Commit da3922ef authored by Dave Jones's avatar Dave Jones Committed by Linus Torvalds

[PATCH] Handle empty E820 regions correctly.

parent bde1c93c
......@@ -14,6 +14,9 @@
* Moved CPU detection code to cpu/${cpu}.c
* Patrick Mochel <mochel@osdl.org>, March 2002
*
* Provisions for empty E820 memory regions (reported by certain BIOSes).
* Alex Achenbach <xela@slit.de>, December 2002.
*
*/
/*
......@@ -279,7 +282,7 @@ static int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
int chgidx, still_changing;
int overlap_entries;
int new_bios_entry;
int old_nr, new_nr;
int old_nr, new_nr, chg_nr;
int i;
/*
......@@ -333,20 +336,24 @@ static int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
for (i=0; i < 2*old_nr; i++)
change_point[i] = &change_point_list[i];
/* record all known change-points (starting and ending addresses) */
/* record all known change-points (starting and ending addresses),
omitting those that are for empty memory regions */
chgidx = 0;
for (i=0; i < old_nr; i++) {
if (biosmap[i].size != 0) {
change_point[chgidx]->addr = biosmap[i].addr;
change_point[chgidx++]->pbios = &biosmap[i];
change_point[chgidx]->addr = biosmap[i].addr + biosmap[i].size;
change_point[chgidx++]->pbios = &biosmap[i];
}
}
chg_nr = chgidx; /* true number of change-points */
/* sort change-point list by memory addresses (low -> high) */
still_changing = 1;
while (still_changing) {
still_changing = 0;
for (i=1; i < 2*old_nr; i++) {
for (i=1; i < chg_nr; i++) {
/* if <current_addr> > <last_addr>, swap */
/* or, if current=<start_addr> & last=<end_addr>, swap */
if ((change_point[i]->addr < change_point[i-1]->addr) ||
......@@ -369,7 +376,7 @@ static int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map)
last_type = 0; /* start with undefined memory type */
last_addr = 0; /* start with 0 as last starting address */
/* loop through change-points, determining affect on the new bios map */
for (chgidx=0; chgidx < 2*old_nr; chgidx++)
for (chgidx=0; chgidx < chg_nr; chgidx++)
{
/* keep track of all overlapping bios entries */
if (change_point[chgidx]->addr == change_point[chgidx]->pbios->addr)
......
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