- Update to 3.4-rc7.
[linux-flexiantxendom0-3.2.10.git] / arch / x86 / kernel / setup_percpu.c
index ab896b3..2e440b9 100644 (file)
@@ -1,3 +1,5 @@
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.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);
 
@@ -55,6 +51,7 @@ EXPORT_SYMBOL(__per_cpu_offset);
 #define PERCPU_FIRST_CHUNK_RESERVE     0
 #endif
 
+#ifdef CONFIG_X86_32
 /**
  * pcpu_need_numa - determine percpu allocation needs to consider NUMA
  *
@@ -83,6 +80,7 @@ static bool __init pcpu_need_numa(void)
 #endif
        return false;
 }
+#endif
 
 /**
  * pcpu_alloc_bootmem - NUMA friendly alloc_bootmem wrapper for percpu
@@ -114,8 +112,8 @@ static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size,
        } 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));
+               pr_debug("per cpu data for cpu%d %lu bytes on node%d at %016lx\n",
+                        cpu, size, node, __pa(ptr));
        }
        return ptr;
 #else
@@ -126,9 +124,9 @@ static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size,
 /*
  * Helpers for first chunk memory allocation
  */
-static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size)
+static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
 {
-       return pcpu_alloc_bootmem(cpu, size, size);
+       return pcpu_alloc_bootmem(cpu, size, align);
 }
 
 static void __init pcpu_fc_free(void *ptr, size_t size)
@@ -136,256 +134,23 @@ static void __init pcpu_fc_free(void *ptr, size_t size)
        free_bootmem(__pa(ptr), size);
 }
 
