Commit 486df8bc authored by Andreas Schwab's avatar Andreas Schwab Committed by Geert Uytterhoeven
Browse files

m68k: Increase initial mapping to 8 or 16 MiB if possible 



If the size of the first memory chunk is at least 8 or 16 MiB increase the
initial mapping to 8 resp. 16 MiB instead of 4 MiB.
This makes it possible to
  1. Map more memory in the first node without running out of space for the
     page tables,
  2. Boot kernels that don't fit in 4 MiB (e.g. multi_defconfig).

Signed-off-by: default avatarAndreas Schwab <schwab@linux-m68k.org>

  - Add support for 8 MiB,
  - Store initial mapping size in head.S for later reuse,
  - Add comment about large kernels.

Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
parent 44074e89

arch/m68k/kernel/head.S

+17 −2
Original line number Diff line number Diff line
@@ -292,6 +292,7 @@ 


.globl kernel_pg_dir

.globl availmem

.globl m68k_init_mapped_size

.globl m68k_pgtable_cachemode

.globl m68k_supervisor_cachemode

#ifdef CONFIG_MVME16x
@@ -907,10 +908,21 @@ L(nocon): 
 *

 *	This block of code does what's necessary to map in the various kinds

 *	of machines for execution of Linux.

 *	First map the first 4 MB of kernel code & data

 */



	mmu_map	#PAGE_OFFSET,%pc@(L(phys_kernel_start)),#4*1024*1024,\

 *	First map the first 4, 8, or 16 MB of kernel code & data

 */



	get_bi_record BI_MEMCHUNK

	movel	%a0@(4),%d0

	movel	#16*1024*1024,%d1

	cmpl	%d0,%d1

	jls	1f

	lsrl	#1,%d1

	cmpl	%d0,%d1

	jls	1f

	lsrl	#1,%d1

1:

	movel	%d1,m68k_init_mapped_size

	mmu_map	#PAGE_OFFSET,%pc@(L(phys_kernel_start)),%d1,\

		%pc@(m68k_supervisor_cachemode)



	putc	'C'
@@ -3730,6 +3742,9 @@ func_return console_plot_pixel 
__INITDATA

	.align	4



m68k_init_mapped_size:

	.long	0



#if defined(CONFIG_ATARI) || defined(CONFIG_AMIGA) || \

    defined(CONFIG_HP300) || defined(CONFIG_APOLLO)

L(custom):

arch/m68k/mm/motorola.c

+6 −4
Original line number Diff line number Diff line
@@ -45,7 +45,7 @@ EXPORT_SYMBOL(mm_cachebits); 
#endif



/* size of memory already mapped in head.S */

#define INIT_MAPPED_SIZE	(4UL<<20)

extern __initdata unsigned long m68k_init_mapped_size;



extern unsigned long availmem;
@@ -271,10 +271,12 @@ void __init paging_init(void) 
	 */

	addr = m68k_memory[0].addr;

	size = m68k_memory[0].size;

	free_bootmem_node(NODE_DATA(0), availmem, min(INIT_MAPPED_SIZE, size) - (availmem - addr));

	free_bootmem_node(NODE_DATA(0), availmem,

			  min(m68k_init_mapped_size, size) - (availmem - addr));

	map_node(0);

	if (size > INIT_MAPPED_SIZE)

		free_bootmem_node(NODE_DATA(0), addr + INIT_MAPPED_SIZE, size - INIT_MAPPED_SIZE);

	if (size > m68k_init_mapped_size)

		free_bootmem_node(NODE_DATA(0), addr + m68k_init_mapped_size,

				  size - m68k_init_mapped_size);



	for (i = 1; i < m68k_num_memory; i++)

		map_node(i);

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