diff options
| -rw-r--r-- | include/linux/percpu.h | 29 | ||||
| -rw-r--r-- | mm/Kconfig | 8 | ||||
| -rw-r--r-- | mm/Makefile | 7 | ||||
| -rw-r--r-- | mm/percpu-km.c | 2 | ||||
| -rw-r--r-- | mm/percpu.c | 60 | ||||
| -rw-r--r-- | mm/percpu_up.c | 30 |
6 files changed, 71 insertions, 65 deletions
diff --git a/include/linux/percpu.h b/include/linux/percpu.h index fc8130a7cac..aeeeef1093c 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -39,8 +39,6 @@ preempt_enable(); \ } while (0) -#ifdef CONFIG_SMP - /* minimum unit size, also is the maximum supported allocation size */ #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10) @@ -137,37 +135,20 @@ extern int __init pcpu_page_first_chunk(size_t reserved_size, * dynamically allocated. Non-atomic access to the current CPU's * version should probably be combined with get_cpu()/put_cpu(). */ +#ifdef CONFIG_SMP #define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu))) +#else +#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); VERIFY_PERCPU_PTR((ptr)); }) +#endif extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align); extern bool is_kernel_percpu_address(unsigned long addr); -#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA +#if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) extern void __init setup_per_cpu_areas(void); #endif extern void __init percpu_init_late(void); -#else /* CONFIG_SMP */ - -#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); VERIFY_PERCPU_PTR((ptr)); }) - -/* can't distinguish from other static vars, always false */ -static inline bool is_kernel_percpu_address(unsigned long addr) -{ - return false; -} - -static inline void __init setup_per_cpu_areas(void) { } - -static inline void __init percpu_init_late(void) { } - -static inline void *pcpu_lpage_remapped(void *kaddr) -{ - return NULL; -} - -#endif /* CONFIG_SMP */ - extern void __percpu *__alloc_percpu(size_t size, size_t align); extern void free_percpu(void __percpu *__pdata); extern phys_addr_t per_cpu_ptr_to_phys(void *addr); diff --git a/mm/Kconfig b/mm/Kconfig index f4e516e9c37..01a57447a41 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -301,3 +301,11 @@ config NOMMU_INITIAL_TRIM_EXCESS of 1 says that all excess pages should be trimmed. See Documentation/nommu-mmap.txt for more information. + +# +# UP and nommu archs use km based percpu allocator +# +config NEED_PER_CPU_KM + depends on !SMP + bool + default y diff --git a/mm/Makefile b/mm/Makefile index 34b2546a9e3..f73f75a29f8 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -11,7 +11,7 @@ obj-y := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \ maccess.o page_alloc.o page-writeback.o \ readahead.o swap.o truncate.o vmscan.o shmem.o \ prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \ - page_isolation.o mm_init.o mmu_context.o \ + page_isolation.o mm_init.o mmu_context.o percpu.o \ $(mmu-y) obj-y += init-mm.o @@ -36,11 +36,6 @@ obj-$(CONFIG_FAILSLAB) += failslab.o obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o obj-$(CONFIG_FS_XIP) += filemap_xip.o obj-$(CONFIG_MIGRATION) += migrate.o -ifdef CONFIG_SMP -obj-y += percpu.o -else -obj-y += percpu_up.o -endif obj-$(CONFIG_QUICKLIST) += quicklist.o obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o diff --git a/mm/percpu-km.c b/mm/percpu-km.c index df680855540..7037bc73bfa 100644 --- a/mm/percpu-km.c +++ b/mm/percpu-km.c @@ -27,7 +27,7 @@ * chunk size is not aligned. percpu-km code will whine about it. */ -#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK +#if defined(CONFIG_SMP) && defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK) #error "contiguous percpu allocation is incompatible with paged first chunk" #endif diff --git a/mm/percpu.c b/mm/percpu.c index 58c572b18b0..fa70122dfdd 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -76,6 +76,7 @@ #define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */ #define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */ +#ifdef CONFIG_SMP /* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */ #ifndef __addr_to_pcpu_ptr #define __addr_to_pcpu_ptr(addr) \ @@ -89,6 +90,11 @@ (unsigned long)pcpu_base_addr - \ (unsigned long)__per_cpu_start) #endif +#else /* CONFIG_SMP */ +/* on UP, it's always identity mapped */ +#define __addr_to_pcpu_ptr(addr) (void __percpu *)(addr) +#define __pcpu_ptr_to_addr(ptr) (void __force *)(ptr) +#endif /* CONFIG_SMP */ struct pcpu_chunk { struct list_head list; /* linked to pcpu_slot lists */ @@ -949,6 +955,7 @@ EXPORT_SYMBOL_GPL(free_percpu); */ bool is_kernel_percpu_address(unsigned long addr) { +#ifdef CONFIG_SMP const size_t static_size = __per_cpu_end - __per_cpu_start; void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); unsigned int cpu; @@ -959,6 +966,8 @@ bool is_kernel_percpu_address(unsigned long addr) if ((void *)addr >= start && (void *)addr < start + static_size) return true; } +#endif + /* on UP, can't distinguish from other static vars, always false */ return false; } @@ -1066,6 +1075,8 @@ void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) free_bootmem(__pa(ai), ai->__ai_size); } +#if defined(CONFIG_SMP) && (defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \ + defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK)) /** * pcpu_build_alloc_info - build alloc_info considering distances between CPUs * @reserved_size: the size of reserved percpu area in bytes @@ -1220,6 +1231,8 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info( return ai; } +#endif /* CONFIG_SMP && (CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK || + CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK) */ /** * pcpu_dump_alloc_info - print out information about pcpu_alloc_info @@ -1363,7 +1376,9 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, /* sanity checks */ PCPU_SETUP_BUG_ON(ai->nr_groups <= 0); +#ifdef CONFIG_SMP PCPU_SETUP_BUG_ON(!ai->static_size); +#endif PCPU_SETUP_BUG_ON(!base_addr); PCPU_SETUP_BUG_ON(ai->unit_size < size_sum); PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK); @@ -1488,6 +1503,8 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, return 0; } +#ifdef CONFIG_SMP + const char *pcpu_fc_names[PCPU_FC_NR] __initdata = { [PCPU_FC_AUTO] = "auto", [PCPU_FC_EMBED] = "embed", @@ -1758,8 +1775,9 @@ out_free_ar: } #endif /* CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK */ +#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA /* - * Generic percpu area setup. + * Generic SMP percpu area setup. * * The embedding helper is used because its behavior closely resembles * the original non-dynamic generic percpu area setup. This is @@ -1770,7 +1788,6 @@ out_free_ar: * on the physical linear memory mapping which uses large page * mappings on applicable archs. */ -#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; EXPORT_SYMBOL(__per_cpu_offset); @@ -1799,13 +1816,48 @@ void __init setup_per_cpu_areas(void) PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL, pcpu_dfl_fc_alloc, pcpu_dfl_fc_free); if (rc < 0) - panic("Failed to initialized percpu areas."); + panic("Failed to initialize percpu areas."); delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; for_each_possible_cpu(cpu) __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu]; } -#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ +#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ + +#else /* CONFIG_SMP */ + +/* + * UP percpu area setup. + * + * UP always uses km-based percpu allocator with identity mapping. + * Static percpu variables are indistinguishable from the usual static + * variables and don't require any special preparation. + */ +void __init setup_per_cpu_areas(void) +{ + const size_t unit_size = + roundup_pow_of_two(max_t(size_t, PCPU_MIN_UNIT_SIZE, + PERCPU_DYNAMIC_RESERVE)); + struct pcpu_alloc_info *ai; + void *fc; + + ai = pcpu_alloc_alloc_info(1, 1); + fc = __alloc_bootmem(unit_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS)); + if (!ai || !fc) + panic("Failed to allocate memory for percpu areas."); + + ai->dyn_size = unit_size; + ai->unit_size = unit_size; + ai->atom_size = unit_size; + ai->alloc_size = unit_size; + ai->groups[0].nr_units = 1; + ai->groups[0].cpu_map[0] = 0; + + if (pcpu_setup_first_chunk(ai, fc) < 0) + panic("Failed to initialize percpu areas."); +} + +#endif /* CONFIG_SMP */ /* * First and reserved chunks are initialized with temporary allocation diff --git a/mm/percpu_up.c b/mm/percpu_up.c deleted file mode 100644 index db884fae572..00000000000 --- a/mm/percpu_up.c +++ /dev/null @@ -1,30 +0,0 @@ -/* - * mm/percpu_up.c - dummy percpu memory allocator implementation for UP - */ - -#include <linux/module.h> -#include <linux/percpu.h> -#include <linux/slab.h> - -void __percpu *__alloc_percpu(size_t size, size_t align) -{ - /* - * Can't easily make larger alignment work with kmalloc. WARN - * on it. Larger alignment should only be used for module - * percpu sections on SMP for which this path isn't used. - */ - WARN_ON_ONCE(align > SMP_CACHE_BYTES); - return (void __percpu __force *)kzalloc(size, GFP_KERNEL); -} -EXPORT_SYMBOL_GPL(__alloc_percpu); - -void free_percpu(void __percpu *p) -{ - kfree(this_cpu_ptr(p)); -} -EXPORT_SYMBOL_GPL(free_percpu); - -phys_addr_t per_cpu_ptr_to_phys(void *addr) -{ - return __pa(addr); -} |