-/*
- * Large page 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
-struct pcpul_ent {
-       unsigned int    cpu;
-       void            *ptr;
-};
-
-static size_t pcpul_size;
-static struct pcpul_ent *pcpul_map;
-static struct vm_struct pcpul_vm;
-
-static struct page * __init pcpul_get_page(unsigned int cpu, int pageno)
-{
-       size_t off = (size_t)pageno << PAGE_SHIFT;
-
-       if (off >= pcpul_size)
-               return NULL;
-
-       return virt_to_page(pcpul_map[cpu].ptr + off);
-}
-
-static ssize_t __init setup_pcpu_lpage(size_t static_size, bool chosen)
+static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
 {
-       size_t map_size, dyn_size;
-       unsigned int cpu;
-       int i, j;
-       ssize_t ret;
-
-       if (!chosen) {
-               size_t vm_size = VMALLOC_END - VMALLOC_START;
-               size_t tot_size = num_possible_cpus() * PMD_SIZE;
-
-               /* on non-NUMA, embedding is better */
-               if (!pcpu_need_numa())
-                       return -EINVAL;
-
-               /* don't consume more than 20% of vmalloc area */
-               if (tot_size > vm_size / 5) {
-                       pr_info("PERCPU: too large chunk size %zuMB for "
-                               "large page remap\n", tot_size >> 20);
-                       return -EINVAL;
-               }
-       }
-
-       /* need PSE */
-       if (!cpu_has_pse) {
-               pr_warning("PERCPU: lpage allocator requires PSE\n");
-               return -EINVAL;
-       }
-
-       /*
-        * Currently supports only single page.  Supporting multiple
-        * pages won't be too difficult if it ever becomes necessary.
-        */
-       pcpul_size = PFN_ALIGN(static_size + PERCPU_MODULE_RESERVE +
-                              PERCPU_DYNAMIC_RESERVE);
-       if (pcpul_size > PMD_SIZE) {
-               pr_warning("PERCPU: static data is larger than large page, "
-                          "can't use large page\n");
-               return -EINVAL;
-       }
-       dyn_size = pcpul_size - static_size - PERCPU_FIRST_CHUNK_RESERVE;
-
-       /* allocate pointer array and alloc large pages */
-       map_size = PFN_ALIGN(num_possible_cpus() * sizeof(pcpul_map[0]));
-       pcpul_map = alloc_bootmem(map_size);
-
-       for_each_possible_cpu(cpu) {
-               pcpul_map[cpu].cpu = cpu;
-               pcpul_map[cpu].ptr = pcpu_alloc_bootmem(cpu, PMD_SIZE,
-                                                       PMD_SIZE);
-               if (!pcpul_map[cpu].ptr) {
-                       pr_warning("PERCPU: failed to allocate large page "
-                                  "for cpu%u\n", cpu);
-                       goto enomem;
-               }
-
-               /*
-                * Only use pcpul_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(pcpul_map[cpu].ptr + pcpul_size),
-                            PMD_SIZE - pcpul_size);
-
-               memcpy(pcpul_map[cpu].ptr, __per_cpu_load, static_size);
-       }
-
-       /* allocate address and map */
-       pcpul_vm.flags = VM_ALLOC;
-       pcpul_vm.size = num_possible_cpus() * PMD_SIZE;
-       vm_area_register_early(&pcpul_vm, PMD_SIZE);
-
-       for_each_possible_cpu(cpu) {
-               pmd_t *pmd, pmd_v;
-
-               pmd = populate_extra_pmd((unsigned long)pcpul_vm.addr +
-                                        cpu * PMD_SIZE);
-               pmd_v = pfn_pmd(page_to_pfn(virt_to_page(pcpul_map[cpu].ptr)),
-                               PAGE_KERNEL_LARGE);
-               set_pmd(pmd, pmd_v);
-       }
-
-       /* we're ready, commit */
-       pr_info("PERCPU: Remapped at %p with large pages, static data "
-               "%zu bytes\n", pcpul_vm.addr, static_size);
-
-       ret = pcpu_setup_first_chunk(pcpul_get_page, static_size,
-                                    PERCPU_FIRST_CHUNK_RESERVE, dyn_size,
-                                    PMD_SIZE, pcpul_vm.addr, NULL);
-
-       /* sort pcpul_map array for pcpu_lpage_remapped() */
-       for (i = 0; i < num_possible_cpus() - 1; i++)
-               for (j = i + 1; j < num_possible_cpus(); j++)
-                       if (pcpul_map[i].ptr > pcpul_map[j].ptr) {
-                               struct pcpul_ent tmp = pcpul_map[i];
-                               pcpul_map[i] = pcpul_map[j];
-                               pcpul_map[j] = tmp;
-                       }
-
-       return ret;
-
-enomem:
-       for_each_possible_cpu(cpu)
-               if (pcpul_map[cpu].ptr)
-                       free_bootmem(__pa(pcpul_map[cpu].ptr), pcpul_size);
-       free_bootmem(__pa(pcpul_map), map_size);
-       return -ENOMEM;
-}
-
-/**
- * pcpu_lpage_remapped - determine whether a kaddr is in pcpul recycled area
- * @kaddr: the kernel address in question
- *
- * Determine whether @kaddr falls in the pcpul recycled area.  This is
- * used by pageattr to detect VM aliases and break up the pcpu PMD
- * mapping such that the same physical page is not mapped under
- * different attributes.
- *
- * The recycled area is always at the tail of a partially used PMD
- * page.
- *
- * RETURNS:
- * Address of corresponding remapped pcpu address if match is found;
- * otherwise, NULL.
- */
-void *pcpu_lpage_remapped(void *kaddr)
-{
-       void *pmd_addr = (void *)((unsigned long)kaddr & PMD_MASK);
-       unsigned long offset = (unsigned long)kaddr & ~PMD_MASK;
-       int left = 0, right = num_possible_cpus() - 1;
-       int pos;
-
-       /* pcpul in use at all? */
-       if (!pcpul_map)
-               return NULL;
-
-       /* okay, perform binary search */
-       while (left <= right) {
-               pos = (left + right) / 2;
-
-               if (pcpul_map[pos].ptr < pmd_addr)
-                       left = pos + 1;
-               else if (pcpul_map[pos].ptr > pmd_addr)
-                       right = pos - 1;
-               else {
-                       /* it shouldn't be in the area for the first chunk */
-                       WARN_ON(offset < pcpul_size);
-
-                       return pcpul_vm.addr +
-                               pcpul_map[pos].cpu * PMD_SIZE + offset;
-               }
-       }
-
-       return NULL;
-}
+#ifdef CONFIG_NEED_MULTIPLE_NODES
+       if (early_cpu_to_node(from) == early_cpu_to_node(to))
+               return LOCAL_DISTANCE;
+       else
+               return REMOTE_DISTANCE;
 #else
-static ssize_t __init setup_pcpu_lpage(size_t static_size, bool chosen)
-{
-       return -EINVAL;
-}
+       return LOCAL_DISTANCE;
 #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, bool chosen)
-{
-       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 (!chosen && (!cpu_has_pse || pcpu_need_numa()))
-               return -EINVAL;
-
-       return pcpu_embed_first_chunk(static_size, PERCPU_FIRST_CHUNK_RESERVE,
-                                     reserve - PERCPU_FIRST_CHUNK_RESERVE);
 }
 
