core: Move early_res from arch/x86 to kernel/

This makes the range reservation feature available to other
architectures.

-v2: add get_max_mapped, max_pfn_mapped only defined in x86...
     to fix PPC compiling
-v3: according to hpa, add CONFIG_HAVE_EARLY_RES
-v4: fix typo about EARLY_RES in config

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4B7B5723.4070009@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

2 files changed, 514 insertions, 0 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index ad47330ccf32..1292b863d667 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -11,6 +11,7 @@ obj-y     = sched.o fork.o exec_domain.o panic.o printk.o \
             hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
             notifier.o ksysfs.o pm_qos_params.o sched_clock.o cred.o \
             async.o range.o
+obj-$(CONFIG_HAVE_EARLY_RES) += early_res.o
 obj-y += groups.o
 
 ifdef CONFIG_FUNCTION_TRACER
diff --git a/kernel/early_res.c b/kernel/early_res.c
new file mode 100644
index 000000000000..aa5494ac4462
--- /dev/null
+++ b/kernel/early_res.c
@@ -0,0 +1,513 @@
+/*
+ * early_res, could be used to replace bootmem
+ */
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/mm.h>
+#include <linux/early_res.h>
+
+/*
+ * Early reserved memory areas.
+ */
+/*
+ * need to make sure this one is bigger enough before
+ * find_fw_memmap_area could be used
+ */
+#define MAX_EARLY_RES_X 32
+
+struct early_res {
+        u64 start, end;
+        char name[15];
+        char overlap_ok;
+};
+static struct early_res early_res_x[MAX_EARLY_RES_X] __initdata;
+
+static int max_early_res __initdata = MAX_EARLY_RES_X;
+static struct early_res *early_res __initdata = &early_res_x[0];
+static int early_res_count __initdata;
+
+static int __init find_overlapped_early(u64 start, u64 end)
+{
+        int i;
+        struct early_res *r;
+
+        for (i = 0; i < max_early_res && early_res[i].end; i++) {
+                r = &early_res[i];
+                if (end > r->start && start < r->end)
+                        break;
+        }
+
+        return i;
+}
+
+/*
+ * Drop the i-th range from the early reservation map,
+ * by copying any higher ranges down one over it, and
+ * clearing what had been the last slot.
+ */
+static void __init drop_range(int i)
+{
+        int j;
+
+        for (j = i + 1; j < max_early_res && early_res[j].end; j++)
+                ;
+
+        memmove(&early_res[i], &early_res[i + 1],
+               (j - 1 - i) * sizeof(struct early_res));
+
+        early_res[j - 1].end = 0;
+        early_res_count--;
+}
+
+/*
+ * Split any existing ranges that:
+ *  1) are marked 'overlap_ok', and
+ *  2) overlap with the stated range [start, end)
+ * into whatever portion (if any) of the existing range is entirely
+ * below or entirely above the stated range.  Drop the portion
+ * of the existing range that overlaps with the stated range,
+ * which will allow the caller of this routine to then add that
+ * stated range without conflicting with any existing range.
+ */
+static void __init drop_overlaps_that_are_ok(u64 start, u64 end)
+{
+        int i;
+        struct early_res *r;
+        u64 lower_start, lower_end;
+        u64 upper_start, upper_end;
+        char name[15];
+
+        for (i = 0; i < max_early_res && early_res[i].end; i++) {
+                r = &early_res[i];
+
+                /* Continue past non-overlapping ranges */
+                if (end <= r->start || start >= r->end)
+                        continue;
+
+                /*
+                 * Leave non-ok overlaps as is; let caller
+                 * panic "Overlapping early reservations"
+                 * when it hits this overlap.
+                 */
+                if (!r->overlap_ok)
+                        return;
+
+                /*
+                 * We have an ok overlap.  We will drop it from the early
+                 * reservation map, and add back in any non-overlapping
+                 * portions (lower or upper) as separate, overlap_ok,
+                 * non-overlapping ranges.
