*
* To use this allocator, arch code should do the followings.
*
- * - drop CONFIG_HAVE_LEGACY_PER_CPU_AREA
- *
* - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate
* regular address to percpu pointer and back if they need to be
* different from the default
#include <linux/bitmap.h>
#include <linux/bootmem.h>
+#include <linux/err.h>
#include <linux/list.h>
#include <linux/log2.h>
#include <linux/mm.h>
#include <asm/cacheflush.h>
#include <asm/sections.h>
#include <asm/tlbflush.h>
+#include <asm/io.h>
#define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */
#define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */
struct list_head list; /* linked to pcpu_slot lists */
int free_size; /* free bytes in the chunk */
int contig_hint; /* max contiguous size hint */
- struct vm_struct *vm; /* mapped vmalloc region */
+ void *base_addr; /* base address of this chunk */
int map_used; /* # of map entries used */
int map_alloc; /* # of map entries allocated */
int *map; /* allocation map */
+ struct vm_struct **vms; /* mapped vmalloc regions */
bool immutable; /* no [de]population allowed */
unsigned long populated[]; /* populated bitmap */
};
static int pcpu_unit_pages __read_mostly;
static int pcpu_unit_size __read_mostly;
static int pcpu_nr_units __read_mostly;
-static int pcpu_chunk_size __read_mostly;
+static int pcpu_atom_size __read_mostly;
static int pcpu_nr_slots __read_mostly;
static size_t pcpu_chunk_struct_size __read_mostly;
void *pcpu_base_addr __read_mostly;
EXPORT_SYMBOL_GPL(pcpu_base_addr);
-/* cpu -> unit map */
-const int *pcpu_unit_map __read_mostly;
+static const int *pcpu_unit_map __read_mostly; /* cpu -> unit */
+const unsigned long *pcpu_unit_offsets __read_mostly; /* cpu -> unit offset */
+
+/* group information, used for vm allocation */
+static int pcpu_nr_groups __read_mostly;
+static const unsigned long *pcpu_group_offsets __read_mostly;
+static const size_t *pcpu_group_sizes __read_mostly;
/*
* The first chunk which always exists. Note that unlike other
*
* During allocation, pcpu_alloc_mutex is kept locked all the time and
* pcpu_lock is grabbed and released as necessary. All actual memory
- * allocations are done using GFP_KERNEL with pcpu_lock released.
+ * allocations are done using GFP_KERNEL with pcpu_lock released. In
+ * general, percpu memory can't be allocated with irq off but
+ * irqsave/restore are still used in alloc path so that it can be used
+ * from early init path - sched_init() specifically.
*
* Free path accesses and alters only the index data structures, so it
* can be safely called from atomic context. When memory needs to be
static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk,
unsigned int cpu, int page_idx)
{
- return (unsigned long)chunk->vm->addr +
- (pcpu_page_idx(cpu, page_idx) << PAGE_SHIFT);
+ return (unsigned long)chunk->base_addr + pcpu_unit_offsets[cpu] +
+ (page_idx << PAGE_SHIFT);
}
static struct page *pcpu_chunk_page(struct pcpu_chunk *chunk,
*/
static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
{
- void *first_start = pcpu_first_chunk->vm->addr;
+ void *first_start = pcpu_first_chunk->base_addr;
/* is it in the first chunk? */
if (addr >= first_start && addr < first_start + pcpu_unit_size) {
* space. Note that any possible cpu id can be used here, so
* there's no need to worry about preemption or cpu hotplug.
*/
- addr += pcpu_unit_map[smp_processor_id()] * pcpu_unit_size;
+ addr += pcpu_unit_offsets[raw_smp_processor_id()];
return pcpu_get_page_chunk(vmalloc_to_page(addr));
}
/**
- * pcpu_extend_area_map - extend area map for allocation
- * @chunk: target chunk
+ * pcpu_need_to_extend - determine whether chunk area map needs to be extended
+ * @chunk: chunk of interest
*
- * Extend area map of @chunk so that it can accomodate an allocation.
- * A single allocation can split an area into three areas, so this
- * function makes sure that @chunk->map has at least two extra slots.
+ * Determine whether area map of @chunk needs to be extended to
+ * accomodate a new allocation.
*
* CONTEXT:
- * pcpu_alloc_mutex, pcpu_lock. pcpu_lock is released and reacquired
- * if area map is extended.
+ * pcpu_lock.
*
* RETURNS:
- * 0 if noop, 1 if successfully extended, -errno on failure.
+ * New target map allocation length if extension is necessary, 0
+ * otherwise.
*/
-static int pcpu_extend_area_map(struct pcpu_chunk *chunk)
+static int pcpu_need_to_extend(struct pcpu_chunk *chunk)
{
int new_alloc;
- int *new;
- size_t size;
- /* has enough? */
if (chunk->map_alloc >= chunk->map_used + 2)
return 0;
- spin_unlock_irq(&pcpu_lock);
-
new_alloc = PCPU_DFL_MAP_ALLOC;
while (new_alloc < chunk->map_used + 2)
new_alloc *= 2;
- new = pcpu_mem_alloc(new_alloc * sizeof(new[0]));
- if (!new) {
- spin_lock_irq(&pcpu_lock);
+ return new_alloc;
+}
+
+/**
+ * pcpu_extend_area_map - extend area map of a chunk
+ * @chunk: chunk of interest
+ * @new_alloc: new target allocation length of the area map
+ *
+ * Extend area map of @chunk to have @new_alloc entries.
+ *
+ * CONTEXT:
+ * Does GFP_KERNEL allocation. Grabs and releases pcpu_lock.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc)
+{
+ int *old = NULL, *new = NULL;
+ size_t old_size = 0, new_size = new_alloc * sizeof(new[0]);
+ unsigned long flags;
+
+ new = pcpu_mem_alloc(new_size);
+ if (!new)
return -ENOMEM;
- }
- /*
- * Acquire pcpu_lock and switch to new area map. Only free
- * could have happened inbetween, so map_used couldn't have
- * grown.
- */
- spin_lock_irq(&pcpu_lock);
- BUG_ON(new_alloc < chunk->map_used + 2);
+ /* acquire pcpu_lock and switch to new area map */
+ spin_lock_irqsave(&pcpu_lock, flags);
+
+ if (new_alloc <= chunk->map_alloc)
+ goto out_unlock;
- size = chunk->map_alloc * sizeof(chunk->map[0]);
- memcpy(new, chunk->map, size);
+ old_size = chunk->map_alloc * sizeof(chunk->map[0]);
+ memcpy(new, chunk->map, old_size);
/*
* map_alloc < PCPU_DFL_MAP_ALLOC indicates that the chunk is
* one of the first chunks and still using static map.
*/
if (chunk->map_alloc >= PCPU_DFL_MAP_ALLOC)
- pcpu_mem_free(chunk->map, size);
+ old = chunk->map;
chunk->map_alloc = new_alloc;
chunk->map = new;
+ new = NULL;
+
+out_unlock:
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+
+ /*
+ * pcpu_mem_free() might end up calling vfree() which uses
+ * IRQ-unsafe lock and thus can't be called under pcpu_lock.
