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authorYinghai Lu <yinghai@kernel.org>2010-02-16 18:40:35 -0800
committerH. Peter Anvin <hpa@zytor.com>2010-02-16 21:43:39 -0800
commit580e0ad21d6d6f932461d24b47041e3dd499c23f (patch)
tree3476c71849c0f9aa54c160b9a994bf4d211bd697 /kernel/early_res.c
parentdd645cee7b50b61cb2d05b59eb6027679c437af6 (diff)
downloadlinux-580e0ad21d6d6f932461d24b47041e3dd499c23f.tar.bz2
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>
Diffstat (limited to 'kernel/early_res.c')
-rw-r--r--kernel/early_res.c513
1 files changed, 513 insertions, 0 deletions
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;
+}