percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward

Unit map handling will be generalized and extended and used for
embedding sparse first chunk and other purposes.  Relocate two
unit_map related functions upward in preparation.  This patch just
moves the code without any actual change.

Signed-off-by: Tejun Heo <tj@kernel.org>

2 files changed, 180 insertions, 173 deletions

diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index d385dbcf190b..570fb18de2ba 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -78,6 +78,14 @@ typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
 typedef void (*pcpu_fc_map_fn_t)(void *ptr, size_t size, void *addr);
 
+#ifdef CONFIG_NEED_PER_CPU_LPAGE_FIRST_CHUNK
+extern int __init pcpu_lpage_build_unit_map(
+                                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);
+#endif
+
 extern size_t __init pcpu_setup_first_chunk(
                                 size_t static_size, size_t reserved_size,
                                 size_t dyn_size, size_t unit_size,
@@ -97,12 +105,6 @@ extern ssize_t __init pcpu_page_first_chunk(
 #endif
 
 #ifdef CONFIG_NEED_PER_CPU_LPAGE_FIRST_CHUNK
-extern int __init pcpu_lpage_build_unit_map(
-                                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);
-
 extern ssize_t __init pcpu_lpage_first_chunk(
                                 size_t reserved_size, size_t dyn_size,
                                 size_t unit_size, size_t lpage_size,
diff --git a/mm/percpu.c b/mm/percpu.c
index 3316e3aac7ee..2b9c4b2a2fc0 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1231,6 +1231,178 @@ void free_percpu(void *ptr)
 }
 EXPORT_SYMBOL_GPL(free_percpu);
 
+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;
+}
+
+#ifdef CONFIG_NEED_PER_CPU_LPAGE_FIRST_CHUNK
+/**
+ * pcpu_lpage_build_unit_map - build unit_map for large page remapping
+ * @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 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;
+        const size_t static_size = __per_cpu_end - __per_cpu_start;
+        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 */
+}
+
+static bool __init pcpul_unit_to_cpu(int unit, const int *unit_map,
+                                     unsigned int *cpup);
+
+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");
+}
+#endif
+
 /**
  * pcpu_setup_first_chunk - initialize the first percpu chunk
  * @static_size: the size of static percpu area in bytes
@@ -1441,20 +1613,6 @@ static int __init percpu_alloc_setup(char *str)
 }
 early_param("percpu_alloc", percpu_alloc_setup);
 
-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;
-}
-
 #if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \
         !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
 /**
@@ -1637,122 +1795,6 @@ out_free_ar:
 #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
- * @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 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;
-        const size_t static_size = __per_cpu_end - __per_cpu_start;
-        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;
@@ -1778,43 +1820,6 @@ static bool __init pcpul_unit_to_cpu(int unit, const int *unit_map,
         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
  * @reserved_size: the size of reserved percpu area in bytes