Commit 4e82c9a6 authored by David S. Miller's avatar David S. Miller
Browse files

[SPARC64]: Move ramdisk discovery code out to seperate function. 



And add some comments explaining all of the quirks involved in
the way the bootloader provides this information.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7347aefb

arch/sparc64/mm/init.c

+33 −24
Original line number Diff line number Diff line
@@ -883,6 +883,37 @@ static void __init trim_pavail(unsigned long *cur_size_p, 
	}

}



static void __init find_ramdisk(unsigned long phys_base)

{

#ifdef CONFIG_BLK_DEV_INITRD

	if (sparc_ramdisk_image || sparc_ramdisk_image64) {

		unsigned long ramdisk_image;



		/* Older versions of the bootloader only supported a

		 * 32-bit physical address for the ramdisk image

		 * location, stored at sparc_ramdisk_image.  Newer

		 * SILO versions set sparc_ramdisk_image to zero and

		 * provide a full 64-bit physical address at

		 * sparc_ramdisk_image64.

		 */

		ramdisk_image = sparc_ramdisk_image;

		if (!ramdisk_image)

			ramdisk_image = sparc_ramdisk_image64;



		/* Another bootloader quirk.  The bootloader normalizes

		 * the physical address to KERNBASE, so we have to

		 * factor that back out and add in the lowest valid

		 * physical page address to get the true physical address.

		 */

		ramdisk_image -= KERNBASE;

		ramdisk_image += phys_base;



		initrd_start = ramdisk_image;

		initrd_end = ramdisk_image + sparc_ramdisk_size;

	}

#endif

}



/* About pages_avail, this is the value we will use to calculate

 * the zholes_size[] argument given to free_area_init_node().  The

 * page allocator uses this to calculate nr_kernel_pages,
@@ -912,30 +943,6 @@ static unsigned long __init bootmem_init(unsigned long *pages_avail, 
		bytes_avail += pavail[i].reg_size;

	}



	/* 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 */

	if (sparc_ramdisk_image || sparc_ramdisk_image64) {

		unsigned long ramdisk_image = sparc_ramdisk_image ?

			sparc_ramdisk_image : sparc_ramdisk_image64;

		ramdisk_image -= KERNBASE;

		initrd_start = ramdisk_image + phys_base;

		initrd_end = initrd_start + sparc_ramdisk_size;

		if (initrd_end > end_of_phys_memory) {

			printk(KERN_CRIT "initrd extends beyond end of memory "

		                 	 "(0x%016lx > 0x%016lx)\ndisabling initrd\n",

			       initrd_end, end_of_phys_memory);

			initrd_start = 0;

			initrd_end = 0;

		}

	}

#endif	



	if (cmdline_memory_size &&

	    bytes_avail > cmdline_memory_size)

		trim_pavail(&bytes_avail,
@@ -1337,6 +1344,8 @@ void __init paging_init(void) 
	for (i = 0; i < pavail_ents; i++)

		phys_base = min(phys_base, pavail[i].phys_addr);



	find_ramdisk(phys_base);



	set_bit(0, mmu_context_bmap);



	shift = kern_base + PAGE_OFFSET - ((unsigned long)KERNBASE);