| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/bootmem.h> |
| #include <linux/percpu.h> |
| #include <linux/kexec.h> |
| #include <linux/crash_dump.h> |
| #include <linux/smp.h> |
| #include <linux/topology.h> |
| #include <linux/pfn.h> |
| #include <asm/sections.h> |
| #include <asm/processor.h> |
| #include <asm/setup.h> |
| #include <asm/mpspec.h> |
| #include <asm/apicdef.h> |
| #include <asm/highmem.h> |
| #include <asm/proto.h> |
| #include <asm/cpumask.h> |
| #include <asm/cpu.h> |
| #include <asm/stackprotector.h> |
| |
| #ifdef CONFIG_DEBUG_PER_CPU_MAPS |
| # define DBG(x...) printk(KERN_DEBUG x) |
| #else |
| # define DBG(x...) |
| #endif |
| |
| DEFINE_PER_CPU(int, cpu_number); |
| EXPORT_PER_CPU_SYMBOL(cpu_number); |
| |
| #ifdef CONFIG_X86_64 |
| #define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load) |
| #else |
| #define BOOT_PERCPU_OFFSET 0 |
| #endif |
| |
| DEFINE_PER_CPU(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET; |
| EXPORT_PER_CPU_SYMBOL(this_cpu_off); |
| |
| unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = { |
| [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET, |
| }; |
| EXPORT_SYMBOL(__per_cpu_offset); |
| |
| /** |
| * pcpu_need_numa - determine percpu allocation needs to consider NUMA |
| * |
| * If NUMA is not configured or there is only one NUMA node available, |
| * there is no reason to consider NUMA. This function determines |
| * whether percpu allocation should consider NUMA or not. |
| * |
| * RETURNS: |
| * true if NUMA should be considered; otherwise, false. |
| */ |
| static bool __init pcpu_need_numa(void) |
| { |
| #ifdef CONFIG_NEED_MULTIPLE_NODES |
| pg_data_t *last = NULL; |
| unsigned int cpu; |
| |
| for_each_possible_cpu(cpu) { |
| int node = early_cpu_to_node(cpu); |
| |
| if (node_online(node) && NODE_DATA(node) && |
| last && last != NODE_DATA(node)) |
| return true; |
| |
| last = NODE_DATA(node); |
| } |
| #endif |
| return false; |
| } |
| |
| /** |
| * pcpu_alloc_bootmem - NUMA friendly alloc_bootmem wrapper for percpu |
| * @cpu: cpu to allocate for |
| * @size: size allocation in bytes |
| * @align: alignment |
| * |
| * Allocate @size bytes aligned at @align for cpu @cpu. This wrapper |
| * does the right thing for NUMA regardless of the current |
| * configuration. |
| * |
| * RETURNS: |
| * Pointer to the allocated area on success, NULL on failure. |
| */ |
| static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size, |
| unsigned long align) |
| { |
| const unsigned long goal = __pa(MAX_DMA_ADDRESS); |
| #ifdef CONFIG_NEED_MULTIPLE_NODES |
| int node = early_cpu_to_node(cpu); |
| void *ptr; |
| |
| if (!node_online(node) || !NODE_DATA(node)) { |
| ptr = __alloc_bootmem_nopanic(size, align, goal); |
| pr_info("cpu %d has no node %d or node-local memory\n", |
| cpu, node); |
| pr_debug("per cpu data for cpu%d %lu bytes at %016lx\n", |
| cpu, size, __pa(ptr)); |
| } else { |
| ptr = __alloc_bootmem_node_nopanic(NODE_DATA(node), |
| size, align, goal); |
| pr_debug("per cpu data for cpu%d %lu bytes on node%d at " |
| "%016lx\n", cpu, size, node, __pa(ptr)); |
| } |
| return ptr; |
| #else |
| return __alloc_bootmem_nopanic(size, align, goal); |
| #endif |
| } |
| |
| /* |
| * Remap allocator |
| * |
| * This allocator uses PMD page as unit. A PMD page is allocated for |
| * each cpu and each is remapped into vmalloc area using PMD mapping. |
