I got kind of tired waiting for this to get fixed. There are people out there
who have product plans that are really getting messed up by this whole
business. It seemed time to help them out.
So I did the following.
First, using David Jone's MSR reading program, I read all the K7 MSRs by
walking the entire 2^32 space. This took about 16 hours. Then I did the same
thing on a PII. Then I compared the output of the two runs to isolate the
MSRs that are K7-specific. Turns out there is a range of K7 MSRs at
0xcxxxxxxx not found on any Pentium. These looked like they might be worth
trying. There were hidden MSRs on the PII to manipulate the cache; it was
worth seeing if these MSRs would fix the performance problem.
Then, for every combination of DRAM I care about, I plugged in:
1x128
2x128
1x256
2x256
128+256
256+128
And then dumped the 0xcxxxxxxx MSRs. Then I wrote a program that sets the
MSRs based on this DRAM configuration. The idea is to boot under linuxbios,
then run this program, set the MSRs as set by the BIOS, and see if things
work.
The result is I can boot linuxbios, run my program, and get good K7 behavior.
I am not intepreting what MSR does what. I am simply loading all the MSRs
that seem to be K7-specific. This code will be going into linuxbios in the
next day or so. It will be in the K7 setup code. Obviously, if you plug in a
non-supported DRAM configuration I can't help you. But this is at least a
start.
So, it appears that for K7 uniprocessor, with 2 dram slots, and variations of
128 and 256 MB, we are back on the air.
Note that no NDA material was used in the making of this code. It is a very
straightforward loading of MSRs, as programmed by the normal BIOS, into the
MSRs in a LinuxBIOS system. Also no reverse assembly, etc. was used. All I did
was run a program that queries the MSR space.
Finally, the conclusion: NDAs are stupid.
The program is attached. To invoke it you run 'fixmsr <variation>' where
variation is a variation of memory config. This is here for reference only,
this code will be going into linuxbios so you don't need to care how it works.
ron
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
struct msrval {
unsigned long msr, lo, hi;
};
// the pattern is:
// 1x128 2x128, 0x1x256, 0x2x256, 128+256, 0x256+128
char *fixit[] = {"1x128", "2x128", "1x256", "2x256",
"128+256", "256+128"};
struct msrval fixmsr[6][40] = {
{
0xc0000080, 0x00000000, 0x00000000,
0xc0000081, 0x00000000, 0x00000000,
0xc0010000, 0xff8d7df7, 0x00000000,
0xc0010001, 0xff9fee9f, 0x00000000,
0xc0010002, 0xff1fffbe, 0x00000000,
0xc0010003, 0xff9fff9f, 0x00000000,
0xc0010004, 0xfffeefff, 0x0000ffee,
0xc0010005, 0xffbffdf7, 0x0000ffff,
0xc0010006, 0x7ffffff7, 0x0000ff7d,
0xc0010007, 0xcffbfeff, 0x0000fffb,
0xc0010010, 0x00160604, 0x00000000,
0xc0010015, 0x0e001008, 0x00000000,
0xc0010016, 0x00000000, 0x00000000,
0xc0010017, 0x00000000, 0x00000000,
0xc0010018, 0xd0000018, 0x00000000,
0xc0010019, 0xfc000800, 0x0000000f,
