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: Andreas 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: Geert Uytterhoeven <geert@linux-m68k.org>
This commit is contained in:
Andreas Schwab 2014-04-24 12:24:48 +02:00 committed by Geert Uytterhoeven
parent 44074e892c
commit 486df8bc46
2 changed files with 23 additions and 6 deletions

View File

@ -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
* First map the first 4, 8, or 16 MB of kernel code & data
*/
mmu_map #PAGE_OFFSET,%pc@(L(phys_kernel_start)),#4*1024*1024,\
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):

View File

@ -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);