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Kernel v2.6.26-rc1 /lib/lmb.c

Filename:/lib/lmb.c
Lines Added:509
Lines Deleted:0
Also changed in: (Previous) 2.6.25-git20  2.6.25-git19  2.6.25-git18  2.6.25-git17  2.6.25-git16  2.6.25-git15 
(Following) 2.6.26-rc2  2.6.26-rc2-git4  2.6.26-rc2-git5  2.6.26-rc3  2.6.26-rc3-git2  2.6.26-rc3-git3 

Location
[  2.6.26-rc1
  [  lib
     o  lmb.c

Patch

diff --git a/lib/lmb.c b/lib/lmb.c
new file mode 100644
index 0000000..83287d3
--- /dev/null
+++ b/lib/lmb.c
@@ -0,0 +1,509 @@
+/*
+ * Procedures for maintaining information about logical memory blocks.
+ *
+ * Peter Bergner, IBM Corp.   June 2001.
+ * Copyright (C) 2001 Peter Bergner.
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/lmb.h>
+
+#define LMB_ALLOC_ANYWHERE   0
+
+struct lmb lmb;
+
+void lmb_dump_all(void)
+{
+#ifdef DEBUG
+   unsigned long i;
+
+   pr_debug("lmb_dump_all:\n");
+   pr_debug("    memory.cnt        = 0x%lx\n", lmb.memory.cnt);
+   pr_debug("    memory.size        = 0x%llx\n",
+       (unsigned long long)lmb.memory.size);
+   for (i=0; i < lmb.memory.cnt ;i++) {
+      pr_debug("    memory.region[0x%x].base       = 0x%llx\n",
+          i, (unsigned long long)lmb.memory.region[i].base);
+      pr_debug("            .size     = 0x%llx\n",
+          (unsigned long long)lmb.memory.region[i].size);
+   }
+
+   pr_debug("    reserved.cnt     = 0x%lx\n", lmb.reserved.cnt);
+   pr_debug("    reserved.size     = 0x%lx\n", lmb.reserved.size);
+   for (i=0; i < lmb.reserved.cnt ;i++) {
+      pr_debug("    reserved.region[0x%x].base       = 0x%llx\n",
+          i, (unsigned long long)lmb.reserved.region[i].base);
+      pr_debug("            .size     = 0x%llx\n",
+          (unsigned long long)lmb.reserved.region[i].size);
+   }
+#endif /* DEBUG */
+}
+
+static unsigned long lmb_addrs_overlap(u64 base1, u64 size1, u64 base2,
+               u64 size2)
+{
+   return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
+}
+
+static long lmb_addrs_adjacent(u64 base1, u64 size1, u64 base2, u64 size2)
+{
+   if (base2 == base1 + size1)
+      return 1;
+   else if (base1 == base2 + size2)
+      return -1;
+
+   return 0;
+}
+
+static long lmb_regions_adjacent(struct lmb_region *rgn,
+      unsigned long r1, unsigned long r2)
+{
+   u64 base1 = rgn->region[r1].base;
+   u64 size1 = rgn->region[r1].size;
+   u64 base2 = rgn->region[r2].base;
+   u64 size2 = rgn->region[r2].size;
+
+   return lmb_addrs_adjacent(base1, size1, base2, size2);
+}
+
+static void lmb_remove_region(struct lmb_region *rgn, unsigned long r)
+{
+   unsigned long i;
+
+   for (i = r; i < rgn->cnt - 1; i++) {
+      rgn->region[i].base = rgn->region[i + 1].base;
+      rgn->region[i].size = rgn->region[i + 1].size;
+   }
+   rgn->cnt--;
+}
+
+/* Assumption: base addr of region 1 < base addr of region 2 */
+static void lmb_coalesce_regions(struct lmb_region *rgn,
+      unsigned long r1, unsigned long r2)
+{
+   rgn->region[r1].size += rgn->region[r2].size;
+   lmb_remove_region(rgn, r2);
+}
+
+void __init lmb_init(void)
+{
+   /* Create a dummy zero size LMB which will get coalesced away later.
+    * This simplifies the lmb_add() code below...
