#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/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)
# define DBG(x...)
#endif
-/*
- * Could be inside CONFIG_HAVE_SETUP_PER_CPU_AREA with other stuff but
- * voyager wants cpu_number too.
- */
-#ifdef CONFIG_SMP
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
-#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
+DEFINE_PER_CPU(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
+EXPORT_PER_CPU_SYMBOL(this_cpu_off);
-#ifdef CONFIG_X86_64
unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
- [0] = (unsigned long)__per_cpu_load,
+ [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
};
+EXPORT_SYMBOL(__per_cpu_offset);
+
+/*
+ * On x86_64 symbols referenced from code should be reachable using
+ * 32bit relocations. Reserve space for static percpu variables in
+ * modules so that they are always served from the first chunk which
+ * is located at the percpu segment base. On x86_32, anything can
+ * address anywhere. No need to reserve space in the first chunk.
+ */
+#ifdef CONFIG_X86_64
+#define PERCPU_FIRST_CHUNK_RESERVE PERCPU_MODULE_RESERVE
#else
-unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
+#define PERCPU_FIRST_CHUNK_RESERVE 0
#endif
-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, dyn_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_MODULE_RESERVE +
+ 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;
+ }
+ dyn_size = pcpur_size - static_size - PERCPU_FIRST_CHUNK_RESERVE;
+
+ /* 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,
+ PERCPU_FIRST_CHUNK_RESERVE, dyn_size,
+ PMD_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
+ * module and dynamic reserves and embedded into linear physical
+ * mapping so that it can use PMD mapping without additional TLB
+ * pressure.
+ */
+static ssize_t __init setup_pcpu_embed(size_t static_size)
+{
+ size_t reserve = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
+
+ /*
+ * 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;
+
+ return pcpu_embed_first_chunk(static_size, PERCPU_FIRST_CHUNK_RESERVE,
+ reserve - PERCPU_FIRST_CHUNK_RESERVE, -1);
+}
+
+/*
+ * 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,
+ PERCPU_FIRST_CHUNK_RESERVE, -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:
*/
void __init setup_per_cpu_areas(void)
{
- ssize_t size;
- char *ptr;
- int cpu;
-
- /* Copy section for each CPU (we discard the original) */
- size = roundup(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
+ 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);
- pr_info("PERCPU: Allocating %zd bytes of per cpu data\n", size);
+ /*
+ * 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);
- for_each_possible_cpu(cpu) {
-#ifndef CONFIG_NEED_MULTIPLE_NODES
- ptr = alloc_bootmem_pages(size);
-#else
- int node = early_cpu_to_node(cpu);
- if (!node_online(node) || !NODE_DATA(node)) {
- ptr = alloc_bootmem_pages(size);
- pr_info("cpu %d has no node %d or node-local memory\n",
- cpu, node);
- pr_debug("per cpu data for cpu%d at %016lx\n",
- cpu, __pa(ptr));
- } else {
- ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
- pr_debug("per cpu data for cpu%d on node%d at %016lx\n",
- cpu, node, __pa(ptr));
- }
-#endif
+ pcpu_unit_size = ret;
- memcpy(ptr, __per_cpu_load, __per_cpu_end - __per_cpu_start);
- per_cpu_offset(cpu) = ptr - __per_cpu_start;
+ /* 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.
+ * 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);
+ 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);
+ 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;
+ 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);
+ early_per_cpu_map(x86_cpu_to_node_map, cpu);
+#endif
#endif
/*
- * Up to this point, CPU0 has been using .data.init
- * area. Reload %gs offset for CPU0.
+ * Up to this point, the boot CPU has been using .data.init
+ * area. Reload any changed state for the boot CPU.
*/
- if (cpu == 0)
- load_gs_base(cpu);
-#endif
-
- DBG("PERCPU: cpu %4d %p\n", cpu, ptr);
+ 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 cpu initialized, callin, callout masks */
setup_cpu_local_masks();
}
-
-#endif
-
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff