[PATCH -v2 06/13] x86, mm: Separate out calculate_table_space_size()

From: Yinghai Lu
Date: Sun Sep 02 2012 - 03:50:39 EST


it should take physical address range that will need to be mapped.
and find_early_table_space should take range that pgt buff should be in.
Separate those two to reduce confusion.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
arch/x86/mm/init.c | 39 ++++++++++++++++++++++++++++-----------
1 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 0ada295..fcb44c5 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -37,11 +37,10 @@ struct map_range {

static int page_size_mask;

-static void __init find_early_table_space(unsigned long begin,
+static unsigned long __init calculate_table_space_size(unsigned long begin,
unsigned long end)
{
- unsigned long puds, pmds, ptes, tables, start = 0, good_end = end;
- phys_addr_t base;
+ unsigned long puds, pmds, ptes, tables;

puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
@@ -76,9 +75,17 @@ static void __init find_early_table_space(unsigned long begin,
#ifdef CONFIG_X86_32
/* for fixmap */
tables += roundup(__end_of_fixed_addresses * sizeof(pte_t), PAGE_SIZE);
- good_end = max_pfn_mapped << PAGE_SHIFT;
#endif

+ return tables;
+}
+
+static void __init find_early_table_space(unsigned long start,
+ unsigned long good_end,
+ unsigned long tables)
+{
+ phys_addr_t base;
+
base = memblock_find_in_range(start, good_end, tables, PAGE_SIZE);
if (!base)
panic("Cannot find space for the kernel page tables");
@@ -86,10 +93,6 @@ static void __init find_early_table_space(unsigned long begin,
pgt_buf_start = base >> PAGE_SHIFT;
pgt_buf_end = pgt_buf_start;
pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT);
-
- printk(KERN_DEBUG "kernel direct mapping tables up to %#lx @ [mem %#010lx-%#010lx]\n",
- end - 1, pgt_buf_start << PAGE_SHIFT,
- (pgt_buf_top << PAGE_SHIFT) - 1);
}

static void __init probe_page_size_mask(void)
@@ -282,6 +285,8 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,

void __init init_mem_mapping(void)
{
+ unsigned long tables, good_end, end;
+
probe_page_size_mask();

/*
@@ -292,10 +297,18 @@ void __init init_mem_mapping(void)
* nodes are discovered.
*/
#ifdef CONFIG_X86_64
- find_early_table_space(0, max_pfn<<PAGE_SHIFT);
+ end = max_pfn << PAGE_SHIFT;
+ good_end = end;
#else
- find_early_table_space(0, max_low_pfn<<PAGE_SHIFT);
+ end = max_low_pfn << PAGE_SHIFT;
+ good_end = max_pfn_mapped << PAGE_SHIFT;
#endif
+ tables = calculate_table_space_size(0, end);
+ find_early_table_space(0, good_end, tables);
+ printk(KERN_DEBUG "kernel direct mapping tables up to %#lx @ [mem %#010lx-%#010lx] prealloc\n",
+ end - 1, pgt_buf_start << PAGE_SHIFT,
+ (pgt_buf_top << PAGE_SHIFT) - 1);
+
max_low_pfn_mapped = init_memory_mapping(0, max_low_pfn<<PAGE_SHIFT);
max_pfn_mapped = max_low_pfn_mapped;

@@ -322,9 +335,13 @@ void __init init_mem_mapping(void)
* RO all the pagetable pages, including the ones that are beyond
* pgt_buf_end at that time.
*/
- if (pgt_buf_end > pgt_buf_start)
+ if (pgt_buf_end > pgt_buf_start) {
+ printk(KERN_DEBUG "kernel direct mapping tables up to %#lx @ [mem %#010lx-%#010lx] final\n",
+ end - 1, pgt_buf_start << PAGE_SHIFT,
+ (pgt_buf_end << PAGE_SHIFT) - 1);
x86_init.mapping.pagetable_reserve(PFN_PHYS(pgt_buf_start),
PFN_PHYS(pgt_buf_end));
+ }

/* stop the wrong using */
pgt_buf_top = 0;
--
1.7.7

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