[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>

diff --git a/mm/bootmem.c b/mm/bootmem.c
index e136c08..23c3317 100644 (file)
--- 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;