pfn_to_section_nr(pfn)); +} + static int memory_subsys_online(struct device *dev); static int memory_subsys_offline(struct device *dev);
@@ -591,10 +596,9 @@ int __weak arch_get_memory_phys_device(unsigned long start_pfn) * A reference for the returned object is held and the reference for the * hinted object is released. */ -struct memory_block *find_memory_block_hinted(struct mem_section *section, - struct memory_block *hint) +static struct memory_block *find_memory_block_by_id(int block_id, + struct memory_block *hint) { - int block_id = base_memory_block_id(__section_nr(section)); struct device *hintdev = hint ? &hint->dev : NULL; struct device *dev;
@@ -606,6 +610,14 @@ struct memory_block *find_memory_block_hinted(struct mem_section *section, return to_memory_block(dev); }
+struct memory_block *find_memory_block_hinted(struct mem_section *section, + struct memory_block *hint) +{ + int block_id = base_memory_block_id(__section_nr(section)); + + return find_memory_block_by_id(block_id, hint); +} + /* * For now, we have a linear search to go find the appropriate * memory_block corresponding to a particular phys_index. If @@ -667,6 +679,11 @@ static int init_memory_block(struct memory_block **memory, int block_id, unsigned long start_pfn; int ret = 0;
+ mem = find_memory_block_by_id(block_id, NULL); + if (mem) { + put_device(&mem->dev); + return -EEXIST; + } mem = kzalloc(sizeof(*mem), GFP_KERNEL); if (!mem) return -ENOMEM; @@ -704,44 +721,53 @@ static int add_memory_block(int base_section_nr) return 0; }
+static void unregister_memory(struct memory_block *memory) +{ + if (WARN_ON_ONCE(memory->dev.bus != &memory_subsys)) + return; + + /* drop the ref. we got via find_memory_block() */ + put_device(&memory->dev); + device_unregister(&memory->dev); +} + /* - * need an interface for the VM to add new memory regions, - * but without onlining it. + * Create memory block devices for the given memory area. Start and size + * have to be aligned to memory block granularity. Memory block devices + * will be initialized as offline. */ -int hotplug_memory_register(int nid, struct mem_section *section) +int create_memory_block_devices(unsigned long start, unsigned long size) { - int block_id = base_memory_block_id(__section_nr(section)); - int ret = 0; + const int start_block_id = pfn_to_block_id(PFN_DOWN(start)); + int end_block_id = pfn_to_block_id(PFN_DOWN(start + size)); struct memory_block *mem; + unsigned long block_id; + int ret = 0;
- mutex_lock(&mem_sysfs_mutex); + if (WARN_ON_ONCE(!IS_ALIGNED(start, memory_block_size_bytes()) || + !IS_ALIGNED(size, memory_block_size_bytes()))) + return -EINVAL;
- mem = find_memory_block(section); - if (mem) { - mem->section_count++; - put_device(&mem->dev); - } else { + mutex_lock(&mem_sysfs_mutex); + for (block_id = start_block_id; block_id != end_block_id; block_id++) { ret = init_memory_block(&mem, block_id, MEM_OFFLINE); if (ret) - goto out; - mem->section_count++; + break; + mem->section_count = sections_per_block; + } + if (ret) { + end_block_id = block_id; + for (block_id = start_block_id; block_id != end_block_id; + block_id++) { + mem = find_memory_block_by_id(block_id, NULL); + mem->section_count = 0; + unregister_memory(mem); + } } - -out: mutex_unlock(&mem_sysfs_mutex); return ret; }
-static void -unregister_memory(struct memory_block *memory) -{ - BUG_ON(memory->dev.bus != &memory_subsys); - - /* drop the ref. we got via find_memory_block() */ - put_device(&memory->dev); - device_unregister(&memory->dev); -} - void unregister_memory_section(struct mem_section *section) { struct memory_block *mem; diff --git a/include/linux/memory.h b/include/linux/memory.h index 474c7c60c8f2..db3e8567f900 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -111,7 +111,7 @@ extern int register_memory_notifier(struct notifier_block *nb); extern void unregister_memory_notifier(struct notifier_block *nb); extern int register_memory_isolate_notifier(struct notifier_block *nb); extern void unregister_memory_isolate_notifier(struct notifier_block *nb); -int hotplug_memory_register(int nid, struct mem_section *section); +int create_memory_block_devices(unsigned long start, unsigned long size); extern void unregister_memory_section(struct mem_section *); extern int memory_dev_init(void); extern int memory_notify(unsigned long val, void *v); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 6b5ce0bd907f..414771114685 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -256,13 +256,7 @@ static int __meminit __add_section(int nid, unsigned long phys_start_pfn, return -EEXIST;
ret = sparse_add_one_section(nid, phys_start_pfn, altmap); - if (ret < 0) - return ret; - - if (!want_memblock) - return 0; - - return hotplug_memory_register(nid, __pfn_to_section(phys_start_pfn)); + return ret < 0 ? ret : 0; }
/* @@ -1096,6 +1090,13 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online) if (ret < 0) goto error;
+ /* create memory block devices after memory was added */ + ret = create_memory_block_devices(start, size); + if (ret) { + arch_remove_memory(nid, start, size, NULL); + goto error; + } + if (new_node) { /* If sysfs file of new node can't be created, cpu on the node * can't be hot-added. There is no rollback way now.