-/*
- * 4k allocator
- *
- * Boring fallback 4k allocator.  This allocator puts more pressure on
- * PTE TLBs but other than that behaves nicely on both UMA and NUMA.
- */
-static void __init pcpu4k_populate_pte(unsigned long addr)
+static void __init pcpup_populate_pte(unsigned long addr)
 {
        populate_extra_pte(addr);
 }
 
-static ssize_t __init setup_pcpu_4k(size_t static_size)
-{
-       return pcpu_4k_first_chunk(static_size, PERCPU_FIRST_CHUNK_RESERVE,
-                                  pcpu_fc_alloc, pcpu_fc_free,
-                                  pcpu4k_populate_pte);
-}
-
-/* for explicit first chunk allocator selection */
-static char pcpu_chosen_alloc[16] __initdata;
-
-static int __init percpu_alloc_setup(char *str)
-{
-       strncpy(pcpu_chosen_alloc, str, sizeof(pcpu_chosen_alloc) - 1);
-       return 0;
-}
-early_param("percpu_alloc", percpu_alloc_setup);
-
 static inline void setup_percpu_segment(int cpu)
 {
 #ifdef CONFIG_X86_32
@@ -401,52 +166,60 @@ static inline void setup_percpu_segment(int cpu)
 
 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;
+       int rc;
 
        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.
+        * Allocate percpu area.  Embedding allocator is our favorite;
+        * however, on NUMA configurations, it can result in very
+        * sparse unit mapping and vmalloc area isn't spacious enough
+        * on 32bit.  Use page in that case.
         */
-       ret = -EINVAL;
-       if (strlen(pcpu_chosen_alloc)) {
-               if (strcmp(pcpu_chosen_alloc, "4k")) {
-                       if (!strcmp(pcpu_chosen_alloc, "lpage"))
-                               ret = setup_pcpu_lpage(static_size, true);
-                       else if (!strcmp(pcpu_chosen_alloc, "embed"))
-                               ret = setup_pcpu_embed(static_size, true);
-                       else
-                               pr_warning("PERCPU: unknown allocator %s "
-                                          "specified\n", pcpu_chosen_alloc);
-                       if (ret < 0)
-                               pr_warning("PERCPU: %s allocator failed (%zd), "
-                                          "falling back to 4k\n",
-                                          pcpu_chosen_alloc, ret);
-               }
-       } else {
-               ret = setup_pcpu_lpage(static_size, false);
-               if (ret < 0)
-                       ret = setup_pcpu_embed(static_size, false);
-       }
-       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);
+#ifdef CONFIG_X86_32
+       if (pcpu_chosen_fc == PCPU_FC_AUTO && pcpu_need_numa())
+               pcpu_chosen_fc = PCPU_FC_PAGE;
+#endif
+       rc = -EINVAL;
+       if (pcpu_chosen_fc != PCPU_FC_PAGE) {
+               const size_t dyn_size = PERCPU_MODULE_RESERVE +
+                       PERCPU_DYNAMIC_RESERVE - PERCPU_FIRST_CHUNK_RESERVE;
+               size_t atom_size;
 
