Messages in this thread | | | Subject | linux-2.6.13 PCI bogus resource allocation | Date | Tue, 30 Aug 2005 11:21:22 -0400 | From | "linux-os \(Dick Johnson\)" <> |
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Hello, more problems are being found with linux-2.6.13
Some imaging systems reserve large amounts of contiguous DMA RAM (16 megabytes) by booting with 'mem='. In the subject systems, we boot with "mem=768m" which makes the first available RAM at 768 * 1024 * 1024 = 0x30000000.
Certain versions of Linux have been spoiling the first page by writing something there. Therefore, we have been starting at 0x30001000. Now, with Linux-2.6.13, I see that PCI/Bus resources are being allocated on top of this RAM!!! This should not be. In my BIOS I always check for RAM before allocating PCI resources. It's trivial, write 0L, read it back after reading from some dummy location, if it's 0L, it's RAM. The dummy read from somewhere else is necessary to discharge bus capacity that can store bits for a few ns in the absence of RAM.
00000000-0009fbff : System RAM 0009fc00-0009ffff : reserved 000a0000-000bffff : Video RAM area 000c0000-000cfbff : Video ROM 000d0000-000d0bff : Adapter ROM 000d1000-000d57ff : Adapter ROM 000f0000-000fffff : System ROM 00100000-2fffffff : System RAM 00100000-003494f0 : Kernel code 003494f1-00403607 : Kernel data
Linux-2.6.13 Somebody put PCI/Bus stuff right on top of my reserved RAM!
30000000-300fffff : PCI Bus #02 ^^^^^^^^^^^^^^^^|__ This is RAM 30000000-3001ffff : 0000:02:01.0 30020000-3002ffff : 0000:02:00.0 30100000-301003ff : 0000:00:1f.1
30200000-34203fff : Analogic Corp DLB e8000000-f7ffffff : PCI Bus #01 e8000000-efffffff : 0000:01:00.0 f0000000-f007ffff : 0000:01:00.0 f0080000-f009ffff : 0000:01:00.0 f8000000-fbffffff : 0000:00:00.0 fc000000-fdffffff : PCI Bus #01 fc000000-fcffffff : 0000:01:00.0 fe000000-fe1fffff : PCI Bus #02 fe000000-fe0fffff : 0000:02:03.0 fe000000-fe0fffff : Analogic Corp DLB fe130000-fe130fff : 0000:02:00.0 fe130000-fe130fff : aic7xxx fe131000-fe131fff : 0000:02:07.0 fe132000-fe132fff : 0000:02:08.0 fe132000-fe132fff : e100 fe133000-fe13307f : 0000:02:01.0 fe133400-fe1335ff : 0000:02:03.0 fe133400-fe1335ff : Analogic Corp DLB fe200000-fe2003ff : 0000:00:1d.7 fe200000-fe2003ff : ehci_hcd fe200400-fe2005ff : 0000:00:1f.5 fe200800-fe2008ff : 0000:00:1f.5
Linux-2.6.12.5 works and (almost) avoids my RAM.
00000000-0009fbff : System RAM 0009fc00-0009ffff : reserved 000a0000-000bffff : Video RAM area 000c0000-000cfbff : Video ROM 000d0000-000d0bff : Adapter ROM 000d1000-000d57ff : Adapter ROM 000f0000-000fffff : System ROM 00100000-2fffffff : System RAM 00100000-0033d080 : Kernel code 0033d081-003f32ff : Kernel data
30000000-300003ff : 0000:00:1f.1 ^^^^^^^^^^^^^^^^^|__ This is RAM!
30200000-34203fff : Analogic Corp DLB e8000000-f7ffffff : PCI Bus #01 e8000000-efffffff : 0000:01:00.0 f0000000-f007ffff : 0000:01:00.0 f8000000-fbffffff : 0000:00:00.0 fc000000-fdffffff : PCI Bus #01 fc000000-fcffffff : 0000:01:00.0 fe000000-fe0fffff : 0000:02:03.0 fe000000-fe0fffff : Analogic Corp DLB fe130000-fe130fff : 0000:02:00.0 fe130000-fe130fff : aic7xxx fe131000-fe131fff : 0000:02:07.0 fe132000-fe132fff : 0000:02:08.0 fe132000-fe132fff : e100 fe133000-fe13307f : 0000:02:01.0 fe133400-fe1335ff : 0000:02:03.0 fe133400-fe1335ff : Analogic Corp DLB fe200000-fe2003ff : 0000:00:1d.7 fe200000-fe2003ff : ehci_hcd fe200400-fe2005ff : 0000:00:1f.5 fe200800-fe2008ff : 0000:00:1f.5
Cheers, Dick Johnson Penguin : Linux version 2.6.12.5 on an i686 machine (5537.79 BogoMips). Warning : 98.36% of all statistics are fiction. . I apologize for the following. I tried to kill it with the above dot :
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