Commit 6fc5bae7 authored by David S. Miller's avatar David S. Miller
Browse files

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



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: default avatarDavid S. Miller <davem@davemloft.net>
parent bfff6e92

arch/sparc64/mm/init.c

+124 −23
Original line number Diff line number Diff line
@@ -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);

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