-       pcpu_unit_size = ret;
+               /*
+                * On 64bit, use PMD_SIZE for atom_size so that embedded
+                * percpu areas are aligned to PMD.  This, in the future,
+                * can also allow using PMD mappings in vmalloc area.  Use
+                * PAGE_SIZE on 32bit as vmalloc space is highly contended
+                * and large vmalloc area allocs can easily fail.
+                */
+#ifdef CONFIG_X86_64
+               atom_size = PMD_SIZE;
+#else
+               atom_size = PAGE_SIZE;
+#endif
+               rc = pcpu_embed_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
+                                           dyn_size, atom_size,
+                                           pcpu_cpu_distance,
+                                           pcpu_fc_alloc, pcpu_fc_free);
+               if (rc < 0)
+                       pr_warning("%s allocator failed (%d), falling back to page size\n",
+                                  pcpu_fc_names[pcpu_chosen_fc], rc);
+       }
+       if (rc < 0)
+               rc = pcpu_page_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
+                                          pcpu_fc_alloc, pcpu_fc_free,
+                                          pcpup_populate_pte);
+       if (rc < 0)
+               panic("cannot initialize percpu area (err=%d)", rc);
 
        /* 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_offset(cpu) = delta + pcpu_unit_offsets[cpu];
                per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
                per_cpu(cpu_number, cpu) = cpu;
                setup_percpu_segment(cpu);
@@ -458,44 +231,56 @@ void __init setup_per_cpu_areas(void)
                 * are zeroed indicating that the static arrays are
                 * gone.
                 */
+#ifndef CONFIG_XEN
 #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_32
+               per_cpu(x86_cpu_to_logical_apicid, cpu) =
+                       early_per_cpu_map(x86_cpu_to_logical_apicid, cpu);
+#endif
+#endif
 #ifdef CONFIG_X86_64
                per_cpu(irq_stack_ptr, cpu) =
                        per_cpu(irq_stack_union.irq_stack, cpu) +
                        IRQ_STACK_SIZE - 64;
+#endif
 #ifdef CONFIG_NUMA
                per_cpu(x86_cpu_to_node_map, cpu) =
                        early_per_cpu_map(x86_cpu_to_node_map, cpu);
-#endif
+               /*
+                * Ensure that the boot cpu numa_node is correct when the boot
+                * cpu is on a node that doesn't have memory installed.
+                * Also cpu_up() will call cpu_to_node() for APs when
+                * MEMORY_HOTPLUG is defined, before per_cpu(numa_node) is set
+                * up later with c_init aka intel_init/amd_init.
+                * So set them all (boot cpu and all APs).
+                */
+               set_cpu_numa_node(cpu, early_cpu_to_node(cpu));
 #endif
                /*
-                * Up to this point, the boot CPU has been using .data.init
+                * Up to this point, the boot CPU has been using .init.data
                 * area.  Reload any changed state for the boot CPU.
                 */
-               if (cpu == boot_cpu_id)
+               if (!cpu)
                        switch_to_new_gdt(cpu);
        }
 
        /* indicate the early static arrays will soon be gone */
+#ifndef CONFIG_XEN
 #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;
+#ifdef CONFIG_X86_32
+       early_per_cpu_ptr(x86_cpu_to_logical_apicid) = NULL;
 #endif
-
-#if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
-       /*
-        * make sure boot cpu node_number is right, when boot cpu is on the
-        * node that doesn't have mem installed
-        */
-       per_cpu(node_number, boot_cpu_id) = cpu_to_node(boot_cpu_id);
+#endif
+#ifdef CONFIG_NUMA
+       early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
 #endif
 
        /* Setup node to cpumask map */