+    */
+   lmb.memory.region[0].base = 0;
+   lmb.memory.region[0].size = 0;
+   lmb.memory.cnt = 1;
+
+   /* Ditto. */
+   lmb.reserved.region[0].base = 0;
+   lmb.reserved.region[0].size = 0;
+   lmb.reserved.cnt = 1;
+}
+
+void __init lmb_analyze(void)
+{
+   int i;
+
+   lmb.memory.size = 0;
+
+   for (i = 0; i < lmb.memory.cnt; i++)
+      lmb.memory.size += lmb.memory.region[i].size;
+}
+
+static long lmb_add_region(struct lmb_region *rgn, u64 base, u64 size)
+{
+   unsigned long coalesced = 0;
+   long adjacent, i;
+
+   if ((rgn->cnt == 1) && (rgn->region[0].size == 0)) {
+      rgn->region[0].base = base;
+      rgn->region[0].size = size;
+      return 0;
+   }
+
+   /* First try and coalesce this LMB with another. */
+   for (i = 0; i < rgn->cnt; i++) {
+      u64 rgnbase = rgn->region[i].base;
+      u64 rgnsize = rgn->region[i].size;
+
+      if ((rgnbase == base) && (rgnsize == size))
+         /* Already have this region, so we're done */
+         return 0;
+
+      adjacent = lmb_addrs_adjacent(base, size, rgnbase, rgnsize);
+      if (adjacent > 0) {
+         rgn->region[i].base -= size;
+         rgn->region[i].size += size;
+         coalesced++;
+         break;
+      } else if (adjacent < 0) {
+         rgn->region[i].size += size;
+         coalesced++;
+         break;
+      }
+   }
+
+   if ((i < rgn->cnt - 1) && lmb_regions_adjacent(rgn, i, i+1)) {
+      lmb_coalesce_regions(rgn, i, i+1);
+      coalesced++;
+   }
+
+   if (coalesced)
+      return coalesced;
+   if (rgn->cnt >= MAX_LMB_REGIONS)
+      return -1;
+
+   /* Couldn't coalesce the LMB, so add it to the sorted table. */
+   for (i = rgn->cnt - 1; i >= 0; i--) {
+      if (base < rgn->region[i].base) {
+         rgn->region[i+1].base = rgn->region[i].base;
+         rgn->region[i+1].size = rgn->region[i].size;
+      } else {
+         rgn->region[i+1].base = base;
+         rgn->region[i+1].size = size;
+         break;
+      }
+   }
+
+   if (base < rgn->region[0].base) {
+      rgn->region[0].base = base;
+      rgn->region[0].size = size;
+   }
+   rgn->cnt++;
+
+   return 0;
+}
+
+long lmb_add(u64 base, u64 size)
+{
+   struct lmb_region *_rgn = &lmb.memory;
+
+   /* On pSeries LPAR systems, the first LMB is our RMO region. */
+   if (base == 0)
+      lmb.rmo_size = size;
+
+   return lmb_add_region(_rgn, base, size);
+
+}
+
+long lmb_remove(u64 base, u64 size)
+{
+   struct lmb_region *rgn = &(lmb.memory);
+   u64 rgnbegin, rgnend;
+   u64 end = base + size;
+   int i;
+
+   rgnbegin = rgnend = 0; /* supress gcc warnings */
+
+   /* Find the region where (base, size) belongs to */
+   for (i=0; i < rgn->cnt; i++) {
+      rgnbegin = rgn->region[i].base;
+      rgnend = rgnbegin + rgn->region[i].size;
+
+      if ((rgnbegin <= base) && (end <= rgnend))
+         break;
+   }
+
+   /* Didn't find the region */
+   if (i == rgn->cnt)
+      return -1;
+
+   /* Check to see if we are removing entire region */
+   if ((rgnbegin == base) && (rgnend == end)) {
+      lmb_remove_region(rgn, i);
+      return 0;
+   }
+
+   /* Check to see if region is matching at the front */
+   if (rgnbegin == base) {
+      rgn->region[i].base = end;
+      rgn->region[i].size -= size;
+      return 0;
+   }
+
+   /* Check to see if the region is matching at the end */
+   if (rgnend == end) {
+      rgn->region[i].size -= size;
+      return 0;
+   }
+
+   /*
+    * We need to split the entry -  adjust the current one to the
+    * beginging of the hole and add the region after hole.
