[PATCH] bootmem: use pfn/page conversion macros

It also creates get_mapsize() helper in order to make the code more readable
when it calculates the boot bitmap size.

Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 45 insertions, 37 deletions

diff --git a/mm/bootmem.c b/mm/bootmem.c
index e136c086fd98..23c3317c09ed 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -9,6 +9,7 @@
  *  system memory and memory holes as well.
  */
 #include <linux/init.h>
+#include <linux/pfn.h>
 #include <linux/bootmem.h>
 #include <linux/module.h>
 
@@ -68,6 +69,18 @@ static void __init link_bootmem(bootmem_data_t *bdata)
         return;
 }
 
+/*
+ * Given an initialised bdata, it returns the size of the boot bitmap
+ */
+static unsigned long __init get_mapsize(bootmem_data_t *bdata)
+{
+        unsigned long mapsize;
+        unsigned long start = PFN_DOWN(bdata->node_boot_start);
+        unsigned long end = bdata->node_low_pfn;
+
+        mapsize = ((end - start) + 7) / 8;
+        return ALIGN(mapsize, sizeof(long));
+}
 
 /*
  * Called once to set up the allocator itself.
@@ -76,11 +89,10 @@ static unsigned long __init init_bootmem_core (pg_data_t *pgdat,
         unsigned long mapstart, unsigned long start, unsigned long end)
 {
         bootmem_data_t *bdata = pgdat->bdata;
-        unsigned long mapsize = ((end - start)+7)/8;
+        unsigned long mapsize;
 
-        mapsize = ALIGN(mapsize, sizeof(long));
-        bdata->node_bootmem_map = phys_to_virt(mapstart << PAGE_SHIFT);
-        bdata->node_boot_start = (start << PAGE_SHIFT);
+        bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart));
+        bdata->node_boot_start = PFN_PHYS(start);
         bdata->node_low_pfn = end;
         link_bootmem(bdata);
 
@@ -88,6 +100,7 @@ static unsigned long __init init_bootmem_core (pg_data_t *pgdat,
          * Initially all pages are reserved - setup_arch() has to
          * register free RAM areas explicitly.
          */
+        mapsize = get_mapsize(bdata);
         memset(bdata->node_bootmem_map, 0xff, mapsize);
 
         return mapsize;
@@ -101,20 +114,19 @@ static unsigned long __init init_bootmem_core (pg_data_t *pgdat,
 static void __init reserve_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
                                         unsigned long size)
 {
+        unsigned long sidx, eidx;
         unsigned long i;
+
         /*
          * round up, partially reserved pages are considered
          * fully reserved.
          */
-        unsigned long sidx = (addr - bdata->node_boot_start)/PAGE_SIZE;
-        unsigned long eidx = (addr + size - bdata->node_boot_start + 
-                                                        PAGE_SIZE-1)/PAGE_SIZE;
-        unsigned long end = (addr + size + PAGE_SIZE-1)/PAGE_SIZE;
-
         BUG_ON(!size);
-        BUG_ON(sidx >= eidx);
-        BUG_ON((addr >> PAGE_SHIFT) >= bdata->node_low_pfn);
-        BUG_ON(end > bdata->node_low_pfn);
+        BUG_ON(PFN_DOWN(addr) >= bdata->node_low_pfn);
+        BUG_ON(PFN_UP(addr + size) > bdata->node_low_pfn);
+
+        sidx = PFN_DOWN(addr - bdata->node_boot_start);
+        eidx = PFN_UP(addr + size - bdata->node_boot_start);
 
         for (i = sidx; i < eidx; i++)
                 if (test_and_set_bit(i, bdata->node_bootmem_map)) {
@@ -127,18 +139,15 @@ static void __init reserve_bootmem_core(bootmem_data_t *bdata, unsigned long add
 static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
                                      unsigned long size)
 {
+        unsigned long sidx, eidx;
         unsigned long i;
-        unsigned long start;
+
         /*
          * round down end of usable mem, partially free pages are
          * considered reserved.
          */
-        unsigned long sidx;
-        unsigned long eidx = (addr + size - bdata->node_boot_start)/PAGE_SIZE;
-        unsigned long end = (addr + size)/PAGE_SIZE;
-
         BUG_ON(!size);
-        BUG_ON(end > bdata->node_low_pfn);
+        BUG_ON(PFN_DOWN(addr + size) > bdata->node_low_pfn);
 