+ */
+ pcpu_mem_free(old, old_size);
+ pcpu_mem_free(new, new_size);
+
return 0;
}
{
if (!chunk)
return;
- if (chunk->vm)
- free_vm_area(chunk->vm);
+ if (chunk->vms)
+ pcpu_free_vm_areas(chunk->vms, pcpu_nr_groups);
pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0]));
kfree(chunk);
}
chunk->map_alloc = PCPU_DFL_MAP_ALLOC;
chunk->map[chunk->map_used++] = pcpu_unit_size;
- chunk->vm = get_vm_area(pcpu_chunk_size, VM_ALLOC);
- if (!chunk->vm) {
+ chunk->vms = pcpu_get_vm_areas(pcpu_group_offsets, pcpu_group_sizes,
+ pcpu_nr_groups, pcpu_atom_size,
+ GFP_KERNEL);
+ if (!chunk->vms) {
free_pcpu_chunk(chunk);
return NULL;
}
INIT_LIST_HEAD(&chunk->list);
chunk->free_size = pcpu_unit_size;
chunk->contig_hint = pcpu_unit_size;
+ chunk->base_addr = chunk->vms[0]->addr - pcpu_group_offsets[0];
return chunk;
}
*/
static void *pcpu_alloc(size_t size, size_t align, bool reserved)
{
+ static int warn_limit = 10;
struct pcpu_chunk *chunk;
- int slot, off;
+ const char *err;
+ int slot, off, new_alloc;
+ unsigned long flags;
if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) {
WARN(true, "illegal size (%zu) or align (%zu) for "
}
mutex_lock(&pcpu_alloc_mutex);
- spin_lock_irq(&pcpu_lock);
+ spin_lock_irqsave(&pcpu_lock, flags);
/* serve reserved allocations from the reserved chunk if available */
if (reserved && pcpu_reserved_chunk) {
chunk = pcpu_reserved_chunk;
- if (size > chunk->contig_hint ||
- pcpu_extend_area_map(chunk) < 0)
+
+ if (size > chunk->contig_hint) {
+ err = "alloc from reserved chunk failed";
goto fail_unlock;
+ }
+
+ while ((new_alloc = pcpu_need_to_extend(chunk))) {
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+ if (pcpu_extend_area_map(chunk, new_alloc) < 0) {
+ err = "failed to extend area map of reserved chunk";
+ goto fail_unlock_mutex;
+ }
+ spin_lock_irqsave(&pcpu_lock, flags);
+ }
+
off = pcpu_alloc_area(chunk, size, align);
if (off >= 0)
goto area_found;
+
+ err = "alloc from reserved chunk failed";
goto fail_unlock;
}
if (size > chunk->contig_hint)
continue;
- switch (pcpu_extend_area_map(chunk)) {
- case 0:
- break;
- case 1:
- goto restart; /* pcpu_lock dropped, restart */
- default:
- goto fail_unlock;
+ new_alloc = pcpu_need_to_extend(chunk);
+ if (new_alloc) {
+ spin_unlock_irqrestore(&pcpu_lock, flags);
+ if (pcpu_extend_area_map(chunk,
+ new_alloc) < 0) {
+ err = "failed to extend area map";
+ goto fail_unlock_mutex;
+ }
+ spin_lock_irqsave(&pcpu_lock, flags);
+ /*
+ * pcpu_lock has been dropped, need to
+ * restart cpu_slot list walking.
+ */
+ goto restart;
}
off = pcpu_alloc_area(chunk, size, align);
}
/* hmmm... no space left, create a new chunk */
- spin_unlock_irq(&pcpu_lock);
+ spin_unlock_irqrestore(&pcpu_lock, flags);
chunk = alloc_pcpu_chunk();
- if (!chunk)
+ if (!chunk) {
+ err = "failed to allocate new chunk";
goto fail_unlock_mutex;
+ }
- spin_lock_irq(&pcpu_lock);
+ spin_lock_irqsave(&pcpu_lock, flags);
pcpu_chunk_relocate(chunk, -1);
goto restart;
area_found:
- spin_unlock_irq(&pcpu_lock);
+ spin_unlock_irqrestore(&pcpu_lock, flags);
/* populate, map and clear the area */
if (pcpu_populate_chunk(chunk, off, size)) {
- spin_lock_irq(&pcpu_lock);
+ spin_lock_irqsave(&pcpu_lock, flags);
pcpu_free_area(chunk, off);
+ err = "failed to populate";
goto fail_unlock;
}
mutex_unlock(&pcpu_alloc_mutex);
- /* return address relative to unit0 */
- return __addr_to_pcpu_ptr(chunk->vm->addr + off);
+ /* return address relative to base address */
+ return __addr_to_pcpu_ptr(chunk->base_addr + off);
fail_unlock:
- spin_unlock_irq(&pcpu_lock);
+ spin_unlock_irqrestore(&pcpu_lock, flags);
fail_unlock_mutex:
mutex_unlock(&pcpu_alloc_mutex);
+ if (warn_limit) {
+ pr_warning("PERCPU: allocation failed, size=%zu align=%zu, "
+ "%s\n", size, align, err);
+ dump_stack();
+ if (!--warn_limit)
+ pr_info("PERCPU: limit reached, disable warning\n");
+ }
return NULL;
}
*/
void free_percpu(void *ptr)
{
- void *addr = __pcpu_ptr_to_addr(ptr);
+ void *addr;
struct pcpu_chunk *chunk;
unsigned long flags;
int off;
if (!ptr)
return;
+ addr = __pcpu_ptr_to_addr(ptr);
+
spin_lock_irqsave(&pcpu_lock, flags);
chunk = pcpu_chunk_addr_search(addr);
- off = addr - chunk->vm->addr;
+ off = addr - chunk->base_addr;
pcpu_free_area(chunk, off);
EXPORT_SYMBOL_GPL(free_percpu);
/**
- * pcpu_setup_first_chunk - initialize the first percpu chunk
- * @static_size: the size of static percpu area in bytes
- * @reserved_size: the size of reserved percpu area in bytes, 0 for none
+ * per_cpu_ptr_to_phys - convert translated percpu address to physical address
+ * @addr: the address to be converted to physical address
+ *
+ * Given @addr which is dereferenceable address obtained via one of
+ * percpu access macros, this function translates it into its physical
+ * address. The caller is responsible for ensuring @addr stays valid
+ * until this function finishes.
+ *
+ * RETURNS:
+ * The physical address for @addr.
+ */
+phys_addr_t per_cpu_ptr_to_phys(void *addr)
+{
+ if ((unsigned long)addr < VMALLOC_START ||
+ (unsigned long)addr >= VMALLOC_END)
+ return __pa(addr);
+ else
+ return page_to_phys(vmalloc_to_page(addr));
+}
+
+static inline size_t pcpu_calc_fc_sizes(size_t static_size,
+ size_t reserved_size,
+ ssize_t *dyn_sizep)
+{
+ size_t size_sum;
+
+ size_sum = PFN_ALIGN(static_size + reserved_size +
+ (*dyn_sizep >= 0 ? *dyn_sizep : 0));
+ if (*dyn_sizep != 0)
+ *dyn_sizep = size_sum - static_size - reserved_size;
+
+ return size_sum;
+}
+
+/**
+ * pcpu_alloc_alloc_info - allocate percpu allocation info
+ * @nr_groups: the number of groups
+ * @nr_units: the number of units
+ *
+ * Allocate ai which is large enough for @nr_groups groups containing
+ * @nr_units units. The returned ai's groups[0].cpu_map points to the
+ * cpu_map array which is long enough for @nr_units and filled with
+ * NR_CPUS. It's the caller's responsibility to initialize cpu_map
+ * pointer of other groups.
+ *
+ * RETURNS:
+ * Pointer to the allocated pcpu_alloc_info on success, NULL on
+ * failure.
+ */
+struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
+ int nr_units)
+{
+ struct pcpu_alloc_info *ai;
+ size_t base_size, ai_size;
+ void *ptr;
+ int unit;
+
+ base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]),
+ __alignof__(ai->groups[0].cpu_map[0]));
+ ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]);
+
+ ptr = alloc_bootmem_nopanic(PFN_ALIGN(ai_size));
+ if (!ptr)
+ return NULL;
+ ai = ptr;
+ ptr += base_size;
+
+ ai->groups[0].cpu_map = ptr;
+
+ for (unit = 0; unit < nr_units; unit++)
+ ai->groups[0].cpu_map[unit] = NR_CPUS;
+
+ ai->nr_groups = nr_groups;
+ ai->__ai_size = PFN_ALIGN(ai_size);
+
+ return ai;
+}
+
+/**
+ * pcpu_free_alloc_info - free percpu allocation info
+ * @ai: pcpu_alloc_info to free
+ *
+ * Free @ai which was allocated by pcpu_alloc_alloc_info().
+ */
+void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai)
+{
+ free_bootmem(__pa(ai), ai->__ai_size);
+}
+
+/**
+ * pcpu_build_alloc_info - build alloc_info considering distances between CPUs
+ * @reserved_size: the size of reserved percpu area in bytes
* @dyn_size: free size for dynamic allocation in bytes, -1 for auto
- * @unit_size: unit size in bytes, must be multiple of PAGE_SIZE
+ * @atom_size: allocation atom size
+ * @cpu_distance_fn: callback to determine distance between cpus, optional
+ *
+ * This function determines grouping of units, their mappings to cpus
+ * and other parameters considering needed percpu size, allocation
+ * atom size and distances between CPUs.
+ *
+ * Groups are always mutliples of atom size and CPUs which are of
+ * LOCAL_DISTANCE both ways are grouped together and share space for
+ * units in the same group. The returned configuration is guaranteed
+ * to have CPUs on different nodes on different groups and >=75% usage
+ * of allocated virtual address space.
+ *
+ * RETURNS:
+ * On success, pointer to the new allocation_info is returned. On
+ * failure, ERR_PTR value is returned.
+ */
+struct pcpu_alloc_info * __init pcpu_build_alloc_info(
+ size_t reserved_size, ssize_t dyn_size,
+ size_t atom_size,
+ pcpu_fc_cpu_distance_fn_t cpu_distance_fn)
+{
+ static int group_map[NR_CPUS] __initdata;
+ static int group_cnt[NR_CPUS] __initdata;
+ const size_t static_size = __per_cpu_end - __per_cpu_start;
+ int group_cnt_max = 0, nr_groups = 1, nr_units = 0;
+ size_t size_sum, min_unit_size, alloc_size;
+ int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */
+ int last_allocs, group, unit;
+ unsigned int cpu, tcpu;
+ struct pcpu_alloc_info *ai;
+ unsigned int *cpu_map;
+
+ /* this function may be called multiple times */
+ memset(group_map, 0, sizeof(group_map));
+ memset(group_cnt, 0, sizeof(group_map));
+
+ /*
+ * Determine min_unit_size, alloc_size and max_upa such that
+ * alloc_size is multiple of atom_size and is the smallest
+ * which can accomodate 4k aligned segments which are equal to
+ * or larger than min_unit_size.
+ */
+ size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, &dyn_size);
+ min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE);
+
+ alloc_size = roundup(min_unit_size, atom_size);
+ upa = alloc_size / min_unit_size;
+ while (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK))
+ upa--;
+ max_upa = upa;
+
+ /* group cpus according to their proximity */
+ for_each_possible_cpu(cpu) {
+ group = 0;
+ next_group:
+ for_each_possible_cpu(tcpu) {
+ if (cpu == tcpu)
+ break;
+ if (group_map[tcpu] == group && cpu_distance_fn &&
+ (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE ||
+ cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) {
+ group++;
+ nr_groups = max(nr_groups, group + 1);
+ goto next_group;
+ }
+ }
+ group_map[cpu] = group;
+ group_cnt[group]++;
+ group_cnt_max = max(group_cnt_max, group_cnt[group]);
+ }
+
+ /*
+ * Expand unit size until address space usage goes over 75%
+ * and then as much as possible without using more address
+ * space.
+ */
+ last_allocs = INT_MAX;
+ for (upa = max_upa; upa; upa--) {
+ int allocs = 0, wasted = 0;
+
+ if (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK))
+ continue;
+
+ for (group = 0; group < nr_groups; group++) {
+ int this_allocs = DIV_ROUND_UP(group_cnt[group], upa);
+ allocs += this_allocs;
+ wasted += this_allocs * upa - group_cnt[group];
+ }
+
+ /*
+ * Don't accept if wastage is over 25%. The
+ * greater-than comparison ensures upa==1 always
+ * passes the following check.
+ */
+ if (wasted > num_possible_cpus() / 3)
+ continue;
+
+ /* and then don't consume more memory */
+ if (allocs > last_allocs)
+ break;
+ last_allocs = allocs;
+ best_upa = upa;
+ }
+ upa = best_upa;
+
+ /* allocate and fill alloc_info */
+ for (group = 0; group < nr_groups; group++)
+ nr_units += roundup(group_cnt[group], upa);
+
+ ai = pcpu_alloc_alloc_info(nr_groups, nr_units);
+ if (!ai)
+ return ERR_PTR(-ENOMEM);
+ cpu_map = ai->groups[0].cpu_map;
+
+ for (group = 0; group < nr_groups; group++) {
+ ai->groups[group].cpu_map = cpu_map;
+ cpu_map += roundup(group_cnt[group], upa);
+ }
+
+ ai->static_size = static_size;
+ ai->reserved_size = reserved_size;
+ ai->dyn_size = dyn_size;
+ ai->unit_size = alloc_size / upa;
+ ai->atom_size = atom_size;
+ ai->alloc_size = alloc_size;
+
+ for (group = 0, unit = 0; group_cnt[group]; group++) {
+ struct pcpu_group_info *gi = &ai->groups[group];
+
+ /*
+ * Initialize base_offset as if all groups are located
+ * back-to-back. The caller should update this to
+ * reflect actual allocation.
+ */
+ gi->base_offset = unit * ai->unit_size;
+
+ for_each_possible_cpu(cpu)
+ if (group_map[cpu] == group)
+ gi->cpu_map[gi->nr_units++] = cpu;
+ gi->nr_units = roundup(gi->nr_units, upa);
+ unit += gi->nr_units;
+ }
+ BUG_ON(unit != nr_units);
+
+ return ai;
+}
+
+/**
+ * pcpu_dump_alloc_info - print out information about pcpu_alloc_info
+ * @lvl: loglevel
+ * @ai: allocation info to dump
+ *
+ * Print out information about @ai using loglevel @lvl.
+ */
+static void pcpu_dump_alloc_info(const char *lvl,
+ const struct pcpu_alloc_info *ai)
+{
+ int group_width = 1, cpu_width = 1, width;
+ char empty_str[] = "--------";
+ int alloc = 0, alloc_end = 0;
+ int group, v;
+ int upa, apl; /* units per alloc, allocs per line */
+
+ v = ai->nr_groups;
+ while (v /= 10)
+ group_width++;
+
+ v = num_possible_cpus();
+ while (v /= 10)
+ cpu_width++;
+ empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0';
+
+ upa = ai->alloc_size / ai->unit_size;
+ width = upa * (cpu_width + 1) + group_width + 3;
+ apl = rounddown_pow_of_two(max(60 / width, 1));
+
+ printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu",
+ lvl, ai->static_size, ai->reserved_size, ai->dyn_size,
+ ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size);
+
+ for (group = 0; group < ai->nr_groups; group++) {
+ const struct pcpu_group_info *gi = &ai->groups[group];
+ int unit = 0, unit_end = 0;
+
+ BUG_ON(gi->nr_units % upa);
+ for (alloc_end += gi->nr_units / upa;
+ alloc < alloc_end; alloc++) {
+ if (!(alloc % apl)) {
+ printk("\n");
+ printk("%spcpu-alloc: ", lvl);
+ }
+ printk("[%0*d] ", group_width, group);
+
+ for (unit_end += upa; unit < unit_end; unit++)
+ if (gi->cpu_map[unit] != NR_CPUS)
+ printk("%0*d ", cpu_width,
+ gi->cpu_map[unit]);
+ else
+ printk("%s ", empty_str);
+ }
+ }
+ printk("\n");
+}
+
+/**
+ * pcpu_setup_first_chunk - initialize the first percpu chunk
+ * @ai: pcpu_alloc_info describing how to percpu area is shaped
* @base_addr: mapped address
- * @unit_map: cpu -> unit map, NULL for sequential mapping
*
* Initialize the first percpu chunk which contains the kernel static
* perpcu area. This function is to be called from arch percpu area
* setup path.
*
- * @reserved_size, if non-zero, specifies the amount of bytes to
+ * @ai contains all information necessary to initialize the first
+ * chunk and prime the dynamic percpu allocator.
+ *
+ * @ai->static_size is the size of static percpu area.
+ *
+ * @ai->reserved_size, if non-zero, specifies the amount of bytes to
* reserve after the static area in the first chunk. This reserves
* the first chunk such that it's available only through reserved
* percpu allocation. This is primarily used to serve module percpu
* limited offset range for symbol relocations to guarantee module
* percpu symbols fall inside the relocatable range.
*
- * @dyn_size, if non-negative, determines the number of bytes
- * available for dynamic allocation in the first chunk. Specifying
- * non-negative value makes percpu leave alone the area beyond
- * @static_size + @reserved_size + @dyn_size.
+ * @ai->dyn_size determines the number of bytes available for dynamic
+ * allocation in the first chunk. The area between @ai->static_size +
+ * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused.
+ *
+ * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE
+ * and equal to or larger than @ai->static_size + @ai->reserved_size +
+ * @ai->dyn_size.
+ *
+ * @ai->atom_size is the allocation atom size and used as alignment
+ * for vm areas.
*
- * @unit_size specifies unit size and must be aligned to PAGE_SIZE and
- * equal to or larger than @static_size + @reserved_size + if
- * non-negative, @dyn_size.
+ * @ai->alloc_size is the allocation size and always multiple of
+ * @ai->atom_size. This is larger than @ai->atom_size if
+ * @ai->unit_size is larger than @ai->atom_size.
+ *
+ * @ai->nr_groups and @ai->groups describe virtual memory layout of
+ * percpu areas. Units which should be colocated are put into the
+ * same group. Dynamic VM areas will be allocated according to these
+ * groupings. If @ai->nr_groups is zero, a single group containing
+ * all units is assumed.
*
* The caller should have mapped the first chunk at @base_addr and
* copied static data to each unit.
* and available for dynamic allocation like any other chunks.
*
* RETURNS:
- * The determined pcpu_unit_size which can be used to initialize
- * percpu access.
+ * 0 on success, -errno on failure.
*/
-size_t __init pcpu_setup_first_chunk(size_t static_size, size_t reserved_size,
- ssize_t dyn_size, size_t unit_size,
- void *base_addr, const int *unit_map)
+int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
+ void *base_addr)
{
- static struct vm_struct first_vm;
+ static char cpus_buf[4096] __initdata;
static int smap[2], dmap[2];
- size_t size_sum = static_size + reserved_size +
- (dyn_size >= 0 ? dyn_size : 0);
+ size_t dyn_size = ai->dyn_size;
+ size_t size_sum = ai->static_size + ai->reserved_size + dyn_size;
struct pcpu_chunk *schunk, *dchunk = NULL;
- unsigned int cpu, tcpu;
- int i;
+ unsigned long *group_offsets;
+ size_t *group_sizes;
+ unsigned long *unit_off;
+ unsigned int cpu;
+ int *unit_map;
+ int group, unit, i;
+
+ cpumask_scnprintf(cpus_buf, sizeof(cpus_buf), cpu_possible_mask);
+
+#define PCPU_SETUP_BUG_ON(cond) do { \
+ if (unlikely(cond)) { \
+ pr_emerg("PERCPU: failed to initialize, %s", #cond); \
+ pr_emerg("PERCPU: cpu_possible_mask=%s\n", cpus_buf); \
+ pcpu_dump_alloc_info(KERN_EMERG, ai); \
+ BUG(); \
+ } \
+} while (0)
/* sanity checks */
BUILD_BUG_ON(ARRAY_SIZE(smap) >= PCPU_DFL_MAP_ALLOC ||
ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC);
- BUG_ON(!static_size);
- BUG_ON(!base_addr);
- BUG_ON(unit_size < size_sum);
- BUG_ON(unit_size & ~PAGE_MASK);
- BUG_ON(unit_size < PCPU_MIN_UNIT_SIZE);
-
- /* determine number of units and verify and initialize pcpu_unit_map */
- if (unit_map) {
- int first_unit = INT_MAX, last_unit = INT_MIN;
-
- for_each_possible_cpu(cpu) {
- int unit = unit_map[cpu];
-
- BUG_ON(unit < 0);
- for_each_possible_cpu(tcpu) {
- if (tcpu == cpu)
- break;
- /* the mapping should be one-to-one */
- BUG_ON(unit_map[tcpu] == unit);
- }
+ PCPU_SETUP_BUG_ON(ai->nr_groups <= 0);
+ PCPU_SETUP_BUG_ON(!ai->static_size);
+ PCPU_SETUP_BUG_ON(!base_addr);
+ PCPU_SETUP_BUG_ON(ai->unit_size < size_sum);
+ PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK);
+ PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE);
+
+ /* process group information and build config tables accordingly */
+ group_offsets = alloc_bootmem(ai->nr_groups * sizeof(group_offsets[0]));
+ group_sizes = alloc_bootmem(ai->nr_groups * sizeof(group_sizes[0]));
+ unit_map = alloc_bootmem(nr_cpu_ids * sizeof(unit_map[0]));
+ unit_off = alloc_bootmem(nr_cpu_ids * sizeof(unit_off[0]));
+
+ for (cpu = 0; cpu < nr_cpu_ids; cpu++)
+ unit_map[cpu] = UINT_MAX;
+ pcpu_first_unit_cpu = NR_CPUS;
+
+ for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) {
+ const struct pcpu_group_info *gi = &ai->groups[group];
+
+ group_offsets[group] = gi->base_offset;
+ group_sizes[group] = gi->nr_units * ai->unit_size;
+
+ for (i = 0; i < gi->nr_units; i++) {
+ cpu = gi->cpu_map[i];
+ if (cpu == NR_CPUS)
+ continue;
+
+ PCPU_SETUP_BUG_ON(cpu > nr_cpu_ids);
+ PCPU_SETUP_BUG_ON(!cpu_possible(cpu));
+ PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX);
+
+ unit_map[cpu] = unit + i;
+ unit_off[cpu] = gi->base_offset + i * ai->unit_size;
- if (unit < first_unit) {
+ if (pcpu_first_unit_cpu == NR_CPUS)
pcpu_first_unit_cpu = cpu;
- first_unit = unit;
- }
- if (unit > last_unit) {
- pcpu_last_unit_cpu = cpu;
- last_unit = unit;
- }
}
- pcpu_nr_units = last_unit + 1;
- pcpu_unit_map = unit_map;
- } else {
- int *identity_map;
+ }
+ pcpu_last_unit_cpu = cpu;
+ pcpu_nr_units = unit;
- /* #units == #cpus, identity mapped */
- identity_map = alloc_bootmem(nr_cpu_ids *
- sizeof(identity_map[0]));
+ for_each_possible_cpu(cpu)
+ PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX);
- for_each_possible_cpu(cpu)
- identity_map[cpu] = cpu;
+ /* we're done parsing the input, undefine BUG macro and dump config */
+#undef PCPU_SETUP_BUG_ON
+ pcpu_dump_alloc_info(KERN_INFO, ai);
- pcpu_first_unit_cpu = 0;
- pcpu_last_unit_cpu = pcpu_nr_units - 1;
- pcpu_nr_units = nr_cpu_ids;
- pcpu_unit_map = identity_map;
- }
+ pcpu_nr_groups = ai->nr_groups;
+ pcpu_group_offsets = group_offsets;
+ pcpu_group_sizes = group_sizes;
+ pcpu_unit_map = unit_map;
+ pcpu_unit_offsets = unit_off;
/* determine basic parameters */
- pcpu_unit_pages = unit_size >> PAGE_SHIFT;
+ pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT;
pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT;
- pcpu_chunk_size = pcpu_nr_units * pcpu_unit_size;
+ pcpu_atom_size = ai->atom_size;
pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) +
BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long);
- if (dyn_size < 0)
- dyn_size = pcpu_unit_size - static_size - reserved_size;
-
- first_vm.flags = VM_ALLOC;
- first_vm.size = pcpu_chunk_size;
- first_vm.addr = base_addr;
-
/*
* Allocate chunk slots. The additional last slot is for
* empty chunks.