+    */
+   rgn->region[i].size = base - rgn->region[i].base;
+   return lmb_add_region(rgn, end, rgnend - end);
+}
+
+long __init lmb_reserve(u64 base, u64 size)
+{
+   struct lmb_region *_rgn = &lmb.reserved;
+
+   BUG_ON(0 == size);
+
+   return lmb_add_region(_rgn, base, size);
+}
+
+long __init lmb_overlaps_region(struct lmb_region *rgn, u64 base, u64 size)
+{
+   unsigned long i;
+
+   for (i = 0; i < rgn->cnt; i++) {
+      u64 rgnbase = rgn->region[i].base;
+      u64 rgnsize = rgn->region[i].size;
+      if (lmb_addrs_overlap(base, size, rgnbase, rgnsize))
+         break;
+   }
+
+   return (i < rgn->cnt) ? i : -1;
+}
+
+static u64 lmb_align_down(u64 addr, u64 size)
+{
+   return addr & ~(size - 1);
+}
+
+static u64 lmb_align_up(u64 addr, u64 size)
+{
+   return (addr + (size - 1)) & ~(size - 1);
+}
+
+static u64 __init lmb_alloc_nid_unreserved(u64 start, u64 end,
+                  u64 size, u64 align)
+{
+   u64 base, res_base;
+   long j;
+
+   base = lmb_align_down((end - size), align);
+   while (start <= base) {
+      j = lmb_overlaps_region(&lmb.reserved, base, size);
+      if (j < 0) {
+         /* this area isn't reserved, take it */
+         if (lmb_add_region(&lmb.reserved, base,
+                  lmb_align_up(size, align)) < 0)
+            base = ~(u64)0;
+         return base;
+      }
+      res_base = lmb.reserved.region[j].base;
+      if (res_base < size)
+         break;
+      base = lmb_align_down(res_base - size, align);
+   }
+
+   return ~(u64)0;
+}
+
+static u64 __init lmb_alloc_nid_region(struct lmb_property *mp,
+                   u64 (*nid_range)(u64, u64, int *),
+                   u64 size, u64 align, int nid)
+{
+   u64 start, end;
+
+   start = mp->base;
+   end = start + mp->size;
+
+   start = lmb_align_up(start, align);
+   while (start < end) {
+      u64 this_end;
+      int this_nid;
+
+      this_end = nid_range(start, end, &this_nid);
+      if (this_nid == nid) {
+         u64 ret = lmb_alloc_nid_unreserved(start, this_end,
+                        size, align);
+         if (ret != ~(u64)0)
+            return ret;
+      }
+      start = this_end;
+   }
+
+   return ~(u64)0;
+}
+
+u64 __init lmb_alloc_nid(u64 size, u64 align, int nid,
+          u64 (*nid_range)(u64 start, u64 end, int *nid))
+{
+   struct lmb_region *mem = &lmb.memory;
+   int i;
+
+   for (i = 0; i < mem->cnt; i++) {
+      u64 ret = lmb_alloc_nid_region(&mem->region[i],
+                      nid_range,
+                      size, align, nid);
+      if (ret != ~(u64)0)
+         return ret;
+   }
+
+   return lmb_alloc(size, align);
+}
+
+u64 __init lmb_alloc(u64 size, u64 align)
+{
+   return lmb_alloc_base(size, align, LMB_ALLOC_ANYWHERE);
+}
+
+u64 __init lmb_alloc_base(u64 size, u64 align, u64 max_addr)
+{
+   u64 alloc;
+
+   alloc = __lmb_alloc_base(size, align, max_addr);
+
+   if (alloc == 0)
+      panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
+            (unsigned long long) size, (unsigned long long) max_addr);
+
+   return alloc;
+}
+
+u64 __init __lmb_alloc_base(u64 size, u64 align, u64 max_addr)
+{
+   long i, j;
+   u64 base = 0;
+   u64 res_base;
+
+   BUG_ON(0 == size);
+
+   /* On some platforms, make sure we allocate lowmem */
+   /* Note that LMB_REAL_LIMIT may be LMB_ALLOC_ANYWHERE */
+   if (max_addr == LMB_ALLOC_ANYWHERE)
+      max_addr = LMB_REAL_LIMIT;
+
+   for (i = lmb.memory.cnt - 1; i >= 0; i--) {