+                 */
+
+                /* 1. Note any non-overlapping (lower or upper) ranges. */
+                strncpy(name, r->name, sizeof(name) - 1);
+
+                lower_start = lower_end = 0;
+                upper_start = upper_end = 0;
+                if (r->start < start) {
+                        lower_start = r->start;
+                        lower_end = start;
+                }
+                if (r->end > end) {
+                        upper_start = end;
+                        upper_end = r->end;
+                }
+
+                /* 2. Drop the original ok overlapping range */
+                drop_range(i);
+
+                i--;            /* resume for-loop on copied down entry */
+
+                /* 3. Add back in any non-overlapping ranges. */
+                if (lower_end)
+                        reserve_early_overlap_ok(lower_start, lower_end, name);
+                if (upper_end)
+                        reserve_early_overlap_ok(upper_start, upper_end, name);
+        }
+}
+
+static void __init __reserve_early(u64 start, u64 end, char *name,
+                                                int overlap_ok)
+{
+        int i;
+        struct early_res *r;
+
+        i = find_overlapped_early(start, end);
+        if (i >= max_early_res)
+                panic("Too many early reservations");
+        r = &early_res[i];
+        if (r->end)
+                panic("Overlapping early reservations "
+                      "%llx-%llx %s to %llx-%llx %s\n",
+                      start, end - 1, name ? name : "", r->start,
+                      r->end - 1, r->name);
+        r->start = start;
+        r->end = end;
+        r->overlap_ok = overlap_ok;
+        if (name)
+                strncpy(r->name, name, sizeof(r->name) - 1);
+        early_res_count++;
+}
+
+/*
+ * A few early reservtations come here.
+ *
+ * The 'overlap_ok' in the name of this routine does -not- mean it
+ * is ok for these reservations to overlap an earlier reservation.
+ * Rather it means that it is ok for subsequent reservations to
+ * overlap this one.
+ *
+ * Use this entry point to reserve early ranges when you are doing
+ * so out of "Paranoia", reserving perhaps more memory than you need,
+ * just in case, and don't mind a subsequent overlapping reservation
+ * that is known to be needed.
+ *
+ * The drop_overlaps_that_are_ok() call here isn't really needed.
+ * It would be needed if we had two colliding 'overlap_ok'
+ * reservations, so that the second such would not panic on the
+ * overlap with the first.  We don't have any such as of this
+ * writing, but might as well tolerate such if it happens in
+ * the future.
+ */
+void __init reserve_early_overlap_ok(u64 start, u64 end, char *name)
+{
+        drop_overlaps_that_are_ok(start, end);
+        __reserve_early(start, end, name, 1);
+}
+
+static void __init __check_and_double_early_res(u64 ex_start, u64 ex_end)
+{
+        u64 start, end, size, mem;
+        struct early_res *new;
+
+        /* do we have enough slots left ? */
+        if ((max_early_res - early_res_count) > max(max_early_res/8, 2))
+                return;
+
+        /* double it */
+        mem = -1ULL;
+        size = sizeof(struct early_res) * max_early_res * 2;
+        if (early_res == early_res_x)
+                start = 0;
+        else
+                start = early_res[0].end;
+        end = ex_start;
+        if (start + size < end)
+                mem = find_fw_memmap_area(start, end, size,
+                                         sizeof(struct early_res));
+        if (mem == -1ULL) {
+                start = ex_end;
+                end = get_max_mapped();
+                if (start + size < end)
+                        mem = find_fw_memmap_area(start, end, size,
+                                                 sizeof(struct early_res));
+        }
+        if (mem == -1ULL)
+                panic("can not find more space for early_res array");
+
+        new = __va(mem);
+        /* save the first one for own */
+        new[0].start = mem;
+        new[0].end = mem + size;
+        new[0].overlap_ok = 0;
+        /* copy old to new */
+        if (early_res == early_res_x) {
+                memcpy(&new[1], &early_res[0],
+                         sizeof(struct early_res) * max_early_res);
+                memset(&new[max_early_res+1], 0,
+                         sizeof(struct early_res) * (max_early_res - 1));
+                early_res_count++;
+        } else {
+                memcpy(&new[1], &early_res[1],
+                         sizeof(struct early_res) * (max_early_res - 1));
+                memset(&new[max_early_res], 0,
+                         sizeof(struct early_res) * max_early_res);
+        }
+        memset(&early_res[0], 0, sizeof(struct early_res) * max_early_res);
+        early_res = new;
+        max_early_res *= 2;
+        printk(KERN_DEBUG "early_res array is doubled to %d at [%llx - %llx]\n",
+                max_early_res, mem, mem + size - 1);
+}
+
+/*
+ * Most early reservations come here.
