Skip to content

Commit

Permalink
---
Browse files Browse the repository at this point in the history
yaml
---
r: 138659
b: refs/heads/master
c: b68adb1
h: refs/heads/master
i:
  138657: 473ce76
  138655: 8ee083f
v: v3
  • Loading branch information
Yinghai Lu authored and Ingo Molnar committed Mar 4, 2009
1 parent 42ba229 commit c2fd2e4
Show file tree
Hide file tree
Showing 2 changed files with 95 additions and 33 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: a71edd1f46c8a599509bda478fb4eea27fb0da63
refs/heads/master: b68adb16f29c8ea02f21f5ebf65bcabffe217e9f
126 changes: 94 additions & 32 deletions trunk/arch/x86/mm/init_32.c
Original file line number Diff line number Diff line change
Expand Up @@ -885,29 +885,55 @@ static void __init find_early_table_space(unsigned long end, int use_pse)
(table_start << PAGE_SHIFT) + tables);
}

struct map_range {
unsigned long start;
unsigned long end;
unsigned page_size_mask;
};

#define NR_RANGE_MR 3

static int save_mr(struct map_range *mr, int nr_range,
unsigned long start_pfn, unsigned long end_pfn,
unsigned long page_size_mask)
{
if (start_pfn < end_pfn) {
if (nr_range >= NR_RANGE_MR)
panic("run out of range for init_memory_mapping\n");
mr[nr_range].start = start_pfn<<PAGE_SHIFT;
mr[nr_range].end = end_pfn<<PAGE_SHIFT;
mr[nr_range].page_size_mask = page_size_mask;
nr_range++;
}

return nr_range;
}

unsigned long __init_refok init_memory_mapping(unsigned long start,
unsigned long end)
{
pgd_t *pgd_base = swapper_pg_dir;
unsigned long page_size_mask = 0;
unsigned long start_pfn, end_pfn;
unsigned long big_page_start;
unsigned long pos;

struct map_range mr[NR_RANGE_MR];
int nr_range, i;
int use_pse;

printk(KERN_INFO "init_memory_mapping: %08lx-%08lx\n", start, end);

#ifdef CONFIG_DEBUG_PAGEALLOC
/*
* For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
* This will simplify cpa(), which otherwise needs to support splitting
* large pages into small in interrupt context, etc.
*/
int use_pse = 0;
use_pse = 0;
#else
int use_pse = cpu_has_pse;
use_pse = cpu_has_pse;
#endif

/*
* Find space for the kernel direct mapping tables.
*/
if (!after_init_bootmem)
find_early_table_space(end, use_pse);

#ifdef CONFIG_X86_PAE
set_nx();
if (nx_enabled)
Expand All @@ -924,45 +950,81 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
__supported_pte_mask |= _PAGE_GLOBAL;
}

memset(mr, 0, sizeof(mr));
nr_range = 0;

if (use_pse)
page_size_mask |= 1 << PG_LEVEL_2M;

/*
* Don't use a large page for the first 2/4MB of memory
* because there are often fixed size MTRRs in there
* and overlapping MTRRs into large pages can cause
* slowdowns.
*/
big_page_start = PMD_SIZE;

if (start < big_page_start) {
start_pfn = start >> PAGE_SHIFT;
end_pfn = min(big_page_start>>PAGE_SHIFT, end>>PAGE_SHIFT);
} else {
/* head is not big page alignment ? */
start_pfn = start >> PAGE_SHIFT;
end_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
/* head could not be big page alignment ? */
start_pfn = start >> PAGE_SHIFT;
pos = start_pfn << PAGE_SHIFT;
if (pos == 0)
end_pfn = 1<<(PMD_SHIFT - PAGE_SHIFT);
else
end_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
<< (PMD_SHIFT - PAGE_SHIFT);
if (end_pfn > (end>>PAGE_SHIFT))
end_pfn = end>>PAGE_SHIFT;
if (start_pfn < end_pfn) {
nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
pos = end_pfn << PAGE_SHIFT;
}
if (start_pfn < end_pfn)
kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn, 0);

/* big page range */
start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
<< (PMD_SHIFT - PAGE_SHIFT);
if (start_pfn < (big_page_start >> PAGE_SHIFT))
start_pfn = big_page_start >> PAGE_SHIFT;
end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
if (start_pfn < end_pfn)
kernel_physical_mapping_init(pgd_base, start_pfn, end_pfn,
use_pse);
if (start_pfn < end_pfn) {
nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
page_size_mask & (1<<PG_LEVEL_2M));
pos = end_pfn << PAGE_SHIFT;
}

/* tail is not big page alignment ? */
start_pfn = end_pfn;
if (start_pfn > (big_page_start>>PAGE_SHIFT)) {
end_pfn = end >> PAGE_SHIFT;
if (start_pfn < end_pfn)
kernel_physical_mapping_init(pgd_base, start_pfn,
end_pfn, 0);
start_pfn = pos>>PAGE_SHIFT;
end_pfn = end>>PAGE_SHIFT;
if (start_pfn < end_pfn)
nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);

/* try to merge same page size and continuous */
for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
unsigned long old_start;
if (mr[i].end != mr[i+1].start ||
mr[i].page_size_mask != mr[i+1].page_size_mask)
continue;
/* move it */
old_start = mr[i].start;
memmove(&mr[i], &mr[i+1],
(nr_range - 1 - i) * sizeof(struct map_range));
mr[i--].start = old_start;
nr_range--;
}

for (i = 0; i < nr_range; i++)
printk(KERN_DEBUG " %08lx - %08lx page %s\n",
mr[i].start, mr[i].end,
(mr[i].page_size_mask & (1<<PG_LEVEL_2M)) ?
"big page" : "4k");

/*
* Find space for the kernel direct mapping tables.
*/
if (!after_init_bootmem)
find_early_table_space(end, use_pse);

for (i = 0; i < nr_range; i++)
kernel_physical_mapping_init(pgd_base,
mr[i].start >> PAGE_SHIFT,
mr[i].end >> PAGE_SHIFT,
mr[i].page_size_mask == (1<<PG_LEVEL_2M));

early_ioremap_page_table_range_init(pgd_base);

load_cr3(swapper_pg_dir);
Expand Down

0 comments on commit c2fd2e4

Please sign in to comment.