| * As PMD page is quite large, only part of it is used for the first |
| * chunk. Unused part is returned to the bootmem allocator. |
| * |
| * So, the PMD pages are mapped twice - once to the physical mapping |
| * and to the vmalloc area for the first percpu chunk. The double |
| * mapping does add one more PMD TLB entry pressure but still is much |
| * better than only using 4k mappings while still being NUMA friendly. |
| */ |
| #ifdef CONFIG_NEED_MULTIPLE_NODES |
| static size_t pcpur_size __initdata; |
| static void **pcpur_ptrs __initdata; |
| |
| static struct page * __init pcpur_get_page(unsigned int cpu, int pageno) |
| { |
| size_t off = (size_t)pageno << PAGE_SHIFT; |
| |
| if (off >= pcpur_size) |
| return NULL; |
| |
| return virt_to_page(pcpur_ptrs[cpu] + off); |
| } |
| |
| static ssize_t __init setup_pcpu_remap(size_t static_size) |
| { |
| static struct vm_struct vm; |
| pg_data_t *last; |
| size_t ptrs_size; |
| unsigned int cpu; |
| ssize_t ret; |
| |
| /* |
| * If large page isn't supported, there's no benefit in doing |
| * this. Also, on non-NUMA, embedding is better. |
| */ |
| if (!cpu_has_pse || pcpu_need_numa()) |
| return -EINVAL; |
| |
| last = NULL; |
| for_each_possible_cpu(cpu) { |
| int node = early_cpu_to_node(cpu); |
| |
| if (node_online(node) && NODE_DATA(node) && |
| last && last != NODE_DATA(node)) |
| goto proceed; |
| |
| last = NODE_DATA(node); |
| } |
| return -EINVAL; |
| |
| proceed: |
| /* |
| * Currently supports only single page. Supporting multiple |
| * pages won't be too difficult if it ever becomes necessary. |
| */ |
| pcpur_size = PFN_ALIGN(static_size + PERCPU_DYNAMIC_RESERVE); |
| if (pcpur_size > PMD_SIZE) { |
| pr_warning("PERCPU: static data is larger than large page, " |
| "can't use large page\n"); |
| return -EINVAL; |
| } |
| |
| /* allocate pointer array and alloc large pages */ |
| ptrs_size = PFN_ALIGN(num_possible_cpus() * sizeof(pcpur_ptrs[0])); |
| pcpur_ptrs = alloc_bootmem(ptrs_size); |
| |
| for_each_possible_cpu(cpu) { |
| pcpur_ptrs[cpu] = pcpu_alloc_bootmem(cpu, PMD_SIZE, PMD_SIZE); |
| if (!pcpur_ptrs[cpu]) |
| goto enomem; |
| |
| /* |
| * Only use pcpur_size bytes and give back the rest. |
| * |
| * Ingo: The 2MB up-rounding bootmem is needed to make |
| * sure the partial 2MB page is still fully RAM - it's |
| * not well-specified to have a PAT-incompatible area |
| * (unmapped RAM, device memory, etc.) in that hole. |
| */ |
| free_bootmem(__pa(pcpur_ptrs[cpu] + pcpur_size), |
| PMD_SIZE - pcpur_size); |
| |
| memcpy(pcpur_ptrs[cpu], __per_cpu_load, static_size); |
| } |
| |
| /* allocate address and map */ |
| vm.flags = VM_ALLOC; |
| vm.size = num_possible_cpus() * PMD_SIZE; |
| vm_area_register_early(&vm, PMD_SIZE); |
| |
| for_each_possible_cpu(cpu) { |
| pmd_t *pmd; |
| |
| pmd = populate_extra_pmd((unsigned long)vm.addr |
| + cpu * PMD_SIZE); |
| set_pmd(pmd, pfn_pmd(page_to_pfn(virt_to_page(pcpur_ptrs[cpu])), |
| PAGE_KERNEL_LARGE)); |
| } |
| |
| /* we're ready, commit */ |
| pr_info("PERCPU: Remapped at %p with large pages, static data " |
| "%zu bytes\n", vm.addr, static_size); |
| |
| ret = pcpu_setup_first_chunk(pcpur_get_page, static_size, PMD_SIZE, |
| pcpur_size - static_size, vm.addr, NULL); |
| goto out_free_ar; |
| |
| enomem: |
| for_each_possible_cpu(cpu) |
| if (pcpur_ptrs[cpu]) |
| free_bootmem(__pa(pcpur_ptrs[cpu]), PMD_SIZE); |
| ret = -ENOMEM; |
| out_free_ar: |
| free_bootmem(__pa(pcpur_ptrs), ptrs_size); |
