AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity

x86, pat: fix reserve_memtype() for legacy 1MB range

Browse Source 
Thierry Vignaud reported:
> http://bugzilla.kernel.org/show_bug.cgi?id=12372
>
> On P4 with an SiS motherboard (video card is a SiS 651)
> X server fails to start with error:
> xf86MapVidMem: Could not mmap framebuffer (0x00000000,0x2000) (Invalid
> argument)

Here X is trying to map first 8KB of memory using /dev/mem. Existing
code treats first 0-4KB of memory as non-RAM and 4KB-8KB as RAM. Recent
code changes don't allow to map memory with different attributes
at the same time.

Fix this by treating the first 1MB legacy region as special and always
track the attribute requests with in this region using linear linked
list (and don't bother if the range is RAM or non-RAM or mixed)

Reported-and-tested-by: Thierry Vignaud <tvignaud@mandriva.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Suresh Siddha 2009-01-09 14:35:20 -08:00 committed by Ingo Molnar
parent c8399943bd
commit 5cca0cf15a
1 changed files with 27 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
arch/x86/mm/pat.c
View File

@ -333,11 +333,20 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
req_type & _PAGE_CACHE_MASK);
}
is_range_ram = pagerange_is_ram(start, end);
if (is_range_ram == 1)
return reserve_ram_pages_type(start, end, req_type, new_type);
else if (is_range_ram < 0)
return -EINVAL;
/*
* For legacy reasons, some parts of the physical address range in the
* legacy 1MB region is treated as non-RAM (even when listed as RAM in
* the e820 tables). So we will track the memory attributes of this
* legacy 1MB region using the linear memtype_list always.
*/
if (end >= ISA_END_ADDRESS) {
is_range_ram = pagerange_is_ram(start, end);
if (is_range_ram == 1)
return reserve_ram_pages_type(start, end, req_type,
new_type);
else if (is_range_ram < 0)
return -EINVAL;
}
new = kmalloc(sizeof(struct memtype), GFP_KERNEL);
if (!new)
@ -437,11 +446,19 @@ int free_memtype(u64 start, u64 end)
if (is_ISA_range(start, end - 1))
return 0;
is_range_ram = pagerange_is_ram(start, end);
if (is_range_ram == 1)
return free_ram_pages_type(start, end);
else if (is_range_ram < 0)
return -EINVAL;
/*
* For legacy reasons, some parts of the physical address range in the
* legacy 1MB region is treated as non-RAM (even when listed as RAM in
* the e820 tables). So we will track the memory attributes of this
* legacy 1MB region using the linear memtype_list always.
*/
if (end >= ISA_END_ADDRESS) {
is_range_ram = pagerange_is_ram(start, end);
if (is_range_ram == 1)
return free_ram_pages_type(start, end);
else if (is_range_ram < 0)
return -EINVAL;
}
spin_lock(&memtype_lock);
list_for_each_entry(entry, &memtype_list, nd) {