On Jul 9, 2009, at 1:17 PM, Ira W. Snyder wrote:
On Thu, Jul 09, 2009 at 12:58:53PM -0500, Kumar Gala wrote:
Hello Kumar,
I must not understand something going on here. Your proposed code
doesn't work at all on my board. The
/sys/devices/system/edac/mc/mc0/size_mb doesn't come out correctly.
What does it come out as? How much memory do you have in the system?
The size_mb shows as 0 with your code. See the explanation below. With
my code it shows as 256MB, as expected.
I have 256MB memory in the system.
The attached patch DOES work on my board, but I'm confident that it
does
NOT work on a system with PAGE_SIZE != 4096. Any idea what I did
wrong?
If I'm reading things correctly:
csrow->first_page full address of the first page (NOT pfn)
csrow->last_page full address of the last page (NOT pfn)
csrow->nr_pages number of pages
The EDAC subsystem does csrow->nr_pages * PAGE_SIZE to get the
size_mb
sysfs value.
If csrow->first_page and csrow->last_page ARE supposed to be the
pfn,
then I think the original code got it wrong, and the calculation for
csrow->nr_pages needs to be changed.
Thanks,
Ira
[snip]
/************************ MC SYSFS parts
***********************************/
@@ -790,18 +792,19 @@ static void __devinit
mpc85xx_init_csrows(struct
mem_ctl_info *mci)
csrow = &mci->csrows[index];
cs_bnds = in_be32(pdata->mc_vbase + MPC85XX_MC_CS_BNDS_0 +
(index * MPC85XX_MC_CS_BNDS_OFS));
- start = (cs_bnds & 0xfff0000) << 4;
- end = ((cs_bnds & 0xfff) << 20);
- if (start)
- start |= 0xfffff;
- if (end)
- end |= 0xfffff;
can you printk what cs_bnds values are in your setup.
I am only using a single chip select. CS0_BNDS (register 0xe0002000)
is
0x0000000F.
+
+ start = (cs_bnds & 0xffff0000) >> 16;
+ end = (cs_bnds & 0x0000ffff);
This is the same in both our versions.
start == 0x0
end == 0xF
if (start == end)
continue; /* not populated */
- csrow->first_page = start >> PAGE_SHIFT;
- csrow->last_page = end >> PAGE_SHIFT;
+ start <<= PAGE_SHIFT;
+ end <<= PAGE_SHIFT;
+ end |= (1 << PAGE_SHIFT) - 1;
+
MY VERSION
start == 0x0
end == 0xffff
first_page == 0x0
last_page == 0xffff
YOUR VERSION (<<= (20 - PAGE_SHIFT), etc.)
My math was wrong it should be ( <<= (24 - PAGE_SHIFT) )
With that I think things work out.
- k
start == 0x0
end == 0xfff
first_page == 0x0
last_page == 0x0
+ csrow->first_page = start;
+ csrow->last_page = end;
This seems odd to me... I can't believe this is working out properly.
csrow->nr_pages = csrow->last_page + 1 - csrow->first_page;
The calculation is unchanged here from the original code. Due to the
">> PAGE_SHIFT", nr_pages ends up as 1 in your version.
MY VERSION
nr_pages == 0xffff + 1 - 0 == 0x10000
0x10000 * 4096 / 1024 / 1024 == 256 MB
YOUR VERSION
nr_pages == 0x0 + 1 - 0x0 == 1
0x1 * 4096 / 1024 / 1024 == 0MB
csrow->grain = 8;
csrow->mtype = mtype;
Lets get some real values on the table for your system so I can get a
sense of what's really going on.
Thanks for the help.
Ira
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