*/
schunk = alloc_bootmem(pcpu_chunk_struct_size);
INIT_LIST_HEAD(&schunk->list);
- schunk->vm = &first_vm;
+ schunk->base_addr = base_addr;
schunk->map = smap;
schunk->map_alloc = ARRAY_SIZE(smap);
schunk->immutable = true;
bitmap_fill(schunk->populated, pcpu_unit_pages);
- if (reserved_size) {
- schunk->free_size = reserved_size;
+ if (ai->reserved_size) {
+ schunk->free_size = ai->reserved_size;
pcpu_reserved_chunk = schunk;
- pcpu_reserved_chunk_limit = static_size + reserved_size;
+ pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size;
} else {
schunk->free_size = dyn_size;
dyn_size = 0; /* dynamic area covered */
}
schunk->contig_hint = schunk->free_size;
- schunk->map[schunk->map_used++] = -static_size;
+ schunk->map[schunk->map_used++] = -ai->static_size;
if (schunk->free_size)
schunk->map[schunk->map_used++] = schunk->free_size;
if (dyn_size) {
dchunk = alloc_bootmem(pcpu_chunk_struct_size);
INIT_LIST_HEAD(&dchunk->list);
- dchunk->vm = &first_vm;
+ dchunk->base_addr = base_addr;
dchunk->map = dmap;
dchunk->map_alloc = ARRAY_SIZE(dmap);
dchunk->immutable = true;
pcpu_chunk_relocate(pcpu_first_chunk, -1);
/* we're done */
- pcpu_base_addr = schunk->vm->addr;
- return pcpu_unit_size;
+ pcpu_base_addr = base_addr;
+ return 0;
}
-static inline size_t pcpu_calc_fc_sizes(size_t static_size,
- size_t reserved_size,
- ssize_t *dyn_sizep)
-{
- size_t size_sum;
+const char *pcpu_fc_names[PCPU_FC_NR] __initdata = {
+ [PCPU_FC_AUTO] = "auto",
+ [PCPU_FC_EMBED] = "embed",
+ [PCPU_FC_PAGE] = "page",
+};
- size_sum = PFN_ALIGN(static_size + reserved_size +
- (*dyn_sizep >= 0 ? *dyn_sizep : 0));
- if (*dyn_sizep != 0)
- *dyn_sizep = size_sum - static_size - reserved_size;
+enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO;
- return size_sum;
+static int __init percpu_alloc_setup(char *str)
+{
+ if (0)
+ /* nada */;
+#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
+ else if (!strcmp(str, "embed"))
+ pcpu_chosen_fc = PCPU_FC_EMBED;
+#endif
+#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
+ else if (!strcmp(str, "page"))
+ pcpu_chosen_fc = PCPU_FC_PAGE;
+#endif
+ else
+ pr_warning("PERCPU: unknown allocator %s specified\n", str);
+
+ return 0;
}
+early_param("percpu_alloc", percpu_alloc_setup);
#if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \
!defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
/**
* pcpu_embed_first_chunk - embed the first percpu chunk into bootmem
- * @static_size: the size of static percpu area in bytes
* @reserved_size: the size of reserved percpu area in bytes
* @dyn_size: free size for dynamic allocation in bytes, -1 for auto
+ * @atom_size: allocation atom size
+ * @cpu_distance_fn: callback to determine distance between cpus, optional
+ * @alloc_fn: function to allocate percpu page
+ * @free_fn: funtion to free percpu page
*
* This is a helper to ease setting up embedded first percpu chunk and
* can be called where pcpu_setup_first_chunk() is expected.
*
* If this function is used to setup the first chunk, it is 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 mapping which often uses larger
- * page size.
+ * by calling @alloc_fn and used as-is without being mapped into
+ * vmalloc area. Allocations are always whole multiples of @atom_size
+ * aligned to @atom_size.
+ *
+ * This enables the first chunk to piggy back on the linear physical
+ * mapping which often uses larger page size. Please note that this
+ * can result in very sparse cpu->unit mapping on NUMA machines thus
+ * requiring large vmalloc address space. Don't use this allocator if
+ * vmalloc space is not orders of magnitude larger than distances
+ * between node memory addresses (ie. 32bit NUMA machines).
*
* When @dyn_size is positive, dynamic area might be larger than
* specified to fill page alignment. When @dyn_size is auto,
* and reserved areas.
*
* If the needed size is smaller than the minimum or specified unit
- * size, the leftover is returned to the bootmem allocator.
+ * size, the leftover is returned using @free_fn.
*
* RETURNS:
- * The determined pcpu_unit_size which can be used to initialize
- * percpu access on success, -errno on failure.
+ * 0 on success, -errno on failure.
