432 строки
12 KiB
C
432 строки
12 KiB
C
#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/bootmem.h>
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#include <linux/percpu.h>
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#include <linux/kexec.h>
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#include <linux/crash_dump.h>
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#include <linux/smp.h>
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#include <linux/topology.h>
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#include <linux/pfn.h>
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#include <asm/sections.h>
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#include <asm/processor.h>
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#include <asm/setup.h>
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#include <asm/mpspec.h>
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#include <asm/apicdef.h>
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#include <asm/highmem.h>
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#include <asm/proto.h>
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#include <asm/cpumask.h>
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#include <asm/cpu.h>
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#include <asm/stackprotector.h>
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#ifdef CONFIG_DEBUG_PER_CPU_MAPS
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# define DBG(x...) printk(KERN_DEBUG x)
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#else
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# define DBG(x...)
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#endif
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DEFINE_PER_CPU(int, cpu_number);
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EXPORT_PER_CPU_SYMBOL(cpu_number);
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#ifdef CONFIG_X86_64
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#define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load)
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#else
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#define BOOT_PERCPU_OFFSET 0
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#endif
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DEFINE_PER_CPU(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
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EXPORT_PER_CPU_SYMBOL(this_cpu_off);
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unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
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[0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
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};
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EXPORT_SYMBOL(__per_cpu_offset);
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/*
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* On x86_64 symbols referenced from code should be reachable using
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* 32bit relocations. Reserve space for static percpu variables in
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* modules so that they are always served from the first chunk which
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* is located at the percpu segment base. On x86_32, anything can
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* address anywhere. No need to reserve space in the first chunk.
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*/
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#ifdef CONFIG_X86_64
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#define PERCPU_FIRST_CHUNK_RESERVE PERCPU_MODULE_RESERVE
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#else
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#define PERCPU_FIRST_CHUNK_RESERVE 0
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#endif
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/**
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* pcpu_need_numa - determine percpu allocation needs to consider NUMA
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*
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* If NUMA is not configured or there is only one NUMA node available,
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* there is no reason to consider NUMA. This function determines
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* whether percpu allocation should consider NUMA or not.
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*
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* RETURNS:
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* true if NUMA should be considered; otherwise, false.
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*/
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static bool __init pcpu_need_numa(void)
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{
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#ifdef CONFIG_NEED_MULTIPLE_NODES
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pg_data_t *last = NULL;
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unsigned int cpu;
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for_each_possible_cpu(cpu) {
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int node = early_cpu_to_node(cpu);
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if (node_online(node) && NODE_DATA(node) &&
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last && last != NODE_DATA(node))
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return true;
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last = NODE_DATA(node);
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}
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#endif
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return false;
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}
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/**
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* pcpu_alloc_bootmem - NUMA friendly alloc_bootmem wrapper for percpu
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* @cpu: cpu to allocate for
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* @size: size allocation in bytes
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* @align: alignment
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*
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* Allocate @size bytes aligned at @align for cpu @cpu. This wrapper
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* does the right thing for NUMA regardless of the current
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* configuration.
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*
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* RETURNS:
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* Pointer to the allocated area on success, NULL on failure.
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*/
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static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size,
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unsigned long align)
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{
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const unsigned long goal = __pa(MAX_DMA_ADDRESS);
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#ifdef CONFIG_NEED_MULTIPLE_NODES
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int node = early_cpu_to_node(cpu);
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void *ptr;
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if (!node_online(node) || !NODE_DATA(node)) {
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ptr = __alloc_bootmem_nopanic(size, align, goal);
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pr_info("cpu %d has no node %d or node-local memory\n",
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cpu, node);
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pr_debug("per cpu data for cpu%d %lu bytes at %016lx\n",
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cpu, size, __pa(ptr));
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} else {
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ptr = __alloc_bootmem_node_nopanic(NODE_DATA(node),
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size, align, goal);
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pr_debug("per cpu data for cpu%d %lu bytes on node%d at "
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"%016lx\n", cpu, size, node, __pa(ptr));
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}
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return ptr;
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#else
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return __alloc_bootmem_nopanic(size, align, goal);
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#endif
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}
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/*
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* Remap allocator
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*
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* This allocator uses PMD page as unit. A PMD page is allocated for
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* each cpu and each is remapped into vmalloc area using PMD mapping.
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* As PMD page is quite large, only part of it is used for the first
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* chunk. Unused part is returned to the bootmem allocator.
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*
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* So, the PMD pages are mapped twice - once to the physical mapping
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* and to the vmalloc area for the first percpu chunk. The double
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* mapping does add one more PMD TLB entry pressure but still is much
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* better than only using 4k mappings while still being NUMA friendly.