| return ret; |
| } |
| #else |
| static ssize_t __init setup_pcpu_remap(size_t static_size) |
| { |
| return -EINVAL; |
| } |
| #endif |
| |
| /* |
| * Embedding allocator |
| * |
| * The first chunk is sized to just contain the static area plus |
| * PERCPU_DYNAMIC_RESERVE and allocated as a contiguous area using |
| * bootmem allocator and used as-is without being mapped into vmalloc |
| * area. This enables the first chunk to piggy back on the linear |
| * physical PMD mapping and doesn't add any additional pressure to |
| * TLB. |
| */ |
| static void *pcpue_ptr __initdata; |
| static size_t pcpue_unit_size __initdata; |
| |
| static struct page * __init pcpue_get_page(unsigned int cpu, int pageno) |
| { |
| return virt_to_page(pcpue_ptr + cpu * pcpue_unit_size |
| + ((size_t)pageno << PAGE_SHIFT)); |
| } |
| |
| static ssize_t __init setup_pcpu_embed(size_t static_size) |
| { |
| unsigned int cpu; |
| |
| /* |
| * If large page isn't supported, there's no benefit in doing |
| * this. Also, embedding allocation doesn't play well with |
| * NUMA. |
| */ |
| if (!cpu_has_pse || pcpu_need_numa()) |
| return -EINVAL; |
| |
| /* allocate and copy */ |
| pcpue_unit_size = PFN_ALIGN(static_size + PERCPU_DYNAMIC_RESERVE); |
| pcpue_unit_size = max_t(size_t, pcpue_unit_size, PCPU_MIN_UNIT_SIZE); |
| pcpue_ptr = pcpu_alloc_bootmem(0, num_possible_cpus() * pcpue_unit_size, |
| PAGE_SIZE); |
| if (!pcpue_ptr) |
| return -ENOMEM; |
| |
| for_each_possible_cpu(cpu) |
| memcpy(pcpue_ptr + cpu * pcpue_unit_size, __per_cpu_load, |
| static_size); |
| |
| /* we're ready, commit */ |
| pr_info("PERCPU: Embedded %zu pages at %p, static data %zu bytes\n", |
| pcpue_unit_size >> PAGE_SHIFT, pcpue_ptr, static_size); |
| |
| return pcpu_setup_first_chunk(pcpue_get_page, static_size, |
| pcpue_unit_size, |
| pcpue_unit_size - static_size, pcpue_ptr, |
| NULL); |
| } |
| |
| /* |
| * 4k page allocator |
| * |
| * This is the basic allocator. Static percpu area is allocated |
| * page-by-page and most of initialization is done by the generic |
| * setup function. |
| */ |
| static struct page **pcpu4k_pages __initdata; |
| static int pcpu4k_nr_static_pages __initdata; |
| |
| static struct page * __init pcpu4k_get_page(unsigned int cpu, int pageno) |
| { |
| if (pageno < pcpu4k_nr_static_pages) |
| return pcpu4k_pages[cpu * pcpu4k_nr_static_pages + pageno]; |
| return NULL; |
| } |
| |
| static void __init pcpu4k_populate_pte(unsigned long addr) |
| { |
| populate_extra_pte(addr); |
| } |
| |
| static ssize_t __init setup_pcpu_4k(size_t static_size) |
| { |
| size_t pages_size; |
| unsigned int cpu; |
| int i, j; |
| ssize_t ret; |
| |
| pcpu4k_nr_static_pages = PFN_UP(static_size); |
| |
| /* unaligned allocations can't be freed, round up to page size */ |
| pages_size = PFN_ALIGN(pcpu4k_nr_static_pages * num_possible_cpus() |
| * sizeof(pcpu4k_pages[0])); |
| pcpu4k_pages = alloc_bootmem(pages_size); |
| |
| /* allocate and copy */ |
| j = 0; |
| for_each_possible_cpu(cpu) |
| for (i = 0; i < pcpu4k_nr_static_pages; i++) { |
| void *ptr; |
| |
| ptr = pcpu_alloc_bootmem(cpu, PAGE_SIZE, PAGE_SIZE); |
| if (!ptr) |
| goto enomem; |
| |
| memcpy(ptr, __per_cpu_load + i * PAGE_SIZE, PAGE_SIZE); |
| pcpu4k_pages[j++] = virt_to_page(ptr); |
| } |
| |
| /* we're ready, commit */ |
| pr_info("PERCPU: Allocated %d 4k pages, static data %zu bytes\n", |
| pcpu4k_nr_static_pages, static_size); |