0xc001001a, 0x07800000, 0x00000000,
0xc001001b, 0x29679223, 0x00000000,
0xc001001d, 0x00000000, 0x00000000,
0xc0010030, 0x20444d41, 0x6c687441,
0xc0010031, 0x74286e6f, 0x5020296d,
0xc0010032, 0x65636f72, 0x726f7373,
0xc0010033, 0x00000000, 0x00000000,
0xc0010034, 0x00000000, 0x00000000,
0xc0010035, 0x00000000, 0x00000000,
0xc0010100, 0xfc000000, 0x00000000,
0xc0010101, 0x00000000, 0x00000000,
0xc0010102, 0xf8000000, 0x00000000,
0xc0010103, 0xf8000000, 0x00000000,
0xc0010104, 0x00000011, 0x00000000,
0xc0010105, 0x00050002, 0x00000000,
0xc0010106, 0x00050002, 0x00000000,
0xc0010111, 0x000b0000, 0x00000000,
0xc0010112, 0x00000000, 0x00000000,
0xc0010113, 0x00000001, 0x00000000,
0xc0010114, 0xffffffff, 0x00000008,
0xc0010115, 0xffffffff, 0xffffffff,
0xc0010116, 0x00000027, 0x00000008,
0xc0010117, 0x00000027, 0x00000027,
0,0,0},
{
0xc0000080, 0x00000000, 0x00000000,
0xc0000081, 0x00000000, 0x00000000,
0xc0010000, 0x9f8dfdf7, 0x00000000,
0xc0010001, 0xff97fe9f, 0x00000000,
0xc0010002, 0xff1fffbf, 0x00000000,
0xc0010003, 0xff9fff9f, 0x00000000,
0xc0010004, 0xfffeefff, 0x0000ffee,
0xc0010005, 0xffbffdf7, 0x0000ffff,
0xc0010006, 0x7fffffff, 0x0000dfdc,
0xc0010007, 0xeffbfeff, 0x0000ffff,
0xc0010010, 0x00160604, 0x00000000,
0xc0010015, 0x0e001008, 0x00000000,
0xc0010016, 0x00000000, 0x00000000,
0xc0010017, 0x00000000, 0x00000000,
0xc0010018, 0xd0000018, 0x00000000,
0xc0010019, 0xfc000800, 0x0000000f,
0xc001001a, 0x0f800000, 0x00000000,
0xc001001b, 0x29679223, 0x00000000,
0xc001001d, 0x00000000, 0x00000000,
0xc0010030, 0x20444d41, 0x6c687441,
0xc0010031, 0x74286e6f, 0x5020296d,
0xc0010032, 0x65636f72, 0x726f7373,
0xc0010033, 0x00000000, 0x00000000,
0xc0010034, 0x00000000, 0x00000000,
0xc0010035, 0x00000000, 0x00000000,
0xc0010100, 0xfc000000, 0x00000000,
0xc0010101, 0x00000000, 0x00000000,
0xc0010102, 0xf8000000, 0x00000000,
0xc0010103, 0xf8000000, 0x00000000,
0xc0010104, 0x00000011, 0x00000000,
0xc0010105, 0x00050002, 0x00000000,
0xc0010106, 0x00050002, 0x00000000,
0xc0010111, 0x000b0000, 0x00000000,
0xc0010112, 0x00000000, 0x00000000,
0xc0010113, 0x00000001, 0x00000000,
0xc0010114, 0xffffffff, 0x00000008,
0xc0010115, 0xffffffff, 0xffffffff,
0xc0010116, 0x00000027, 0x00000008,
0xc0010117, 0x00000027, 0x00000027,
0,0,0},
{
0xc0000080, 0x00000000, 0x00000000,
0xc0000081, 0x00000000, 0x00000000,
0xc0010000, 0x9f8dfcf7, 0x00000000,
0xc0010001, 0xff97ffdd, 0x00000000,
0xc0010002, 0xff1dffbf, 0x00000000,
0xc0010003, 0xff9fff9f, 0x00000000,
0xc0010004, 0xdffeefff, 0x0000ffee,
0xc0010005, 0xbfbefdf7, 0x0000ffff,
0xc0010006, 0xffffffff, 0x0000dfdc,
0xc0010007, 0xcffbfeff, 0x0000fffb,
0xc0010010, 0x00160604, 0x00000000,
0xc0010015, 0x0e001008, 0x00000000,
0xc0010016, 0x00000000, 0x00000000,
0xc0010017, 0x00000000, 0x00000000,
0xc0010018, 0xd0000018, 0x00000000,
0xc0010019, 0xfc000800, 0x0000000f,
0xc001001a, 0x0f800000, 0x00000000,
0xc001001b, 0x29679223, 0x00000000,
0xc001001d, 0x00000000, 0x00000000,
0xc0010030, 0x20444d41, 0x6c687441,
0xc0010031, 0x74286e6f, 0x5020296d,