         if (addr < bdata->last_success)
                 bdata->last_success = addr;
@@ -146,8 +155,8 @@ static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
         /*
          * Round up the beginning of the address.
          */
-        start = (addr + PAGE_SIZE-1) / PAGE_SIZE;
-        sidx = start - (bdata->node_boot_start/PAGE_SIZE);
+        sidx = PFN_UP(addr) - PFN_DOWN(bdata->node_boot_start);
+        eidx = PFN_DOWN(addr + size - bdata->node_boot_start);
 
         for (i = sidx; i < eidx; i++) {
                 if (unlikely(!test_and_clear_bit(i, bdata->node_bootmem_map)))
@@ -173,7 +182,7 @@ __alloc_bootmem_core(struct bootmem_data *bdata, unsigned long size,
               unsigned long align, unsigned long goal, unsigned long limit)
 {
         unsigned long offset, remaining_size, areasize, preferred;
-        unsigned long i, start = 0, incr, eidx, end_pfn = bdata->node_low_pfn;
+        unsigned long i, start = 0, incr, eidx, end_pfn;
         void *ret;
 
         if(!size) {
@@ -185,23 +194,22 @@ __alloc_bootmem_core(struct bootmem_data *bdata, unsigned long size,
         if (limit && bdata->node_boot_start >= limit)
                 return NULL;
 
-        limit >>=PAGE_SHIFT;
+        end_pfn = bdata->node_low_pfn;
+        limit = PFN_DOWN(limit);
         if (limit && end_pfn > limit)
                 end_pfn = limit;
 
-        eidx = end_pfn - (bdata->node_boot_start >> PAGE_SHIFT);
+        eidx = end_pfn - PFN_DOWN(bdata->node_boot_start);
         offset = 0;
-        if (align &&
-            (bdata->node_boot_start & (align - 1UL)) != 0)
-                offset = (align - (bdata->node_boot_start & (align - 1UL)));
-        offset >>= PAGE_SHIFT;
+        if (align && (bdata->node_boot_start & (align - 1UL)) != 0)
+                offset = align - (bdata->node_boot_start & (align - 1UL));
+        offset = PFN_DOWN(offset);
 
         /*
          * We try to allocate bootmem pages above 'goal'
          * first, then we try to allocate lower pages.
          */
-        if (goal && (goal >= bdata->node_boot_start) && 
-            ((goal >> PAGE_SHIFT) < end_pfn)) {
+        if (goal && goal >= bdata->node_boot_start && PFN_DOWN(goal) < end_pfn) {
                 preferred = goal - bdata->node_boot_start;
 
                 if (bdata->last_success >= preferred)
@@ -210,9 +218,8 @@ __alloc_bootmem_core(struct bootmem_data *bdata, unsigned long size,
         } else
                 preferred = 0;
 
-        preferred = ALIGN(preferred, align) >> PAGE_SHIFT;
-        preferred += offset;
-        areasize = (size+PAGE_SIZE-1)/PAGE_SIZE;
+        preferred = PFN_DOWN(ALIGN(preferred, align)) + offset;
+        areasize = (size + PAGE_SIZE-1) / PAGE_SIZE;
         incr = align >> PAGE_SHIFT ? : 1;
 
 restart_scan:
@@ -243,7 +250,7 @@ restart_scan:
         return NULL;
 
 found:
-        bdata->last_success = start << PAGE_SHIFT;
+        bdata->last_success = PFN_PHYS(start);
         BUG_ON(start >= eidx);
 
         /*
@@ -301,8 +308,8 @@ static unsigned long __init free_all_bootmem_core(pg_data_t *pgdat)
 
         count = 0;
         /* first extant page of the node */
-        pfn = bdata->node_boot_start >> PAGE_SHIFT;
-        idx = bdata->node_low_pfn - (bdata->node_boot_start >> PAGE_SHIFT);
+        pfn = PFN_DOWN(bdata->node_boot_start);
+        idx = bdata->node_low_pfn - pfn;
         map = bdata->node_bootmem_map;
         /* Check physaddr is O(LOG2(BITS_PER_LONG)) page aligned */
         if (bdata->node_boot_start == 0 ||
@@ -343,9 +350,10 @@ static unsigned long __init free_all_bootmem_core(pg_data_t *pgdat)
          */
         page = virt_to_page(bdata->node_bootmem_map);
         count = 0;
-        for (i = 0; i < ((bdata->node_low_pfn-(bdata->node_boot_start >> PAGE_SHIFT))/8 + PAGE_SIZE-1)/PAGE_SIZE; i++,page++) {
-                count++;
+        idx = (get_mapsize(bdata) + PAGE_SIZE-1) >> PAGE_SHIFT;
+        for (i = 0; i < idx; i++, page++) {
                 __free_pages_bootmem(page, 0);
+                count++;
         }
         total += count;
         bdata->node_bootmem_map = NULL;