[PATCH] x86: fix init_memory_mapping for [dc000000 - e0000000) -v2
From: Yinghai Lu
Date: Tue Oct 28 2008 - 15:40:48 EST
Impact: change over-mapping to precise mapping, fix /proc/meminfo output
v2: fix less 1G ram system handling
when gart aperture is 0xdc000000 - 0xe0000000
it return 0xc0000000 - 0xe0000000
that is not right.
this patch fix that will get exact mapping
on 256g sytem with that aperture after patch
LBSuse:~ # cat /proc/meminfo
MemTotal: 264742432 kB
MemFree: 263920628 kB
Buffers: 1416 kB
Cached: 24468 kB
...
DirectMap4k: 5760 kB
DirectMap2M: 3205120 kB
DirectMap1G: 265289728 kB
it is consistent to
LBSuse:~ # cat /sys/kernel/debug/kernel_page_tables
..
---[ Low Kernel Mapping ]---
0xffff880000000000-0xffff880000200000 2M RW GLB x pte
0xffff880000200000-0xffff880040000000 1022M RW PSE GLB x pmd
0xffff880040000000-0xffff8800c0000000 2G RW PSE GLB NX pud
0xffff8800c0000000-0xffff8800d7e00000 382M RW PSE GLB NX pmd
0xffff8800d7e00000-0xffff8800d7fa0000 1664K RW GLB NX pte
0xffff8800d7fa0000-0xffff8800d8000000 384K pte
0xffff8800d8000000-0xffff8800dc000000 64M pmd
0xffff8800dc000000-0xffff8800e0000000 64M RW PSE GLB NX pmd
0xffff8800e0000000-0xffff880100000000 512M pmd
0xffff880100000000-0xffff880800000000 28G RW PSE GLB NX pud
0xffff880800000000-0xffff880824600000 582M RW PSE GLB NX pmd
0xffff880824600000-0xffff8808247f0000 1984K RW GLB NX pte
0xffff8808247f0000-0xffff880824800000 64K RW PCD GLB NX pte
0xffff880824800000-0xffff880840000000 440M RW PSE GLB NX pmd
0xffff880840000000-0xffff884000000000 223G RW PSE GLB NX pud
0xffff884000000000-0xffff884028000000 640M RW PSE GLB NX pmd
0xffff884028000000-0xffff884040000000 384M pmd
0xffff884040000000-0xffff888000000000 255G pud
0xffff888000000000-0xffffc20000000000 58880G pgd
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
arch/x86/mm/init_64.c | 50 +++++++++++++++++++++++++++++++++-----------------
1 file changed, 33 insertions(+), 17 deletions(-)
Index: linux-2.6/arch/x86/mm/init_64.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/init_64.c
+++ linux-2.6/arch/x86/mm/init_64.c
@@ -671,12 +671,13 @@ unsigned long __init_refok init_memory_m
unsigned long last_map_addr = 0;
unsigned long page_size_mask = 0;
unsigned long start_pfn, end_pfn;
+ unsigned long pos;
struct map_range mr[NR_RANGE_MR];
int nr_range, i;
int use_pse, use_gbpages;
- printk(KERN_INFO "init_memory_mapping\n");
+ printk(KERN_INFO "init_memory_mapping: %016lx-%016lx\n", start, end);
/*
* Find space for the kernel direct mapping tables.
@@ -710,35 +711,50 @@ unsigned long __init_refok init_memory_m
/* head if not big page alignment ?*/
start_pfn = start >> PAGE_SHIFT;
- end_pfn = ((start + (PMD_SIZE - 1)) >> PMD_SHIFT)
+ pos = start_pfn << PAGE_SHIFT;
+ end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT)
<< (PMD_SHIFT - PAGE_SHIFT);
- nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
+ if (start_pfn < end_pfn) {
+ nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
+ pos = end_pfn << PAGE_SHIFT;
+ }
/* big page (2M) range*/
- start_pfn = ((start + (PMD_SIZE - 1))>>PMD_SHIFT)
+ start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
<< (PMD_SHIFT - PAGE_SHIFT);
- end_pfn = ((start + (PUD_SIZE - 1))>>PUD_SHIFT)
+ end_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
<< (PUD_SHIFT - PAGE_SHIFT);
- if (end_pfn > ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT)))
- end_pfn = ((end>>PUD_SHIFT)<<(PUD_SHIFT - PAGE_SHIFT));
- nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
- page_size_mask & (1<<PG_LEVEL_2M));
+ if (end_pfn > ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT)))
+ end_pfn = ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT));
+ 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;
+ }
/* big page (1G) range */
- start_pfn = end_pfn;
- end_pfn = (end>>PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
- nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
+ start_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
+ << (PUD_SHIFT - PAGE_SHIFT);
+ end_pfn = (end >> PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
+ if (start_pfn < end_pfn) {
+ nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
page_size_mask &
((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
+ pos = end_pfn << PAGE_SHIFT;
+ }
/* tail is not big page (1G) alignment */
- start_pfn = end_pfn;
- end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
- nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
- page_size_mask & (1<<PG_LEVEL_2M));
+ start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
+ << (PMD_SHIFT - PAGE_SHIFT);
+ end_pfn = (end >> PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
+ 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 (2M) alignment */
- start_pfn = end_pfn;
+ start_pfn = pos>>PAGE_SHIFT;
end_pfn = end>>PAGE_SHIFT;
nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
--
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