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[SPARC64]: Fix "mem=xxx" handling.

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We were not being careful enough.  When we trim the physical
memory areas, we have to make sure we don't remove the kernel
image or initial ramdisk image ranges.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2006-12-28 21:00:23 -08:00
parent bfff6e92a3
commit 6fc5bae797
1 changed files with 124 additions and 23 deletions
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147
arch/sparc64/mm/init.c
View file

@ -872,6 +872,115 @@ static unsigned long __init choose_bootmap_pfn(unsigned long start_pfn,
prom_halt();
}
static void __init trim_pavail(unsigned long *cur_size_p,
unsigned long *end_of_phys_p)
{
unsigned long to_trim = *cur_size_p - cmdline_memory_size;
unsigned long avoid_start, avoid_end;
int i;
to_trim = PAGE_ALIGN(to_trim);
avoid_start = avoid_end = 0;
#ifdef CONFIG_BLK_DEV_INITRD
avoid_start = initrd_start;
avoid_end = PAGE_ALIGN(initrd_end);
#endif
/* Trim some pavail[] entries in order to satisfy the
* requested "mem=xxx" kernel command line specification.
*
* We must not trim off the kernel image area nor the
* initial ramdisk range (if any). Also, we must not trim
* any pavail[] entry down to zero in order to preserve
* the invariant that all pavail[] entries have a non-zero
* size which is assumed by all of the code in here.
*/
for (i = 0; i < pavail_ents; i++) {
unsigned long start, end, kern_end;
unsigned long trim_low, trim_high, n;
kern_end = PAGE_ALIGN(kern_base + kern_size);
trim_low = start = pavail[i].phys_addr;
trim_high = end = start + pavail[i].reg_size;
if (kern_base >= start &&
kern_base < end) {
trim_low = kern_base;
if (kern_end >= end)
continue;
}
if (kern_end >= start &&
kern_end < end) {
trim_high = kern_end;
}
if (avoid_start &&
avoid_start >= start &&
avoid_start < end) {
if (trim_low > avoid_start)
trim_low = avoid_start;
if (avoid_end >= end)
continue;
}
if (avoid_end &&
avoid_end >= start &&
avoid_end < end) {
if (trim_high < avoid_end)
trim_high = avoid_end;
}
if (trim_high <= trim_low)
continue;
if (trim_low == start && trim_high == end) {
/* Whole chunk is available for trimming.
* Trim all except one page, in order to keep
* entry non-empty.
*/
n = (end - start) - PAGE_SIZE;
if (n > to_trim)
n = to_trim;
if (n) {
pavail[i].phys_addr += n;
pavail[i].reg_size -= n;
to_trim -= n;
}
} else {
n = (trim_low - start);
if (n > to_trim)
n = to_trim;
if (n) {
pavail[i].phys_addr += n;
pavail[i].reg_size -= n;
to_trim -= n;
}
if (to_trim) {
n = end - trim_high;
if (n > to_trim)
n = to_trim;
if (n) {
pavail[i].reg_size -= n;
to_trim -= n;
}
}
}
if (!to_trim)
break;
}
/* Recalculate. */
*cur_size_p = 0UL;
for (i = 0; i < pavail_ents; i++) {
*end_of_phys_p = pavail[i].phys_addr +
pavail[i].reg_size;
*cur_size_p += pavail[i].reg_size;
}
}
static unsigned long __init bootmem_init(unsigned long *pages_avail,
unsigned long phys_base)
{
@ -889,31 +998,13 @@ static unsigned long __init bootmem_init(unsigned long *pages_avail,
end_of_phys_memory = pavail[i].phys_addr +
pavail[i].reg_size;
bytes_avail += pavail[i].reg_size;
if (cmdline_memory_size) {
if (bytes_avail > cmdline_memory_size) {
unsigned long slack = bytes_avail - cmdline_memory_size;
bytes_avail -= slack;
end_of_phys_memory -= slack;
pavail[i].reg_size -= slack;
if ((long)pavail[i].reg_size <= 0L) {
pavail[i].phys_addr = 0xdeadbeefUL;
pavail[i].reg_size = 0UL;
pavail_ents = i;
} else {
pavail[i+1].reg_size = 0Ul;
pavail[i+1].phys_addr = 0xdeadbeefUL;
pavail_ents = i + 1;
}
break;
}
}
}
*pages_avail = bytes_avail >> PAGE_SHIFT;
end_pfn = end_of_phys_memory >> PAGE_SHIFT;
/* Determine the location of the initial ramdisk before trying
* to honor the "mem=xxx" command line argument. We must know
* where the kernel image and the ramdisk image are so that we
* do not trim those two areas from the physical memory map.
*/
#ifdef CONFIG_BLK_DEV_INITRD
/* Now have to check initial ramdisk, so that bootmap does not overwrite it */
@ -932,6 +1023,16 @@ static unsigned long __init bootmem_init(unsigned long *pages_avail,
}
}
#endif
if (cmdline_memory_size &&
bytes_avail > cmdline_memory_size)
trim_pavail(&bytes_avail,
&end_of_phys_memory);
*pages_avail = bytes_avail >> PAGE_SHIFT;
end_pfn = end_of_phys_memory >> PAGE_SHIFT;
/* Initialize the boot-time allocator. */
max_pfn = max_low_pfn = end_pfn;
min_low_pfn = (phys_base >> PAGE_SHIFT);