+ *
+ * We first have drop_overlaps_that_are_ok() drop any pre-existing
+ * 'overlap_ok' ranges, so that we can then reserve this memory
+ * range without risk of panic'ing on an overlapping overlap_ok
+ * early reservation.
+ */
+void __init reserve_early(u64 start, u64 end, char *name)
+{
+        if (start >= end)
+                return;
+
+        __check_and_double_early_res(start, end);
+
+        drop_overlaps_that_are_ok(start, end);
+        __reserve_early(start, end, name, 0);
+}
+
+void __init reserve_early_without_check(u64 start, u64 end, char *name)
+{
+        struct early_res *r;
+
+        if (start >= end)
+                return;
+
+        __check_and_double_early_res(start, end);
+
+        r = &early_res[early_res_count];
+
+        r->start = start;
+        r->end = end;
+        r->overlap_ok = 0;
+        if (name)
+                strncpy(r->name, name, sizeof(r->name) - 1);
+        early_res_count++;
+}
+
+void __init free_early(u64 start, u64 end)
+{
+        struct early_res *r;
+        int i;
+
+        i = find_overlapped_early(start, end);
+        r = &early_res[i];
+        if (i >= max_early_res || r->end != end || r->start != start)
+                panic("free_early on not reserved area: %llx-%llx!",
+                         start, end - 1);
+
+        drop_range(i);
+}
+
+#ifdef CONFIG_NO_BOOTMEM
+static void __init subtract_early_res(struct range *range, int az)
+{
+        int i, count;
+        u64 final_start, final_end;
+        int idx = 0;
+
+        count  = 0;
+        for (i = 0; i < max_early_res && early_res[i].end; i++)
+                count++;
+
+        /* need to skip first one ?*/
+        if (early_res != early_res_x)
+                idx = 1;
+
+#define DEBUG_PRINT_EARLY_RES 1
+
+#if DEBUG_PRINT_EARLY_RES
+        printk(KERN_INFO "Subtract (%d early reservations)\n", count);
+#endif
+        for (i = idx; i < count; i++) {
+                struct early_res *r = &early_res[i];
+#if DEBUG_PRINT_EARLY_RES
+                printk(KERN_INFO "  #%d [%010llx - %010llx] %15s\n", i,
+                        r->start, r->end, r->name);
+#endif
+                final_start = PFN_DOWN(r->start);
+                final_end = PFN_UP(r->end);
+                if (final_start >= final_end)
+                        continue;
+                subtract_range(range, az, final_start, final_end);
+        }
+
+}
+
+int __init get_free_all_memory_range(struct range **rangep, int nodeid)
+{
+        int i, count;
+        u64 start = 0, end;
+        u64 size;
+        u64 mem;
+        struct range *range;
+        int nr_range;
+
+        count  = 0;
+        for (i = 0; i < max_early_res && early_res[i].end; i++)
+                count++;
+
+        count *= 2;
+
+        size = sizeof(struct range) * count;
+        end = get_max_mapped();
+#ifdef MAX_DMA32_PFN
+        if (end > (MAX_DMA32_PFN << PAGE_SHIFT))
+                start = MAX_DMA32_PFN << PAGE_SHIFT;
+#endif
+        mem = find_fw_memmap_area(start, end, size, sizeof(struct range));
+        if (mem == -1ULL)
+                panic("can not find more space for range free");
+
+        range = __va(mem);
+        /* use early_node_map[] and early_res to get range array at first */
+        memset(range, 0, size);
+        nr_range = 0;
+
+        /* need to go over early_node_map to find out good range for node */
+        nr_range = add_from_early_node_map(range, count, nr_range, nodeid);
+#ifdef CONFIG_X86_32
+        subtract_range(range, count, max_low_pfn, -1ULL);
+#endif
+        subtract_early_res(range, count);
+        nr_range = clean_sort_range(range, count);
+
+        /* need to clear it ? */
+        if (nodeid == MAX_NUMNODES) {
+                memset(&early_res[0], 0,
+                         sizeof(struct early_res) * max_early_res);
+                early_res = NULL;
+                max_early_res = 0;
+        }
+
+        *rangep = range;
+        return nr_range;
+}
+#else
+void __init early_res_to_bootmem(u64 start, u64 end)
+{
+        int i, count;
+        u64 final_start, final_end;
+        int idx = 0;
+
+        count  = 0;
+        for (i = 0; i < max_early_res && early_res[i].end; i++)
+                count++;