0xc0010032, 0x65636f72, 0x726f7373,
0xc0010033, 0x00000000, 0x00000000,
0xc0010034, 0x00000000, 0x00000000,
0xc0010035, 0x00000000, 0x00000000,
0xc0010100, 0xfc000000, 0x00000000,
0xc0010101, 0x00000000, 0x00000000,
0xc0010102, 0xf8000000, 0x00000000,
0xc0010103, 0xf8000000, 0x00000000,
0xc0010104, 0x00000011, 0x00000000,
0xc0010105, 0x00050002, 0x00000000,
0xc0010106, 0x00050002, 0x00000000,
0xc0010111, 0x000b0000, 0x00000000,
0xc0010112, 0x00000000, 0x00000000,
0xc0010113, 0x00000001, 0x00000000,
0xc0010114, 0xffffffff, 0x00000008,
0xc0010115, 0xffffffff, 0xffffffff,
0xc0010116, 0x00000027, 0x00000008,
0xc0010117, 0x00000027, 0x00000027,
0,0,0},
{
0xc0000080, 0x00000000, 0x00000000,
0xc0000081, 0x00000000, 0x00000000,
0xc0010000, 0xff8ffdf7, 0x00000000,
0xc0010001, 0xff9fee9f, 0x00000000,
0xc0010002, 0xff1fffbf, 0x00000000,
0xc0010003, 0xff9fff9f, 0x00000000,
0xc0010004, 0xfffeefff, 0x0000b7ee,
0xc0010005, 0xffbffdf7, 0x0000ffff,
0xc0010006, 0x7fffffff, 0x0000dfdd,
0xc0010007, 0xcffbffff, 0x0000efff,
0xc0010010, 0x00160604, 0x00000000,
0xc0010015, 0x0e001008, 0x00000000,
0xc0010016, 0x00000000, 0x00000000,
0xc0010017, 0x00000000, 0x00000000,
0xc0010018, 0xd0000018, 0x00000000,
0xc0010019, 0xfc000800, 0x0000000f,
0xc001001a, 0x1f800000, 0x00000000,
0xc001001b, 0x29679223, 0x00000000,
0xc001001d, 0x00000000, 0x00000000,
0xc0010030, 0x20444d41, 0x6c687441,
0xc0010031, 0x74286e6f, 0x5020296d,
0xc0010032, 0x65636f72, 0x726f7373,
0xc0010033, 0x00000000, 0x00000000,
0xc0010034, 0x00000000, 0x00000000,
0xc0010035, 0x00000000, 0x00000000,
0xc0010100, 0xfc000000, 0x00000000,
0xc0010101, 0x00000000, 0x00000000,
0xc0010102, 0xf8000000, 0x00000000,
0xc0010103, 0xf8000000, 0x00000000,
0xc0010104, 0x00000011, 0x00000000,
0xc0010105, 0x00050002, 0x00000000,
0xc0010106, 0x00050002, 0x00000000,
0xc0010111, 0x000b0000, 0x00000000,
0xc0010112, 0x00000000, 0x00000000,
0xc0010113, 0x00000001, 0x00000000,
0xc0010114, 0xffffffff, 0x00000008,
0xc0010115, 0xffffffff, 0xffffffff,
0xc0010116, 0x00000027, 0x00000008,
0xc0010117, 0x00000027, 0x00000027,
0,0,0},
{
0xc0000080, 0x00000000, 0x00000000,
0xc0000081, 0x00000000, 0x00000000,
0xc0010000, 0x9f8dfdf7, 0x00000000,
0xc0010001, 0xff97fe9f, 0x00000000,
0xc0010002, 0xff1fffbf, 0x00000000,
0xc0010003, 0xff9fffdf, 0x00000000,
0xc0010004, 0xfffeefff, 0x0000ffee,
0xc0010005, 0xbfbffdf7, 0x0000ffff,
0xc0010006, 0x7fffffff, 0x0000dfdd,
0xc0010007, 0xcffbfeff, 0x0000fffb,
0xc0010010, 0x00160604, 0x00000000,
0xc0010015, 0x0e001008, 0x00000000,
0xc0010016, 0x00000000, 0x00000000,
0xc0010017, 0x00000000, 0x00000000,
0xc0010018, 0xd0000018, 0x00000000,
0xc0010019, 0xfc000800, 0x0000000f,
0xc001001a, 0x17800000, 0x00000000,
0xc001001b, 0x29679223, 0x00000000,
0xc001001d, 0x00000000, 0x00000000,
0xc0010030, 0x20444d41, 0x6c687441,
0xc0010031, 0x74286e6f, 0x5020296d,
0xc0010032, 0x65636f72, 0x726f7373,
0xc0010033, 0x00000000, 0x00000000,
0xc0010034, 0x00000000, 0x00000000,
0xc0010035, 0x00000000, 0x00000000,