*/
-ssize_t __init pcpu_embed_first_chunk(size_t static_size, size_t reserved_size,
- ssize_t dyn_size)
+int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size,
+ size_t atom_size,
+ pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
+ pcpu_fc_alloc_fn_t alloc_fn,
+ pcpu_fc_free_fn_t free_fn)
{
- size_t size_sum, unit_size, chunk_size;
- void *base;
- unsigned int cpu;
+ void *base = (void *)ULONG_MAX;
+ void **areas = NULL;
+ struct pcpu_alloc_info *ai;
+ size_t size_sum, areas_size, max_distance;
+ int group, i, rc;
+
+ ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size,
+ cpu_distance_fn);
+ if (IS_ERR(ai))
+ return PTR_ERR(ai);
+
+ size_sum = ai->static_size + ai->reserved_size + ai->dyn_size;
+ areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *));
+
+ areas = alloc_bootmem_nopanic(areas_size);
+ if (!areas) {
+ rc = -ENOMEM;
+ goto out_free;
+ }
- /* determine parameters and allocate */
- size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, &dyn_size);
+ /* allocate, copy and determine base address */
+ for (group = 0; group < ai->nr_groups; group++) {
+ struct pcpu_group_info *gi = &ai->groups[group];
+ unsigned int cpu = NR_CPUS;
+ void *ptr;
- unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE);
- chunk_size = unit_size * nr_cpu_ids;
+ for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++)
+ cpu = gi->cpu_map[i];
+ BUG_ON(cpu == NR_CPUS);
- base = __alloc_bootmem_nopanic(chunk_size, PAGE_SIZE,
- __pa(MAX_DMA_ADDRESS));
- if (!base) {
- pr_warning("PERCPU: failed to allocate %zu bytes for "
- "embedding\n", chunk_size);
- return -ENOMEM;
+ /* allocate space for the whole group */
+ ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size);
+ if (!ptr) {
+ rc = -ENOMEM;
+ goto out_free_areas;
+ }
+ areas[group] = ptr;
+
+ base = min(ptr, base);
+
+ for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) {
+ if (gi->cpu_map[i] == NR_CPUS) {
+ /* unused unit, free whole */
+ free_fn(ptr, ai->unit_size);
+ continue;
+ }
+ /* copy and return the unused part */
+ memcpy(ptr, __per_cpu_load, ai->static_size);
+ free_fn(ptr + size_sum, ai->unit_size - size_sum);
+ }
}
- /* return the leftover and copy */
- for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
- void *ptr = base + cpu * unit_size;
+ /* base address is now known, determine group base offsets */
+ max_distance = 0;
+ for (group = 0; group < ai->nr_groups; group++) {
+ ai->groups[group].base_offset = areas[group] - base;
+ max_distance = max_t(size_t, max_distance,
+ ai->groups[group].base_offset);
+ }
+ max_distance += ai->unit_size;
- if (cpu_possible(cpu)) {
- free_bootmem(__pa(ptr + size_sum),
- unit_size - size_sum);
- memcpy(ptr, __per_cpu_load, static_size);
- } else
- free_bootmem(__pa(ptr), unit_size);
+ /* warn if maximum distance is further than 75% of vmalloc space */
+ if (max_distance > (VMALLOC_END - VMALLOC_START) * 3 / 4) {
+ pr_warning("PERCPU: max_distance=0x%zx too large for vmalloc "
+ "space 0x%lx\n",
+ max_distance, VMALLOC_END - VMALLOC_START);
+#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
+ /* and fail if we have fallback */
+ rc = -EINVAL;
+ goto out_free;
+#endif
}
- /* we're ready, commit */
pr_info("PERCPU: Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n",
- PFN_DOWN(size_sum), base, static_size, reserved_size, dyn_size,
- unit_size);
-
- return pcpu_setup_first_chunk(static_size, reserved_size, dyn_size,
- unit_size, base, NULL);
+ PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size,
+ ai->dyn_size, ai->unit_size);
+
+ rc = pcpu_setup_first_chunk(ai, base);
+ goto out_free;
+
+out_free_areas:
+ for (group = 0; group < ai->nr_groups; group++)
+ free_fn(areas[group],
+ ai->groups[group].nr_units * ai->unit_size);
+out_free:
+ pcpu_free_alloc_info(ai);
+ if (areas)
+ free_bootmem(__pa(areas), areas_size);
+ return rc;
}
#endif /* CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK ||
!CONFIG_HAVE_SETUP_PER_CPU_AREA */
#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
/**
* pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages
- * @static_size: the size of static percpu area in bytes
* @reserved_size: the size of reserved percpu area in bytes
* @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE
* @free_fn: funtion to free percpu page, always called with PAGE_SIZE
* page-by-page into vmalloc area.
*
* RETURNS:
- * The determined pcpu_unit_size which can be used to initialize
- * percpu access on success, -errno on failure.
+ * 0 on success, -errno on failure.
*/
-ssize_t __init pcpu_page_first_chunk(size_t static_size, size_t reserved_size,
- pcpu_fc_alloc_fn_t alloc_fn,
- pcpu_fc_free_fn_t free_fn,
- pcpu_fc_populate_pte_fn_t populate_pte_fn)
+int __init pcpu_page_first_chunk(size_t reserved_size,
+ pcpu_fc_alloc_fn_t alloc_fn,
+ pcpu_fc_free_fn_t free_fn,
+ pcpu_fc_populate_pte_fn_t populate_pte_fn)
{
static struct vm_struct vm;
+ struct pcpu_alloc_info *ai;
char psize_str[16];
int unit_pages;
size_t pages_size;
struct page **pages;
- unsigned int cpu;
- int i, j;
- ssize_t ret;
+ int unit, i, j, rc;
snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10);
- unit_pages = PFN_UP(max_t(size_t, static_size + reserved_size,
- PCPU_MIN_UNIT_SIZE));
+ ai = pcpu_build_alloc_info(reserved_size, -1, PAGE_SIZE, NULL);
+ if (IS_ERR(ai))
+ return PTR_ERR(ai);
+ BUG_ON(ai->nr_groups != 1);
+ BUG_ON(ai->groups[0].nr_units != num_possible_cpus());
+
+ unit_pages = ai->unit_size >> PAGE_SHIFT;
/* unaligned allocations can't be freed, round up to page size */
- pages_size = PFN_ALIGN(unit_pages * nr_cpu_ids * sizeof(pages[0]));
+ pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() *
+ sizeof(pages[0]));
pages = alloc_bootmem(pages_size);
/* allocate pages */
j = 0;
- for_each_possible_cpu(cpu)
+ for (unit = 0; unit < num_possible_cpus(); unit++)
for (i = 0; i < unit_pages; i++) {
+ unsigned int cpu = ai->groups[0].cpu_map[unit];
void *ptr;
- ptr = alloc_fn(cpu, PAGE_SIZE);
+ ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE);
if (!ptr) {
pr_warning("PERCPU: failed to allocate %s page "
"for cpu%u\n", psize_str, cpu);
/* allocate vm area, map the pages and copy static data */
vm.flags = VM_ALLOC;
- vm.size = nr_cpu_ids * unit_pages << PAGE_SHIFT;
+ vm.size = num_possible_cpus() * ai->unit_size;
vm_area_register_early(&vm, PAGE_SIZE);
- for_each_possible_cpu(cpu) {
- unsigned long unit_addr = (unsigned long)vm.addr +
- (cpu * unit_pages << PAGE_SHIFT);
+ for (unit = 0; unit < num_possible_cpus(); unit++) {
+ unsigned long unit_addr =
+ (unsigned long)vm.addr + unit * ai->unit_size;
for (i = 0; i < unit_pages; i++)
populate_pte_fn(unit_addr + (i << PAGE_SHIFT));
/* pte already populated, the following shouldn't fail */
- ret = __pcpu_map_pages(unit_addr, &pages[cpu * unit_pages],
- unit_pages);
- if (ret < 0)
- panic("failed to map percpu area, err=%zd\n", ret);
+ rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages],
+ unit_pages);
+ if (rc < 0)
+ panic("failed to map percpu area, err=%d\n", rc);
/*
* FIXME: Archs with virtual cache should flush local
*/
/* copy static data */
- memcpy((void *)unit_addr, __per_cpu_load, static_size);
+ memcpy((void *)unit_addr, __per_cpu_load, ai->static_size);
}
/* we're ready, commit */
- pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu\n",
- unit_pages, psize_str, vm.addr, static_size, reserved_size);
+ pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu d%zu\n",
+ unit_pages, psize_str, vm.addr, ai->static_size,
+ ai->reserved_size, ai->dyn_size);
- ret = pcpu_setup_first_chunk(static_size, reserved_size, -1,
- unit_pages << PAGE_SHIFT, vm.addr, NULL);
+ rc = pcpu_setup_first_chunk(ai, vm.addr);
goto out_free_ar;
enomem:
while (--j >= 0)
free_fn(page_address(pages[j]), PAGE_SIZE);
- ret = -ENOMEM;
+ rc = -ENOMEM;
out_free_ar:
free_bootmem(__pa(pages), pages_size);
- return ret;
+ pcpu_free_alloc_info(ai);
+ return rc;
}
#endif /* CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK */
-#ifdef CONFIG_NEED_PER_CPU_LPAGE_FIRST_CHUNK
-/**
- * pcpu_lpage_build_unit_map - build unit_map for large page remapping
- * @static_size: the size of static percpu area in bytes
- * @reserved_size: the size of reserved percpu area in bytes
- * @dyn_sizep: in/out parameter for dynamic size, -1 for auto
- * @unit_sizep: out parameter for unit size
- * @unit_map: unit_map to be filled
- * @cpu_distance_fn: callback to determine distance between cpus
- *
- * This function builds cpu -> unit map and determine other parameters
- * considering needed percpu size, large page size and distances
- * between CPUs in NUMA.