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*/
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#ifdef CONFIG_NEED_MULTIPLE_NODES
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static size_t pcpur_size __initdata;
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static void **pcpur_ptrs __initdata;
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static struct page * __init pcpur_get_page(unsigned int cpu, int pageno)
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{
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size_t off = (size_t)pageno << PAGE_SHIFT;
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if (off >= pcpur_size)
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return NULL;
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return virt_to_page(pcpur_ptrs[cpu] + off);
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}
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static ssize_t __init setup_pcpu_remap(size_t static_size)
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{
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static struct vm_struct vm;
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size_t ptrs_size, dyn_size;
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unsigned int cpu;
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ssize_t ret;
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/*
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* If large page isn't supported, there's no benefit in doing
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* this. Also, on non-NUMA, embedding is better.
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*/
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if (!cpu_has_pse || !pcpu_need_numa())
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return -EINVAL;
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/*
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* Currently supports only single page. Supporting multiple
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* pages won't be too difficult if it ever becomes necessary.
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*/
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pcpur_size = PFN_ALIGN(static_size + PERCPU_MODULE_RESERVE +
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PERCPU_DYNAMIC_RESERVE);
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if (pcpur_size > PMD_SIZE) {
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pr_warning("PERCPU: static data is larger than large page, "
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"can't use large page\n");
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return -EINVAL;
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}
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dyn_size = pcpur_size - static_size - PERCPU_FIRST_CHUNK_RESERVE;
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/* allocate pointer array and alloc large pages */
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ptrs_size = PFN_ALIGN(num_possible_cpus() * sizeof(pcpur_ptrs[0]));
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pcpur_ptrs = alloc_bootmem(ptrs_size);
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for_each_possible_cpu(cpu) {
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pcpur_ptrs[cpu] = pcpu_alloc_bootmem(cpu, PMD_SIZE, PMD_SIZE);
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if (!pcpur_ptrs[cpu])
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goto enomem;
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/*
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* Only use pcpur_size bytes and give back the rest.
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*
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* Ingo: The 2MB up-rounding bootmem is needed to make
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* sure the partial 2MB page is still fully RAM - it's
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* not well-specified to have a PAT-incompatible area
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* (unmapped RAM, device memory, etc.) in that hole.
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*/
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free_bootmem(__pa(pcpur_ptrs[cpu] + pcpur_size),
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PMD_SIZE - pcpur_size);
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memcpy(pcpur_ptrs[cpu], __per_cpu_load, static_size);
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}
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/* allocate address and map */
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vm.flags = VM_ALLOC;
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vm.size = num_possible_cpus() * PMD_SIZE;
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vm_area_register_early(&vm, PMD_SIZE);
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for_each_possible_cpu(cpu) {
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pmd_t *pmd;
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pmd = populate_extra_pmd((unsigned long)vm.addr
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+ cpu * PMD_SIZE);
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set_pmd(pmd, pfn_pmd(page_to_pfn(virt_to_page(pcpur_ptrs[cpu])),
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PAGE_KERNEL_LARGE));
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}
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/* we're ready, commit */
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pr_info("PERCPU: Remapped at %p with large pages, static data "
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"%zu bytes\n", vm.addr, static_size);
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ret = pcpu_setup_first_chunk(pcpur_get_page, static_size,
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PERCPU_FIRST_CHUNK_RESERVE, dyn_size,
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PMD_SIZE, vm.addr, NULL);
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goto out_free_ar;
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enomem:
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for_each_possible_cpu(cpu)
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if (pcpur_ptrs[cpu])
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free_bootmem(__pa(pcpur_ptrs[cpu]), PMD_SIZE);
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ret = -ENOMEM;
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out_free_ar:
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free_bootmem(__pa(pcpur_ptrs), ptrs_size);
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return ret;
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}
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#else
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static ssize_t __init setup_pcpu_remap(size_t static_size)
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{
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return -EINVAL;
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}
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#endif
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/*
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* Embedding allocator
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*
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* The first chunk is sized to just contain the static area plus
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* module and dynamic reserves and embedded into linear physical
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* mapping so that it can use PMD mapping without additional TLB
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* pressure.
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*/
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static ssize_t __init setup_pcpu_embed(size_t static_size)
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{
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size_t reserve = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
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/*
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* If large page isn't supported, there's no benefit in doing
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* this. Also, embedding allocation doesn't play well with
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* NUMA.
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*/
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if (!cpu_has_pse || pcpu_need_numa())
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return -EINVAL;
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return pcpu_embed_first_chunk(static_size, PERCPU_FIRST_CHUNK_RESERVE,
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reserve - PERCPU_FIRST_CHUNK_RESERVE, -1);
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}
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/*
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* 4k page allocator
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*
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* This is the basic allocator. Static percpu area is allocated
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* page-by-page and most of initialization is done by the generic
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* setup function.