+
+        /* need to skip first one ?*/
+        if (early_res != early_res_x)
+                idx = 1;
+
+        printk(KERN_INFO "(%d/%d early reservations) ==> bootmem [%010llx - %010llx]\n",
+                         count - idx, max_early_res, start, end);
+        for (i = idx; i < count; i++) {
+                struct early_res *r = &early_res[i];
+                printk(KERN_INFO "  #%d [%010llx - %010llx] %16s", i,
+                        r->start, r->end, r->name);
+                final_start = max(start, r->start);
+                final_end = min(end, r->end);
+                if (final_start >= final_end) {
+                        printk(KERN_CONT "\n");
+                        continue;
+                }
+                printk(KERN_CONT " ==> [%010llx - %010llx]\n",
+                        final_start, final_end);
+                reserve_bootmem_generic(final_start, final_end - final_start,
+                                BOOTMEM_DEFAULT);
+        }
+        /* clear them */
+        memset(&early_res[0], 0, sizeof(struct early_res) * max_early_res);
+        early_res = NULL;
+        max_early_res = 0;
+        early_res_count = 0;
+}
+#endif
+
+/* Check for already reserved areas */
+static inline int __init bad_addr(u64 *addrp, u64 size, u64 align)
+{
+        int i;
+        u64 addr = *addrp;
+        int changed = 0;
+        struct early_res *r;
+again:
+        i = find_overlapped_early(addr, addr + size);
+        r = &early_res[i];
+        if (i < max_early_res && r->end) {
+                *addrp = addr = round_up(r->end, align);
+                changed = 1;
+                goto again;
+        }
+        return changed;
+}
+
+/* Check for already reserved areas */
+static inline int __init bad_addr_size(u64 *addrp, u64 *sizep, u64 align)
+{
+        int i;
+        u64 addr = *addrp, last;
+        u64 size = *sizep;
+        int changed = 0;
+again:
+        last = addr + size;
+        for (i = 0; i < max_early_res && early_res[i].end; i++) {
+                struct early_res *r = &early_res[i];
+                if (last > r->start && addr < r->start) {
+                        size = r->start - addr;
+                        changed = 1;
+                        goto again;
+                }
+                if (last > r->end && addr < r->end) {
+                        addr = round_up(r->end, align);
+                        size = last - addr;
+                        changed = 1;
+                        goto again;
+                }
+                if (last <= r->end && addr >= r->start) {
+                        (*sizep)++;
+                        return 0;
+                }
+        }
+        if (changed) {
+                *addrp = addr;
+                *sizep = size;
+        }
+        return changed;
+}
+
+/*
+ * Find a free area with specified alignment in a specific range.
+ * only with the area.between start to end is active range from early_node_map
+ * so they are good as RAM
+ */
+u64 __init find_early_area(u64 ei_start, u64 ei_last, u64 start, u64 end,
+                         u64 size, u64 align)
+{
+        u64 addr, last;
+
+        addr = round_up(ei_start, align);
+        if (addr < start)
+                addr = round_up(start, align);
+        if (addr >= ei_last)
+                goto out;
+        while (bad_addr(&addr, size, align) && addr+size <= ei_last)
+                ;
+        last = addr + size;
+        if (last > ei_last)
+                goto out;
+        if (last > end)
+                goto out;
+
+        return addr;
+
+out:
+        return -1ULL;
+}
+
+u64 __init find_early_area_size(u64 ei_start, u64 ei_last, u64 start,
+                         u64 *sizep, u64 align)
+{
+        u64 addr, last;
+
+        addr = round_up(ei_start, align);
+        if (addr < start)
+                addr = round_up(start, align);
+        if (addr >= ei_last)
+                goto out;
+        *sizep = ei_last - addr;
+        while (bad_addr_size(&addr, sizep, align) && addr + *sizep <= ei_last)
+                ;
+        last = addr + *sizep;
+        if (last > ei_last)
+                goto out;
+
+        return addr;
+
+out:
+        return -1ULL;
+}