- *
- * CPUs which are of LOCAL_DISTANCE both ways are grouped together and
- * may share units in the same large page. The returned configuration
- * is guaranteed to have CPUs on different nodes on different large
- * pages and >=75% usage of allocated virtual address space.
- *
- * RETURNS:
- * On success, fills in @unit_map, sets *@dyn_sizep, *@unit_sizep and
- * returns the number of units to be allocated. -errno on failure.
- */
-int __init pcpu_lpage_build_unit_map(size_t static_size, size_t reserved_size,
- ssize_t *dyn_sizep, size_t *unit_sizep,
- size_t lpage_size, int *unit_map,
- pcpu_fc_cpu_distance_fn_t cpu_distance_fn)
-{
- static int group_map[NR_CPUS] __initdata;
- static int group_cnt[NR_CPUS] __initdata;
- int group_cnt_max = 0;
- size_t size_sum, min_unit_size, alloc_size;
- int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */
- int last_allocs;
- unsigned int cpu, tcpu;
- int group, unit;
-
- /*
- * Determine min_unit_size, alloc_size and max_upa such that
- * alloc_size is multiple of lpage_size and is the smallest
- * which can accomodate 4k aligned segments which are equal to
- * or larger than min_unit_size.
- */
- size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, dyn_sizep);
- min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE);
-
- alloc_size = roundup(min_unit_size, lpage_size);
- upa = alloc_size / min_unit_size;
- while (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK))
- upa--;
- max_upa = upa;
-
- /* group cpus according to their proximity */
- for_each_possible_cpu(cpu) {
- group = 0;
- next_group:
- for_each_possible_cpu(tcpu) {
- if (cpu == tcpu)
- break;
- if (group_map[tcpu] == group &&
- (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE ||
- cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) {
- group++;
- goto next_group;
- }
- }
- group_map[cpu] = group;
- group_cnt[group]++;
- group_cnt_max = max(group_cnt_max, group_cnt[group]);
- }
-
- /*
- * Expand unit size until address space usage goes over 75%
- * and then as much as possible without using more address
- * space.
- */
- last_allocs = INT_MAX;
- for (upa = max_upa; upa; upa--) {
- int allocs = 0, wasted = 0;
-
- if (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK))
- continue;
-
- for (group = 0; group_cnt[group]; group++) {
- int this_allocs = DIV_ROUND_UP(group_cnt[group], upa);
- allocs += this_allocs;
- wasted += this_allocs * upa - group_cnt[group];
- }
-
- /*
- * Don't accept if wastage is over 25%. The
- * greater-than comparison ensures upa==1 always
- * passes the following check.
- */
- if (wasted > num_possible_cpus() / 3)
- continue;
-
- /* and then don't consume more memory */
- if (allocs > last_allocs)
- break;
- last_allocs = allocs;
- best_upa = upa;
- }
- *unit_sizep = alloc_size / best_upa;
-
- /* assign units to cpus accordingly */
- unit = 0;
- for (group = 0; group_cnt[group]; group++) {
- for_each_possible_cpu(cpu)
- if (group_map[cpu] == group)
- unit_map[cpu] = unit++;
- unit = roundup(unit, best_upa);
- }
-
- return unit; /* unit contains aligned number of units */
-}
-
-struct pcpul_ent {
- void *ptr;
- void *map_addr;
-};
-
-static size_t pcpul_size;
-static size_t pcpul_lpage_size;
-static int pcpul_nr_lpages;
-static struct pcpul_ent *pcpul_map;
-
-static bool __init pcpul_unit_to_cpu(int unit, const int *unit_map,
- unsigned int *cpup)
-{
- unsigned int cpu;
-
- for_each_possible_cpu(cpu)
- if (unit_map[cpu] == unit) {
- if (cpup)
- *cpup = cpu;
- return true;
- }
-
- return false;
-}
-
-static void __init pcpul_lpage_dump_cfg(const char *lvl, size_t static_size,
- size_t reserved_size, size_t dyn_size,
- size_t unit_size, size_t lpage_size,
- const int *unit_map, int nr_units)
-{
- int width = 1, v = nr_units;
- char empty_str[] = "--------";
- int upl, lpl; /* units per lpage, lpage per line */
- unsigned int cpu;
- int lpage, unit;
-
- while (v /= 10)
- width++;
- empty_str[min_t(int, width, sizeof(empty_str) - 1)] = '\0';
-
- upl = max_t(int, lpage_size / unit_size, 1);
- lpl = rounddown_pow_of_two(max_t(int, 60 / (upl * (width + 1) + 2), 1));
-
- printk("%spcpu-lpage: sta/res/dyn=%zu/%zu/%zu unit=%zu lpage=%zu", lvl,
- static_size, reserved_size, dyn_size, unit_size, lpage_size);
-
- for (lpage = 0, unit = 0; unit < nr_units; unit++) {
- if (!(unit % upl)) {
- if (!(lpage++ % lpl)) {
- printk("\n");
- printk("%spcpu-lpage: ", lvl);
- } else
- printk("| ");
- }
- if (pcpul_unit_to_cpu(unit, unit_map, &cpu))
- printk("%0*d ", width, cpu);
- else
- printk("%s ", empty_str);
- }
- printk("\n");
-}
-
-/**
- * pcpu_lpage_first_chunk - remap the first percpu chunk using large page
- * @static_size: the size of static percpu area in bytes
- * @reserved_size: the size of reserved percpu area in bytes
- * @dyn_size: free size for dynamic allocation in bytes
- * @unit_size: unit size in bytes
- * @lpage_size: the size of a large page
- * @unit_map: cpu -> unit mapping
- * @nr_units: the number of units
- * @alloc_fn: function to allocate percpu lpage, always called with lpage_size
- * @free_fn: function to free percpu memory, @size <= lpage_size
- * @map_fn: function to map percpu lpage, always called with lpage_size
- *
- * This allocator uses large page to build and map the first chunk.