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*/
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static struct page **pcpu4k_pages __initdata;
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static int pcpu4k_nr_static_pages __initdata;
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static struct page * __init pcpu4k_get_page(unsigned int cpu, int pageno)
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{
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if (pageno < pcpu4k_nr_static_pages)
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return pcpu4k_pages[cpu * pcpu4k_nr_static_pages + pageno];
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return NULL;
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}
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static void __init pcpu4k_populate_pte(unsigned long addr)
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{
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populate_extra_pte(addr);
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}
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static ssize_t __init setup_pcpu_4k(size_t static_size)
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{
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size_t pages_size;
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unsigned int cpu;
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int i, j;
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ssize_t ret;
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pcpu4k_nr_static_pages = PFN_UP(static_size);
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/* unaligned allocations can't be freed, round up to page size */
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pages_size = PFN_ALIGN(pcpu4k_nr_static_pages * num_possible_cpus()
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* sizeof(pcpu4k_pages[0]));
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pcpu4k_pages = alloc_bootmem(pages_size);
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/* allocate and copy */
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j = 0;
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for_each_possible_cpu(cpu)
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for (i = 0; i < pcpu4k_nr_static_pages; i++) {
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void *ptr;
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ptr = pcpu_alloc_bootmem(cpu, PAGE_SIZE, PAGE_SIZE);
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if (!ptr)
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goto enomem;
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memcpy(ptr, __per_cpu_load + i * PAGE_SIZE, PAGE_SIZE);
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pcpu4k_pages[j++] = virt_to_page(ptr);
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}
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/* we're ready, commit */
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pr_info("PERCPU: Allocated %d 4k pages, static data %zu bytes\n",
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pcpu4k_nr_static_pages, static_size);
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ret = pcpu_setup_first_chunk(pcpu4k_get_page, static_size,
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PERCPU_FIRST_CHUNK_RESERVE, -1,
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-1, NULL, pcpu4k_populate_pte);
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goto out_free_ar;
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enomem:
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while (--j >= 0)
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free_bootmem(__pa(page_address(pcpu4k_pages[j])), PAGE_SIZE);
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ret = -ENOMEM;
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out_free_ar:
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free_bootmem(__pa(pcpu4k_pages), pages_size);
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return ret;
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}
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static inline void setup_percpu_segment(int cpu)
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{
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#ifdef CONFIG_X86_32
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struct desc_struct gdt;
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pack_descriptor(&gdt, per_cpu_offset(cpu), 0xFFFFF,
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0x2 | DESCTYPE_S, 0x8);
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gdt.s = 1;
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write_gdt_entry(get_cpu_gdt_table(cpu),
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GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S);
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#endif
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}
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/*
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* Great future plan:
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* Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
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* Always point %gs to its beginning
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*/
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void __init setup_per_cpu_areas(void)
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{
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size_t static_size = __per_cpu_end - __per_cpu_start;
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unsigned int cpu;
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unsigned long delta;
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size_t pcpu_unit_size;
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ssize_t ret;
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pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n",
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NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
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/*
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* Allocate percpu area. If PSE is supported, try to make use
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* of large page mappings. Please read comments on top of
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* each allocator for details.
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*/
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ret = setup_pcpu_remap(static_size);
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if (ret < 0)
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ret = setup_pcpu_embed(static_size);
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if (ret < 0)
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ret = setup_pcpu_4k(static_size);
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if (ret < 0)
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panic("cannot allocate static percpu area (%zu bytes, err=%zd)",
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static_size, ret);
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pcpu_unit_size = ret;
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/* alrighty, percpu areas up and running */
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delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
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for_each_possible_cpu(cpu) {
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per_cpu_offset(cpu) = delta + cpu * pcpu_unit_size;
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per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
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per_cpu(cpu_number, cpu) = cpu;
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setup_percpu_segment(cpu);
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setup_stack_canary_segment(cpu);
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/*
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* Copy data used in early init routines from the
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* initial arrays to the per cpu data areas. These
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* arrays then become expendable and the *_early_ptr's
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* are zeroed indicating that the static arrays are
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* gone.
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*/
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#ifdef CONFIG_X86_LOCAL_APIC
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per_cpu(x86_cpu_to_apicid, cpu) =
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early_per_cpu_map(x86_cpu_to_apicid, cpu);
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per_cpu(x86_bios_cpu_apicid, cpu) =
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early_per_cpu_map(x86_bios_cpu_apicid, cpu);
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#endif
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#ifdef CONFIG_X86_64
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per_cpu(irq_stack_ptr, cpu) =
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per_cpu(irq_stack_union.irq_stack, cpu) +
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IRQ_STACK_SIZE - 64;
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#ifdef CONFIG_NUMA
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per_cpu(x86_cpu_to_node_map, cpu) =
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early_per_cpu_map(x86_cpu_to_node_map, cpu);
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#endif
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#endif
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/*
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* Up to this point, the boot CPU has been using .data.init
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* area. Reload any changed state for the boot CPU.
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*/
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if (cpu == boot_cpu_id)
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switch_to_new_gdt(cpu);
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}
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/* indicate the early static arrays will soon be gone */
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#ifdef CONFIG_X86_LOCAL_APIC
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early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
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early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
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#endif
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#if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
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early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
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#endif
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/* Setup node to cpumask map */
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setup_node_to_cpumask_map();
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/* Setup cpu initialized, callin, callout masks */
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setup_cpu_local_masks();
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}
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