Re: Linux port failing on MIPS32 24Kc

[joe seb <joe.seb8@gmail.com>]

[-- Attachment #1.1: Type: text/plain, Size: 694 bytes --]

Hi,

We made the following changes and tried,

-> applied the patch given by you.
-> changed the PHYS_OFFSET to 0x10000000 to match our memory offset.
-> cache write back mode enabled

Still we face the same problem. It crashes at different points when it
enters the user space. I have attached one of the logs.

But in cache write through mode it works.

One comment about the patch, it tries to change the start of the valid pfn
range from ARCH_PFN_OFFSET to min_low_pfn.
But in bootmem_init() present in arch/mips/kernel/setup.c, line 324,
min_low_pfn = ARCH_PFN_OFFSET;

So appears like the previous pfn_valid check was also doing something
similar. Correct me if I am wrong.

Regards,
Joe

[-- Attachment #1.2: Type: text/html, Size: 790 bytes --]

[-- Attachment #2: log_1 --]
[-- Type: application/octet-stream, Size: 3635 bytes --]

Linux version 2.6.29.4 (gcc version 4.3.2 (Sourcery G
++ Lite 4.3-51) ) #8 PREEMPT Wed Jul 8 17:24:31 IST 2009
CPU revision is: 0101937c (MIPS 24Kc)
Determined physical RAM map:
User-defined physical RAM map:
 memory: 01000000 @ 10000000 (usable)
Initrd not found or empty - disabling initrd
Zone PFN ranges:
  Normal   0x00010000 -> 0x00011000
Movable zone start PFN for each node
early_node_map[1] active PFN ranges
    0: 0x00010000 -> 0x00011000
Built 1 zonelists in Zone order, mobility grouping off.  Total pages: 4064
Kernel command line: mem=16M@256M console=ttyS0,9600
Primary instruction cache 32kB, VIPT, 4-way, linesize 32 bytes.
Primary data cache 32kB, 4-way, PIPT, no aliases, linesize 32 bytes
Using cache attribute 3
Writing ErrCtl register=00000000
Readback ErrCtl register=00000000
PID hash table entries: 64 (order: 6, 256 bytes)
CPU frequency 50.00 MHz
console [ttyS0] enabled
Dentry cache hash table entries: 2048 (order: 1, 8192 bytes)
Inode-cache hash table entries: 1024 (order: 0, 4096 bytes)
Memory: 13768k/16384k available (1212k kernel code, 2616k reserved, 240k data, 6
76k init, 0k highmem)
Calibrating delay loop... 33.17 BogoMIPS (lpj=165888)
Mount-cache hash table entries: 512
VFS: Disk quotas dquot_6.5.2
Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
msgmni has been set to 26
Serial: 8250/16550 driver, 2 ports, IRQ sharing enabled
serial8250: ttyS0 at MMIO 0xa1a30000 (irq = 188) is a 16550A
serial8250: ttyS1 at MMIO 0xa1a40000 (irq = 189) is a 16550A
Freeing unused kernel memory: 676k freed
Algorithmics/MIPS FPU Emulator v1.5
vmalloc fault 
CPU 0 Unable to handle kernel paging request at virtual address ccccccf4, epc ==
 90081b5c, ra == 9008bd58 fo - 0
Oops[#1]:
Cpu 0
$ 0   : 00000000 90fab68a cccccccc ccccccf0
$ 4   : 9021241c 9021256c cccccccc 9021241c
$ 8   : 00000001 90240000 00400000 00000121
$12   : 00040000 00000000 92e9a1a3 3723702a
$16   : 90ddb58c 9021241c 90210c60 00000000
$20   : 90212490 90210c60 00000000 90de54a0
$24   : 00000000 00000000                  
$28   : 90204000 90205c48 08001875 9008bd58
Hi    : 0098963a
Lo    : ceb11100
epc   : 90081b5c vma_prio_tree_add+0x20/0x74
    Not tainted
ra    : 9008bd58 vma_link+0x8c/0x11c
Status: 10004403    KERNEL EXL IE 
Cause : 00800008
BadVA : ccccccf4
PrId  : 0101937c (MIPS 24Kc)
Process rcS (pid: 10, threadinfo=90204000, task=90202978, tls=0053f470)
Stack : 00000002 30e26b23 00000000 9021241c 90212488 900698f4 90212488 00400000
        90212490 9021241c 00000001 9008d818 90210c94 90106f58 90215520 90210c60
        90212488 00000000 90de54a0 00000000 00000000 00400000 00000121 90ddb4f4
        00000000 90210c94 00000000 fffff000 00400000 00121000 90205f30 90de54a0
        00000005 00000000 00000000 900cce58 90212470 00000000 00121000 00006012
        ...
Call Trace:
[<90081b5c>] vma_prio_tree_add+0x20/0x74
[<9008bd58>] vma_link+0x8c/0x11c
[<9008d818>] mmap_region+0x3a8/0x5c4
[<900cce58>] elf_map+0x148/0x1a0
[<900cd448>] load_elf_binary+0x598/0x1410
[<900a04ec>] search_binary_handler+0xa0/0x2bc
[<900cb710>] load_script+0x2d0/0x2e0
[<900a04ec>] search_binary_handler+0xa0/0x2bc
[<900a1adc>] do_execve+0x298/0x300
[<9000c69c>] sys_execve+0x4c/0x78
[<90002398>] stack_done+0x20/0x3c


Code: 8ca60030  10c00008  24c30024 <8cc20028> 24840024  ace30024  acc40028  ac44
0000  03e00008 
note: rcS[10] exited with preempt_count 1
BUG: scheduling while atomic: rcS/10/0x00000002
Call Trace:
[<90003fd8>] dump_stack+0x8/0x38
[<900048a8>] schedule+0x560/0x72c
[<9000782c>] __down_read+0xe8/0x188
[<9002a9b8>] exit_mm+0x3c/0x268
[<9002cec0>] do_exit+0xf4/0x88c
[<9000e05c>] nmi_exception_handler+0x0/0x34