0xc0010100, 0xfc000000, 0x00000000,
0xc0010101, 0x00000000, 0x00000000,
0xc0010102, 0xf8000000, 0x00000000,
0xc0010103, 0xf8000000, 0x00000000,
0xc0010104, 0x00000011, 0x00000000,
0xc0010105, 0x00050002, 0x00000000,
0xc0010106, 0x00050002, 0x00000000,
0xc0010111, 0x000b0000, 0x00000000,
0xc0010112, 0x00000000, 0x00000000,
0xc0010113, 0x00000001, 0x00000000,
0xc0010114, 0xffffffff, 0x00000008,
0xc0010115, 0xffffffff, 0xffffffff,
0xc0010116, 0x00000027, 0x00000008,
0xc0010117, 0x00000027, 0x00000027,
0,0,0},
{
0xc0000080, 0x00000000, 0x00000000,
0xc0000081, 0x00000000, 0x00000000,
0xc0010000, 0x9f8dfdf7, 0x00000000,
0xc0010001, 0xff9fefdf, 0x00000000,
0xc0010002, 0xff1dffbe, 0x00000000,
0xc0010003, 0xff9fff9f, 0x00000000,
0xc0010004, 0xdffeefff, 0x0000ffff,
0xc0010005, 0xffbffdf7, 0x0000ffff,
0xc0010006, 0x7fffffff, 0x0000dfdc,
0xc0010007, 0xeffbfeff, 0x0000eff9,
0xc0010010, 0x00160604, 0x00000000,
0xc0010015, 0x0e001008, 0x00000000,
0xc0010016, 0x00000000, 0x00000000,
0xc0010017, 0x00000000, 0x00000000,
0xc0010018, 0xd0000018, 0x00000000,
0xc0010019, 0xfc000800, 0x0000000f,
0xc001001a, 0x17800000, 0x00000000,
0xc001001b, 0x29679223, 0x00000000,
0xc001001d, 0x00000000, 0x00000000,
0xc0010030, 0x20444d41, 0x6c687441,
0xc0010031, 0x74286e6f, 0x5020296d,
0xc0010032, 0x65636f72, 0x726f7373,
0xc0010033, 0x00000000, 0x00000000,
0xc0010034, 0x00000000, 0x00000000,
0xc0010035, 0x00000000, 0x00000000,
0xc0010100, 0xfc000000, 0x00000000,
0xc0010101, 0x00000000, 0x00000000,
0xc0010102, 0xf8000000, 0x00000000,
0xc0010103, 0xf8000000, 0x00000000,
0xc0010104, 0x00000011, 0x00000000,
0xc0010105, 0x00050002, 0x00000000,
0xc0010106, 0x00050002, 0x00000000,
0xc0010111, 0x000b0000, 0x00000000,
0xc0010112, 0x00000000, 0x00000000,
0xc0010113, 0x00000001, 0x00000000,
0xc0010114, 0xffffffff, 0x00000008,
0xc0010115, 0xffffffff, 0xffffffff,
0xc0010116, 0x00000027, 0x00000008,
0xc0010117, 0x00000027, 0x00000027,
0,0,0,
}};
int writemsr(struct msrval *v)
{
char cpuname[16];
unsigned long buffer[2];
int fh;
int cpu = 0;
sprintf (cpuname, "/dev/cpu/%d/msr", cpu);
fh = open (cpuname, O_RDWR);
if (fh==-1)
return (0);
lseek (fh, v->msr, SEEK_CUR);
buffer[0] = v->lo; buffer[1] = v->hi;
if (fh != -1) {
printf("%#x: lo %#x, hi %#x\n",
v->msr, v->lo, v->hi);
if (write (fh, buffer, 8) != 8) {
perror("Write failed");
fprintf(stderr, "%#x: lo %#x, hi %#x\n",
v->msr, v->lo, v->hi);
close (fh);
return (0);
}
}
close(fh);
fh = open (cpuname, O_RDWR);
if (fh==-1)
return (0);
lseek (fh, v->msr, SEEK_CUR);
if (read (fh, buffer, 8) != 8) {
perror("Read failed");
close (fh);
return (0);
}
if (buffer[0] != v->lo)
printf("set lo fails, is %#x want %#x\n",
buffer[0], v->lo);
if (buffer[1] != v->hi)
printf("set hi fails, is %#x want %#x\n",
buffer[1], v->hi);
close (fh);
return (1);
}
main(int argc, char *argv[])
{
int i = 0, j;
if (argc > 1)
i = strtol(argv[1], 0, 0);
printf("Fixing MSRs with offset %d(%s)\n", i, fixit[i]);
for(j = 0; fixmsr[i][j].msr; j++)
writemsr(&fixmsr[i][j]);
}