| |
| ret = pcpu_setup_first_chunk(pcpu4k_get_page, static_size, -1, -1, NULL, |
| pcpu4k_populate_pte); |
| goto out_free_ar; |
| |
| enomem: |
| while (--j >= 0) |
| free_bootmem(__pa(page_address(pcpu4k_pages[j])), PAGE_SIZE); |
| ret = -ENOMEM; |
| out_free_ar: |
| free_bootmem(__pa(pcpu4k_pages), pages_size); |
| return ret; |
| } |
| |
| static inline void setup_percpu_segment(int cpu) |
| { |
| #ifdef CONFIG_X86_32 |
| struct desc_struct gdt; |
| |
| pack_descriptor(&gdt, per_cpu_offset(cpu), 0xFFFFF, |
| 0x2 | DESCTYPE_S, 0x8); |
| gdt.s = 1; |
| write_gdt_entry(get_cpu_gdt_table(cpu), |
| GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S); |
| #endif |
| } |
| |
| /* |
| * Great future plan: |
| * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data. |
| * Always point %gs to its beginning |
| */ |
| void __init setup_per_cpu_areas(void) |
| { |
| size_t static_size = __per_cpu_end - __per_cpu_start; |
| unsigned int cpu; |
| unsigned long delta; |
| size_t pcpu_unit_size; |
| ssize_t ret; |
| |
| pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n", |
| NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids); |
| |
| /* |
| * Allocate percpu area. If PSE is supported, try to make use |
| * of large page mappings. Please read comments on top of |
| * each allocator for details. |
| */ |
| ret = setup_pcpu_remap(static_size); |
| if (ret < 0) |
| ret = setup_pcpu_embed(static_size); |
| if (ret < 0) |
| ret = setup_pcpu_4k(static_size); |
| if (ret < 0) |
| panic("cannot allocate static percpu area (%zu bytes, err=%zd)", |
| static_size, ret); |
| |
| pcpu_unit_size = ret; |
| |
| /* alrighty, percpu areas up and running */ |
| delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; |
| for_each_possible_cpu(cpu) { |
| per_cpu_offset(cpu) = delta + cpu * pcpu_unit_size; |
| per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu); |
| per_cpu(cpu_number, cpu) = cpu; |
| setup_percpu_segment(cpu); |
| setup_stack_canary_segment(cpu); |
| /* |
| * Copy data used in early init routines from the |
| * initial arrays to the per cpu data areas. These |
| * arrays then become expendable and the *_early_ptr's |
| * are zeroed indicating that the static arrays are |
| * gone. |
| */ |
| #ifdef CONFIG_X86_LOCAL_APIC |
| per_cpu(x86_cpu_to_apicid, cpu) = |
| early_per_cpu_map(x86_cpu_to_apicid, cpu); |
| per_cpu(x86_bios_cpu_apicid, cpu) = |
| early_per_cpu_map(x86_bios_cpu_apicid, cpu); |
| #endif |
| #ifdef CONFIG_X86_64 |
| per_cpu(irq_stack_ptr, cpu) = |
| per_cpu(irq_stack_union.irq_stack, cpu) + |
| IRQ_STACK_SIZE - 64; |
| #ifdef CONFIG_NUMA |
| per_cpu(x86_cpu_to_node_map, cpu) = |
| early_per_cpu_map(x86_cpu_to_node_map, cpu); |
| #endif |
| #endif |
| /* |
| * Up to this point, the boot CPU has been using .data.init |
| * area. Reload any changed state for the boot CPU. |
| */ |
| if (cpu == boot_cpu_id) |
| switch_to_new_gdt(cpu); |
| } |
| |
| /* indicate the early static arrays will soon be gone */ |
| #ifdef CONFIG_X86_LOCAL_APIC |
| early_per_cpu_ptr(x86_cpu_to_apicid) = NULL; |
| early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL; |
| #endif |
| #if defined(CONFIG_X86_64) && defined(CONFIG_NUMA) |
| early_per_cpu_ptr(x86_cpu_to_node_map) = NULL; |
| #endif |
| |
| /* Setup node to cpumask map */ |
| setup_node_to_cpumask_map(); |
| |
| /* Setup cpu initialized, callin, callout masks */ |
| setup_cpu_local_masks(); |
| } |