- * Unlike other helpers, the caller should always specify @dyn_size
- * and @unit_size. These parameters along with @unit_map and
- * @nr_units can be determined using pcpu_lpage_build_unit_map().
- * This two stage initialization is to allow arch code to evaluate the
- * parameters before committing to it.
- *
- * Large pages are allocated as directed by @unit_map and other
- * parameters and mapped to vmalloc space. Unused holes are returned
- * to the page allocator. Note that these holes end up being actively
- * mapped twice - once to the physical mapping and to the vmalloc area
- * for the first percpu chunk. Depending on architecture, this might
- * cause problem when changing page attributes of the returned area.
- * These double mapped areas can be detected using
- * pcpu_lpage_remapped().
- *
- * RETURNS:
- * The determined pcpu_unit_size which can be used to initialize
- * percpu access on success, -errno on failure.
- */
-ssize_t __init pcpu_lpage_first_chunk(size_t static_size, size_t reserved_size,
- size_t dyn_size, size_t unit_size,
- size_t lpage_size, const int *unit_map,
- int nr_units,
- pcpu_fc_alloc_fn_t alloc_fn,
- pcpu_fc_free_fn_t free_fn,
- pcpu_fc_map_fn_t map_fn)
-{
- static struct vm_struct vm;
- size_t chunk_size = unit_size * nr_units;
- size_t map_size;
- unsigned int cpu;
- ssize_t ret;
- int i, j, unit;
-
- pcpul_lpage_dump_cfg(KERN_DEBUG, static_size, reserved_size, dyn_size,
- unit_size, lpage_size, unit_map, nr_units);
-
- BUG_ON(chunk_size % lpage_size);
-
- pcpul_size = static_size + reserved_size + dyn_size;
- pcpul_lpage_size = lpage_size;
- pcpul_nr_lpages = chunk_size / lpage_size;
-
- /* allocate pointer array and alloc large pages */
- map_size = pcpul_nr_lpages * sizeof(pcpul_map[0]);
- pcpul_map = alloc_bootmem(map_size);
-
- /* allocate all pages */
- for (i = 0; i < pcpul_nr_lpages; i++) {
- size_t offset = i * lpage_size;
- int first_unit = offset / unit_size;
- int last_unit = (offset + lpage_size - 1) / unit_size;
- void *ptr;
-
- /* find out which cpu is mapped to this unit */
- for (unit = first_unit; unit <= last_unit; unit++)
- if (pcpul_unit_to_cpu(unit, unit_map, &cpu))
- goto found;
- continue;
- found:
- ptr = alloc_fn(cpu, lpage_size);
- if (!ptr) {
- pr_warning("PERCPU: failed to allocate large page "
- "for cpu%u\n", cpu);
- goto enomem;
- }
-
- pcpul_map[i].ptr = ptr;
- }
-
- /* return unused holes */
- for (unit = 0; unit < nr_units; unit++) {
- size_t start = unit * unit_size;
- size_t end = start + unit_size;
- size_t off, next;
-
- /* don't free used part of occupied unit */
- if (pcpul_unit_to_cpu(unit, unit_map, NULL))
- start += pcpul_size;
-
- /* unit can span more than one page, punch the holes */
- for (off = start; off < end; off = next) {
- void *ptr = pcpul_map[off / lpage_size].ptr;
- next = min(roundup(off + 1, lpage_size), end);
- if (ptr)
- free_fn(ptr + off % lpage_size, next - off);
- }
- }
-
- /* allocate address, map and copy */
- vm.flags = VM_ALLOC;
- vm.size = chunk_size;
- vm_area_register_early(&vm, unit_size);
-
- for (i = 0; i < pcpul_nr_lpages; i++) {
- if (!pcpul_map[i].ptr)
- continue;
- pcpul_map[i].map_addr = vm.addr + i * lpage_size;
- map_fn(pcpul_map[i].ptr, lpage_size, pcpul_map[i].map_addr);
- }
-
- for_each_possible_cpu(cpu)
- memcpy(vm.addr + unit_map[cpu] * unit_size, __per_cpu_load,
- static_size);
-
- /* we're ready, commit */
- pr_info("PERCPU: large pages @%p s%zu r%zu d%zu u%zu\n",
- vm.addr, static_size, reserved_size, dyn_size, unit_size);
-
- ret = pcpu_setup_first_chunk(static_size, reserved_size, dyn_size,
- unit_size, vm.addr, unit_map);
-
- /*
- * Sort pcpul_map array for pcpu_lpage_remapped(). Unmapped
- * lpages are pushed to the end and trimmed.
- */
- for (i = 0; i < pcpul_nr_lpages - 1; i++)
- for (j = i + 1; j < pcpul_nr_lpages; j++) {
- struct pcpul_ent tmp;
-
- if (!pcpul_map[j].ptr)
- continue;
- if (pcpul_map[i].ptr &&
- pcpul_map[i].ptr < pcpul_map[j].ptr)
- continue;
-
- tmp = pcpul_map[i];
- pcpul_map[i] = pcpul_map[j];
- pcpul_map[j] = tmp;
- }
-
- while (pcpul_nr_lpages && !pcpul_map[pcpul_nr_lpages - 1].ptr)
- pcpul_nr_lpages--;
-
- return ret;
-
-enomem:
- for (i = 0; i < pcpul_nr_lpages; i++)
- if (pcpul_map[i].ptr)
- free_fn(pcpul_map[i].ptr, lpage_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 large
- * page 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 large
- * page.
- *
- * RETURNS:
- * Address of corresponding remapped pcpu address if match is found;
- * otherwise, NULL.
- */
-void *pcpu_lpage_remapped(void *kaddr)
-{
- unsigned long lpage_mask = pcpul_lpage_size - 1;
- void *lpage_addr = (void *)((unsigned long)kaddr & ~lpage_mask);
- unsigned long offset = (unsigned long)kaddr & lpage_mask;
- int left = 0, right = pcpul_nr_lpages - 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 < lpage_addr)
- left = pos + 1;
- else if (pcpul_map[pos].ptr > lpage_addr)
- right = pos - 1;
- else
- return pcpul_map[pos].map_addr + offset;
- }
-
- return NULL;
-}
-#endif /* CONFIG_NEED_PER_CPU_LPAGE_FIRST_CHUNK */
-
/*
* Generic percpu area setup.
*
unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
EXPORT_SYMBOL(__per_cpu_offset);
+static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size,
+ size_t align)
+{
+ return __alloc_bootmem_nopanic(size, align, __pa(MAX_DMA_ADDRESS));
+}
+
+static void __init pcpu_dfl_fc_free(void *ptr, size_t size)
+{
+ free_bootmem(__pa(ptr), size);
+}
+
void __init setup_per_cpu_areas(void)
{
- size_t static_size = __per_cpu_end - __per_cpu_start;
- ssize_t unit_size;
unsigned long delta;
unsigned int cpu;
+ int rc;
/*
* Always reserve area for module percpu variables. That's
* what the legacy allocator did.
*/
- unit_size = pcpu_embed_first_chunk(static_size, PERCPU_MODULE_RESERVE,
- PERCPU_DYNAMIC_RESERVE);
- if (unit_size < 0)
+ rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
+ PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL,
+ pcpu_dfl_fc_alloc, pcpu_dfl_fc_free);
+ if (rc < 0)
panic("Failed to initialized percpu areas.");
delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
for_each_possible_cpu(cpu)
- __per_cpu_offset[cpu] = delta + cpu * unit_size;
+ __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
}
#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
Code Review / linux-3.10.git / blobdiff