x86/boot/e820: Simplify e820__update_table()

 - Remove the now unnecessary __e820__update_table() wrappery

 - Move statics out from function scope, to make the logic clearer

 - Rename local variables to be more in line with the rest of 820.c

 - Remove unnecessary local variables: old_nr, *nr_entries

No change in functionality.

Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 2da2f7238a72b572d3e329829ef0e682ca32c7d5..e2fb20ac51351243060d22ab6918d32ec4ffc027 100644 (file)
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -235,6 +235,11 @@ struct change_member {
        unsigned long long      addr;
 };
 
+static struct change_member    change_point_list[2*E820_MAX_ENTRIES]   __initdata;
+static struct change_member    *change_point[2*E820_MAX_ENTRIES]       __initdata;
+static struct e820_entry       *overlap_list[E820_MAX_ENTRIES]         __initdata;
+static struct e820_entry       new_entries[E820_MAX_ENTRIES]           __initdata;
+
 static int __init cpcompare(const void *a, const void *b)
 {
        struct change_member * const *app = a, * const *bpp = b;
@@ -252,51 +257,46 @@ static int __init cpcompare(const void *a, const void *b)
        return (ap->addr != ap->entry->addr) - (bp->addr != bp->entry->addr);
 }
 
-static int __init __e820__update_table(struct e820_entry *entries, u32 max_nr_entries, u32 *nr_entries)
+int __init e820__update_table(struct e820_table *table)
 {
-       static struct change_member change_point_list[2*E820_MAX_ENTRIES] __initdata;
-       static struct change_member *change_point[2*E820_MAX_ENTRIES] __initdata;
-       static struct e820_entry *overlap_list[E820_MAX_ENTRIES] __initdata;
-       static struct e820_entry new_entries[E820_MAX_ENTRIES] __initdata;
+       struct e820_entry *entries = table->entries;
+       u32 max_nr_entries = ARRAY_SIZE(table->entries);
        enum e820_type current_type, last_type;
        unsigned long long last_addr;
-       u32 chgidx;
-       u32 overlap_entries;
-       u32 new_nr_entries;
-       u32 old_nr, new_nr, chg_nr;
-       u32 i;
+       u32 new_nr_entries, overlap_entries;
+       u32 i, chg_idx, chg_nr;
 
        /* If there's only one memory region, don't bother: */
-       if (*nr_entries < 2)
+       if (table->nr_entries < 2)
                return -1;
 
-       old_nr = *nr_entries;
-       BUG_ON(old_nr > max_nr_entries);
+       table->nr_entries = table->nr_entries;
+       BUG_ON(table->nr_entries > max_nr_entries);
 
        /* Bail out if we find any unreasonable addresses in the map: */
-       for (i = 0; i < old_nr; i++) {
+       for (i = 0; i < table->nr_entries; i++) {
                if (entries[i].addr + entries[i].size < entries[i].addr)
                        return -1;
        }
 
        /* Create pointers for initial change-point information (for sorting): */
-       for (i = 0; i < 2 * old_nr; i++)
+       for (i = 0; i < 2 * table->nr_entries; i++)
                change_point[i] = &change_point_list[i];
 
        /*
         * Record all known change-points (starting and ending addresses),
         * omitting empty memory regions:
         */
-       chgidx = 0;
-       for (i = 0; i < old_nr; i++)    {
+       chg_idx = 0;
+       for (i = 0; i < table->nr_entries; i++) {
                if (entries[i].size != 0) {
-                       change_point[chgidx]->addr      = entries[i].addr;
-                       change_point[chgidx++]->entry   = &entries[i];
-                       change_point[chgidx]->addr      = entries[i].addr + entries[i].size;
-                       change_point[chgidx++]->entry   = &entries[i];
+                       change_point[chg_idx]->addr     = entries[i].addr;
+                       change_point[chg_idx++]->entry  = &entries[i];
+                       change_point[chg_idx]->addr     = entries[i].addr + entries[i].size;
+                       change_point[chg_idx++]->entry  = &entries[i];
                }
        }
-       chg_nr = chgidx;
+       chg_nr = chg_idx;
 
        /* Sort change-point list by memory addresses (low -> high): */
        sort(change_point, chg_nr, sizeof(*change_point), cpcompare, NULL);
@@ -308,15 +308,15 @@ static int __init __e820__update_table(struct e820_entry *entries, u32 max_nr_en
        last_addr = 0;           /* Start with 0 as last starting address */
 
        /* Loop through change-points, determining effect on the new map: */
-       for (chgidx = 0; chgidx < chg_nr; chgidx++) {
+       for (chg_idx = 0; chg_idx < chg_nr; chg_idx++) {
                /* Keep track of all overlapping entries */
-               if (change_point[chgidx]->addr == change_point[chgidx]->entry->addr) {
+               if (change_point[chg_idx]->addr == change_point[chg_idx]->entry->addr) {
                        /* Add map entry to overlap list (> 1 entry implies an overlap) */
-                       overlap_list[overlap_entries++] = change_point[chgidx]->entry;
+                       overlap_list[overlap_entries++] = change_point[chg_idx]->entry;
                } else {
                        /* Remove entry from list (order independent, so swap with last): */
                        for (i = 0; i < overlap_entries; i++) {
-                               if (overlap_list[i] == change_point[chgidx]->entry)
+                               if (overlap_list[i] == change_point[chg_idx]->entry)
                                        overlap_list[i] = overlap_list[overlap_entries-1];
                        }
                        overlap_entries--;
@@ -335,7 +335,7 @@ static int __init __e820__update_table(struct e820_entry *entries, u32 max_nr_en
                /* Continue building up new map based on this information: */
                if (current_type != last_type || current_type == E820_TYPE_PRAM) {
                        if (last_type != 0)      {
-                               new_entries[new_nr_entries].size = change_point[chgidx]->addr - last_addr;
+                               new_entries[new_nr_entries].size = change_point[chg_idx]->addr - last_addr;
                                /* Move forward only if the new size was non-zero: */
                                if (new_entries[new_nr_entries].size != 0)
                                        /* No more space left for new entries? */
@@ -343,29 +343,21 @@ static int __init __e820__update_table(struct e820_entry *entries, u32 max_nr_en
                                                break;
                        }
                        if (current_type != 0)  {
-                               new_entries[new_nr_entries].addr = change_point[chgidx]->addr;
+                               new_entries[new_nr_entries].addr = change_point[chg_idx]->addr;
                                new_entries[new_nr_entries].type = current_type;
-                               last_addr = change_point[chgidx]->addr;
+                               last_addr = change_point[chg_idx]->addr;
                        }
                        last_type = current_type;
                }
        }
 
-       /* Retain count for the new entries: */
-       new_nr = new_nr_entries;
-
        /* Copy the new entries into the original location: */
-       memcpy(entries, new_entries, new_nr*sizeof(*entries));
-       *nr_entries = new_nr;
+       memcpy(entries, new_entries, new_nr_entries*sizeof(*entries));
+       table->nr_entries = new_nr_entries;
 
        return 0;
 }
 
-int __init e820__update_table(struct e820_table *table)
-{
-       return __e820__update_table(table->entries, ARRAY_SIZE(table->entries), &table->nr_entries);
-}
-
 static int __init __append_e820_table(struct boot_e820_entry *entries, u32 nr_entries)
 {
        struct boot_e820_entry *entry = entries;