+ 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
+ * @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
+ *
+ * Initialize the first percpu chunk which contains the kernel static
+ * perpcu area. This function is to be called from arch percpu area
+ * setup path.
+ *
+ * @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
+ * static areas on architectures where the addressing model has
+ * limited offset range for symbol relocations to guarantee module
+ * percpu symbols fall inside the relocatable range.
+ *
+ * @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.
+ *
+ * @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.
+ *
+ * If the first chunk ends up with both reserved and dynamic areas, it
+ * is served by two chunks - one to serve the core static and reserved
+ * areas and the other for the dynamic area. They share the same vm
+ * and page map but uses different area allocation map to stay away
+ * from each other. The latter chunk is circulated in the chunk slots
+ * and available for dynamic allocation like any other chunks.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
+ void *base_addr)
+{
+ static char cpus_buf[4096] __initdata;
+ static int smap[2], dmap[2];
+ 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 long *group_offsets;
+ size_t *group_sizes;
+ unsigned long *unit_off;