+      u64 lmbbase = lmb.memory.region[i].base;
+      u64 lmbsize = lmb.memory.region[i].size;
+
+      if (lmbsize < size)
+         continue;
+      if (max_addr == LMB_ALLOC_ANYWHERE)
+         base = lmb_align_down(lmbbase + lmbsize - size, align);
+      else if (lmbbase < max_addr) {
+         base = min(lmbbase + lmbsize, max_addr);
+         base = lmb_align_down(base - size, align);
+      } else
+         continue;
+
+      while (base && lmbbase <= base) {
+         j = lmb_overlaps_region(&lmb.reserved, base, size);
+         if (j < 0) {
+            /* this area isn't reserved, take it */
+            if (lmb_add_region(&lmb.reserved, base,
+                     lmb_align_up(size, align)) < 0)
+               return 0;
+            return base;
+         }
+         res_base = lmb.reserved.region[j].base;
+         if (res_base < size)
+            break;
+         base = lmb_align_down(res_base - size, align);
+      }
+   }
+   return 0;
+}
+
+/* You must call lmb_analyze() before this. */
+u64 __init lmb_phys_mem_size(void)
+{
+   return lmb.memory.size;
+}
+
+u64 __init lmb_end_of_DRAM(void)
+{
+   int idx = lmb.memory.cnt - 1;
+
+   return (lmb.memory.region[idx].base + lmb.memory.region[idx].size);
+}
+
+/* You must call lmb_analyze() after this. */
+void __init lmb_enforce_memory_limit(u64 memory_limit)
+{
+   unsigned long i;
+   u64 limit;
+   struct lmb_property *p;
+
+   if (!memory_limit)
+      return;
+
+   /* Truncate the lmb regions to satisfy the memory limit. */
+   limit = memory_limit;
+   for (i = 0; i < lmb.memory.cnt; i++) {
+      if (limit > lmb.memory.region[i].size) {
+         limit -= lmb.memory.region[i].size;
+         continue;
+      }
+
+      lmb.memory.region[i].size = limit;
+      lmb.memory.cnt = i + 1;
+      break;
+   }
+
+   if (lmb.memory.region[0].size < lmb.rmo_size)
+      lmb.rmo_size = lmb.memory.region[0].size;
+
+   /* And truncate any reserves above the limit also. */
+   for (i = 0; i < lmb.reserved.cnt; i++) {
+      p = &lmb.reserved.region[i];
+
+      if (p->base > memory_limit)
+         p->size = 0;
+      else if ((p->base + p->size) > memory_limit)
+         p->size = memory_limit - p->base;
+
+      if (p->size == 0) {
+         lmb_remove_region(&lmb.reserved, i);
+         i--;
+      }
+   }
+}
+
+int __init lmb_is_reserved(u64 addr)
+{
+   int i;
+
+   for (i = 0; i < lmb.reserved.cnt; i++) {
+      u64 upper = lmb.reserved.region[i].base +
+         lmb.reserved.region[i].size - 1;
+      if ((addr >= lmb.reserved.region[i].base) && (addr <= upper))
+         return 1;
+   }
+   return 0;
+}
+
+/*
+ * Given a <base, len>, find which memory regions belong to this range.
+ * Adjust the request and return a contiguous chunk.
+ */
+int lmb_find(struct lmb_property *res)
+{
+   int i;
+   u64 rstart, rend;
+
+   rstart = res->base;
+   rend = rstart + res->size - 1;
+
+   for (i = 0; i < lmb.memory.cnt; i++) {
+      u64 start = lmb.memory.region[i].base;
+      u64 end = start + lmb.memory.region[i].size - 1;
+
+      if (start > rend)
+         return -1;
+
+      if ((end >= rstart) && (start < rend)) {
+         /* adjust the request */
+         if (rstart < start)
+            rstart = start;
+         if (rend > end)
+            rend = end;
+         res->base = rstart;
+         res->size = rend - rstart + 1;
+         return 0;
+      }
+   }
+   return -1;
+}


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