diff options
Diffstat (limited to 'mm/percpu.c')
| -rw-r--r-- | mm/percpu.c | 60 |
1 files changed, 56 insertions, 4 deletions
diff --git a/mm/percpu.c b/mm/percpu.c index 58c572b18b07..fa70122dfdd0 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 |